diff options
| author | Heiko Stuebner <heiko@sntech.de> | 2022-07-07 01:15:35 +0200 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-07-28 15:30:51 -0700 |
| commit | 1631ba1259d6d7f49b6028f2a1a0fa02be1c522a (patch) | |
| tree | 224d5329d0ce1579c48f8f2b68b7a2c989dd9a96 /arch/riscv/include/asm/errata_list.h | |
| parent | d1afce6709595b39cd159bdc54fe2093808c02fc (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/errata_list.h')
| -rw-r--r-- | arch/riscv/include/asm/errata_list.h | 19 |
1 files changed, 18 insertions, 1 deletions
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 |