1 files changed, 399 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
new file mode 100644
index 000000000..d12ba47b3
--- /dev/null
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2013 Red Hat
+ * Author: Rob Clark <robdclark@gmail.com>
+ */
+
+#include <linux/adreno-smmu-priv.h>
+#include <linux/io-pgtable.h>
+#include "msm_drv.h"
+#include "msm_mmu.h"
+
+struct msm_iommu {
+	struct msm_mmu base;
+	struct iommu_domain *domain;
+	atomic_t pagetables;
+};
+
+#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;
+	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
+	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);
+}
+
+/* based on iommu_pgsize() in iommu.c: */
+static size_t calc_pgsize(struct msm_iommu_pagetable *pagetable,
+			   unsigned long iova, phys_addr_t paddr,
+			   size_t size, size_t *count)
+{
+	unsigned int pgsize_idx, pgsize_idx_next;
+	unsigned long pgsizes;
+	size_t offset, pgsize, pgsize_next;
+	unsigned long addr_merge = paddr | iova;
+
+	/* Page sizes supported by the hardware and small enough for @size */
+	pgsizes = pagetable->pgsize_bitmap & GENMASK(__fls(size), 0);
+
+	/* Constrain the page sizes further based on the maximum alignment */
+	if (likely(addr_merge))
+		pgsizes &= GENMASK(__ffs(addr_merge), 0);
+
+	/* Make sure we have at least one suitable page size */
+	BUG_ON(!pgsizes);
+
+	/* Pick the biggest page size remaining */
+	pgsize_idx = __fls(pgsizes);
+	pgsize = BIT(pgsize_idx);
+	if (!count)
+		return pgsize;
+
+	/* Find the next biggest support page size, if it exists */
+	pgsizes = pagetable->pgsize_bitmap & ~GENMASK(pgsize_idx, 0);
+	if (!pgsizes)
+		goto out_set_count;
+
+	pgsize_idx_next = __ffs(pgsizes);
+	pgsize_next = BIT(pgsize_idx_next);
+
+	/*
+	 * There's no point trying a bigger page size unless the virtual
+	 * and physical addresses are similarly offset within the larger page.
+	 */
+	if ((iova ^ paddr) & (pgsize_next - 1))
+		goto out_set_count;
+
+	/* Calculate the offset to the next page size alignment boundary */
+	offset = pgsize_next - (addr_merge & (pgsize_next - 1));
+
+	/*
+	 * If size is big enough to accommodate the larger page, reduce
+	 * the number of smaller pages.
+	 */
+	if (offset + pgsize_next <= size)
+		size = offset;
+
+out_set_count:
+	*count = size >> pgsize_idx;
+	return pgsize;
+}
+
+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;
+
+	while (size) {
+		size_t unmapped, pgsize, count;
+
+		pgsize = calc_pgsize(pagetable, iova, iova, size, &count);
+
+		unmapped = ops->unmap_pages(ops, iova, pgsize, count, NULL);
+		if (!unmapped)
+			break;
+
+		iova += unmapped;
+		size -= unmapped;
+	}
+
+	iommu_flush_iotlb_all(to_msm_iommu(pagetable->parent)->domain);
+
+	return (size == 0) ? 0 : -EINVAL;
+}
+
+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;
+	u64 addr = iova;
+	unsigned int i;
+
+	for_each_sgtable_sg(sgt, sg, i) {
+		size_t size = sg->length;
+		phys_addr_t phys = sg_phys(sg);
+
+		while (size) {
+			size_t pgsize, count, mapped = 0;
+			int ret;
+
+			pgsize = calc_pgsize(pagetable, addr, phys, size, &count);
+
+			ret = ops->map_pages(ops, addr, phys, pgsize, count,
+					     prot, GFP_KERNEL, &mapped);
+
+			/* map_pages could fail after mapping some of the pages,
+			 * so update the counters before error handling.
+			 */
+			phys += mapped;
+			addr += mapped;
+			size -= mapped;
+
+			if (ret) {
+				msm_iommu_pagetable_unmap(mmu, iova, addr - iova);
+				return -EINVAL;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static void msm_iommu_pagetable_destroy(struct msm_mmu *mmu)
+{
+	struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
+	struct msm_iommu *iommu = to_msm_iommu(pagetable->parent);
+	struct adreno_smmu_priv *adreno_smmu =
+		dev_get_drvdata(pagetable->parent->dev);
+
+	/*
+	 * If this is the last attached pagetable for the parent,
+	 * disable TTBR0 in the arm-smmu driver
+	 */
+	if (atomic_dec_return(&iommu->pagetables) == 0)
+		adreno_smmu->set_ttbr0_cfg(adreno_smmu->cookie, NULL);
+
+	free_io_pgtable_ops(pagetable->pgtbl_ops);
+	kfree(pagetable);
+}
+
+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,
+};
+
+static void msm_iommu_tlb_flush_all(void *cookie)
+{
+}
+
+static void msm_iommu_tlb_flush_walk(unsigned long iova, size_t size,
+		size_t granule, void *cookie)
+{
+}
+
+static void msm_iommu_tlb_add_page(struct iommu_iotlb_gather *gather,
+		unsigned long iova, size_t granule, void *cookie)
+{
+}
+
+static const struct iommu_flush_ops null_tlb_ops = {
+	.tlb_flush_all = msm_iommu_tlb_flush_all,
+	.tlb_flush_walk = msm_iommu_tlb_flush_walk,
+	.tlb_add_page = msm_iommu_tlb_add_page,
+};
+
+static int msm_fault_handler(struct iommu_domain *domain, struct device *dev,
+		unsigned long iova, int flags, void *arg);
+
+struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
+{
+	struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(parent->dev);
+	struct msm_iommu *iommu = to_msm_iommu(parent);
+	struct msm_iommu_pagetable *pagetable;
+	const struct io_pgtable_cfg *ttbr1_cfg = NULL;
+	struct io_pgtable_cfg ttbr0_cfg;
+	int ret;
+
+	/* Get the pagetable configuration from the domain */
+	if (adreno_smmu->cookie)
+		ttbr1_cfg = adreno_smmu->get_ttbr1_cfg(adreno_smmu->cookie);
+
+	/*
+	 * If you hit this WARN_ONCE() you are probably missing an entry in
+	 * qcom_smmu_impl_of_match[] in arm-smmu-qcom.c
+	 */
+	if (WARN_ONCE(!ttbr1_cfg, "No per-process page tables"))
+		return ERR_PTR(-ENODEV);
+
+	/*
+	 * Defer setting the fault handler until we have a valid adreno_smmu
+	 * to avoid accidentially installing a GPU specific fault handler for
+	 * the display's iommu
+	 */
+	iommu_set_fault_handler(iommu->domain, msm_fault_handler, iommu);
+
+	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);
+
+	/* Clone the TTBR1 cfg as starting point for TTBR0 cfg: */
+	ttbr0_cfg = *ttbr1_cfg;
+
+	/* The incoming cfg will have the TTBR1 quirk enabled */
+	ttbr0_cfg.quirks &= ~IO_PGTABLE_QUIRK_ARM_TTBR1;
+	ttbr0_cfg.tlb = &null_tlb_ops;
+
+	pagetable->pgtbl_ops = alloc_io_pgtable_ops(ARM_64_LPAE_S1,
+		&ttbr0_cfg, iommu->domain);
+
+	if (!pagetable->pgtbl_ops) {
+		kfree(pagetable);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/*
+	 * If this is the first pagetable that we've allocated, send it back to
+	 * the arm-smmu driver as a trigger to set up TTBR0
+	 */
+	if (atomic_inc_return(&iommu->pagetables) == 1) {
+		/* Enable stall on iommu fault: */
+		adreno_smmu->set_stall(adreno_smmu->cookie, true);
+
+		ret = adreno_smmu->set_ttbr0_cfg(adreno_smmu->cookie, &ttbr0_cfg);
+		if (ret) {
+			free_io_pgtable_ops(pagetable->pgtbl_ops);
+			kfree(pagetable);
+			return ERR_PTR(ret);
+		}
+	}
+
+	/* Needed later for TLB flush */
+	pagetable->parent = parent;
+	pagetable->pgsize_bitmap = ttbr0_cfg.pgsize_bitmap;
+	pagetable->ttbr = ttbr0_cfg.arm_lpae_s1_cfg.ttbr;
+
+	/*
+	 * TODO we would like each set of page tables to have a unique ASID
+	 * to optimize TLB invalidation.  But iommu_flush_iotlb_all() will
+	 * end up flushing the ASID used for TTBR1 pagetables, which is not
+	 * what we want.  So for now just use the same ASID as TTBR1.
+	 */
+	pagetable->asid = 0;
+
+	return &pagetable->base;
+}
+
+static int msm_fault_handler(struct iommu_domain *domain, struct device *dev,
+		unsigned long iova, int flags, void *arg)
+{
+	struct msm_iommu *iommu = arg;
+	struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(iommu->base.dev);
+	struct adreno_smmu_fault_info info, *ptr = NULL;
+
+	if (adreno_smmu->get_fault_info) {
+		adreno_smmu->get_fault_info(adreno_smmu->cookie, &info);
+		ptr = &info;
+	}
+
+	if (iommu->base.handler)
+		return iommu->base.handler(iommu->base.arg, iova, flags, ptr);
+
+	pr_warn_ratelimited("*** fault: iova=%16lx, flags=%d\n", iova, flags);
+	return 0;
+}
+
+static void msm_iommu_resume_translation(struct msm_mmu *mmu)
+{
+	struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(mmu->dev);
+
+	adreno_smmu->resume_translation(adreno_smmu->cookie, true);
+}
+
+static void msm_iommu_detach(struct msm_mmu *mmu)
+{
+	struct msm_iommu *iommu = to_msm_iommu(mmu);
+
+	iommu_detach_device(iommu->domain, mmu->dev);
+}
+
+static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
+		struct sg_table *sgt, size_t len, int prot)
+{
+	struct msm_iommu *iommu = to_msm_iommu(mmu);
+	size_t ret;
+
+	/* The arm-smmu driver expects the addresses to be sign extended */
+	if (iova & BIT_ULL(48))
+		iova |= GENMASK_ULL(63, 49);
+
+	ret = iommu_map_sgtable(iommu->domain, iova, sgt, prot);
+	WARN_ON(!ret);
+
+	return (ret == len) ? 0 : -EINVAL;
+}
+
+static int msm_iommu_unmap(struct msm_mmu *mmu, uint64_t iova, size_t len)
+{
+	struct msm_iommu *iommu = to_msm_iommu(mmu);
+
+	if (iova & BIT_ULL(48))
+		iova |= GENMASK_ULL(63, 49);
+
+	iommu_unmap(iommu->domain, iova, len);
+
+	return 0;
+}
+
+static void msm_iommu_destroy(struct msm_mmu *mmu)
+{
+	struct msm_iommu *iommu = to_msm_iommu(mmu);
+	iommu_domain_free(iommu->domain);
+	kfree(iommu);
+}
+
+static const struct msm_mmu_funcs funcs = {
+		.detach = msm_iommu_detach,
+		.map = msm_iommu_map,
+		.unmap = msm_iommu_unmap,
+		.destroy = msm_iommu_destroy,
+		.resume_translation = msm_iommu_resume_translation,
+};
+
+struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
+{
+	struct msm_iommu *iommu;
+	int ret;
+
+	if (!domain)
+		return ERR_PTR(-ENODEV);
+
+	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
+	if (!iommu)
+		return ERR_PTR(-ENOMEM);
+
+	iommu->domain = domain;
+	msm_mmu_init(&iommu->base, dev, &funcs, MSM_MMU_IOMMU);
+
+	atomic_set(&iommu->pagetables, 0);
+
+	ret = iommu_attach_device(iommu->domain, dev);
+	if (ret) {
+		kfree(iommu);
+		return ERR_PTR(ret);
+	}
+
+	return &iommu->base;
+}