On Tue, Jul 21, 2020 at 8:51 AM Christoph Hellwig <hch(a)lst.de> wrote:
>
> On Wed, Jul 15, 2020 at 10:35:11AM -0400, Jim Quinlan wrote:
> > The new field 'dma_range_map' in struct device is used to facilitate the
> > use of single or multiple offsets between mapping regions of cpu addrs and
> > dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only
> > capable of holding a single uniform offset and had no region bounds
> > checking.
> >
> > The function of_dma_get_range() has been modified so that it takes a single
> > argument -- the device node -- and returns a map, NULL, or an error code.
> > The map is an array that holds the information regarding the DMA regions.
> > Each range entry contains the address offset, the cpu_start address, the
> > dma_start address, and the size of the region.
> >
> > of_dma_configure() is the typical manner to set range offsets but there are
> > a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel
> > driver code. These cases now invoke the function
> > dma_attach_offset_range(dev, cpu_addr, dma_addr, size).
>
> So my main higher level issue here is the dma_attach_offset_range
> function. I think it should keep the old functionality and just
> set a global range from 0 to (phys_addr_t)-1, and bail out if there
> are DMA ranges already:
>
> int dma_set_global_offset(struct device *dev, u64 offset);
Hi Christoph,
I had it this way in [V1...V5] but Robin requested that for V6 I
should change this function to
o add bounds to the call
o if there is a mapping already, check if what is requested is
already covered and return success.
Can you and Robin please discuss this and let me know which way to move forward?
>
>
> otherwise there is all kinds of minor nitpicks that aren't too
> substantial, let me know what you think of something like this
> hacked up version:
Kind of hard to see what you have changed but I will diff both of our
diffs and make the changes.
Thanks,
Jim Quinlan
Broadcom STB
>
>
> diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> index bdd80ddbca3451..2405afeb79573a 100644
> --- a/arch/arm/include/asm/dma-mapping.h
> +++ b/arch/arm/include/asm/dma-mapping.h
> @@ -35,8 +35,11 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
> #ifndef __arch_pfn_to_dma
> static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
> {
> - if (dev)
> - pfn -= dev->dma_pfn_offset;
> + if (dev) {
> + phys_addr_t paddr = PFN_PHYS(pfn);
> +
> + pfn -= (dma_offset_from_phys_addr(dev, paddr) >> PAGE_SHIFT);
> + }
> return (dma_addr_t)__pfn_to_bus(pfn);
> }
>
> @@ -45,8 +48,7 @@ static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
> unsigned long pfn = __bus_to_pfn(addr);
>
> if (dev)
> - pfn += dev->dma_pfn_offset;
> -
> + pfn += (dma_offset_from_dma_addr(dev, addr) >> PAGE_SHIFT);
> return pfn;
> }
>
> diff --git a/arch/arm/mach-keystone/keystone.c b/arch/arm/mach-keystone/keystone.c
> index 638808c4e12247..7539679205fbf7 100644
> --- a/arch/arm/mach-keystone/keystone.c
> +++ b/arch/arm/mach-keystone/keystone.c
> @@ -8,6 +8,7 @@
> */
> #include <linux/io.h>
> #include <linux/of.h>
> +#include <linux/dma-mapping.h>
> #include <linux/init.h>
> #include <linux/of_platform.h>
> #include <linux/of_address.h>
> @@ -24,8 +25,6 @@
>
> #include "keystone.h"
>
> -static unsigned long keystone_dma_pfn_offset __read_mostly;
> -
> static int keystone_platform_notifier(struct notifier_block *nb,
> unsigned long event, void *data)
> {
> @@ -38,9 +37,12 @@ static int keystone_platform_notifier(struct notifier_block *nb,
> return NOTIFY_BAD;
>
> if (!dev->of_node) {
> - dev->dma_pfn_offset = keystone_dma_pfn_offset;
> - dev_err(dev, "set dma_pfn_offset%08lx\n",
> - dev->dma_pfn_offset);
> + int ret = dma_set_offset_range(dev, KEYSTONE_HIGH_PHYS_START,
> + KEYSTONE_LOW_PHYS_START,
> + KEYSTONE_HIGH_PHYS_SIZE);
> + dev_err(dev, "set dma_offset%08llx%s\n",
> + KEYSTONE_HIGH_PHYS_START - KEYSTONE_LOW_PHYS_START,
> + ret ? " failed" : "");
> }
> return NOTIFY_OK;
> }
> @@ -51,11 +53,8 @@ static struct notifier_block platform_nb = {
>
> static void __init keystone_init(void)
> {
> - if (PHYS_OFFSET >= KEYSTONE_HIGH_PHYS_START) {
> - keystone_dma_pfn_offset = PFN_DOWN(KEYSTONE_HIGH_PHYS_START -
> - KEYSTONE_LOW_PHYS_START);
> + if (PHYS_OFFSET >= KEYSTONE_HIGH_PHYS_START)
> bus_register_notifier(&platform_bus_type, &platform_nb);
> - }
> keystone_pm_runtime_init();
> }
>
> diff --git a/arch/sh/drivers/pci/pcie-sh7786.c b/arch/sh/drivers/pci/pcie-sh7786.c
> index e0b568aaa7014c..e929f85c503852 100644
> --- a/arch/sh/drivers/pci/pcie-sh7786.c
> +++ b/arch/sh/drivers/pci/pcie-sh7786.c
> @@ -12,6 +12,7 @@
> #include <linux/io.h>
> #include <linux/async.h>
> #include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> #include <linux/slab.h>
> #include <linux/clk.h>
> #include <linux/sh_clk.h>
> @@ -31,6 +32,8 @@ struct sh7786_pcie_port {
> static struct sh7786_pcie_port *sh7786_pcie_ports;
> static unsigned int nr_ports;
> static unsigned long dma_pfn_offset;
> +size_t memsize;
> +u64 memstart;
>
> static struct sh7786_pcie_hwops {
> int (*core_init)(void);
> @@ -301,7 +304,6 @@ static int __init pcie_init(struct sh7786_pcie_port *port)
> struct pci_channel *chan = port->hose;
> unsigned int data;
> phys_addr_t memstart, memend;
> - size_t memsize;
> int ret, i, win;
>
> /* Begin initialization */
> @@ -368,8 +370,6 @@ static int __init pcie_init(struct sh7786_pcie_port *port)
> memstart = ALIGN_DOWN(memstart, memsize);
> memsize = roundup_pow_of_two(memend - memstart);
>
> - dma_pfn_offset = memstart >> PAGE_SHIFT;
> -
> /*
> * If there's more than 512MB of memory, we need to roll over to
> * LAR1/LAMR1.
> @@ -487,7 +487,8 @@ int pcibios_map_platform_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
>
> void pcibios_bus_add_device(struct pci_dev *pdev)
> {
> - pdev->dev.dma_pfn_offset = dma_pfn_offset;
> + dma_set_offset_range(&pdev->dev, __pa(memory_start),
> + __pa(memory_start) - memstart, memsize);
> }
>
> static int __init sh7786_pcie_core_init(void)
> diff --git a/arch/sh/kernel/dma-coherent.c b/arch/sh/kernel/dma-coherent.c
> index d4811691b93cc1..003a91719b3794 100644
> --- a/arch/sh/kernel/dma-coherent.c
> +++ b/arch/sh/kernel/dma-coherent.c
> @@ -14,6 +14,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
> {
> void *ret, *ret_nocache;
> int order = get_order(size);
> + phys_addr_t phys;
>
> gfp |= __GFP_ZERO;
>
> @@ -34,12 +35,10 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
> return NULL;
> }
>
> - split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
> -
> - *dma_handle = virt_to_phys(ret);
> - if (!WARN_ON(!dev))
> - *dma_handle -= PFN_PHYS(dev->dma_pfn_offset);
> + phys = virt_to_phys(ret);
> + split_page(pfn_to_page(PHYS_PFN(phys)), order);
>
> + *dma_handle = (dma_addr_t)phys - dma_offset_from_phys_addr(dev, phys);
> return ret_nocache;
> }
>
> @@ -47,12 +46,10 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,
> dma_addr_t dma_handle, unsigned long attrs)
> {
> int order = get_order(size);
> - unsigned long pfn = (dma_handle >> PAGE_SHIFT);
> + unsigned long pfn;
> int k;
>
> - if (!WARN_ON(!dev))
> - pfn += dev->dma_pfn_offset;
> -
> + pfn = PHYS_PFN(dma_handle + dma_offset_from_dma_addr(dev, dma_handle));
> for (k = 0; k < (1 << order); k++)
> __free_pages(pfn_to_page(pfn + k), 0);
>
> diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c
> index c313d784efabb9..ea3a58323f81d1 100644
> --- a/arch/x86/pci/sta2x11-fixup.c
> +++ b/arch/x86/pci/sta2x11-fixup.c
> @@ -12,6 +12,7 @@
> #include <linux/export.h>
> #include <linux/list.h>
> #include <linux/dma-direct.h>
> +#include <linux/dma-mapping.h>
> #include <asm/iommu.h>
>
> #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
> @@ -133,7 +134,7 @@ static void sta2x11_map_ep(struct pci_dev *pdev)
> struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
> struct device *dev = &pdev->dev;
> u32 amba_base, max_amba_addr;
> - int i;
> + int i, ret;
>
> if (!instance)
> return;
> @@ -141,7 +142,9 @@ static void sta2x11_map_ep(struct pci_dev *pdev)
> pci_read_config_dword(pdev, AHB_BASE(0), &amba_base);
> max_amba_addr = amba_base + STA2X11_AMBA_SIZE - 1;
>
> - dev->dma_pfn_offset = PFN_DOWN(-amba_base);
> + ret = dma_set_offset_range(dev, 0, amba_base, STA2X11_AMBA_SIZE);
> + if (ret)
> + dev_err(dev, "sta2x11: could not set DMA offset\n");
>
> dev->bus_dma_limit = max_amba_addr;
> pci_set_consistent_dma_mask(pdev, max_amba_addr);
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 28a6b387e80e28..a3e04c003a2187 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -1142,8 +1142,9 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
> *dma_addr = dmaaddr;
> *dma_size = size;
>
> - dev->dma_pfn_offset = PFN_DOWN(offset);
> - dev_dbg(dev, "dma_pfn_offset(%#08llx)\n", offset);
> + ret = dma_set_offset_range(dev, dmaaddr + offset, dmaaddr, size);
> +
> + dev_dbg(dev, "dma_offset(%#08llx)%s\n", offset, ret ? " failed!" : "");
> }
>
> static void __init acpi_iort_register_irq(int hwirq, const char *name,
> diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
> index 072ea113e6be55..48a4adf1f04edc 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_backend.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
> @@ -11,6 +11,7 @@
> #include <linux/module.h>
> #include <linux/of_device.h>
> #include <linux/of_graph.h>
> +#include <linux/dma-mapping.h>
> #include <linux/platform_device.h>
> #include <linux/reset.h>
>
> @@ -812,7 +813,9 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
> * on our device since the RAM mapping is at 0 for the DMA bus,
> * unlike the CPU.
> */
> - drm->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> + ret = dma_set_offset_range(drm->dev, PHYS_OFFSET, 0, SZ_4G);
> + if (ret)
> + return ret;
> }
>
> backend->engine.node = dev->of_node;
> diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> index 04fbd4bf0ff9fd..d5542df9aacc01 100644
> --- a/drivers/iommu/io-pgtable-arm.c
> +++ b/drivers/iommu/io-pgtable-arm.c
> @@ -754,7 +754,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
> if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS)
> return NULL;
>
> - if (!selftest_running && cfg->iommu_dev->dma_pfn_offset) {
> + if (!selftest_running && cfg->iommu_dev->dma_range_map) {
> dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n");
> return NULL;
> }
> diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> index eff34ded63055d..d6eda02fd3fc93 100644
> --- a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> +++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> @@ -7,6 +7,7 @@
> */
>
> #include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> #include <linux/interrupt.h>
> #include <linux/module.h>
> #include <linux/mutex.h>
> @@ -183,7 +184,9 @@ static int sun4i_csi_probe(struct platform_device *pdev)
> return ret;
> } else {
> #ifdef PHYS_PFN_OFFSET
> - csi->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> + ret = dma_set_offset_range(csi->dev, PHYS_OFFSET, 0, SZ_4G);
> + if (ret)
> + return ret;
> #endif
> }
>
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> index 055eb0b8e39692..450fce6cd8d21b 100644
> --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> @@ -898,7 +898,9 @@ static int sun6i_csi_probe(struct platform_device *pdev)
>
> sdev->dev = &pdev->dev;
> /* The DMA bus has the memory mapped at 0 */
> - sdev->dev->dma_pfn_offset = PHYS_OFFSET >> PAGE_SHIFT;
> + ret = dma_set_offset_range(sdev->dev, PHYS_OFFSET, 0, SZ_4G);
> + if (ret)
> + return ret;
>
> ret = sun6i_csi_resource_request(sdev, pdev);
> if (ret)
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 8eea3f6e29a441..083ec3531bcceb 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -918,33 +918,33 @@ void __iomem *of_io_request_and_map(struct device_node *np, int index,
> }
> EXPORT_SYMBOL(of_io_request_and_map);
>
> +#ifdef CONFIG_HAS_DMA
> /**
> - * of_dma_get_range - Get DMA range info
> + * of_dma_get_range - Get DMA range info and put it into a map array
> * @np: device node to get DMA range info
> - * @dma_addr: pointer to store initial DMA address of DMA range
> - * @paddr: pointer to store initial CPU address of DMA range
> - * @size: pointer to store size of DMA range
> + * @map: dma range structure to return
> *
> * Look in bottom up direction for the first "dma-ranges" property
> - * and parse it.
> - * dma-ranges format:
> + * and parse it. Put the information into a DMA offset map array.
> + *
> + * dma-ranges format:
> * DMA addr (dma_addr) : naddr cells
> * CPU addr (phys_addr_t) : pna cells
> * size : nsize cells
> *
> - * It returns -ENODEV if "dma-ranges" property was not found
> - * for this device in DT.
> + * It returns -ENODEV if "dma-ranges" property was not found for this
> + * device in the DT.
> */
> -int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size)
> +int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
> {
> struct device_node *node = of_node_get(np);
> const __be32 *ranges = NULL;
> - int len;
> - int ret = 0;
> bool found_dma_ranges = false;
> struct of_range_parser parser;
> struct of_range range;
> - u64 dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
> + struct bus_dma_region *r;
> + int len, num_ranges = 0;
> + int ret;
>
> while (node) {
> ranges = of_get_property(node, "dma-ranges", &len);
> @@ -970,44 +970,34 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
> }
>
> of_dma_range_parser_init(&parser, node);
> + for_each_of_range(&parser, &range)
> + num_ranges++;
> +
> + of_dma_range_parser_init(&parser, node);
> +
> + ret = -ENOMEM;
> + r = kcalloc(num_ranges + 1, sizeof(*r), GFP_KERNEL);
> + if (!r)
> + goto out;
>
> + /*
> + * Record all info in the generic DMA ranges array for struct device.
> + */
> + *map = r;
> for_each_of_range(&parser, &range) {
> pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
> range.bus_addr, range.cpu_addr, range.size);
> -
> - if (dma_offset && range.cpu_addr - range.bus_addr != dma_offset) {
> - pr_warn("Can't handle multiple dma-ranges with different offsets on node(%pOF)\n", node);
> - /* Don't error out as we'd break some existing DTs */
> - continue;
> - }
> - dma_offset = range.cpu_addr - range.bus_addr;
> -
> - /* Take lower and upper limits */
> - if (range.bus_addr < dma_start)
> - dma_start = range.bus_addr;
> - if (range.bus_addr + range.size > dma_end)
> - dma_end = range.bus_addr + range.size;
> + r->cpu_start = range.cpu_addr;
> + r->dma_start = range.bus_addr;
> + r->size = range.size;
> + r->offset = (u64)range.cpu_addr - (u64)range.bus_addr;
> + r++;
> }
> -
> - if (dma_start >= dma_end) {
> - ret = -EINVAL;
> - pr_debug("Invalid DMA ranges configuration on node(%pOF)\n",
> - node);
> - goto out;
> - }
> -
> - *dma_addr = dma_start;
> - *size = dma_end - dma_start;
> - *paddr = dma_start + dma_offset;
> -
> - pr_debug("final: dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
> - *dma_addr, *paddr, *size);
> -
> out:
> of_node_put(node);
> -
> return ret;
> }
> +#endif
>
> /**
> * of_dma_is_coherent - Check if device is coherent
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index 27203bfd0b22dc..0c84f42a23e42e 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -88,14 +88,14 @@ int of_device_add(struct platform_device *ofdev)
> */
> int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> {
> - u64 dma_addr, paddr, size = 0;
> - int ret;
> - bool coherent;
> - unsigned long offset;
> const struct iommu_ops *iommu;
> - u64 mask, end;
> + const struct bus_dma_region *map = NULL;
> + dma_addr_t dma_start = 0;
> + u64 mask, end, size = 0;
> + bool coherent;
> + int ret;
>
> - ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
> + ret = of_dma_get_range(np, &map);
> if (ret < 0) {
> /*
> * For legacy reasons, we have to assume some devices need
> @@ -104,26 +104,34 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> */
> if (!force_dma)
> return ret == -ENODEV ? 0 : ret;
> -
> - dma_addr = offset = 0;
> } else {
> - offset = PFN_DOWN(paddr - dma_addr);
> + const struct bus_dma_region *r = map;
> + dma_addr_t dma_end = 0;
> +
> + /* Determine the overall bounds of all DMA regions */
> + for (dma_start = ~(dma_addr_t)0; r->size; r++) {
> + /* Take lower and upper limits */
> + if (r->dma_start < dma_start)
> + dma_start = r->dma_start;
> + if (r->dma_start + r->size > dma_end)
> + dma_end = r->dma_start + r->size;
> + }
> + size = dma_end - dma_start;
>
> /*
> * Add a work around to treat the size as mask + 1 in case
> * it is defined in DT as a mask.
> */
> if (size & 1) {
> - dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
> - size);
> + dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", size);
> size = size + 1;
> }
>
> if (!size) {
> dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
> + kfree(map);
> return -EINVAL;
> }
> - dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
> }
>
> /*
> @@ -142,13 +150,11 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> else if (!size)
> size = 1ULL << 32;
>
> - dev->dma_pfn_offset = offset;
> -
> /*
> * Limit coherent and dma mask based on size and default mask
> * set by the driver.
> */
> - end = dma_addr + size - 1;
> + end = dma_start + size - 1;
> mask = DMA_BIT_MASK(ilog2(end) + 1);
> dev->coherent_dma_mask &= mask;
> *dev->dma_mask &= mask;
> @@ -161,14 +167,17 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> coherent ? " " : " not ");
>
> iommu = of_iommu_configure(dev, np);
> - if (PTR_ERR(iommu) == -EPROBE_DEFER)
> + if (PTR_ERR(iommu) == -EPROBE_DEFER) {
> + kfree(map);
> return -EPROBE_DEFER;
> + }
>
> dev_dbg(dev, "device is%sbehind an iommu\n",
> iommu ? " " : " not ");
>
> - arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
> + arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
>
> + dev->dma_range_map = map;
> return 0;
> }
> EXPORT_SYMBOL_GPL(of_dma_configure);
> diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
> index edc682249c0015..768406b4156b21 100644
> --- a/drivers/of/of_private.h
> +++ b/drivers/of/of_private.h
> @@ -157,12 +157,12 @@ extern void __of_sysfs_remove_bin_file(struct device_node *np,
> extern int of_bus_n_addr_cells(struct device_node *np);
> extern int of_bus_n_size_cells(struct device_node *np);
>
> -#ifdef CONFIG_OF_ADDRESS
> -extern int of_dma_get_range(struct device_node *np, u64 *dma_addr,
> - u64 *paddr, u64 *size);
> +struct bus_dma_region;
> +#if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA)
> +int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map);
> #else
> -static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr,
> - u64 *paddr, u64 *size)
> +static inline int of_dma_get_range(struct device_node *np,
> + const struct bus_dma_region **map);
> {
> return -ENODEV;
> }
> diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
> index 398de04fd19c94..8d0c9bf495d2ef 100644
> --- a/drivers/of/unittest.c
> +++ b/drivers/of/unittest.c
> @@ -7,6 +7,7 @@
>
> #include <linux/memblock.h>
> #include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> #include <linux/err.h>
> #include <linux/errno.h>
> #include <linux/hashtable.h>
> @@ -869,10 +870,10 @@ static void __init of_unittest_changeset(void)
> }
>
> static void __init of_unittest_dma_ranges_one(const char *path,
> - u64 expect_dma_addr, u64 expect_paddr, u64 expect_size)
> + u64 expect_dma_addr, u64 expect_paddr)
> {
> struct device_node *np;
> - u64 dma_addr, paddr, size;
> + const struct bus_dma_region *map = NULL;
> int rc;
>
> np = of_find_node_by_path(path);
> @@ -881,16 +882,26 @@ static void __init of_unittest_dma_ranges_one(const char *path,
> return;
> }
>
> - rc = of_dma_get_range(np, &dma_addr, &paddr, &size);
> -
> + rc = of_dma_get_range(np, &map);
> unittest(!rc, "of_dma_get_range failed on node %pOF rc=%i\n", np, rc);
> +
> if (!rc) {
> - unittest(size == expect_size,
> - "of_dma_get_range wrong size on node %pOF size=%llx\n", np, size);
> + phys_addr_t paddr;
> + dma_addr_t dma_addr;
> + struct device dev_bogus;
> +
> + dev_bogus.dma_range_map = map;
> + paddr = (phys_addr_t)expect_dma_addr +
> + dma_offset_from_dma_addr(&dev_bogus, expect_dma_addr);
> + dma_addr = (dma_addr_t)expect_paddr -
> + dma_offset_from_phys_addr(&dev_bogus, expect_paddr);
> +
> unittest(paddr == expect_paddr,
> "of_dma_get_range wrong phys addr (%llx) on node %pOF", paddr, np);
> unittest(dma_addr == expect_dma_addr,
> "of_dma_get_range wrong DMA addr (%llx) on node %pOF", dma_addr, np);
> +
> + kfree(map);
> }
> of_node_put(np);
> }
> @@ -898,11 +909,14 @@ static void __init of_unittest_dma_ranges_one(const char *path,
> static void __init of_unittest_parse_dma_ranges(void)
> {
> of_unittest_dma_ranges_one("/testcase-data/address-tests/device@70000000",
> - 0x0, 0x20000000, 0x40000000);
> + 0x0, 0x20000000);
> of_unittest_dma_ranges_one("/testcase-data/address-tests/bus@80000000/device@1000",
> - 0x10000000, 0x20000000, 0x40000000);
> + 0x10000000, 0x20000000);
> + /* pci@90000000 has two ranges in the dma-range property */
> + of_unittest_dma_ranges_one("/testcase-data/address-tests/pci@90000000",
> + 0x80000000, 0x20000000);
> of_unittest_dma_ranges_one("/testcase-data/address-tests/pci@90000000",
> - 0x80000000, 0x20000000, 0x10000000);
> + 0xc0000000, 0x40000000);
> }
>
> static void __init of_unittest_pci_dma_ranges(void)
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 9f04c30c4aaf7a..49242dd6176e30 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -519,7 +519,7 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
> /* Initialise vdev subdevice */
> snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
> rvdev->dev.parent = &rproc->dev;
> - rvdev->dev.dma_pfn_offset = rproc->dev.parent->dma_pfn_offset;
> + rvdev->dev.dma_range_map = rproc->dev.parent->dma_range_map;
> rvdev->dev.release = rproc_rvdev_release;
> dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
> dev_set_drvdata(&rvdev->dev, rvdev);
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> index 1744e6fcc99980..249e4bddaa4014 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> @@ -230,8 +230,11 @@ int cedrus_hw_probe(struct cedrus_dev *dev)
> */
>
> #ifdef PHYS_PFN_OFFSET
> - if (!(variant->quirks & CEDRUS_QUIRK_NO_DMA_OFFSET))
> - dev->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> + if (!(variant->quirks & CEDRUS_QUIRK_NO_DMA_OFFSET)) {
> + ret = dma_set_offset_range(dev->dev, PHYS_OFFSET, 0, SZ_4G);
> + if (ret)
> + return ret;
> + }
> #endif
>
> ret = of_reserved_mem_device_init(dev->dev);
> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> index 6197938dcc2d8f..376ca258e510bf 100644
> --- a/drivers/usb/core/message.c
> +++ b/drivers/usb/core/message.c
> @@ -1956,10 +1956,10 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
> intf->dev.groups = usb_interface_groups;
> /*
> * Please refer to usb_alloc_dev() to see why we set
> - * dma_mask and dma_pfn_offset.
> + * dma_mask and dma_range_map.
> */
> intf->dev.dma_mask = dev->dev.dma_mask;
> - intf->dev.dma_pfn_offset = dev->dev.dma_pfn_offset;
> + intf->dev.dma_range_map = dev->dev.dma_range_map;
> INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
> intf->minor = -1;
> device_initialize(&intf->dev);
> diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
> index f16c26dc079d79..1f167a2c095e9a 100644
> --- a/drivers/usb/core/usb.c
> +++ b/drivers/usb/core/usb.c
> @@ -611,7 +611,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
> * mask for the entire HCD, so don't do that.
> */
> dev->dev.dma_mask = bus->sysdev->dma_mask;
> - dev->dev.dma_pfn_offset = bus->sysdev->dma_pfn_offset;
> + dev->dev.dma_range_map = bus->sysdev->dma_range_map;
> set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
> dev->state = USB_STATE_ATTACHED;
> dev->lpm_disable_count = 1;
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 15460a5ac024a1..feddefcf3e5c20 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -492,7 +492,7 @@ struct dev_links_info {
> * such descriptors.
> * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
> * DMA limit than the device itself supports.
> - * @dma_pfn_offset: offset of DMA memory range relatively of RAM
> + * @dma_range_map: map for DMA memory ranges relative to that of RAM
> * @dma_parms: A low level driver may set these to teach IOMMU code about
> * segment limitations.
> * @dma_pools: Dma pools (if dma'ble device).
> @@ -577,7 +577,7 @@ struct device {
> 64 bit addresses for consistent
> allocations such descriptors. */
> u64 bus_dma_limit; /* upstream dma constraint */
> - unsigned long dma_pfn_offset;
> + const struct bus_dma_region *dma_range_map;
>
> struct device_dma_parameters *dma_parms;
>
> diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
> index 5184735a0fe8eb..810d27692674bc 100644
> --- a/include/linux/dma-direct.h
> +++ b/include/linux/dma-direct.h
> @@ -13,16 +13,12 @@ extern unsigned int zone_dma_bits;
> #else
> static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
> {
> - dma_addr_t dev_addr = (dma_addr_t)paddr;
> -
> - return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
> + return (dma_addr_t)paddr - dma_offset_from_phys_addr(dev, paddr);
> }
>
> static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
> {
> - phys_addr_t paddr = (phys_addr_t)dev_addr;
> -
> - return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
> + return (phys_addr_t)dev_addr + dma_offset_from_dma_addr(dev, dev_addr);
> }
> #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
>
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index a33ed3954ed465..5938c7ca2abcce 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -255,7 +255,38 @@ static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
>
> size_t dma_direct_max_mapping_size(struct device *dev);
>
> +struct bus_dma_region {
> + phys_addr_t cpu_start;
> + dma_addr_t dma_start;
> + u64 size;
> + u64 offset;
> +};
> +
> #ifdef CONFIG_HAS_DMA
> +static inline u64 dma_offset_from_dma_addr(struct device *dev, dma_addr_t dma_addr)
> +{
> + const struct bus_dma_region *m = dev->dma_range_map;
> +
> + if (!m)
> + return 0;
> + for (; m->size; m++)
> + if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size)
> + return m->offset;
> + return 0;
> +}
> +
> +static inline u64 dma_offset_from_phys_addr(struct device *dev, phys_addr_t paddr)
> +{
> + const struct bus_dma_region *m = dev->dma_range_map;
> +
> + if (!m)
> + return 0;
> + for (; m->size; m++)
> + if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size)
> + return m->offset;
> + return 0;
> +}
> +
> #include <asm/dma-mapping.h>
>
> static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
> @@ -801,6 +832,9 @@ static inline void arch_teardown_dma_ops(struct device *dev)
> }
> #endif /* CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS */
>
> +int dma_set_offset_range(struct device *dev, phys_addr_t cpu_start,
> + dma_addr_t dma_start, u64 size);
> +
> static inline unsigned int dma_get_max_seg_size(struct device *dev)
> {
> if (dev->dma_parms && dev->dma_parms->max_segment_size)
> diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
> index 2a0c4985f38e41..751969d6185325 100644
> --- a/kernel/dma/coherent.c
> +++ b/kernel/dma/coherent.c
> @@ -31,10 +31,12 @@ static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *de
> static inline dma_addr_t dma_get_device_base(struct device *dev,
> struct dma_coherent_mem * mem)
> {
> - if (mem->use_dev_dma_pfn_offset)
> - return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT;
> - else
> - return mem->device_base;
> + if (mem->use_dev_dma_pfn_offset) {
> + u64 base_addr = (u64)mem->pfn_base << PAGE_SHIFT;
> +
> + return base_addr - dma_offset_from_phys_addr(dev, base_addr);
> + }
> + return mem->device_base;
> }
>
> static int dma_init_coherent_memory(phys_addr_t phys_addr,
> diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
> index a8c18c9a796fdc..dc8017a106fd55 100644
> --- a/kernel/dma/mapping.c
> +++ b/kernel/dma/mapping.c
> @@ -11,6 +11,7 @@
> #include <linux/dma-noncoherent.h>
> #include <linux/export.h>
> #include <linux/gfp.h>
> +#include <linux/limits.h>
> #include <linux/of_device.h>
> #include <linux/slab.h>
> #include <linux/vmalloc.h>
> @@ -417,3 +418,62 @@ unsigned long dma_get_merge_boundary(struct device *dev)
> return ops->get_merge_boundary(dev);
> }
> EXPORT_SYMBOL_GPL(dma_get_merge_boundary);
> +
> +static bool dma_range_overlaps(struct device *dev, phys_addr_t cpu_start,
> + dma_addr_t dma_start, u64 size, u64 offset)
> +{
> + const struct bus_dma_region *m = dev->dma_range_map;
> +
> + for (m = dev->dma_range_map; m->size; m++) {
> + if (offset == m->offset &&
> + cpu_start >= m->cpu_start &&
> + size <= m->size &&
> + cpu_start - m->cpu_start <= m->size - size)
> + return true;
> + }
> +
> + return false;
> +}
> +
> +/**
> + * dma_set_offset_range - Assign scalar offset for a single DMA range.
> + * @dev: device pointer; needed to "own" the alloced memory.
> + * @cpu_start: beginning of memory region covered by this offset.
> + * @dma_start: beginning of DMA/PCI region covered by this offset.
> + * @size: size of the region.
> + *
> + * This is for the simple case of a uniform offset which cannot
> + * be discovered by "dma-ranges".
> + *
> + * It returns -ENOMEM if out of memory, -ENODEV if dev == NULL, otherwise 0.
> + */
> +int dma_set_offset_range(struct device *dev, phys_addr_t cpu_start,
> + dma_addr_t dma_start, u64 size)
> +{
> + struct bus_dma_region *map;
> + u64 offset = (u64)cpu_start - (u64)dma_start;
> +
> + if (!offset)
> + return 0;
> +
> + /*
> + * See if a map already exists and we already encompass the new range:
> + */
> + if (dev->dma_range_map) {
> + if (dma_range_overlaps(dev, cpu_start, dma_start, size, offset))
> + return 0;
> + dev_err(dev, "attempt to add conflicting DMA range to existing map\n");
> + return -EINVAL;
> + }
> +
> + map = kcalloc(2, sizeof(*map), GFP_KERNEL);
> + if (!map)
> + return -ENOMEM;
> + map[0].cpu_start = cpu_start;
> + map[0].dma_start = dma_start;
> + map[0].offset = offset;
> + map[0].size = size;
> + dev->dma_range_map = map;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(dma_set_offset_range);
>
> >
> > Signed-off-by: Jim Quinlan <james.quinlan(a)broadcom.com>
> > ---
> > arch/arm/include/asm/dma-mapping.h | 9 +-
> > arch/arm/mach-keystone/keystone.c | 17 ++--
> > arch/sh/drivers/pci/pcie-sh7786.c | 9 +-
> > arch/sh/kernel/dma-coherent.c | 16 ++--
> > arch/x86/pci/sta2x11-fixup.c | 7 +-
> > drivers/acpi/arm64/iort.c | 5 +-
> > drivers/gpu/drm/sun4i/sun4i_backend.c | 5 +-
> > drivers/iommu/io-pgtable-arm.c | 2 +-
> > .../platform/sunxi/sun4i-csi/sun4i_csi.c | 5 +-
> > .../platform/sunxi/sun6i-csi/sun6i_csi.c | 4 +-
> > drivers/of/address.c | 95 ++++++++++---------
> > drivers/of/device.c | 47 +++++----
> > drivers/of/of_private.h | 9 +-
> > drivers/of/unittest.c | 35 +++++--
> > drivers/remoteproc/remoteproc_core.c | 2 +-
> > .../staging/media/sunxi/cedrus/cedrus_hw.c | 7 +-
> > drivers/usb/core/message.c | 4 +-
> > drivers/usb/core/usb.c | 2 +-
> > include/linux/device.h | 4 +-
> > include/linux/dma-direct.h | 10 +-
> > include/linux/dma-mapping.h | 43 +++++++++
> > include/linux/pfn.h | 2 +
> > kernel/dma/coherent.c | 10 +-
> > kernel/dma/mapping.c | 53 +++++++++++
> > 24 files changed, 278 insertions(+), 124 deletions(-)
> >
> > diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> > index bdd80ddbca34..b7cdde9fb83d 100644
> > --- a/arch/arm/include/asm/dma-mapping.h
> > +++ b/arch/arm/include/asm/dma-mapping.h
> > @@ -35,8 +35,9 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
> > #ifndef __arch_pfn_to_dma
> > static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
> > {
> > - if (dev)
> > - pfn -= dev->dma_pfn_offset;
> > + if (dev && dev->dma_range_map)
> > + pfn -= DMA_ADDR_PFN(dma_offset_from_phys_addr(dev, PFN_PHYS(pfn)));
> > +
> > return (dma_addr_t)__pfn_to_bus(pfn);
> > }
> >
> > @@ -44,8 +45,8 @@ static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
> > {
> > unsigned long pfn = __bus_to_pfn(addr);
> >
> > - if (dev)
> > - pfn += dev->dma_pfn_offset;
> > + if (dev && dev->dma_range_map)
> > + pfn += DMA_ADDR_PFN(dma_offset_from_dma_addr(dev, addr));
> >
> > return pfn;
> > }
> > diff --git a/arch/arm/mach-keystone/keystone.c b/arch/arm/mach-keystone/keystone.c
> > index 638808c4e122..a1a19781983b 100644
> > --- a/arch/arm/mach-keystone/keystone.c
> > +++ b/arch/arm/mach-keystone/keystone.c
> > @@ -8,6 +8,7 @@
> > */
> > #include <linux/io.h>
> > #include <linux/of.h>
> > +#include <linux/dma-mapping.h>
> > #include <linux/init.h>
> > #include <linux/of_platform.h>
> > #include <linux/of_address.h>
> > @@ -24,8 +25,6 @@
> >
> > #include "keystone.h"
> >
> > -static unsigned long keystone_dma_pfn_offset __read_mostly;
> > -
> > static int keystone_platform_notifier(struct notifier_block *nb,
> > unsigned long event, void *data)
> > {
> > @@ -38,9 +37,12 @@ static int keystone_platform_notifier(struct notifier_block *nb,
> > return NOTIFY_BAD;
> >
> > if (!dev->of_node) {
> > - dev->dma_pfn_offset = keystone_dma_pfn_offset;
> > - dev_err(dev, "set dma_pfn_offset%08lx\n",
> > - dev->dma_pfn_offset);
> > + int ret = dma_attach_offset_range(dev, KEYSTONE_HIGH_PHYS_START,
> > + KEYSTONE_LOW_PHYS_START,
> > + KEYSTONE_HIGH_PHYS_SIZE);
> > + dev_err(dev, "set dma_offset%08llx%s\n",
> > + KEYSTONE_HIGH_PHYS_START - KEYSTONE_LOW_PHYS_START,
> > + ret ? " failed" : "");
> > }
> > return NOTIFY_OK;
> > }
> > @@ -51,11 +53,8 @@ static struct notifier_block platform_nb = {
> >
> > static void __init keystone_init(void)
> > {
> > - if (PHYS_OFFSET >= KEYSTONE_HIGH_PHYS_START) {
> > - keystone_dma_pfn_offset = PFN_DOWN(KEYSTONE_HIGH_PHYS_START -
> > - KEYSTONE_LOW_PHYS_START);
> > + if (PHYS_OFFSET >= KEYSTONE_HIGH_PHYS_START)
> > bus_register_notifier(&platform_bus_type, &platform_nb);
> > - }
> > keystone_pm_runtime_init();
> > }
> >
> > diff --git a/arch/sh/drivers/pci/pcie-sh7786.c b/arch/sh/drivers/pci/pcie-sh7786.c
> > index e0b568aaa701..716bb99022c6 100644
> > --- a/arch/sh/drivers/pci/pcie-sh7786.c
> > +++ b/arch/sh/drivers/pci/pcie-sh7786.c
> > @@ -12,6 +12,7 @@
> > #include <linux/io.h>
> > #include <linux/async.h>
> > #include <linux/delay.h>
> > +#include <linux/dma-mapping.h>
> > #include <linux/slab.h>
> > #include <linux/clk.h>
> > #include <linux/sh_clk.h>
> > @@ -31,6 +32,8 @@ struct sh7786_pcie_port {
> > static struct sh7786_pcie_port *sh7786_pcie_ports;
> > static unsigned int nr_ports;
> > static unsigned long dma_pfn_offset;
> > +size_t memsize;
> > +u64 memstart;
> >
> > static struct sh7786_pcie_hwops {
> > int (*core_init)(void);
> > @@ -301,7 +304,6 @@ static int __init pcie_init(struct sh7786_pcie_port *port)
> > struct pci_channel *chan = port->hose;
> > unsigned int data;
> > phys_addr_t memstart, memend;
> > - size_t memsize;
> > int ret, i, win;
> >
> > /* Begin initialization */
> > @@ -368,8 +370,6 @@ static int __init pcie_init(struct sh7786_pcie_port *port)
> > memstart = ALIGN_DOWN(memstart, memsize);
> > memsize = roundup_pow_of_two(memend - memstart);
> >
> > - dma_pfn_offset = memstart >> PAGE_SHIFT;
> > -
> > /*
> > * If there's more than 512MB of memory, we need to roll over to
> > * LAR1/LAMR1.
> > @@ -487,7 +487,8 @@ int pcibios_map_platform_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
> >
> > void pcibios_bus_add_device(struct pci_dev *pdev)
> > {
> > - pdev->dev.dma_pfn_offset = dma_pfn_offset;
> > + dma_attach_offset_range(&pdev->dev, __pa(memory_start),
> > + __pa(memory_start) - memstart, memsize);
> > }
> >
> > static int __init sh7786_pcie_core_init(void)
> > diff --git a/arch/sh/kernel/dma-coherent.c b/arch/sh/kernel/dma-coherent.c
> > index d4811691b93c..e00f29c7c443 100644
> > --- a/arch/sh/kernel/dma-coherent.c
> > +++ b/arch/sh/kernel/dma-coherent.c
> > @@ -14,6 +14,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
> > {
> > void *ret, *ret_nocache;
> > int order = get_order(size);
> > + phys_addr_t phys;
> >
> > gfp |= __GFP_ZERO;
> >
> > @@ -34,11 +35,12 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
> > return NULL;
> > }
> >
> > - split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
> > + phys = virt_to_phys(ret);
> > + split_page(pfn_to_page(PHYS_PFN(phys)), order);
> >
> > - *dma_handle = virt_to_phys(ret);
> > - if (!WARN_ON(!dev))
> > - *dma_handle -= PFN_PHYS(dev->dma_pfn_offset);
> > + *dma_handle = (dma_addr_t)phys;
> > + if (!WARN_ON(!dev) && dev->dma_range_map)
> > + *dma_handle -= dma_offset_from_phys_addr(dev, phys);
> >
> > return ret_nocache;
> > }
> > @@ -47,11 +49,11 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,
> > dma_addr_t dma_handle, unsigned long attrs)
> > {
> > int order = get_order(size);
> > - unsigned long pfn = (dma_handle >> PAGE_SHIFT);
> > + unsigned long pfn = PHYS_PFN(dma_handle);
> > int k;
> >
> > - if (!WARN_ON(!dev))
> > - pfn += dev->dma_pfn_offset;
> > + if (!WARN_ON(!dev) && dev->dma_range_map)
> > + pfn += DMA_ADDR_PFN(dma_offset_from_dma_addr(dev, dma_handle));
> >
> > for (k = 0; k < (1 << order); k++)
> > __free_pages(pfn_to_page(pfn + k), 0);
> > diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c
> > index c313d784efab..74633ccf622e 100644
> > --- a/arch/x86/pci/sta2x11-fixup.c
> > +++ b/arch/x86/pci/sta2x11-fixup.c
> > @@ -12,6 +12,7 @@
> > #include <linux/export.h>
> > #include <linux/list.h>
> > #include <linux/dma-direct.h>
> > +#include <linux/dma-mapping.h>
> > #include <asm/iommu.h>
> >
> > #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
> > @@ -133,7 +134,7 @@ static void sta2x11_map_ep(struct pci_dev *pdev)
> > struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
> > struct device *dev = &pdev->dev;
> > u32 amba_base, max_amba_addr;
> > - int i;
> > + int i, ret;
> >
> > if (!instance)
> > return;
> > @@ -141,7 +142,9 @@ static void sta2x11_map_ep(struct pci_dev *pdev)
> > pci_read_config_dword(pdev, AHB_BASE(0), &amba_base);
> > max_amba_addr = amba_base + STA2X11_AMBA_SIZE - 1;
> >
> > - dev->dma_pfn_offset = PFN_DOWN(-amba_base);
> > + ret = dma_attach_offset_range(dev, 0, amba_base, STA2X11_AMBA_SIZE);
> > + if (ret)
> > + dev_err(dev, "sta2x11: could not set DMA offset\n");
> >
> > dev->bus_dma_limit = max_amba_addr;
> > pci_set_consistent_dma_mask(pdev, max_amba_addr);
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index 28a6b387e80e..41c2d861ce43 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -1142,8 +1142,9 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
> > *dma_addr = dmaaddr;
> > *dma_size = size;
> >
> > - dev->dma_pfn_offset = PFN_DOWN(offset);
> > - dev_dbg(dev, "dma_pfn_offset(%#08llx)\n", offset);
> > + ret = dma_attach_offset_range(dev, dmaaddr + offset, dmaaddr, size);
> > +
> > + dev_dbg(dev, "dma_offset(%#08llx)%s\n", offset, ret ? " failed!" : "");
> > }
> >
> > static void __init acpi_iort_register_irq(int hwirq, const char *name,
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
> > index 072ea113e6be..cbe49a07983c 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_backend.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
> > @@ -11,6 +11,7 @@
> > #include <linux/module.h>
> > #include <linux/of_device.h>
> > #include <linux/of_graph.h>
> > +#include <linux/dma-mapping.h>
> > #include <linux/platform_device.h>
> > #include <linux/reset.h>
> >
> > @@ -812,7 +813,9 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
> > * on our device since the RAM mapping is at 0 for the DMA bus,
> > * unlike the CPU.
> > */
> > - drm->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> > + ret = dma_attach_offset_range(drm->dev, PHYS_OFFSET, 0, SZ_4G);
> > + if (ret)
> > + return ret;
> > }
> >
> > backend->engine.node = dev->of_node;
> > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> > index 04fbd4bf0ff9..d5542df9aacc 100644
> > --- a/drivers/iommu/io-pgtable-arm.c
> > +++ b/drivers/iommu/io-pgtable-arm.c
> > @@ -754,7 +754,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
> > if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS)
> > return NULL;
> >
> > - if (!selftest_running && cfg->iommu_dev->dma_pfn_offset) {
> > + if (!selftest_running && cfg->iommu_dev->dma_range_map) {
> > dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n");
> > return NULL;
> > }
> > diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> > index eff34ded6305..95a5d5655056 100644
> > --- a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> > +++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> > @@ -7,6 +7,7 @@
> > */
> >
> > #include <linux/clk.h>
> > +#include <linux/dma-mapping.h>
> > #include <linux/interrupt.h>
> > #include <linux/module.h>
> > #include <linux/mutex.h>
> > @@ -183,7 +184,9 @@ static int sun4i_csi_probe(struct platform_device *pdev)
> > return ret;
> > } else {
> > #ifdef PHYS_PFN_OFFSET
> > - csi->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> > + ret = dma_attach_offset_range(csi->dev, PHYS_OFFSET, 0, SZ_4G);
> > + if (ret)
> > + return ret;
> > #endif
> > }
> >
> > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > index 055eb0b8e396..c26fc1cdd4d2 100644
> > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > @@ -898,7 +898,9 @@ static int sun6i_csi_probe(struct platform_device *pdev)
> >
> > sdev->dev = &pdev->dev;
> > /* The DMA bus has the memory mapped at 0 */
> > - sdev->dev->dma_pfn_offset = PHYS_OFFSET >> PAGE_SHIFT;
> > + ret = dma_attach_offset_range(sdev->dev, PHYS_OFFSET, 0, SZ_4G);
> > + if (ret)
> > + return ret;
> >
> > ret = sun6i_csi_resource_request(sdev, pdev);
> > if (ret)
> > diff --git a/drivers/of/address.c b/drivers/of/address.c
> > index 8eea3f6e29a4..5d9117a1cb16 100644
> > --- a/drivers/of/address.c
> > +++ b/drivers/of/address.c
> > @@ -918,33 +918,65 @@ void __iomem *of_io_request_and_map(struct device_node *np, int index,
> > }
> > EXPORT_SYMBOL(of_io_request_and_map);
> >
> > +static const struct bus_dma_region *dma_create_offset_map(struct device_node *node,
> > + int num_ranges)
> > +{
> > + struct of_range_parser parser;
> > + struct of_range range;
> > + struct bus_dma_region *map, *r;
> > + int ret;
> > +
> > + r = kcalloc(num_ranges + 1, sizeof(*r), GFP_KERNEL);
> > + if (!r)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + map = r;
> > + ret = of_dma_range_parser_init(&parser, node);
> > + if (ret)
> > + return ERR_PTR(ret);
> > +
> > + /*
> > + * Record all info for DMA ranges array. We use our
> > + * our own struct (bus_dma_region) so it is not dependent
> > + * on CONFIG_OF.
> > + */
> > + for_each_of_range(&parser, &range) {
> > + pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
> > + range.bus_addr, range.cpu_addr, range.size);
> > + r->cpu_start = range.cpu_addr;
> > + r->dma_start = range.bus_addr;
> > + r->size = range.size;
> > + r->offset = (u64)range.cpu_addr - (u64)range.bus_addr;
> > + r++;
> > + }
> > + return map;
> > +}
> > +
> > /**
> > - * of_dma_get_range - Get DMA range info
> > + * of_dma_get_range - Get DMA range info and put it into a map array
> > * @np: device node to get DMA range info
> > - * @dma_addr: pointer to store initial DMA address of DMA range
> > - * @paddr: pointer to store initial CPU address of DMA range
> > - * @size: pointer to store size of DMA range
> > *
> > * Look in bottom up direction for the first "dma-ranges" property
> > - * and parse it.
> > - * dma-ranges format:
> > + * and parse it. Put the information into a DMA offset map array.
> > + *
> > + * dma-ranges format:
> > * DMA addr (dma_addr) : naddr cells
> > * CPU addr (phys_addr_t) : pna cells
> > * size : nsize cells
> > *
> > - * It returns -ENODEV if "dma-ranges" property was not found
> > - * for this device in DT.
> > + * It returns -ENODEV if "dma-ranges" property was not found for this
> > + * device in the DT.
> > */
> > -int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size)
> > +const struct bus_dma_region *of_dma_get_range(struct device_node *np)
> > {
> > + const struct bus_dma_region *map = NULL;
> > struct device_node *node = of_node_get(np);
> > + struct of_range_parser parser;
> > const __be32 *ranges = NULL;
> > - int len;
> > - int ret = 0;
> > bool found_dma_ranges = false;
> > - struct of_range_parser parser;
> > struct of_range range;
> > - u64 dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
> > + int len, num_ranges = 0;
> > + int ret = 0;
> >
> > while (node) {
> > ranges = of_get_property(node, "dma-ranges", &len);
> > @@ -971,42 +1003,13 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
> >
> > of_dma_range_parser_init(&parser, node);
> >
> > - for_each_of_range(&parser, &range) {
> > - pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
> > - range.bus_addr, range.cpu_addr, range.size);
> > -
> > - if (dma_offset && range.cpu_addr - range.bus_addr != dma_offset) {
> > - pr_warn("Can't handle multiple dma-ranges with different offsets on node(%pOF)\n", node);
> > - /* Don't error out as we'd break some existing DTs */
> > - continue;
> > - }
> > - dma_offset = range.cpu_addr - range.bus_addr;
> > -
> > - /* Take lower and upper limits */
> > - if (range.bus_addr < dma_start)
> > - dma_start = range.bus_addr;
> > - if (range.bus_addr + range.size > dma_end)
> > - dma_end = range.bus_addr + range.size;
> > - }
> > -
> > - if (dma_start >= dma_end) {
> > - ret = -EINVAL;
> > - pr_debug("Invalid DMA ranges configuration on node(%pOF)\n",
> > - node);
> > - goto out;
> > - }
> > -
> > - *dma_addr = dma_start;
> > - *size = dma_end - dma_start;
> > - *paddr = dma_start + dma_offset;
> > -
> > - pr_debug("final: dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
> > - *dma_addr, *paddr, *size);
> > + for_each_of_range(&parser, &range)
> > + num_ranges++;
> >
> > + map = dma_create_offset_map(node, num_ranges);
> > out:
> > of_node_put(node);
> > -
> > - return ret;
> > + return map ? map : ERR_PTR(ret);
> > }
> >
> > /**
> > diff --git a/drivers/of/device.c b/drivers/of/device.c
> > index 27203bfd0b22..fea2f31d4245 100644
> > --- a/drivers/of/device.c
> > +++ b/drivers/of/device.c
> > @@ -88,14 +88,15 @@ int of_device_add(struct platform_device *ofdev)
> > */
> > int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> > {
> > - u64 dma_addr, paddr, size = 0;
> > - int ret;
> > - bool coherent;
> > - unsigned long offset;
> > const struct iommu_ops *iommu;
> > - u64 mask, end;
> > + const struct bus_dma_region *map;
> > + dma_addr_t dma_start = 0;
> > + u64 mask, end, size = 0;
> > + bool coherent;
> > + int ret;
> >
> > - ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
> > + map = of_dma_get_range(np);
> > + ret = PTR_ERR_OR_ZERO(map);
> > if (ret < 0) {
> > /*
> > * For legacy reasons, we have to assume some devices need
> > @@ -105,25 +106,36 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> > if (!force_dma)
> > return ret == -ENODEV ? 0 : ret;
> >
> > - dma_addr = offset = 0;
> > - } else {
> > - offset = PFN_DOWN(paddr - dma_addr);
> > + dma_start = 0;
> > + map = NULL;
> > + } else if (map) {
> > + const struct bus_dma_region *r = map;
> > + dma_addr_t dma_end = 0;
> > +
> > + /* Determine the overall bounds of all DMA regions */
> > + for (dma_start = ~(dma_addr_t)0; r->size; r++) {
> > + /* Take lower and upper limits */
> > + if (r->dma_start < dma_start)
> > + dma_start = r->dma_start;
> > + if (r->dma_start + r->size > dma_end)
> > + dma_end = r->dma_start + r->size;
> > + }
> > + size = dma_end - dma_start;
> >
> > /*
> > * Add a work around to treat the size as mask + 1 in case
> > * it is defined in DT as a mask.
> > */
> > if (size & 1) {
> > - dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
> > - size);
> > + dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", size);
> > size = size + 1;
> > }
> >
> > if (!size) {
> > dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
> > + kfree(map);
> > return -EINVAL;
> > }
> > - dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
> > }
> >
> > /*
> > @@ -142,13 +154,11 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> > else if (!size)
> > size = 1ULL << 32;
> >
> > - dev->dma_pfn_offset = offset;
> > -
> > /*
> > * Limit coherent and dma mask based on size and default mask
> > * set by the driver.
> > */
> > - end = dma_addr + size - 1;
> > + end = dma_start + size - 1;
> > mask = DMA_BIT_MASK(ilog2(end) + 1);
> > dev->coherent_dma_mask &= mask;
> > *dev->dma_mask &= mask;
> > @@ -161,14 +171,17 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> > coherent ? " " : " not ");
> >
> > iommu = of_iommu_configure(dev, np);
> > - if (PTR_ERR(iommu) == -EPROBE_DEFER)
> > + if (PTR_ERR(iommu) == -EPROBE_DEFER) {
> > + kfree(map);
> > return -EPROBE_DEFER;
> > + }
> >
> > dev_dbg(dev, "device is%sbehind an iommu\n",
> > iommu ? " " : " not ");
> >
> > - arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
> > + arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
> >
> > + dev->dma_range_map = map;
> > return 0;
> > }
> > EXPORT_SYMBOL_GPL(of_dma_configure);
> > diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
> > index edc682249c00..876149e721c5 100644
> > --- a/drivers/of/of_private.h
> > +++ b/drivers/of/of_private.h
> > @@ -157,14 +157,13 @@ extern void __of_sysfs_remove_bin_file(struct device_node *np,
> > extern int of_bus_n_addr_cells(struct device_node *np);
> > extern int of_bus_n_size_cells(struct device_node *np);
> >
> > +struct bus_dma_region;
> > #ifdef CONFIG_OF_ADDRESS
> > -extern int of_dma_get_range(struct device_node *np, u64 *dma_addr,
> > - u64 *paddr, u64 *size);
> > +extern const struct bus_dma_region *of_dma_get_range(struct device_node *np);
> > #else
> > -static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr,
> > - u64 *paddr, u64 *size)
> > +static inline const struct bus_dma_region *of_dma_get_range(struct device_node *np)
> > {
> > - return -ENODEV;
> > + return ERR_PTR(-ENODEV);
> > }
> > #endif
> >
> > diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
> > index 398de04fd19c..542d092f19c2 100644
> > --- a/drivers/of/unittest.c
> > +++ b/drivers/of/unittest.c
> > @@ -7,6 +7,7 @@
> >
> > #include <linux/memblock.h>
> > #include <linux/clk.h>
> > +#include <linux/dma-mapping.h>
> > #include <linux/err.h>
> > #include <linux/errno.h>
> > #include <linux/hashtable.h>
> > @@ -869,10 +870,10 @@ static void __init of_unittest_changeset(void)
> > }
> >
> > static void __init of_unittest_dma_ranges_one(const char *path,
> > - u64 expect_dma_addr, u64 expect_paddr, u64 expect_size)
> > + u64 expect_dma_addr, u64 expect_paddr)
> > {
> > struct device_node *np;
> > - u64 dma_addr, paddr, size;
> > + const struct bus_dma_region *map = NULL;
> > int rc;
> >
> > np = of_find_node_by_path(path);
> > @@ -881,16 +882,27 @@ static void __init of_unittest_dma_ranges_one(const char *path,
> > return;
> > }
> >
> > - rc = of_dma_get_range(np, &dma_addr, &paddr, &size);
> > -
> > + map = of_dma_get_range(np);
> > + rc = PTR_ERR_OR_ZERO(map);
> > unittest(!rc, "of_dma_get_range failed on node %pOF rc=%i\n", np, rc);
> > - if (!rc) {
> > - unittest(size == expect_size,
> > - "of_dma_get_range wrong size on node %pOF size=%llx\n", np, size);
> > +
> > + if (!rc && map) {
> > + phys_addr_t paddr;
> > + dma_addr_t dma_addr;
> > + struct device dev_bogus;
> > +
> > + dev_bogus.dma_range_map = map;
> > + paddr = (phys_addr_t)expect_dma_addr
> > + + dma_offset_from_dma_addr(&dev_bogus, expect_dma_addr);
> > + dma_addr = (dma_addr_t)expect_paddr
> > + - dma_offset_from_phys_addr(&dev_bogus, expect_paddr);
> > +
> > unittest(paddr == expect_paddr,
> > "of_dma_get_range wrong phys addr (%llx) on node %pOF", paddr, np);
> > unittest(dma_addr == expect_dma_addr,
> > "of_dma_get_range wrong DMA addr (%llx) on node %pOF", dma_addr, np);
> > +
> > + kfree(map);
> > }
> > of_node_put(np);
> > }
> > @@ -898,11 +910,14 @@ static void __init of_unittest_dma_ranges_one(const char *path,
> > static void __init of_unittest_parse_dma_ranges(void)
> > {
> > of_unittest_dma_ranges_one("/testcase-data/address-tests/device@70000000",
> > - 0x0, 0x20000000, 0x40000000);
> > + 0x0, 0x20000000);
> > of_unittest_dma_ranges_one("/testcase-data/address-tests/bus@80000000/device@1000",
> > - 0x10000000, 0x20000000, 0x40000000);
> > + 0x10000000, 0x20000000);
> > + /* pci@90000000 has two ranges in the dma-range property */
> > + of_unittest_dma_ranges_one("/testcase-data/address-tests/pci@90000000",
> > + 0x80000000, 0x20000000);
> > of_unittest_dma_ranges_one("/testcase-data/address-tests/pci@90000000",
> > - 0x80000000, 0x20000000, 0x10000000);
> > + 0xc0000000, 0x40000000);
> > }
> >
> > static void __init of_unittest_pci_dma_ranges(void)
> > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> > index 9f04c30c4aaf..49242dd6176e 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -519,7 +519,7 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
> > /* Initialise vdev subdevice */
> > snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
> > rvdev->dev.parent = &rproc->dev;
> > - rvdev->dev.dma_pfn_offset = rproc->dev.parent->dma_pfn_offset;
> > + rvdev->dev.dma_range_map = rproc->dev.parent->dma_range_map;
> > rvdev->dev.release = rproc_rvdev_release;
> > dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
> > dev_set_drvdata(&rvdev->dev, rvdev);
> > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> > index 1744e6fcc999..720b41eca7a3 100644
> > --- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> > @@ -230,8 +230,11 @@ int cedrus_hw_probe(struct cedrus_dev *dev)
> > */
> >
> > #ifdef PHYS_PFN_OFFSET
> > - if (!(variant->quirks & CEDRUS_QUIRK_NO_DMA_OFFSET))
> > - dev->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> > + if (!(variant->quirks & CEDRUS_QUIRK_NO_DMA_OFFSET)) {
> > + ret = dma_attach_offset_range(dev->dev, PHYS_OFFSET, 0, SZ_4G);
> > + if (ret)
> > + return ret;
> > + }
> > #endif
> >
> > ret = of_reserved_mem_device_init(dev->dev);
> > diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> > index 6197938dcc2d..376ca258e510 100644
> > --- a/drivers/usb/core/message.c
> > +++ b/drivers/usb/core/message.c
> > @@ -1956,10 +1956,10 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
> > intf->dev.groups = usb_interface_groups;
> > /*
> > * Please refer to usb_alloc_dev() to see why we set
> > - * dma_mask and dma_pfn_offset.
> > + * dma_mask and dma_range_map.
> > */
> > intf->dev.dma_mask = dev->dev.dma_mask;
> > - intf->dev.dma_pfn_offset = dev->dev.dma_pfn_offset;
> > + intf->dev.dma_range_map = dev->dev.dma_range_map;
> > INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
> > intf->minor = -1;
> > device_initialize(&intf->dev);
> > diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
> > index f16c26dc079d..1f167a2c095e 100644
> > --- a/drivers/usb/core/usb.c
> > +++ b/drivers/usb/core/usb.c
> > @@ -611,7 +611,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
> > * mask for the entire HCD, so don't do that.
> > */
> > dev->dev.dma_mask = bus->sysdev->dma_mask;
> > - dev->dev.dma_pfn_offset = bus->sysdev->dma_pfn_offset;
> > + dev->dev.dma_range_map = bus->sysdev->dma_range_map;
> > set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
> > dev->state = USB_STATE_ATTACHED;
> > dev->lpm_disable_count = 1;
> > diff --git a/include/linux/device.h b/include/linux/device.h
> > index 15460a5ac024..feddefcf3e5c 100644
> > --- a/include/linux/device.h
> > +++ b/include/linux/device.h
> > @@ -492,7 +492,7 @@ struct dev_links_info {
> > * such descriptors.
> > * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
> > * DMA limit than the device itself supports.
> > - * @dma_pfn_offset: offset of DMA memory range relatively of RAM
> > + * @dma_range_map: map for DMA memory ranges relative to that of RAM
> > * @dma_parms: A low level driver may set these to teach IOMMU code about
> > * segment limitations.
> > * @dma_pools: Dma pools (if dma'ble device).
> > @@ -577,7 +577,7 @@ struct device {
> > 64 bit addresses for consistent
> > allocations such descriptors. */
> > u64 bus_dma_limit; /* upstream dma constraint */
> > - unsigned long dma_pfn_offset;
> > + const struct bus_dma_region *dma_range_map;
> >
> > struct device_dma_parameters *dma_parms;
> >
> > diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
> > index cdfa400f89b3..182784d28cfd 100644
> > --- a/include/linux/dma-direct.h
> > +++ b/include/linux/dma-direct.h
> > @@ -15,14 +15,20 @@ static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
> > {
> > dma_addr_t dev_addr = (dma_addr_t)paddr;
> >
> > - return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
> > + if (dev->dma_range_map)
> > + dev_addr -= dma_offset_from_phys_addr(dev, paddr);
> > +
> > + return dev_addr;
> > }
> >
> > static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
> > {
> > phys_addr_t paddr = (phys_addr_t)dev_addr;
> >
> > - return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
> > + if (dev->dma_range_map)
> > + paddr += dma_offset_from_dma_addr(dev, dev_addr);
> > +
> > + return paddr;
> > }
> > #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
> >
> > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> > index 78f677cf45ab..7c8fcac30e74 100644
> > --- a/include/linux/dma-mapping.h
> > +++ b/include/linux/dma-mapping.h
> > @@ -255,7 +255,37 @@ static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
> >
> > size_t dma_direct_max_mapping_size(struct device *dev);
> >
> > +struct bus_dma_region {
> > + phys_addr_t cpu_start;
> > + dma_addr_t dma_start;
> > + u64 size;
> > + u64 offset;
> > +};
> > +
> > #ifdef CONFIG_HAS_DMA
> > +int dma_attach_offset_range(struct device *dev, phys_addr_t cpu_start,
> > + dma_addr_t dma_start, u64 size);
> > +
> > +static inline u64 dma_offset_from_dma_addr(struct device *dev, dma_addr_t dma_addr)
> > +{
> > + const struct bus_dma_region *m = dev->dma_range_map;
> > +
> > + for (; m->size; m++)
> > + if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size)
> > + return m->offset;
> > + return 0;
> > +}
> > +
> > +static inline u64 dma_offset_from_phys_addr(struct device *dev, phys_addr_t paddr)
> > +{
> > + const struct bus_dma_region *m = dev->dma_range_map;
> > +
> > + for (; m->size; m++)
> > + if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size)
> > + return m->offset;
> > + return 0;
> > +}
> > +
> > #include <asm/dma-mapping.h>
> >
> > static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
> > @@ -463,6 +493,19 @@ u64 dma_get_required_mask(struct device *dev);
> > size_t dma_max_mapping_size(struct device *dev);
> > unsigned long dma_get_merge_boundary(struct device *dev);
> > #else /* CONFIG_HAS_DMA */
> > +static inline u64 dma_offset_from_dma_addr(struct device *dev, dma_addr_t dma_addr)
> > +{
> > + return (u64)0;
> > +}
> > +static inline u64 dma_offset_from_phys_addr(struct device *dev, phys_addr_t paddr)
> > +{
> > + return (u64)0;
> > +}
> > +static int dma_attach_offset_range(struct device *dev, phys_addr_t cpu_start,
> > + dma_addr_t dma_start, u64 size)
> > +{
> > + return -EIO;
> > +}
> > static inline dma_addr_t dma_map_page_attrs(struct device *dev,
> > struct page *page, size_t offset, size_t size,
> > enum dma_data_direction dir, unsigned long attrs)
> > diff --git a/include/linux/pfn.h b/include/linux/pfn.h
> > index 14bc053c53d8..eddb535075a0 100644
> > --- a/include/linux/pfn.h
> > +++ b/include/linux/pfn.h
> > @@ -20,5 +20,7 @@ typedef struct {
> > #define PFN_DOWN(x) ((x) >> PAGE_SHIFT)
> > #define PFN_PHYS(x) ((phys_addr_t)(x) << PAGE_SHIFT)
> > #define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT))
> > +#define PFN_DMA_ADDR(x) ((dma_addr_t)(x) << PAGE_SHIFT)
> > +#define DMA_ADDR_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT))
> >
> > #endif
> > diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
> > index 2a0c4985f38e..66b1ac611c61 100644
> > --- a/kernel/dma/coherent.c
> > +++ b/kernel/dma/coherent.c
> > @@ -31,10 +31,12 @@ static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *de
> > static inline dma_addr_t dma_get_device_base(struct device *dev,
> > struct dma_coherent_mem * mem)
> > {
> > - if (mem->use_dev_dma_pfn_offset)
> > - return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT;
> > - else
> > - return mem->device_base;
> > + if (mem->use_dev_dma_pfn_offset && dev->dma_range_map) {
> > + u64 dma_offset = dma_offset_from_phys_addr(dev, PFN_PHYS(mem->pfn_base));
> > +
> > + return PFN_DMA_ADDR(mem->pfn_base) - dma_offset;
> > + }
> > + return mem->device_base;
> > }
> >
> > static int dma_init_coherent_memory(phys_addr_t phys_addr,
> > diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
> > index 98e3d873792e..2c08c4991bfa 100644
> > --- a/kernel/dma/mapping.c
> > +++ b/kernel/dma/mapping.c
> > @@ -11,6 +11,7 @@
> > #include <linux/dma-noncoherent.h>
> > #include <linux/export.h>
> > #include <linux/gfp.h>
> > +#include <linux/limits.h>
> > #include <linux/of_device.h>
> > #include <linux/slab.h>
> > #include <linux/vmalloc.h>
> > @@ -407,3 +408,55 @@ unsigned long dma_get_merge_boundary(struct device *dev)
> > return ops->get_merge_boundary(dev);
> > }
> > EXPORT_SYMBOL_GPL(dma_get_merge_boundary);
> > +
> > +/**
> > + * dma_attach_offset_range - Assign scalar offset for a single DMA range.
> > + * @dev: device pointer; needed to "own" the alloced memory.
> > + * @cpu_start: beginning of memory region covered by this offset.
> > + * @dma_start: beginning of DMA/PCI region covered by this offset.
> > + * @size: size of the region.
> > + *
> > + * This is for the simple case of a uniform offset which cannot
> > + * be discovered by "dma-ranges".
> > + *
> > + * It returns -ENOMEM if out of memory, -ENODEV if dev == NULL, otherwise 0.
> > + */
> > +int dma_attach_offset_range(struct device *dev, phys_addr_t cpu_start,
> > + dma_addr_t dma_start, u64 size)
> > +{
> > + struct bus_dma_region *map;
> > + u64 offset = (u64)cpu_start - (u64)dma_start;
> > +
> > + if (!dev)
> > + return -ENODEV;
> > +
> > + /* See if a map already exists and we already encompass the new range */
> > + if (dev->dma_range_map) {
> > + const struct bus_dma_region *m = dev->dma_range_map;
> > +
> > + for (; m->size; m++)
> > + if (offset == m->offset && cpu_start >= m->cpu_start
> > + && size <= m->size && cpu_start - m->cpu_start <= m->size - size)
> > + return 0;
> > +
> > + dev_err(dev, "attempt to add conflicting DMA range to existing map\n");
> > + return -EINVAL;
> > + }
> > +
> > + if (!offset)
> > + return 0;
> > +
> > + /* Don't use devm_kcalloc() since this may be called as bus a notifier */
> > + map = kcalloc(2, sizeof(*map), GFP_KERNEL);
> > + if (!map)
> > + return -ENOMEM;
> > + dev->dma_range_map = map;
> > +
> > + map->cpu_start = cpu_start;
> > + map->dma_start = dma_start;
> > + map->offset = offset;
> > + map->size = size;
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(dma_attach_offset_range);
> > --
> > 2.17.1
> ---end quoted text---
