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authorHeiko Stuebner <heiko@sntech.de>2022-07-07 01:15:35 +0200
committerPalmer Dabbelt <palmer@rivosinc.com>2022-07-28 15:30:51 -0700
commit1631ba1259d6d7f49b6028f2a1a0fa02be1c522a (patch)
tree224d5329d0ce1579c48f8f2b68b7a2c989dd9a96 /arch/riscv/include/asm/cache.h
parentd1afce6709595b39cd159bdc54fe2093808c02fc (diff)
riscv: Add support for non-coherent devices using zicbom extension
The Zicbom ISA-extension was ratified in november 2021 and introduces instructions for dcache invalidate, clean and flush operations. Implement cache management operations for non-coherent devices based on them. Of course not all cores will support this, so implement an alternative-based mechanism that replaces empty instructions with ones done around Zicbom instructions. As discussed in previous versions, assume the platform being coherent by default so that non-coherent devices need to get marked accordingly by firmware. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220706231536.2041855-4-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/include/asm/cache.h')
-rw-r--r--arch/riscv/include/asm/cache.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/cache.h b/arch/riscv/include/asm/cache.h
index 9b58b104559e..d3036df23ccb 100644
--- a/arch/riscv/include/asm/cache.h
+++ b/arch/riscv/include/asm/cache.h
@@ -11,6 +11,10 @@
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
+#ifdef CONFIG_RISCV_DMA_NONCOHERENT
+#define ARCH_DMA_MINALIGN L1_CACHE_BYTES
+#endif
+
/*
* RISC-V requires the stack pointer to be 16-byte aligned, so ensure that
* the flat loader aligns it accordingly.