Re: [PATCH v2 4/6] drm/msm: Add support to create a local pagetable

On Tue, Jul 07, 2020 at 12:36:42PM +0100, Robin Murphy wrote:

On 2020-06-26 21:04, Jordan Crouse wrote:

...

Add support to create a io-pgtable for use by targets that support per-instance pagetables. In order to support per-instance pagetables the GPU SMMU device needs to have the qcom,adreno-smmu compatible string and split pagetables and auxiliary domains need to be supported and enabled.

Signed-off-by: Jordan Crouse jcrouse@codeaurora.org

drivers/gpu/drm/msm/msm_gpummu.c | 2 +- drivers/gpu/drm/msm/msm_iommu.c | 180 ++++++++++++++++++++++++++++++- drivers/gpu/drm/msm/msm_mmu.h | 16 ++- 3 files changed, 195 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gpummu.c b/drivers/gpu/drm/msm/msm_gpummu.c index 310a31b05faa..aab121f4beb7 100644 --- a/drivers/gpu/drm/msm/msm_gpummu.c +++ b/drivers/gpu/drm/msm/msm_gpummu.c @@ -102,7 +102,7 @@ struct msm_mmu *msm_gpummu_new(struct device *dev, struct msm_gpu *gpu) } gpummu->gpu = gpu;

• msm_mmu_init(&gpummu->base, dev, &funcs);

• msm_mmu_init(&gpummu->base, dev, &funcs, MSM_MMU_GPUMMU); return &gpummu->base;

} diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c index 1b6635504069..f455c597f76d 100644 --- a/drivers/gpu/drm/msm/msm_iommu.c +++ b/drivers/gpu/drm/msm/msm_iommu.c @@ -4,15 +4,192 @@

• Author: Rob Clark robdclark@gmail.com

*/ +#include <linux/io-pgtable.h> #include "msm_drv.h" #include "msm_mmu.h" struct msm_iommu { struct msm_mmu base; struct iommu_domain *domain;

• struct iommu_domain *aux_domain;

};

#define to_msm_iommu(x) container_of(x, struct msm_iommu, base) +struct msm_iommu_pagetable {

• struct msm_mmu base;
• struct msm_mmu *parent;
• struct io_pgtable_ops *pgtbl_ops;
• phys_addr_t ttbr;
• u32 asid;

+};

+static struct msm_iommu_pagetable *to_pagetable(struct msm_mmu *mmu) +{

• return container_of(mmu, struct msm_iommu_pagetable, base);

+}

+static int msm_iommu_pagetable_unmap(struct msm_mmu *mmu, u64 iova,

• size_t size)
  

+{

• struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
• struct io_pgtable_ops *ops = pagetable->pgtbl_ops;
• size_t unmapped = 0;
• /* Unmap the block one page at a time */
• while (size) {

• unmapped += ops->unmap(ops, iova, 4096, NULL);
  

• iova += 4096;
  

• size -= 4096;
  

• }
• iommu_flush_tlb_all(to_msm_iommu(pagetable->parent)->domain);
• return (unmapped == size) ? 0 : -EINVAL;

+}

Remember in patch #1 when you said "Then 'domain' can be used like any other iommu domain to map and unmap iova addresses in the pagetable."?

This appears to be very much not that :/

The code changed but the commit log stayed the same. I'll reword.

Jordan

Robin.

...

+static int msm_iommu_pagetable_map(struct msm_mmu *mmu, u64 iova,

• struct sg_table *sgt, size_t len, int prot)
  

+{

• struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
• struct io_pgtable_ops *ops = pagetable->pgtbl_ops;
• struct scatterlist *sg;
• size_t mapped = 0;
• u64 addr = iova;
• unsigned int i;
• for_each_sg(sgt->sgl, sg, sgt->nents, i) {

• size_t size = sg->length;
  

• phys_addr_t phys = sg_phys(sg);
  

• /* Map the block one page at a time */
  

• while (size) {
  

• 	if (ops->map(ops, addr, phys, 4096, prot)) {
  

• 		msm_iommu_pagetable_unmap(mmu, iova, mapped);
  

• 		return -EINVAL;
  

• 	}
  

• 	phys += 4096;
  

• 	addr += 4096;
  

• 	size -= 4096;
  

• 	mapped += 4096;
  

• }
  

• }
• return 0;

+}

+static void msm_iommu_pagetable_destroy(struct msm_mmu *mmu) +{

• struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
• free_io_pgtable_ops(pagetable->pgtbl_ops);
• kfree(pagetable);

+}

+/*

• • Given a parent device, create and return an aux domain. This will enable the
• • TTBR0 region
• */

+static struct iommu_domain *msm_iommu_get_aux_domain(struct msm_mmu *parent) +{

• struct msm_iommu *iommu = to_msm_iommu(parent);
• struct iommu_domain *domain;
• int ret;
• if (iommu->aux_domain)

• return iommu->aux_domain;
  

• if (!iommu_dev_has_feature(parent->dev, IOMMU_DEV_FEAT_AUX))

• return ERR_PTR(-ENODEV);
  

• domain = iommu_domain_alloc(&platform_bus_type);
• if (!domain)

• return ERR_PTR(-ENODEV);
  

• ret = iommu_aux_attach_device(domain, parent->dev);
• if (ret) {

• iommu_domain_free(domain);
  

• return ERR_PTR(ret);
  

• }
• iommu->aux_domain = domain;
• return domain;

+}

+int msm_iommu_pagetable_params(struct msm_mmu *mmu,

• phys_addr_t *ttbr, int *asid)
  

+{

• struct msm_iommu_pagetable *pagetable;
• if (mmu->type != MSM_MMU_IOMMU_PAGETABLE)

• return -EINVAL;
  

• pagetable = to_pagetable(mmu);
• if (ttbr)

• *ttbr = pagetable->ttbr;
  

• if (asid)

• *asid = pagetable->asid;
  

• return 0;

+}

+static const struct msm_mmu_funcs pagetable_funcs = {

• .map = msm_iommu_pagetable_map,
  

• .unmap = msm_iommu_pagetable_unmap,
  

• .destroy = msm_iommu_pagetable_destroy,
  

+};

+struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent) +{

• static int next_asid = 16;
• struct msm_iommu_pagetable *pagetable;
• struct iommu_domain *aux_domain;
• struct io_pgtable_cfg cfg;
• int ret;
• /* Make sure that the parent has a aux domain attached */
• aux_domain = msm_iommu_get_aux_domain(parent);
• if (IS_ERR(aux_domain))

• return ERR_CAST(aux_domain);
  

• /* Get the pagetable configuration from the aux domain */
• ret = iommu_domain_get_attr(aux_domain, DOMAIN_ATTR_PGTABLE_CFG, &cfg);
• if (ret)

• return ERR_PTR(ret);
  

• pagetable = kzalloc(sizeof(*pagetable), GFP_KERNEL);
• if (!pagetable)

• return ERR_PTR(-ENOMEM);
  

• msm_mmu_init(&pagetable->base, parent->dev, &pagetable_funcs,

• MSM_MMU_IOMMU_PAGETABLE);
  

• cfg.tlb = NULL;
• pagetable->pgtbl_ops = alloc_io_pgtable_ops(ARM_64_LPAE_S1,

• &cfg, aux_domain);
  

• if (!pagetable->pgtbl_ops) {

• kfree(pagetable);
  

• return ERR_PTR(-ENOMEM);
  

• }
• /* Needed later for TLB flush */
• pagetable->parent = parent;
• pagetable->ttbr = cfg.arm_lpae_s1_cfg.ttbr;
• pagetable->asid = next_asid;
• next_asid = (next_asid + 1) % 255;
• if (next_asid < 16)

• next_asid = 16;
  

• return &pagetable->base;

+}

static int msm_fault_handler(struct iommu_domain *domain, struct device *dev, unsigned long iova, int flags, void *arg) { @@ -40,6 +217,7 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova, if (iova & BIT_ULL(48)) iova |= GENMASK_ULL(63, 49);

• ret = iommu_map_sg(iommu->domain, iova, sgt->sgl, sgt->nents, prot); WARN_ON(!ret);

@@ -85,7 +263,7 @@ struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain) return ERR_PTR(-ENOMEM); iommu->domain = domain;

• msm_mmu_init(&iommu->base, dev, &funcs);

• msm_mmu_init(&iommu->base, dev, &funcs, MSM_MMU_IOMMU); iommu_set_fault_handler(domain, msm_fault_handler, iommu); ret = iommu_attach_device(iommu->domain, dev);

diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h index 3a534ee59bf6..61ade89d9e48 100644 --- a/drivers/gpu/drm/msm/msm_mmu.h +++ b/drivers/gpu/drm/msm/msm_mmu.h @@ -17,18 +17,26 @@ struct msm_mmu_funcs { void (*destroy)(struct msm_mmu *mmu); }; +enum msm_mmu_type {

• MSM_MMU_GPUMMU,
• MSM_MMU_IOMMU,
• MSM_MMU_IOMMU_PAGETABLE,

+};

struct msm_mmu { const struct msm_mmu_funcs *funcs; struct device *dev; int (*handler)(void *arg, unsigned long iova, int flags); void *arg;

• enum msm_mmu_type type;

}; static inline void msm_mmu_init(struct msm_mmu *mmu, struct device *dev,

• const struct msm_mmu_funcs *funcs)
  

• const struct msm_mmu_funcs *funcs, enum msm_mmu_type type)
  

{ mmu->dev = dev; mmu->funcs = funcs;

• mmu->type = type;

} struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain); @@ -41,7 +49,13 @@ static inline void msm_mmu_set_fault_handler(struct msm_mmu *mmu, void *arg, mmu->handler = handler; } +struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent);

void msm_gpummu_params(struct msm_mmu *mmu, dma_addr_t *pt_base, dma_addr_t *tran_error);

+int msm_iommu_pagetable_params(struct msm_mmu *mmu, phys_addr_t *ttbr,

• int *asid);
  

#endif /* __MSM_MMU_H__ */