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

Jordan Crouse jcrouse at codeaurora.org
Wed Jul 8 19:35:41 UTC 2020


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 at 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 at 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__ */
> >

-- 
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