Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 537 insertions, 0 deletions

diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
new file mode 100644
index 000000000..ace0e9b8b
--- /dev/null
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -0,0 +1,537 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CPU-agnostic AMD IO page table allocator.
+ *
+ * Copyright (C) 2020 Advanced Micro Devices, Inc.
+ * Author: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
+ */
+
+#define pr_fmt(fmt)     "AMD-Vi: " fmt
+#define dev_fmt(fmt)    pr_fmt(fmt)
+
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/io-pgtable.h>
+#include <linux/kernel.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/barrier.h>
+
+#include "amd_iommu_types.h"
+#include "amd_iommu.h"
+
+static void v1_tlb_flush_all(void *cookie)
+{
+}
+
+static void v1_tlb_flush_walk(unsigned long iova, size_t size,
+				  size_t granule, void *cookie)
+{
+}
+
+static void v1_tlb_add_page(struct iommu_iotlb_gather *gather,
+					 unsigned long iova, size_t granule,
+					 void *cookie)
+{
+}
+
+static const struct iommu_flush_ops v1_flush_ops = {
+	.tlb_flush_all	= v1_tlb_flush_all,
+	.tlb_flush_walk = v1_tlb_flush_walk,
+	.tlb_add_page	= v1_tlb_add_page,
+};
+
+/*
+ * Helper function to get the first pte of a large mapping
+ */
+static u64 *first_pte_l7(u64 *pte, unsigned long *page_size,
+			 unsigned long *count)
+{
+	unsigned long pte_mask, pg_size, cnt;
+	u64 *fpte;
+
+	pg_size  = PTE_PAGE_SIZE(*pte);
+	cnt      = PAGE_SIZE_PTE_COUNT(pg_size);
+	pte_mask = ~((cnt << 3) - 1);
+	fpte     = (u64 *)(((unsigned long)pte) & pte_mask);
+
+	if (page_size)
+		*page_size = pg_size;
+
+	if (count)
+		*count = cnt;
+
+	return fpte;
+}
+
+/****************************************************************************
+ *
+ * The functions below are used the create the page table mappings for
+ * unity mapped regions.
+ *
+ ****************************************************************************/
+
+static void free_pt_page(u64 *pt, struct list_head *freelist)
+{
+	struct page *p = virt_to_page(pt);
+
+	list_add_tail(&p->lru, freelist);
+}
+
+static void free_pt_lvl(u64 *pt, struct list_head *freelist, int lvl)
+{
+	u64 *p;
+	int i;
+
+	for (i = 0; i < 512; ++i) {
+		/* PTE present? */
+		if (!IOMMU_PTE_PRESENT(pt[i]))
+			continue;
+
+		/* Large PTE? */
+		if (PM_PTE_LEVEL(pt[i]) == 0 ||
+		    PM_PTE_LEVEL(pt[i]) == 7)
+			continue;
+
+		/*
+		 * Free the next level. No need to look at l1 tables here since
+		 * they can only contain leaf PTEs; just free them directly.
+		 */
+		p = IOMMU_PTE_PAGE(pt[i]);
+		if (lvl > 2)
+			free_pt_lvl(p, freelist, lvl - 1);
+		else
+			free_pt_page(p, freelist);
+	}
+
+	free_pt_page(pt, freelist);
+}
+
+static void free_sub_pt(u64 *root, int mode, struct list_head *freelist)
+{
+	switch (mode) {
+	case PAGE_MODE_NONE:
+	case PAGE_MODE_7_LEVEL:
+		break;
+	case PAGE_MODE_1_LEVEL:
+		free_pt_page(root, freelist);
+		break;
+	case PAGE_MODE_2_LEVEL:
+	case PAGE_MODE_3_LEVEL:
+	case PAGE_MODE_4_LEVEL:
+	case PAGE_MODE_5_LEVEL:
+	case PAGE_MODE_6_LEVEL:
+		free_pt_lvl(root, freelist, mode);
+		break;
+	default:
+		BUG();
+	}
+}
+
+void amd_iommu_domain_set_pgtable(struct protection_domain *domain,
+				  u64 *root, int mode)
+{
+	u64 pt_root;
+
+	/* lowest 3 bits encode pgtable mode */
+	pt_root = mode & 7;
+	pt_root |= (u64)root;
+
+	amd_iommu_domain_set_pt_root(domain, pt_root);
+}
+
+/*
+ * This function is used to add another level to an IO page table. Adding
+ * another level increases the size of the address space by 9 bits to a size up
+ * to 64 bits.
+ */
+static bool increase_address_space(struct protection_domain *domain,
+				   unsigned long address,
+				   gfp_t gfp)
+{
+	unsigned long flags;
+	bool ret = true;
+	u64 *pte;
+
+	pte = (void *)get_zeroed_page(gfp);
+	if (!pte)
+		return false;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	if (address <= PM_LEVEL_SIZE(domain->iop.mode))
+		goto out;
+
+	ret = false;
+	if (WARN_ON_ONCE(domain->iop.mode == PAGE_MODE_6_LEVEL))
+		goto out;
+
+	*pte = PM_LEVEL_PDE(domain->iop.mode, iommu_virt_to_phys(domain->iop.root));
+
+	domain->iop.root  = pte;
+	domain->iop.mode += 1;
+	amd_iommu_update_and_flush_device_table(domain);
+	amd_iommu_domain_flush_complete(domain);
+
+	/*
+	 * Device Table needs to be updated and flushed before the new root can
+	 * be published.
+	 */
+	amd_iommu_domain_set_pgtable(domain, pte, domain->iop.mode);
+
+	pte = NULL;
+	ret = true;
+
+out:
+	spin_unlock_irqrestore(&domain->lock, flags);
+	free_page((unsigned long)pte);
+
+	return ret;
+}
+
+static u64 *alloc_pte(struct protection_domain *domain,
+		      unsigned long address,
+		      unsigned long page_size,
+		      u64 **pte_page,
+		      gfp_t gfp,
+		      bool *updated)
+{
+	int level, end_lvl;
+	u64 *pte, *page;
+
+	BUG_ON(!is_power_of_2(page_size));
+
+	while (address > PM_LEVEL_SIZE(domain->iop.mode)) {
+		/*
+		 * Return an error if there is no memory to update the
+		 * page-table.
+		 */
+		if (!increase_address_space(domain, address, gfp))
+			return NULL;
+	}
+
+
+	level   = domain->iop.mode - 1;
+	pte     = &domain->iop.root[PM_LEVEL_INDEX(level, address)];
+	address = PAGE_SIZE_ALIGN(address, page_size);
+	end_lvl = PAGE_SIZE_LEVEL(page_size);
+
+	while (level > end_lvl) {
+		u64 __pte, __npte;
+		int pte_level;
+
+		__pte     = *pte;
+		pte_level = PM_PTE_LEVEL(__pte);
+
+		/*
+		 * If we replace a series of large PTEs, we need
+		 * to tear down all of them.
+		 */
+		if (IOMMU_PTE_PRESENT(__pte) &&
+		    pte_level == PAGE_MODE_7_LEVEL) {
+			unsigned long count, i;
+			u64 *lpte;
+
+			lpte = first_pte_l7(pte, NULL, &count);
+
+			/*
+			 * Unmap the replicated PTEs that still match the
+			 * original large mapping
+			 */
+			for (i = 0; i < count; ++i)
+				cmpxchg64(&lpte[i], __pte, 0ULL);
+
+			*updated = true;
+			continue;
+		}
+
+		if (!IOMMU_PTE_PRESENT(__pte) ||
+		    pte_level == PAGE_MODE_NONE) {
+			page = (u64 *)get_zeroed_page(gfp);
+
+			if (!page)
+				return NULL;
+
+			__npte = PM_LEVEL_PDE(level, iommu_virt_to_phys(page));
+
+			/* pte could have been changed somewhere. */
+			if (!try_cmpxchg64(pte, &__pte, __npte))
+				free_page((unsigned long)page);
+			else if (IOMMU_PTE_PRESENT(__pte))
+				*updated = true;
+
+			continue;
+		}
+
+		/* No level skipping support yet */
+		if (pte_level != level)
+			return NULL;
+
+		level -= 1;
+
+		pte = IOMMU_PTE_PAGE(__pte);
+
+		if (pte_page && level == end_lvl)
+			*pte_page = pte;
+
+		pte = &pte[PM_LEVEL_INDEX(level, address)];
+	}
+
+	return pte;
+}
+
+/*
+ * This function checks if there is a PTE for a given dma address. If
+ * there is one, it returns the pointer to it.
+ */
+static u64 *fetch_pte(struct amd_io_pgtable *pgtable,
+		      unsigned long address,
+		      unsigned long *page_size)
+{
+	int level;
+	u64 *pte;
+
+	*page_size = 0;
+
+	if (address > PM_LEVEL_SIZE(pgtable->mode))
+		return NULL;
+
+	level	   =  pgtable->mode - 1;
+	pte	   = &pgtable->root[PM_LEVEL_INDEX(level, address)];
+	*page_size =  PTE_LEVEL_PAGE_SIZE(level);
+
+	while (level > 0) {
+
+		/* Not Present */
+		if (!IOMMU_PTE_PRESENT(*pte))
+			return NULL;
+
+		/* Large PTE */
+		if (PM_PTE_LEVEL(*pte) == 7 ||
+		    PM_PTE_LEVEL(*pte) == 0)
+			break;
+
+		/* No level skipping support yet */
+		if (PM_PTE_LEVEL(*pte) != level)
+			return NULL;
+
+		level -= 1;
+
+		/* Walk to the next level */
+		pte	   = IOMMU_PTE_PAGE(*pte);
+		pte	   = &pte[PM_LEVEL_INDEX(level, address)];
+		*page_size = PTE_LEVEL_PAGE_SIZE(level);
+	}
+
+	/*
+	 * If we have a series of large PTEs, make
+	 * sure to return a pointer to the first one.
+	 */
+	if (PM_PTE_LEVEL(*pte) == PAGE_MODE_7_LEVEL)
+		pte = first_pte_l7(pte, page_size, NULL);
+
+	return pte;
+}
+
+static void free_clear_pte(u64 *pte, u64 pteval, struct list_head *freelist)
+{
+	u64 *pt;
+	int mode;
+
+	while (!try_cmpxchg64(pte, &pteval, 0))
+		pr_warn("AMD-Vi: IOMMU pte changed since we read it\n");
+
+	if (!IOMMU_PTE_PRESENT(pteval))
+		return;
+
+	pt   = IOMMU_PTE_PAGE(pteval);
+	mode = IOMMU_PTE_MODE(pteval);
+
+	free_sub_pt(pt, mode, freelist);
+}
+
+/*
+ * Generic mapping functions. It maps a physical address into a DMA
+ * address space. It allocates the page table pages if necessary.
+ * In the future it can be extended to a generic mapping function
+ * supporting all features of AMD IOMMU page tables like level skipping
+ * and full 64 bit address spaces.
+ */
+static int iommu_v1_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
+			      phys_addr_t paddr, size_t pgsize, size_t pgcount,
+			      int prot, gfp_t gfp, size_t *mapped)
+{
+	struct protection_domain *dom = io_pgtable_ops_to_domain(ops);
+	LIST_HEAD(freelist);
+	bool updated = false;
+	u64 __pte, *pte;
+	int ret, i, count;
+
+	BUG_ON(!IS_ALIGNED(iova, pgsize));
+	BUG_ON(!IS_ALIGNED(paddr, pgsize));
+
+	ret = -EINVAL;
+	if (!(prot & IOMMU_PROT_MASK))
+		goto out;
+
+	while (pgcount > 0) {
+		count = PAGE_SIZE_PTE_COUNT(pgsize);
+		pte   = alloc_pte(dom, iova, pgsize, NULL, gfp, &updated);
+
+		ret = -ENOMEM;
+		if (!pte)
+			goto out;
+
+		for (i = 0; i < count; ++i)
+			free_clear_pte(&pte[i], pte[i], &freelist);
+
+		if (!list_empty(&freelist))
+			updated = true;
+
+		if (count > 1) {
+			__pte = PAGE_SIZE_PTE(__sme_set(paddr), pgsize);
+			__pte |= PM_LEVEL_ENC(7) | IOMMU_PTE_PR | IOMMU_PTE_FC;
+		} else
+			__pte = __sme_set(paddr) | IOMMU_PTE_PR | IOMMU_PTE_FC;
+
+		if (prot & IOMMU_PROT_IR)
+			__pte |= IOMMU_PTE_IR;
+		if (prot & IOMMU_PROT_IW)
+			__pte |= IOMMU_PTE_IW;
+
+		for (i = 0; i < count; ++i)
+			pte[i] = __pte;
+
+		iova  += pgsize;
+		paddr += pgsize;
+		pgcount--;
+		if (mapped)
+			*mapped += pgsize;
+	}
+
+	ret = 0;
+
+out:
+	if (updated) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&dom->lock, flags);
+		/*
+		 * Flush domain TLB(s) and wait for completion. Any Device-Table
+		 * Updates and flushing already happened in
+		 * increase_address_space().
+		 */
+		amd_iommu_domain_flush_tlb_pde(dom);
+		amd_iommu_domain_flush_complete(dom);
+		spin_unlock_irqrestore(&dom->lock, flags);
+	}
+
+	/* Everything flushed out, free pages now */
+	put_pages_list(&freelist);
+
+	return ret;
+}
+
+static unsigned long iommu_v1_unmap_pages(struct io_pgtable_ops *ops,
+					  unsigned long iova,
+					  size_t pgsize, size_t pgcount,
+					  struct iommu_iotlb_gather *gather)
+{
+	struct amd_io_pgtable *pgtable = io_pgtable_ops_to_data(ops);
+	unsigned long long unmapped;
+	unsigned long unmap_size;
+	u64 *pte;
+	size_t size = pgcount << __ffs(pgsize);
+
+	BUG_ON(!is_power_of_2(pgsize));
+
+	unmapped = 0;
+
+	while (unmapped < size) {
+		pte = fetch_pte(pgtable, iova, &unmap_size);
+		if (pte) {
+			int i, count;
+
+			count = PAGE_SIZE_PTE_COUNT(unmap_size);
+			for (i = 0; i < count; i++)
+				pte[i] = 0ULL;
+		} else {
+			return unmapped;
+		}
+
+		iova = (iova & ~(unmap_size - 1)) + unmap_size;
+		unmapped += unmap_size;
+	}
+
+	return unmapped;
+}
+
+static phys_addr_t iommu_v1_iova_to_phys(struct io_pgtable_ops *ops, unsigned long iova)
+{
+	struct amd_io_pgtable *pgtable = io_pgtable_ops_to_data(ops);
+	unsigned long offset_mask, pte_pgsize;
+	u64 *pte, __pte;
+
+	pte = fetch_pte(pgtable, iova, &pte_pgsize);
+
+	if (!pte || !IOMMU_PTE_PRESENT(*pte))
+		return 0;
+
+	offset_mask = pte_pgsize - 1;
+	__pte	    = __sme_clr(*pte & PM_ADDR_MASK);
+
+	return (__pte & ~offset_mask) | (iova & offset_mask);
+}
+
+/*
+ * ----------------------------------------------------
+ */
+static void v1_free_pgtable(struct io_pgtable *iop)
+{
+	struct amd_io_pgtable *pgtable = container_of(iop, struct amd_io_pgtable, iop);
+	struct protection_domain *dom;
+	LIST_HEAD(freelist);
+
+	if (pgtable->mode == PAGE_MODE_NONE)
+		return;
+
+	dom = container_of(pgtable, struct protection_domain, iop);
+
+	/* Page-table is not visible to IOMMU anymore, so free it */
+	BUG_ON(pgtable->mode < PAGE_MODE_NONE ||
+	       pgtable->mode > PAGE_MODE_6_LEVEL);
+
+	free_sub_pt(pgtable->root, pgtable->mode, &freelist);
+
+	/* Update data structure */
+	amd_iommu_domain_clr_pt_root(dom);
+
+	/* Make changes visible to IOMMUs */
+	amd_iommu_domain_update(dom);
+
+	put_pages_list(&freelist);
+}
+
+static struct io_pgtable *v1_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
+{
+	struct amd_io_pgtable *pgtable = io_pgtable_cfg_to_data(cfg);
+
+	cfg->pgsize_bitmap  = AMD_IOMMU_PGSIZES,
+	cfg->ias            = IOMMU_IN_ADDR_BIT_SIZE,
+	cfg->oas            = IOMMU_OUT_ADDR_BIT_SIZE,
+	cfg->tlb            = &v1_flush_ops;
+
+	pgtable->iop.ops.map_pages    = iommu_v1_map_pages;
+	pgtable->iop.ops.unmap_pages  = iommu_v1_unmap_pages;
+	pgtable->iop.ops.iova_to_phys = iommu_v1_iova_to_phys;
+
+	return &pgtable->iop;
+}
+
+struct io_pgtable_init_fns io_pgtable_amd_iommu_v1_init_fns = {
+	.alloc	= v1_alloc_pgtable,
+	.free	= v1_free_pgtable,
+};