On 6/18/19 5:07 AM, Tero Kristo wrote:
On 07/06/2019 22:35, Andrew F. Davis wrote:
This patch adds a driver for the Page-based Address Translator (PAT) present on various TI SoCs. A PAT device performs address translation using tables stored in an internal SRAM. Each PAT supports a set number of pages, each occupying a programmable 4KB, 16KB, 64KB, or 1MB of addresses in a window for which an incoming transaction will be translated.
Signed-off-by: Andrew F. Davis afd@ti.com
drivers/soc/ti/Kconfig | 9 + drivers/soc/ti/Makefile | 1 + drivers/soc/ti/ti-pat.c | 569 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/ti-pat.h | 44 +++ 4 files changed, 623 insertions(+) create mode 100644 drivers/soc/ti/ti-pat.c create mode 100644 include/uapi/linux/ti-pat.h
diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig index f0be35d3dcba..b838ae74d01f 100644 --- a/drivers/soc/ti/Kconfig +++ b/drivers/soc/ti/Kconfig @@ -86,4 +86,13 @@ config TI_SCI_INTA_MSI_DOMAIN help Driver to enable Interrupt Aggregator specific MSI Domain. +config TI_PAT + tristate "TI PAT DMA-BUF exporter" + select REGMAP
What is the reasoning for using regmap for internal register access? Why not just use direct readl/writel for everything? To me it seems this is only used during probe time also...
There are two register spaces, the configuration space, and the actual translation table data. I use regmap for all the configuration space. Direct readl/writel would also work, but I prefer regmap as it lets me work with field names vs using masks and shifts, even if it adds a little extra code in tables at the top.
+ help + Driver for TI Page-based Address Translator (PAT). This driver + provides the an API allowing the remapping of a non-contiguous + DMA-BUF into a contiguous one that is sutable for devices needing + coniguous memory.
Minor typo: contiguous.
ACK
endif # SOC_TI diff --git a/drivers/soc/ti/Makefile b/drivers/soc/ti/Makefile index b3868d392d4f..1369642b40c3 100644 --- a/drivers/soc/ti/Makefile +++ b/drivers/soc/ti/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_AMX3_PM) += pm33xx.o obj-$(CONFIG_WKUP_M3_IPC) += wkup_m3_ipc.o obj-$(CONFIG_TI_SCI_PM_DOMAINS) += ti_sci_pm_domains.o obj-$(CONFIG_TI_SCI_INTA_MSI_DOMAIN) += ti_sci_inta_msi.o +obj-$(CONFIG_TI_PAT) += ti-pat.o diff --git a/drivers/soc/ti/ti-pat.c b/drivers/soc/ti/ti-pat.c new file mode 100644 index 000000000000..7359ea0f7ccf --- /dev/null +++ b/drivers/soc/ti/ti-pat.c @@ -0,0 +1,569 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- TI PAT mapped DMA-BUF memory re-exporter
- Copyright (C) 2018-2019 Texas Instruments Incorporated -
- * Andrew F. Davis afd@ti.com
- */
+#include <linux/fs.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/mod_devicetable.h> +#include <linux/uaccess.h> +#include <linux/miscdevice.h> +#include <linux/regmap.h> +#include <linux/dma-buf.h> +#include <linux/genalloc.h> +#include <linux/vmalloc.h> +#include <linux/slab.h>
+#include <linux/ti-pat.h>
+#define TI_PAT_DRIVER_NAME "ti-pat"
Why do you have a define for this seeing it is only used in single location?
Just habit when starting a driver, but you are right it is not needed here.
+/* TI PAT MMRS registers */ +#define TI_PAT_MMRS_PID 0x0 /* Revision Register */ +#define TI_PAT_MMRS_CONFIG 0x4 /* Config Register */ +#define TI_PAT_MMRS_CONTROL 0x10 /* Control Register */
+/* TI PAT CONTROL register field values */ +#define TI_PAT_CONTROL_ARB_MODE_UF 0x0 /* Updates first */ +#define TI_PAT_CONTROL_ARB_MODE_RR 0x2 /* Round-robin */
+#define TI_PAT_CONTROL_PAGE_SIZE_4KB 0x0 +#define TI_PAT_CONTROL_PAGE_SIZE_16KB 0x1 +#define TI_PAT_CONTROL_PAGE_SIZE_64KB 0x2 +#define TI_PAT_CONTROL_PAGE_SIZE_1MB 0x3
+static unsigned int ti_pat_page_sizes[] = { + [TI_PAT_CONTROL_PAGE_SIZE_4KB] = 4 * 1024, + [TI_PAT_CONTROL_PAGE_SIZE_16KB] = 16 * 1024, + [TI_PAT_CONTROL_PAGE_SIZE_64KB] = 64 * 1024, + [TI_PAT_CONTROL_PAGE_SIZE_1MB] = 1024 * 1024, +};
+enum ti_pat_mmrs_fields { + /* Revision */ + F_PID_MAJOR, + F_PID_MINOR,
+ /* Controls */ + F_CONTROL_ARB_MODE, + F_CONTROL_PAGE_SIZE, + F_CONTROL_REPLACE_OID_EN, + F_CONTROL_EN,
+ /* sentinel */ + F_MAX_FIELDS +};
+static const struct reg_field ti_pat_mmrs_reg_fields[] = { + /* Revision */ + [F_PID_MAJOR] = REG_FIELD(TI_PAT_MMRS_PID, 8, 10), + [F_PID_MINOR] = REG_FIELD(TI_PAT_MMRS_PID, 0, 5), + /* Controls */ + [F_CONTROL_ARB_MODE] = REG_FIELD(TI_PAT_MMRS_CONTROL, 6, 7), + [F_CONTROL_PAGE_SIZE] = REG_FIELD(TI_PAT_MMRS_CONTROL, 4, 5), + [F_CONTROL_REPLACE_OID_EN] = REG_FIELD(TI_PAT_MMRS_CONTROL, 1, 1), + [F_CONTROL_EN] = REG_FIELD(TI_PAT_MMRS_CONTROL, 0, 0), +};
+/**
- struct ti_pat_data - PAT device instance data
- @dev: PAT device structure
- @mdev: misc device
- @mmrs_map: Register map of MMRS region
- @table_base: Base address of TABLE region
Please add kerneldoc comments for all fields.
Will add.
- */
+struct ti_pat_data { + struct device *dev; + struct miscdevice mdev; + struct regmap *mmrs_map; + struct regmap_field *mmrs_fields[F_MAX_FIELDS]; + void __iomem *table_base; + unsigned int page_count; + unsigned int page_size; + phys_addr_t window_base; + struct gen_pool *pool; +};
Kerneldoc comments for below structs would be also useful, especially for ti_pat_buffer.
Will add.
+struct ti_pat_dma_buf_attachment { + struct device *dev; + struct sg_table *table; + struct ti_pat_buffer *buffer; + struct list_head list; +};
+struct ti_pat_buffer { + struct ti_pat_data *pat; + struct dma_buf *i_dma_buf; + size_t size; + unsigned long offset; + struct dma_buf *e_dma_buf;
+ struct dma_buf_attachment *attachment; + struct sg_table *sgt;
+ struct list_head attachments; + int map_count;
+ struct mutex lock; +};
+static const struct regmap_config ti_pat_regmap_config = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, +};
+static int ti_pat_dma_buf_attach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attachment) +{ + struct ti_pat_dma_buf_attachment *a; + struct ti_pat_buffer *buffer = dmabuf->priv;
+ a = kzalloc(sizeof(*a), GFP_KERNEL); + if (!a) + return -ENOMEM;
+ a->dev = attachment->dev; + a->buffer = buffer; + INIT_LIST_HEAD(&a->list);
+ a->table = kzalloc(sizeof(*a->table), GFP_KERNEL); + if (!a->table) { + kfree(a); + return -ENOMEM; + }
+ if (sg_alloc_table(a->table, 1, GFP_KERNEL)) { + kfree(a->table); + kfree(a); + return -ENOMEM; + }
+ sg_set_page(a->table->sgl, pfn_to_page(PFN_DOWN(buffer->offset)), buffer->size, 0);
+ attachment->priv = a;
+ mutex_lock(&buffer->lock); + /* First time attachment we attach to parent */ + if (list_empty(&buffer->attachments)) { + buffer->attachment = dma_buf_attach(buffer->i_dma_buf, buffer->pat->dev); + if (IS_ERR(buffer->attachment)) { + dev_err(buffer->pat->dev, "Unable to attach to parent DMA-BUF\n"); + mutex_unlock(&buffer->lock); + kfree(a->table); + kfree(a); + return PTR_ERR(buffer->attachment); + } + } + list_add(&a->list, &buffer->attachments); + mutex_unlock(&buffer->lock);
+ return 0; +}
+static void ti_pat_dma_buf_detatch(struct dma_buf *dmabuf, + struct dma_buf_attachment *attachment)
Func name should be ti_pat_dma_buf_detach instead?
Good catch, will fix.
Other than that, I can't see anything obvious with my limited experience with dma_buf. Is there a simple way to test this driver btw?
Simple way? No not really.. What I've been doing is allocating a non-contiguous buffer (from system DMA-BUF heaps), writing some test pattern to it, using this driver to convert the buffer, then sending the new handle to our DSS (display subsystem which cannot handle non-contiguous buffers). If all is working the test pattern is displayed correctly.
Thanks, Andrew
-Tero
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