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path: root/kernel/drivers/iommu/io-pgtable-arm.c
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Diffstat (limited to 'kernel/drivers/iommu/io-pgtable-arm.c')
-rw-r--r--kernel/drivers/iommu/io-pgtable-arm.c139
1 files changed, 101 insertions, 38 deletions
diff --git a/kernel/drivers/iommu/io-pgtable-arm.c b/kernel/drivers/iommu/io-pgtable-arm.c
index e29d5d7fe..dad768caa 100644
--- a/kernel/drivers/iommu/io-pgtable-arm.c
+++ b/kernel/drivers/iommu/io-pgtable-arm.c
@@ -26,6 +26,8 @@
#include <linux/slab.h>
#include <linux/types.h>
+#include <asm/barrier.h>
+
#include "io-pgtable.h"
#define ARM_LPAE_MAX_ADDR_BITS 48
@@ -200,6 +202,64 @@ typedef u64 arm_lpae_iopte;
static bool selftest_running = false;
+static dma_addr_t __arm_lpae_dma_addr(void *pages)
+{
+ return (dma_addr_t)virt_to_phys(pages);
+}
+
+static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
+ struct io_pgtable_cfg *cfg)
+{
+ struct device *dev = cfg->iommu_dev;
+ dma_addr_t dma;
+ void *pages = alloc_pages_exact(size, gfp | __GFP_ZERO);
+
+ if (!pages)
+ return NULL;
+
+ if (!selftest_running) {
+ dma = dma_map_single(dev, pages, 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 != virt_to_phys(pages))
+ goto out_unmap;
+ }
+
+ return pages;
+
+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:
+ free_pages_exact(pages, size);
+ return NULL;
+}
+
+static void __arm_lpae_free_pages(void *pages, size_t size,
+ struct io_pgtable_cfg *cfg)
+{
+ if (!selftest_running)
+ dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages),
+ size, DMA_TO_DEVICE);
+ free_pages_exact(pages, size);
+}
+
+static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
+ struct io_pgtable_cfg *cfg)
+{
+ *ptep = pte;
+
+ if (!selftest_running)
+ dma_sync_single_for_device(cfg->iommu_dev,
+ __arm_lpae_dma_addr(ptep),
+ sizeof(pte), DMA_TO_DEVICE);
+}
+
static int __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
unsigned long iova, size_t size, int lvl,
arm_lpae_iopte *ptep);
@@ -210,6 +270,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
arm_lpae_iopte *ptep)
{
arm_lpae_iopte pte = prot;
+ struct io_pgtable_cfg *cfg = &data->iop.cfg;
if (iopte_leaf(*ptep, lvl)) {
/* We require an unmap first */
@@ -228,7 +289,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
return -EINVAL;
}
- if (data->iop.cfg.quirks & IO_PGTABLE_QUIRK_ARM_NS)
+ if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
pte |= ARM_LPAE_PTE_NS;
if (lvl == ARM_LPAE_MAX_LEVELS - 1)
@@ -239,8 +300,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
pte |= ARM_LPAE_PTE_AF | ARM_LPAE_PTE_SH_IS;
pte |= pfn_to_iopte(paddr >> data->pg_shift, data);
- *ptep = pte;
- data->iop.cfg.tlb->flush_pgtable(ptep, sizeof(*ptep), data->iop.cookie);
+ __arm_lpae_set_pte(ptep, pte, cfg);
return 0;
}
@@ -249,14 +309,14 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
int lvl, arm_lpae_iopte *ptep)
{
arm_lpae_iopte *cptep, pte;
- void *cookie = data->iop.cookie;
size_t block_size = ARM_LPAE_BLOCK_SIZE(lvl, data);
+ struct io_pgtable_cfg *cfg = &data->iop.cfg;
/* Find our entry at the current level */
ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
/* If we can install a leaf entry at this level, then do so */
- if (size == block_size && (size & data->iop.cfg.pgsize_bitmap))
+ if (size == block_size && (size & cfg->pgsize_bitmap))
return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);
/* We can't allocate tables at the final level */
@@ -266,18 +326,15 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
/* Grab a pointer to the next level */
pte = *ptep;
if (!pte) {
- cptep = alloc_pages_exact(1UL << data->pg_shift,
- GFP_ATOMIC | __GFP_ZERO);
+ cptep = __arm_lpae_alloc_pages(1UL << data->pg_shift,
+ GFP_ATOMIC, cfg);
if (!cptep)
return -ENOMEM;
- data->iop.cfg.tlb->flush_pgtable(cptep, 1UL << data->pg_shift,
- cookie);
pte = __pa(cptep) | ARM_LPAE_PTE_TYPE_TABLE;
- if (data->iop.cfg.quirks & IO_PGTABLE_QUIRK_ARM_NS)
+ if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
pte |= ARM_LPAE_PTE_NSTABLE;
- *ptep = pte;
- data->iop.cfg.tlb->flush_pgtable(ptep, sizeof(*ptep), cookie);
+ __arm_lpae_set_pte(ptep, pte, cfg);
} else {
cptep = iopte_deref(pte, data);
}
@@ -324,7 +381,7 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
{
struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
arm_lpae_iopte *ptep = data->pgd;
- int lvl = ARM_LPAE_START_LVL(data);
+ int ret, lvl = ARM_LPAE_START_LVL(data);
arm_lpae_iopte prot;
/* If no access, then nothing to do */
@@ -332,7 +389,14 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
return 0;
prot = arm_lpae_prot_to_pte(data, iommu_prot);
- return __arm_lpae_map(data, iova, paddr, size, prot, lvl, ptep);
+ ret = __arm_lpae_map(data, iova, paddr, size, prot, lvl, ptep);
+ /*
+ * 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.
+ */
+ wmb();
+
+ return ret;
}
static void __arm_lpae_free_pgtable(struct arm_lpae_io_pgtable *data, int lvl,
@@ -341,17 +405,18 @@ static void __arm_lpae_free_pgtable(struct arm_lpae_io_pgtable *data, int lvl,
arm_lpae_iopte *start, *end;
unsigned long table_size;
- /* Only leaf entries at the last level */
- if (lvl == ARM_LPAE_MAX_LEVELS - 1)
- return;
-
if (lvl == ARM_LPAE_START_LVL(data))
table_size = data->pgd_size;
else
table_size = 1UL << data->pg_shift;
start = ptep;
- end = (void *)ptep + table_size;
+
+ /* Only leaf entries at the last level */
+ if (lvl == ARM_LPAE_MAX_LEVELS - 1)
+ end = ptep;
+ else
+ end = (void *)ptep + table_size;
while (ptep != end) {
arm_lpae_iopte pte = *ptep++;
@@ -362,7 +427,7 @@ static void __arm_lpae_free_pgtable(struct arm_lpae_io_pgtable *data, int lvl,
__arm_lpae_free_pgtable(data, lvl + 1, iopte_deref(pte, data));
}
- free_pages_exact(start, table_size);
+ __arm_lpae_free_pages(start, table_size, &data->iop.cfg);
}
static void arm_lpae_free_pgtable(struct io_pgtable *iop)
@@ -381,8 +446,7 @@ static int arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
unsigned long blk_start, blk_end;
phys_addr_t blk_paddr;
arm_lpae_iopte table = 0;
- void *cookie = data->iop.cookie;
- const struct iommu_gather_ops *tlb = data->iop.cfg.tlb;
+ struct io_pgtable_cfg *cfg = &data->iop.cfg;
blk_start = iova & ~(blk_size - 1);
blk_end = blk_start + blk_size;
@@ -408,10 +472,9 @@ static int arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
}
}
- *ptep = table;
- tlb->flush_pgtable(ptep, sizeof(*ptep), cookie);
+ __arm_lpae_set_pte(ptep, table, cfg);
iova &= ~(blk_size - 1);
- tlb->tlb_add_flush(iova, blk_size, true, cookie);
+ cfg->tlb->tlb_add_flush(iova, blk_size, true, data->iop.cookie);
return size;
}
@@ -433,13 +496,12 @@ static int __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
/* If the size matches this level, we're in the right place */
if (size == blk_size) {
- *ptep = 0;
- tlb->flush_pgtable(ptep, sizeof(*ptep), cookie);
+ __arm_lpae_set_pte(ptep, 0, &data->iop.cfg);
if (!iopte_leaf(pte, lvl)) {
/* Also flush any partial walks */
tlb->tlb_add_flush(iova, size, false, cookie);
- tlb->tlb_sync(data->iop.cookie);
+ tlb->tlb_sync(cookie);
ptep = iopte_deref(pte, data);
__arm_lpae_free_pgtable(data, lvl + 1, ptep);
} else {
@@ -565,6 +627,11 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS)
return NULL;
+ if (!selftest_running && cfg->iommu_dev->dma_pfn_offset) {
+ dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n");
+ return NULL;
+ }
+
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return NULL;
@@ -655,11 +722,12 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
cfg->arm_lpae_s1_cfg.mair[1] = 0;
/* Looking good; allocate a pgd */
- data->pgd = alloc_pages_exact(data->pgd_size, GFP_KERNEL | __GFP_ZERO);
+ data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
if (!data->pgd)
goto out_free_data;
- cfg->tlb->flush_pgtable(data->pgd, data->pgd_size, cookie);
+ /* Ensure the empty pgd is visible before any actual TTBR write */
+ wmb();
/* TTBRs */
cfg->arm_lpae_s1_cfg.ttbr[0] = virt_to_phys(data->pgd);
@@ -743,11 +811,12 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
cfg->arm_lpae_s2_cfg.vtcr = reg;
/* Allocate pgd pages */
- data->pgd = alloc_pages_exact(data->pgd_size, GFP_KERNEL | __GFP_ZERO);
+ data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
if (!data->pgd)
goto out_free_data;
- cfg->tlb->flush_pgtable(data->pgd, data->pgd_size, cookie);
+ /* Ensure the empty pgd is visible before any actual TTBR write */
+ wmb();
/* VTTBR */
cfg->arm_lpae_s2_cfg.vttbr = virt_to_phys(data->pgd);
@@ -833,16 +902,10 @@ static void dummy_tlb_sync(void *cookie)
WARN_ON(cookie != cfg_cookie);
}
-static void dummy_flush_pgtable(void *ptr, size_t size, void *cookie)
-{
- WARN_ON(cookie != cfg_cookie);
-}
-
static struct iommu_gather_ops dummy_tlb_ops __initdata = {
.tlb_flush_all = dummy_tlb_flush_all,
.tlb_add_flush = dummy_tlb_add_flush,
.tlb_sync = dummy_tlb_sync,
- .flush_pgtable = dummy_flush_pgtable,
};
static void __init arm_lpae_dump_ops(struct io_pgtable_ops *ops)