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authorPalmer Dabbelt <palmer@rivosinc.com>2023-09-08 10:12:55 -0700
committerPalmer Dabbelt <palmer@rivosinc.com>2023-09-08 11:24:21 -0700
commit7f215d003f31d56b458c7c3c8c7185a1697f5076 (patch)
treed0e43b233d7096c00480f85154c23a9a93b8686e
parent580253b518e6be80b1ecc5e418068388fd4dd4d5 (diff)
parent935730160738a478dbf4b61cf0cfc29c1442fb4e (diff)
Merge patch series "riscv: dma-mapping: unify support for cache flushes"
Prabhakar <prabhakar.csengg@gmail.com> says: From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> This patch series is a subset from Arnd's original series [0]. Ive just picked up the bits required for RISC-V unification of cache flushing. Remaining patches from the series [0] will be taken care by Arnd soon. * b4-shazam-merge: riscv: dma-mapping: switch over to generic implementation riscv: dma-mapping: skip invalidation before bidirectional DMA riscv: dma-mapping: only invalidate after DMA, not flush Link: https://lore.kernel.org/r/20230816232336.164413-1-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
-rw-r--r--arch/riscv/mm/dma-noncoherent.c60
1 files changed, 51 insertions, 9 deletions
diff --git a/arch/riscv/mm/dma-noncoherent.c b/arch/riscv/mm/dma-noncoherent.c
index 7270b4d8c05b..f269990e26c3 100644
--- a/arch/riscv/mm/dma-noncoherent.c
+++ b/arch/riscv/mm/dma-noncoherent.c
@@ -14,21 +14,61 @@ static bool noncoherent_supported __ro_after_init;
int dma_cache_alignment __ro_after_init = ARCH_DMA_MINALIGN;
EXPORT_SYMBOL_GPL(dma_cache_alignment);
-void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
- enum dma_data_direction dir)
+static inline void arch_dma_cache_wback(phys_addr_t paddr, size_t size)
+{
+ void *vaddr = phys_to_virt(paddr);
+
+ ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size);
+}
+
+static inline void arch_dma_cache_inv(phys_addr_t paddr, size_t size)
+{
+ void *vaddr = phys_to_virt(paddr);
+
+ ALT_CMO_OP(inval, vaddr, size, riscv_cbom_block_size);
+}
+
+static inline void arch_dma_cache_wback_inv(phys_addr_t paddr, size_t size)
{
void *vaddr = phys_to_virt(paddr);
+ ALT_CMO_OP(flush, vaddr, size, riscv_cbom_block_size);
+}
+
+static inline bool arch_sync_dma_clean_before_fromdevice(void)
+{
+ return true;
+}
+
+static inline bool arch_sync_dma_cpu_needs_post_dma_flush(void)
+{
+ return true;
+}
+
+void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
+{
switch (dir) {
case DMA_TO_DEVICE:
- ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size);
+ arch_dma_cache_wback(paddr, size);
break;
+
case DMA_FROM_DEVICE:
- ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size);
- break;
+ if (!arch_sync_dma_clean_before_fromdevice()) {
+ arch_dma_cache_inv(paddr, size);
+ break;
+ }
+ fallthrough;
+
case DMA_BIDIRECTIONAL:
- ALT_CMO_OP(flush, vaddr, size, riscv_cbom_block_size);
+ /* Skip the invalidate here if it's done later */
+ if (IS_ENABLED(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) &&
+ arch_sync_dma_cpu_needs_post_dma_flush())
+ arch_dma_cache_wback(paddr, size);
+ else
+ arch_dma_cache_wback_inv(paddr, size);
break;
+
default:
break;
}
@@ -37,15 +77,17 @@ void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
enum dma_data_direction dir)
{
- void *vaddr = phys_to_virt(paddr);
-
switch (dir) {
case DMA_TO_DEVICE:
break;
+
case DMA_FROM_DEVICE:
case DMA_BIDIRECTIONAL:
- ALT_CMO_OP(flush, vaddr, size, riscv_cbom_block_size);
+ /* FROM_DEVICE invalidate needed if speculative CPU prefetch only */
+ if (arch_sync_dma_cpu_needs_post_dma_flush())
+ arch_dma_cache_inv(paddr, size);
break;
+
default:
break;
}