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| author | Heiko Stuebner <heiko@sntech.de> | 2022-07-07 01:15:35 +0200 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-07-29 00:30:51 +0200 |
| commit | 1631ba1259d6d7f49b6028f2a1a0fa02be1c522a (patch) | |
| tree | 224d5329d0ce1579c48f8f2b68b7a2c989dd9a96 /arch/riscv/include | |
| parent | dt-bindings: riscv: document cbom-block-size (diff) | |
| download | linux-1631ba1259d6d7f49b6028f2a1a0fa02be1c522a.tar.xz linux-1631ba1259d6d7f49b6028f2a1a0fa02be1c522a.zip | |
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')
| -rw-r--r-- | arch/riscv/include/asm/cache.h | 4 | ||||
| -rw-r--r-- | arch/riscv/include/asm/cacheflush.h | 10 | ||||
| -rw-r--r-- | arch/riscv/include/asm/errata_list.h | 19 | ||||
| -rw-r--r-- | arch/riscv/include/asm/hwcap.h | 1 |
4 files changed, 33 insertions, 1 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. diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h index 23ff70350992..a60acaecfeda 100644 --- a/arch/riscv/include/asm/cacheflush.h +++ b/arch/riscv/include/asm/cacheflush.h @@ -42,6 +42,16 @@ void flush_icache_mm(struct mm_struct *mm, bool local); #endif /* CONFIG_SMP */ +#ifdef CONFIG_RISCV_ISA_ZICBOM +void riscv_init_cbom_blocksize(void); +#else +static inline void riscv_init_cbom_blocksize(void) { } +#endif + +#ifdef CONFIG_RISCV_DMA_NONCOHERENT +void riscv_noncoherent_supported(void); +#endif + /* * Bits in sys_riscv_flush_icache()'s flags argument. */ diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h index 9e2888dbb5b1..f7c015005847 100644 --- a/arch/riscv/include/asm/errata_list.h +++ b/arch/riscv/include/asm/errata_list.h @@ -20,7 +20,8 @@ #endif #define CPUFEATURE_SVPBMT 0 -#define CPUFEATURE_NUMBER 1 +#define CPUFEATURE_ZICBOM 1 +#define CPUFEATURE_NUMBER 2 #ifdef __ASSEMBLY__ @@ -93,6 +94,22 @@ asm volatile(ALTERNATIVE( \ #define ALT_THEAD_PMA(_val) #endif +#define ALT_CMO_OP(_op, _start, _size, _cachesize) \ +asm volatile(ALTERNATIVE( \ + __nops(5), \ + "mv a0, %1\n\t" \ + "j 2f\n\t" \ + "3:\n\t" \ + "cbo." __stringify(_op) " (a0)\n\t" \ + "add a0, a0, %0\n\t" \ + "2:\n\t" \ + "bltu a0, %2, 3b\n\t", 0, \ + CPUFEATURE_ZICBOM, CONFIG_RISCV_ISA_ZICBOM) \ + : : "r"(_cachesize), \ + "r"((unsigned long)(_start) & ~((_cachesize) - 1UL)), \ + "r"((unsigned long)(_start) + (_size)) \ + : "a0") + #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index e48eebdd2631..ed4045e70f7a 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -54,6 +54,7 @@ extern unsigned long elf_hwcap; enum riscv_isa_ext_id { RISCV_ISA_EXT_SSCOFPMF = RISCV_ISA_EXT_BASE, RISCV_ISA_EXT_SVPBMT, + RISCV_ISA_EXT_ZICBOM, RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX, }; |