diff options
Diffstat (limited to 'drivers/iommu/io-pgtable-arm-v7s.c')
| -rw-r--r-- | drivers/iommu/io-pgtable-arm-v7s.c | 991 |
1 files changed, 991 insertions, 0 deletions
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c new file mode 100644 index 000000000..3bcd3afe9 --- /dev/null +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -0,0 +1,991 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CPU-agnostic ARM page table allocator. + * + * ARMv7 Short-descriptor format, supporting + * - Basic memory attributes + * - Simplified access permissions (AP[2:1] model) + * - Backwards-compatible TEX remap + * - Large pages/supersections (if indicated by the caller) + * + * Not supporting: + * - Legacy access permissions (AP[2:0] model) + * + * Almost certainly never supporting: + * - PXN + * - Domains + * + * Copyright (C) 2014-2015 ARM Limited + * Copyright (c) 2014-2015 MediaTek Inc. + */ + +#define pr_fmt(fmt) "arm-v7s io-pgtable: " fmt + +#include <linux/atomic.h> +#include <linux/dma-mapping.h> +#include <linux/gfp.h> +#include <linux/io-pgtable.h> +#include <linux/iommu.h> +#include <linux/kernel.h> +#include <linux/kmemleak.h> +#include <linux/sizes.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include <asm/barrier.h> + +/* Struct accessors */ +#define io_pgtable_to_data(x) \ + container_of((x), struct arm_v7s_io_pgtable, iop) + +#define io_pgtable_ops_to_data(x) \ + io_pgtable_to_data(io_pgtable_ops_to_pgtable(x)) + +/* + * We have 32 bits total; 12 bits resolved at level 1, 8 bits at level 2, + * and 12 bits in a page. With some carefully-chosen coefficients we can + * hide the ugly inconsistencies behind these macros and at least let the + * rest of the code pretend to be somewhat sane. + */ +#define ARM_V7S_ADDR_BITS 32 +#define _ARM_V7S_LVL_BITS(lvl) (16 - (lvl) * 4) +#define ARM_V7S_LVL_SHIFT(lvl) (ARM_V7S_ADDR_BITS - (4 + 8 * (lvl))) +#define ARM_V7S_TABLE_SHIFT 10 + +#define ARM_V7S_PTES_PER_LVL(lvl) (1 << _ARM_V7S_LVL_BITS(lvl)) +#define ARM_V7S_TABLE_SIZE(lvl) \ + (ARM_V7S_PTES_PER_LVL(lvl) * sizeof(arm_v7s_iopte)) + +#define ARM_V7S_BLOCK_SIZE(lvl) (1UL << ARM_V7S_LVL_SHIFT(lvl)) +#define ARM_V7S_LVL_MASK(lvl) ((u32)(~0U << ARM_V7S_LVL_SHIFT(lvl))) +#define ARM_V7S_TABLE_MASK ((u32)(~0U << ARM_V7S_TABLE_SHIFT)) +#define _ARM_V7S_IDX_MASK(lvl) (ARM_V7S_PTES_PER_LVL(lvl) - 1) +#define ARM_V7S_LVL_IDX(addr, lvl) ({ \ + int _l = lvl; \ + ((u32)(addr) >> ARM_V7S_LVL_SHIFT(_l)) & _ARM_V7S_IDX_MASK(_l); \ +}) + +/* + * Large page/supersection entries are effectively a block of 16 page/section + * entries, along the lines of the LPAE contiguous hint, but all with the + * same output address. For want of a better common name we'll call them + * "contiguous" versions of their respective page/section entries here, but + * noting the distinction (WRT to TLB maintenance) that they represent *one* + * entry repeated 16 times, not 16 separate entries (as in the LPAE case). + */ +#define ARM_V7S_CONT_PAGES 16 + +/* PTE type bits: these are all mixed up with XN/PXN bits in most cases */ +#define ARM_V7S_PTE_TYPE_TABLE 0x1 +#define ARM_V7S_PTE_TYPE_PAGE 0x2 +#define ARM_V7S_PTE_TYPE_CONT_PAGE 0x1 + +#define ARM_V7S_PTE_IS_VALID(pte) (((pte) & 0x3) != 0) +#define ARM_V7S_PTE_IS_TABLE(pte, lvl) \ + ((lvl) == 1 && (((pte) & 0x3) == ARM_V7S_PTE_TYPE_TABLE)) + +/* Page table bits */ +#define ARM_V7S_ATTR_XN(lvl) BIT(4 * (2 - (lvl))) +#define ARM_V7S_ATTR_B BIT(2) +#define ARM_V7S_ATTR_C BIT(3) +#define ARM_V7S_ATTR_NS_TABLE BIT(3) +#define ARM_V7S_ATTR_NS_SECTION BIT(19) + +#define ARM_V7S_CONT_SECTION BIT(18) +#define ARM_V7S_CONT_PAGE_XN_SHIFT 15 + +/* + * The attribute bits are consistently ordered*, but occupy bits [17:10] of + * a level 1 PTE vs. bits [11:4] at level 2. Thus we define the individual + * fields relative to that 8-bit block, plus a total shift relative to the PTE. + */ +#define ARM_V7S_ATTR_SHIFT(lvl) (16 - (lvl) * 6) + +#define ARM_V7S_ATTR_MASK 0xff +#define ARM_V7S_ATTR_AP0 BIT(0) +#define ARM_V7S_ATTR_AP1 BIT(1) +#define ARM_V7S_ATTR_AP2 BIT(5) +#define ARM_V7S_ATTR_S BIT(6) +#define ARM_V7S_ATTR_NG BIT(7) +#define ARM_V7S_TEX_SHIFT 2 +#define ARM_V7S_TEX_MASK 0x7 +#define ARM_V7S_ATTR_TEX(val) (((val) & ARM_V7S_TEX_MASK) << ARM_V7S_TEX_SHIFT) + +/* MediaTek extend the two bits for PA 32bit/33bit */ +#define ARM_V7S_ATTR_MTK_PA_BIT32 BIT(9) +#define ARM_V7S_ATTR_MTK_PA_BIT33 BIT(4) + +/* *well, except for TEX on level 2 large pages, of course :( */ +#define ARM_V7S_CONT_PAGE_TEX_SHIFT 6 +#define ARM_V7S_CONT_PAGE_TEX_MASK (ARM_V7S_TEX_MASK << ARM_V7S_CONT_PAGE_TEX_SHIFT) + +/* Simplified access permissions */ +#define ARM_V7S_PTE_AF ARM_V7S_ATTR_AP0 +#define ARM_V7S_PTE_AP_UNPRIV ARM_V7S_ATTR_AP1 +#define ARM_V7S_PTE_AP_RDONLY ARM_V7S_ATTR_AP2 + +/* Register bits */ +#define ARM_V7S_RGN_NC 0 +#define ARM_V7S_RGN_WBWA 1 +#define ARM_V7S_RGN_WT 2 +#define ARM_V7S_RGN_WB 3 + +#define ARM_V7S_PRRR_TYPE_DEVICE 1 +#define ARM_V7S_PRRR_TYPE_NORMAL 2 +#define ARM_V7S_PRRR_TR(n, type) (((type) & 0x3) << ((n) * 2)) +#define ARM_V7S_PRRR_DS0 BIT(16) +#define ARM_V7S_PRRR_DS1 BIT(17) +#define ARM_V7S_PRRR_NS0 BIT(18) +#define ARM_V7S_PRRR_NS1 BIT(19) +#define ARM_V7S_PRRR_NOS(n) BIT((n) + 24) + +#define ARM_V7S_NMRR_IR(n, attr) (((attr) & 0x3) << ((n) * 2)) +#define ARM_V7S_NMRR_OR(n, attr) (((attr) & 0x3) << ((n) * 2 + 16)) + +#define ARM_V7S_TTBR_S BIT(1) +#define ARM_V7S_TTBR_NOS BIT(5) +#define ARM_V7S_TTBR_ORGN_ATTR(attr) (((attr) & 0x3) << 3) +#define ARM_V7S_TTBR_IRGN_ATTR(attr) \ + ((((attr) & 0x1) << 6) | (((attr) & 0x2) >> 1)) + +#ifdef CONFIG_ZONE_DMA32 +#define ARM_V7S_TABLE_GFP_DMA GFP_DMA32 +#define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA32 +#else +#define ARM_V7S_TABLE_GFP_DMA GFP_DMA +#define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA +#endif + +typedef u32 arm_v7s_iopte; + +static bool selftest_running; + +struct arm_v7s_io_pgtable { + struct io_pgtable iop; + + arm_v7s_iopte *pgd; + struct kmem_cache *l2_tables; + spinlock_t split_lock; +}; + +static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl); + +static dma_addr_t __arm_v7s_dma_addr(void *pages) +{ + return (dma_addr_t)virt_to_phys(pages); +} + +static bool arm_v7s_is_mtk_enabled(struct io_pgtable_cfg *cfg) +{ + return IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT) && + (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT); +} + +static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl, + struct io_pgtable_cfg *cfg) +{ + arm_v7s_iopte pte = paddr & ARM_V7S_LVL_MASK(lvl); + + if (!arm_v7s_is_mtk_enabled(cfg)) + return pte; + + if (paddr & BIT_ULL(32)) + pte |= ARM_V7S_ATTR_MTK_PA_BIT32; + if (paddr & BIT_ULL(33)) + pte |= ARM_V7S_ATTR_MTK_PA_BIT33; + return pte; +} + +static phys_addr_t iopte_to_paddr(arm_v7s_iopte pte, int lvl, + struct io_pgtable_cfg *cfg) +{ + arm_v7s_iopte mask; + phys_addr_t paddr; + + if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) + mask = ARM_V7S_TABLE_MASK; + else if (arm_v7s_pte_is_cont(pte, lvl)) + mask = ARM_V7S_LVL_MASK(lvl) * ARM_V7S_CONT_PAGES; + else + mask = ARM_V7S_LVL_MASK(lvl); + + paddr = pte & mask; + if (!arm_v7s_is_mtk_enabled(cfg)) + return paddr; + + if (pte & ARM_V7S_ATTR_MTK_PA_BIT32) + paddr |= BIT_ULL(32); + if (pte & ARM_V7S_ATTR_MTK_PA_BIT33) + paddr |= BIT_ULL(33); + return paddr; +} + +static arm_v7s_iopte *iopte_deref(arm_v7s_iopte pte, int lvl, + struct arm_v7s_io_pgtable *data) +{ + return phys_to_virt(iopte_to_paddr(pte, lvl, &data->iop.cfg)); +} + +static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, + struct arm_v7s_io_pgtable *data) +{ + struct io_pgtable_cfg *cfg = &data->iop.cfg; + struct device *dev = cfg->iommu_dev; + phys_addr_t phys; + dma_addr_t dma; + size_t size = ARM_V7S_TABLE_SIZE(lvl); + void *table = NULL; + + if (lvl == 1) + table = (void *)__get_free_pages( + __GFP_ZERO | ARM_V7S_TABLE_GFP_DMA, get_order(size)); + else if (lvl == 2) + table = kmem_cache_zalloc(data->l2_tables, gfp); + + if (!table) + return NULL; + + phys = virt_to_phys(table); + if (phys != (arm_v7s_iopte)phys) { + /* Doesn't fit in PTE */ + dev_err(dev, "Page table does not fit in PTE: %pa", &phys); + goto out_free; + } + if (!cfg->coherent_walk) { + dma = dma_map_single(dev, table, size, DMA_TO_DEVICE); + if (dma_mapping_error(dev, dma)) + goto out_free; + /* + * We depend on the IOMMU being able to work with any physical + * address directly, so if the DMA layer suggests otherwise by + * translating or truncating them, that bodes very badly... + */ + if (dma != phys) + goto out_unmap; + } + if (lvl == 2) + kmemleak_ignore(table); + return table; + +out_unmap: + dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n"); + dma_unmap_single(dev, dma, size, DMA_TO_DEVICE); +out_free: + if (lvl == 1) + free_pages((unsigned long)table, get_order(size)); + else + kmem_cache_free(data->l2_tables, table); + return NULL; +} + +static void __arm_v7s_free_table(void *table, int lvl, + struct arm_v7s_io_pgtable *data) +{ + struct io_pgtable_cfg *cfg = &data->iop.cfg; + struct device *dev = cfg->iommu_dev; + size_t size = ARM_V7S_TABLE_SIZE(lvl); + + if (!cfg->coherent_walk) + dma_unmap_single(dev, __arm_v7s_dma_addr(table), size, + DMA_TO_DEVICE); + if (lvl == 1) + free_pages((unsigned long)table, get_order(size)); + else + kmem_cache_free(data->l2_tables, table); +} + +static void __arm_v7s_pte_sync(arm_v7s_iopte *ptep, int num_entries, + struct io_pgtable_cfg *cfg) +{ + if (cfg->coherent_walk) + return; + + dma_sync_single_for_device(cfg->iommu_dev, __arm_v7s_dma_addr(ptep), + num_entries * sizeof(*ptep), DMA_TO_DEVICE); +} +static void __arm_v7s_set_pte(arm_v7s_iopte *ptep, arm_v7s_iopte pte, + int num_entries, struct io_pgtable_cfg *cfg) +{ + int i; + + for (i = 0; i < num_entries; i++) + ptep[i] = pte; + + __arm_v7s_pte_sync(ptep, num_entries, cfg); +} + +static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl, + struct io_pgtable_cfg *cfg) +{ + bool ap = !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS); + arm_v7s_iopte pte = ARM_V7S_ATTR_NG | ARM_V7S_ATTR_S; + + if (!(prot & IOMMU_MMIO)) + pte |= ARM_V7S_ATTR_TEX(1); + if (ap) { + pte |= ARM_V7S_PTE_AF; + if (!(prot & IOMMU_PRIV)) + pte |= ARM_V7S_PTE_AP_UNPRIV; + if (!(prot & IOMMU_WRITE)) + pte |= ARM_V7S_PTE_AP_RDONLY; + } + pte <<= ARM_V7S_ATTR_SHIFT(lvl); + + if ((prot & IOMMU_NOEXEC) && ap) + pte |= ARM_V7S_ATTR_XN(lvl); + if (prot & IOMMU_MMIO) + pte |= ARM_V7S_ATTR_B; + else if (prot & IOMMU_CACHE) + pte |= ARM_V7S_ATTR_B | ARM_V7S_ATTR_C; + + pte |= ARM_V7S_PTE_TYPE_PAGE; + if (lvl == 1 && (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)) + pte |= ARM_V7S_ATTR_NS_SECTION; + + return pte; +} + +static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl) +{ + int prot = IOMMU_READ; + arm_v7s_iopte attr = pte >> ARM_V7S_ATTR_SHIFT(lvl); + + if (!(attr & ARM_V7S_PTE_AP_RDONLY)) + prot |= IOMMU_WRITE; + if (!(attr & ARM_V7S_PTE_AP_UNPRIV)) + prot |= IOMMU_PRIV; + if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0) + prot |= IOMMU_MMIO; + else if (pte & ARM_V7S_ATTR_C) + prot |= IOMMU_CACHE; + if (pte & ARM_V7S_ATTR_XN(lvl)) + prot |= IOMMU_NOEXEC; + + return prot; +} + +static arm_v7s_iopte arm_v7s_pte_to_cont(arm_v7s_iopte pte, int lvl) +{ + if (lvl == 1) { + pte |= ARM_V7S_CONT_SECTION; + } else if (lvl == 2) { + arm_v7s_iopte xn = pte & ARM_V7S_ATTR_XN(lvl); + arm_v7s_iopte tex = pte & ARM_V7S_CONT_PAGE_TEX_MASK; + + pte ^= xn | tex | ARM_V7S_PTE_TYPE_PAGE; + pte |= (xn << ARM_V7S_CONT_PAGE_XN_SHIFT) | + (tex << ARM_V7S_CONT_PAGE_TEX_SHIFT) | + ARM_V7S_PTE_TYPE_CONT_PAGE; + } + return pte; +} + +static arm_v7s_iopte arm_v7s_cont_to_pte(arm_v7s_iopte pte, int lvl) +{ + if (lvl == 1) { + pte &= ~ARM_V7S_CONT_SECTION; + } else if (lvl == 2) { + arm_v7s_iopte xn = pte & BIT(ARM_V7S_CONT_PAGE_XN_SHIFT); + arm_v7s_iopte tex = pte & (ARM_V7S_CONT_PAGE_TEX_MASK << + ARM_V7S_CONT_PAGE_TEX_SHIFT); + + pte ^= xn | tex | ARM_V7S_PTE_TYPE_CONT_PAGE; + pte |= (xn >> ARM_V7S_CONT_PAGE_XN_SHIFT) | + (tex >> ARM_V7S_CONT_PAGE_TEX_SHIFT) | + ARM_V7S_PTE_TYPE_PAGE; + } + return pte; +} + +static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl) +{ + if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte, lvl)) + return pte & ARM_V7S_CONT_SECTION; + else if (lvl == 2) + return !(pte & ARM_V7S_PTE_TYPE_PAGE); + return false; +} + +static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *, + struct iommu_iotlb_gather *, unsigned long, + size_t, int, arm_v7s_iopte *); + +static int arm_v7s_init_pte(struct arm_v7s_io_pgtable *data, + unsigned long iova, phys_addr_t paddr, int prot, + int lvl, int num_entries, arm_v7s_iopte *ptep) +{ + struct io_pgtable_cfg *cfg = &data->iop.cfg; + arm_v7s_iopte pte; + int i; + + for (i = 0; i < num_entries; i++) + if (ARM_V7S_PTE_IS_TABLE(ptep[i], lvl)) { + /* + * We need to unmap and free the old table before + * overwriting it with a block entry. + */ + arm_v7s_iopte *tblp; + size_t sz = ARM_V7S_BLOCK_SIZE(lvl); + + tblp = ptep - ARM_V7S_LVL_IDX(iova, lvl); + if (WARN_ON(__arm_v7s_unmap(data, NULL, iova + i * sz, + sz, lvl, tblp) != sz)) + return -EINVAL; + } else if (ptep[i]) { + /* We require an unmap first */ + WARN_ON(!selftest_running); + return -EEXIST; + } + + pte = arm_v7s_prot_to_pte(prot, lvl, cfg); + if (num_entries > 1) + pte = arm_v7s_pte_to_cont(pte, lvl); + + pte |= paddr_to_iopte(paddr, lvl, cfg); + + __arm_v7s_set_pte(ptep, pte, num_entries, cfg); + return 0; +} + +static arm_v7s_iopte arm_v7s_install_table(arm_v7s_iopte *table, + arm_v7s_iopte *ptep, + arm_v7s_iopte curr, + struct io_pgtable_cfg *cfg) +{ + arm_v7s_iopte old, new; + + new = virt_to_phys(table) | ARM_V7S_PTE_TYPE_TABLE; + if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS) + new |= ARM_V7S_ATTR_NS_TABLE; + + /* + * Ensure the table itself is visible before its PTE can be. + * Whilst we could get away with cmpxchg64_release below, this + * doesn't have any ordering semantics when !CONFIG_SMP. + */ + dma_wmb(); + + old = cmpxchg_relaxed(ptep, curr, new); + __arm_v7s_pte_sync(ptep, 1, cfg); + + return old; +} + +static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova, + phys_addr_t paddr, size_t size, int prot, + int lvl, arm_v7s_iopte *ptep, gfp_t gfp) +{ + struct io_pgtable_cfg *cfg = &data->iop.cfg; + arm_v7s_iopte pte, *cptep; + int num_entries = size >> ARM_V7S_LVL_SHIFT(lvl); + + /* Find our entry at the current level */ + ptep += ARM_V7S_LVL_IDX(iova, lvl); + + /* If we can install a leaf entry at this level, then do so */ + if (num_entries) + return arm_v7s_init_pte(data, iova, paddr, prot, + lvl, num_entries, ptep); + + /* We can't allocate tables at the final level */ + if (WARN_ON(lvl == 2)) + return -EINVAL; + + /* Grab a pointer to the next level */ + pte = READ_ONCE(*ptep); + if (!pte) { + cptep = __arm_v7s_alloc_table(lvl + 1, gfp, data); + if (!cptep) + return -ENOMEM; + + pte = arm_v7s_install_table(cptep, ptep, 0, cfg); + if (pte) + __arm_v7s_free_table(cptep, lvl + 1, data); + } else { + /* We've no easy way of knowing if it's synced yet, so... */ + __arm_v7s_pte_sync(ptep, 1, cfg); + } + + if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) { + cptep = iopte_deref(pte, lvl, data); + } else if (pte) { + /* We require an unmap first */ + WARN_ON(!selftest_running); + return -EEXIST; + } + + /* Rinse, repeat */ + return __arm_v7s_map(data, iova, paddr, size, prot, lvl + 1, cptep, gfp); +} + +static int arm_v7s_map(struct io_pgtable_ops *ops, unsigned long iova, + phys_addr_t paddr, size_t size, int prot, gfp_t gfp) +{ + struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); + struct io_pgtable *iop = &data->iop; + int ret; + + /* If no access, then nothing to do */ + if (!(prot & (IOMMU_READ | IOMMU_WRITE))) + return 0; + + if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) || + paddr >= (1ULL << data->iop.cfg.oas))) + return -ERANGE; + + ret = __arm_v7s_map(data, iova, paddr, size, prot, 1, data->pgd, gfp); + /* + * Synchronise all PTE updates for the new mapping before there's + * a chance for anything to kick off a table walk for the new iova. + */ + if (iop->cfg.quirks & IO_PGTABLE_QUIRK_TLBI_ON_MAP) { + io_pgtable_tlb_flush_walk(iop, iova, size, + ARM_V7S_BLOCK_SIZE(2)); + } else { + wmb(); + } + + return ret; +} + +static void arm_v7s_free_pgtable(struct io_pgtable *iop) +{ + struct arm_v7s_io_pgtable *data = io_pgtable_to_data(iop); + int i; + + for (i = 0; i < ARM_V7S_PTES_PER_LVL(1); i++) { + arm_v7s_iopte pte = data->pgd[i]; + + if (ARM_V7S_PTE_IS_TABLE(pte, 1)) + __arm_v7s_free_table(iopte_deref(pte, 1, data), + 2, data); + } + __arm_v7s_free_table(data->pgd, 1, data); + kmem_cache_destroy(data->l2_tables); + kfree(data); +} + +static arm_v7s_iopte arm_v7s_split_cont(struct arm_v7s_io_pgtable *data, + unsigned long iova, int idx, int lvl, + arm_v7s_iopte *ptep) +{ + struct io_pgtable *iop = &data->iop; + arm_v7s_iopte pte; + size_t size = ARM_V7S_BLOCK_SIZE(lvl); + int i; + + /* Check that we didn't lose a race to get the lock */ + pte = *ptep; + if (!arm_v7s_pte_is_cont(pte, lvl)) + return pte; + + ptep -= idx & (ARM_V7S_CONT_PAGES - 1); + pte = arm_v7s_cont_to_pte(pte, lvl); + for (i = 0; i < ARM_V7S_CONT_PAGES; i++) + ptep[i] = pte + i * size; + + __arm_v7s_pte_sync(ptep, ARM_V7S_CONT_PAGES, &iop->cfg); + + size *= ARM_V7S_CONT_PAGES; + io_pgtable_tlb_flush_leaf(iop, iova, size, size); + return pte; +} + +static size_t arm_v7s_split_blk_unmap(struct arm_v7s_io_pgtable *data, + struct iommu_iotlb_gather *gather, + unsigned long iova, size_t size, + arm_v7s_iopte blk_pte, + arm_v7s_iopte *ptep) +{ + struct io_pgtable_cfg *cfg = &data->iop.cfg; + arm_v7s_iopte pte, *tablep; + int i, unmap_idx, num_entries, num_ptes; + + tablep = __arm_v7s_alloc_table(2, GFP_ATOMIC, data); + if (!tablep) + return 0; /* Bytes unmapped */ + + num_ptes = ARM_V7S_PTES_PER_LVL(2); + num_entries = size >> ARM_V7S_LVL_SHIFT(2); + unmap_idx = ARM_V7S_LVL_IDX(iova, 2); + + pte = arm_v7s_prot_to_pte(arm_v7s_pte_to_prot(blk_pte, 1), 2, cfg); + if (num_entries > 1) + pte = arm_v7s_pte_to_cont(pte, 2); + + for (i = 0; i < num_ptes; i += num_entries, pte += size) { + /* Unmap! */ + if (i == unmap_idx) + continue; + + __arm_v7s_set_pte(&tablep[i], pte, num_entries, cfg); + } + + pte = arm_v7s_install_table(tablep, ptep, blk_pte, cfg); + if (pte != blk_pte) { + __arm_v7s_free_table(tablep, 2, data); + + if (!ARM_V7S_PTE_IS_TABLE(pte, 1)) + return 0; + + tablep = iopte_deref(pte, 1, data); + return __arm_v7s_unmap(data, gather, iova, size, 2, tablep); + } + + io_pgtable_tlb_add_page(&data->iop, gather, iova, size); + return size; +} + +static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *data, + struct iommu_iotlb_gather *gather, + unsigned long iova, size_t size, int lvl, + arm_v7s_iopte *ptep) +{ + arm_v7s_iopte pte[ARM_V7S_CONT_PAGES]; + struct io_pgtable *iop = &data->iop; + int idx, i = 0, num_entries = size >> ARM_V7S_LVL_SHIFT(lvl); + + /* Something went horribly wrong and we ran out of page table */ + if (WARN_ON(lvl > 2)) + return 0; + + idx = ARM_V7S_LVL_IDX(iova, lvl); + ptep += idx; + do { + pte[i] = READ_ONCE(ptep[i]); + if (WARN_ON(!ARM_V7S_PTE_IS_VALID(pte[i]))) + return 0; + } while (++i < num_entries); + + /* + * If we've hit a contiguous 'large page' entry at this level, it + * needs splitting first, unless we're unmapping the whole lot. + * + * For splitting, we can't rewrite 16 PTEs atomically, and since we + * can't necessarily assume TEX remap we don't have a software bit to + * mark live entries being split. In practice (i.e. DMA API code), we + * will never be splitting large pages anyway, so just wrap this edge + * case in a lock for the sake of correctness and be done with it. + */ + if (num_entries <= 1 && arm_v7s_pte_is_cont(pte[0], lvl)) { + unsigned long flags; + + spin_lock_irqsave(&data->split_lock, flags); + pte[0] = arm_v7s_split_cont(data, iova, idx, lvl, ptep); + spin_unlock_irqrestore(&data->split_lock, flags); + } + + /* If the size matches this level, we're in the right place */ + if (num_entries) { + size_t blk_size = ARM_V7S_BLOCK_SIZE(lvl); + + __arm_v7s_set_pte(ptep, 0, num_entries, &iop->cfg); + + for (i = 0; i < num_entries; i++) { + if (ARM_V7S_PTE_IS_TABLE(pte[i], lvl)) { + /* Also flush any partial walks */ + io_pgtable_tlb_flush_walk(iop, iova, blk_size, + ARM_V7S_BLOCK_SIZE(lvl + 1)); + ptep = iopte_deref(pte[i], lvl, data); + __arm_v7s_free_table(ptep, lvl + 1, data); + } else if (iop->cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT) { + /* + * Order the PTE update against queueing the IOVA, to + * guarantee that a flush callback from a different CPU + * has observed it before the TLBIALL can be issued. + */ + smp_wmb(); + } else { + io_pgtable_tlb_add_page(iop, gather, iova, blk_size); + } + iova += blk_size; + } + return size; + } else if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte[0], lvl)) { + /* + * Insert a table at the next level to map the old region, + * minus the part we want to unmap + */ + return arm_v7s_split_blk_unmap(data, gather, iova, size, pte[0], + ptep); + } + + /* Keep on walkin' */ + ptep = iopte_deref(pte[0], lvl, data); + return __arm_v7s_unmap(data, gather, iova, size, lvl + 1, ptep); +} + +static size_t arm_v7s_unmap(struct io_pgtable_ops *ops, unsigned long iova, + size_t size, struct iommu_iotlb_gather *gather) +{ + struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); + + if (WARN_ON(upper_32_bits(iova))) + return 0; + + return __arm_v7s_unmap(data, gather, iova, size, 1, data->pgd); +} + +static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops, + unsigned long iova) +{ + struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); + arm_v7s_iopte *ptep = data->pgd, pte; + int lvl = 0; + u32 mask; + + do { + ptep += ARM_V7S_LVL_IDX(iova, ++lvl); + pte = READ_ONCE(*ptep); + ptep = iopte_deref(pte, lvl, data); + } while (ARM_V7S_PTE_IS_TABLE(pte, lvl)); + + if (!ARM_V7S_PTE_IS_VALID(pte)) + return 0; + + mask = ARM_V7S_LVL_MASK(lvl); + if (arm_v7s_pte_is_cont(pte, lvl)) + mask *= ARM_V7S_CONT_PAGES; + return iopte_to_paddr(pte, lvl, &data->iop.cfg) | (iova & ~mask); +} + +static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, + void *cookie) +{ + struct arm_v7s_io_pgtable *data; + + if (cfg->ias > ARM_V7S_ADDR_BITS) + return NULL; + + if (cfg->oas > (arm_v7s_is_mtk_enabled(cfg) ? 34 : ARM_V7S_ADDR_BITS)) + return NULL; + + if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | + IO_PGTABLE_QUIRK_NO_PERMS | + IO_PGTABLE_QUIRK_TLBI_ON_MAP | + IO_PGTABLE_QUIRK_ARM_MTK_EXT | + IO_PGTABLE_QUIRK_NON_STRICT)) + return NULL; + + /* If ARM_MTK_4GB is enabled, the NO_PERMS is also expected. */ + if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT && + !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS)) + return NULL; + + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return NULL; + + spin_lock_init(&data->split_lock); + data->l2_tables = kmem_cache_create("io-pgtable_armv7s_l2", + ARM_V7S_TABLE_SIZE(2), + ARM_V7S_TABLE_SIZE(2), + ARM_V7S_TABLE_SLAB_FLAGS, NULL); + if (!data->l2_tables) + goto out_free_data; + + data->iop.ops = (struct io_pgtable_ops) { + .map = arm_v7s_map, + .unmap = arm_v7s_unmap, + .iova_to_phys = arm_v7s_iova_to_phys, + }; + + /* We have to do this early for __arm_v7s_alloc_table to work... */ + data->iop.cfg = *cfg; + + /* + * Unless the IOMMU driver indicates supersection support by + * having SZ_16M set in the initial bitmap, they won't be used. + */ + cfg->pgsize_bitmap &= SZ_4K | SZ_64K | SZ_1M | SZ_16M; + + /* TCR: T0SZ=0, EAE=0 (if applicable) */ + cfg->arm_v7s_cfg.tcr = 0; + + /* + * TEX remap: the indices used map to the closest equivalent types + * under the non-TEX-remap interpretation of those attribute bits, + * excepting various implementation-defined aspects of shareability. + */ + cfg->arm_v7s_cfg.prrr = ARM_V7S_PRRR_TR(1, ARM_V7S_PRRR_TYPE_DEVICE) | + ARM_V7S_PRRR_TR(4, ARM_V7S_PRRR_TYPE_NORMAL) | + ARM_V7S_PRRR_TR(7, ARM_V7S_PRRR_TYPE_NORMAL) | + ARM_V7S_PRRR_DS0 | ARM_V7S_PRRR_DS1 | + ARM_V7S_PRRR_NS1 | ARM_V7S_PRRR_NOS(7); + cfg->arm_v7s_cfg.nmrr = ARM_V7S_NMRR_IR(7, ARM_V7S_RGN_WBWA) | + ARM_V7S_NMRR_OR(7, ARM_V7S_RGN_WBWA); + + /* Looking good; allocate a pgd */ + data->pgd = __arm_v7s_alloc_table(1, GFP_KERNEL, data); + if (!data->pgd) + goto out_free_data; + + /* Ensure the empty pgd is visible before any actual TTBR write */ + wmb(); + + /* TTBR */ + cfg->arm_v7s_cfg.ttbr = virt_to_phys(data->pgd) | ARM_V7S_TTBR_S | + (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS | + ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | + ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : + (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | + ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); + return &data->iop; + +out_free_data: + kmem_cache_destroy(data->l2_tables); + kfree(data); + return NULL; +} + +struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { + .alloc = arm_v7s_alloc_pgtable, + .free = arm_v7s_free_pgtable, +}; + +#ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST + +static struct io_pgtable_cfg *cfg_cookie __initdata; + +static void __init dummy_tlb_flush_all(void *cookie) +{ + WARN_ON(cookie != cfg_cookie); +} + +static void __init dummy_tlb_flush(unsigned long iova, size_t size, + size_t granule, void *cookie) +{ + WARN_ON(cookie != cfg_cookie); + WARN_ON(!(size & cfg_cookie->pgsize_bitmap)); +} + +static void __init dummy_tlb_add_page(struct iommu_iotlb_gather *gather, + unsigned long iova, size_t granule, + void *cookie) +{ + dummy_tlb_flush(iova, granule, granule, cookie); +} + +static const struct iommu_flush_ops dummy_tlb_ops __initconst = { + .tlb_flush_all = dummy_tlb_flush_all, + .tlb_flush_walk = dummy_tlb_flush, + .tlb_flush_leaf = dummy_tlb_flush, + .tlb_add_page = dummy_tlb_add_page, +}; + +#define __FAIL(ops) ({ \ + WARN(1, "selftest: test failed\n"); \ + selftest_running = false; \ + -EFAULT; \ +}) + +static int __init arm_v7s_do_selftests(void) +{ + struct io_pgtable_ops *ops; + struct io_pgtable_cfg cfg = { + .tlb = &dummy_tlb_ops, + .oas = 32, + .ias = 32, + .coherent_walk = true, + .quirks = IO_PGTABLE_QUIRK_ARM_NS, + .pgsize_bitmap = SZ_4K | SZ_64K | SZ_1M | SZ_16M, + }; + unsigned int iova, size, iova_start; + unsigned int i, loopnr = 0; + + selftest_running = true; + + cfg_cookie = &cfg; + + ops = alloc_io_pgtable_ops(ARM_V7S, &cfg, &cfg); + if (!ops) { + pr_err("selftest: failed to allocate io pgtable ops\n"); + return -EINVAL; + } + + /* + * Initial sanity checks. + * Empty page tables shouldn't provide any translations. + */ + if (ops->iova_to_phys(ops, 42)) + return __FAIL(ops); + + if (ops->iova_to_phys(ops, SZ_1G + 42)) + return __FAIL(ops); + + if (ops->iova_to_phys(ops, SZ_2G + 42)) + return __FAIL(ops); + + /* + * Distinct mappings of different granule sizes. + */ + iova = 0; + for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) { + size = 1UL << i; + if (ops->map(ops, iova, iova, size, IOMMU_READ | + IOMMU_WRITE | + IOMMU_NOEXEC | + IOMMU_CACHE, GFP_KERNEL)) + return __FAIL(ops); + + /* Overlapping mappings */ + if (!ops->map(ops, iova, iova + size, size, + IOMMU_READ | IOMMU_NOEXEC, GFP_KERNEL)) + return __FAIL(ops); + + if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) + return __FAIL(ops); + + iova += SZ_16M; + loopnr++; + } + + /* Partial unmap */ + i = 1; + size = 1UL << __ffs(cfg.pgsize_bitmap); + while (i < loopnr) { + iova_start = i * SZ_16M; + if (ops->unmap(ops, iova_start + size, size, NULL) != size) + return __FAIL(ops); + + /* Remap of partial unmap */ + if (ops->map(ops, iova_start + size, size, size, IOMMU_READ, GFP_KERNEL)) + return __FAIL(ops); + + if (ops->iova_to_phys(ops, iova_start + size + 42) + != (size + 42)) + return __FAIL(ops); + i++; + } + + /* Full unmap */ + iova = 0; + for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) { + size = 1UL << i; + + if (ops->unmap(ops, iova, size, NULL) != size) + return __FAIL(ops); + + if (ops->iova_to_phys(ops, iova + 42)) + return __FAIL(ops); + + /* Remap full block */ + if (ops->map(ops, iova, iova, size, IOMMU_WRITE, GFP_KERNEL)) + return __FAIL(ops); + + if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) + return __FAIL(ops); + + iova += SZ_16M; + } + + free_io_pgtable_ops(ops); + + selftest_running = false; + + pr_info("self test ok\n"); + return 0; +} +subsys_initcall(arm_v7s_do_selftests); +#endif |