iommu/io-pgtable: Replace IO_PGTABLE_QUIRK_NO_DMA with specific flag

IO_PGTABLE_QUIRK_NO_DMA is a bit of a misnomer, since it's really just
an indication of whether or not the page-table walker for the IOMMU is
coherent with the CPU caches. Since cache coherency is more than just a
quirk, replace the flag with its own field in the io_pgtable_cfg
structure.

Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 8 insertions, 11 deletions

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 2454ac11aa97..91d0a4228b58 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -252,7 +252,7 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
 		return NULL;
 
 	pages = page_address(p);
-	if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)) {
+	if (!cfg->coherent_walk) {
 		dma = dma_map_single(dev, pages, size, DMA_TO_DEVICE);
 		if (dma_mapping_error(dev, dma))
 			goto out_free;
@@ -278,7 +278,7 @@ out_free:
 static void __arm_lpae_free_pages(void *pages, size_t size,
 				  struct io_pgtable_cfg *cfg)
 {
-	if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA))
+	if (!cfg->coherent_walk)
 		dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages),
 				 size, DMA_TO_DEVICE);
 	free_pages((unsigned long)pages, get_order(size));
@@ -296,7 +296,7 @@ static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
 {
 	*ptep = pte;
 
-	if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA))
+	if (!cfg->coherent_walk)
 		__arm_lpae_sync_pte(ptep, cfg);
 }
 
@@ -374,8 +374,7 @@ static arm_lpae_iopte arm_lpae_install_table(arm_lpae_iopte *table,
 
 	old = cmpxchg64_relaxed(ptep, curr, new);
 
-	if ((cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA) ||
-	    (old & ARM_LPAE_PTE_SW_SYNC))
+	if (cfg->coherent_walk || (old & ARM_LPAE_PTE_SW_SYNC))
 		return old;
 
 	/* Even if it's not ours, there's no point waiting; just kick it */
@@ -416,8 +415,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
 		pte = arm_lpae_install_table(cptep, ptep, 0, cfg);
 		if (pte)
 			__arm_lpae_free_pages(cptep, tblsz, cfg);
-	} else if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA) &&
-		   !(pte & ARM_LPAE_PTE_SW_SYNC)) {
+	} else if (!cfg->coherent_walk && !(pte & ARM_LPAE_PTE_SW_SYNC)) {
 		__arm_lpae_sync_pte(ptep, cfg);
 	}
 
@@ -799,7 +797,7 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
 	u64 reg;
 	struct arm_lpae_io_pgtable *data;
 
-	if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | IO_PGTABLE_QUIRK_NO_DMA |
+	if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS |
 			    IO_PGTABLE_QUIRK_NON_STRICT))
 		return NULL;
 
@@ -894,8 +892,7 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
 	struct arm_lpae_io_pgtable *data;
 
 	/* The NS quirk doesn't apply at stage 2 */
-	if (cfg->quirks & ~(IO_PGTABLE_QUIRK_NO_DMA |
-			    IO_PGTABLE_QUIRK_NON_STRICT))
+	if (cfg->quirks & ~(IO_PGTABLE_QUIRK_NON_STRICT))
 		return NULL;
 
 	data = arm_lpae_alloc_pgtable(cfg);
@@ -1230,7 +1227,7 @@ static int __init arm_lpae_do_selftests(void)
 	struct io_pgtable_cfg cfg = {
 		.tlb = &dummy_tlb_ops,
 		.oas = 48,
-		.quirks = IO_PGTABLE_QUIRK_NO_DMA,
+		.coherent_walk = true,
 	};
 
 	for (i = 0; i < ARRAY_SIZE(pgsize); ++i) {