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author | Heiko Stuebner <heiko@sntech.de> | 2022-07-07 01:15:36 +0200 |
---|---|---|
committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-08-03 17:29:59 -0700 |
commit | d20ec7529236a2fcdb2d856fc0bd80b409a217fc (patch) | |
tree | 97c41e3c370f0ec170fb1b3aab81c42e8f1d105e /arch | |
parent | 1631ba1259d6d7f49b6028f2a1a0fa02be1c522a (diff) | |
download | linux-stable-d20ec7529236a2fcdb2d856fc0bd80b409a217fc.tar.gz linux-stable-d20ec7529236a2fcdb2d856fc0bd80b409a217fc.tar.bz2 linux-stable-d20ec7529236a2fcdb2d856fc0bd80b409a217fc.zip |
riscv: implement cache-management errata for T-Head SoCs
The T-Head C906 and C910 implement a scheme for handling
cache operations different from the generic Zicbom extension.
Add an errata for it next to the generic dma coherency ops.
Reviewed-by: Samuel Holland <samuel@sholland.org>
Tested-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20220706231536.2041855-5-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/riscv/Kconfig.erratas | 11 | ||||
-rw-r--r-- | arch/riscv/errata/thead/errata.c | 20 | ||||
-rw-r--r-- | arch/riscv/include/asm/errata_list.h | 48 |
3 files changed, 74 insertions, 5 deletions
diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas index 457ac72c9b36..3223e533fd87 100644 --- a/arch/riscv/Kconfig.erratas +++ b/arch/riscv/Kconfig.erratas @@ -55,4 +55,15 @@ config ERRATA_THEAD_PBMT If you don't know what to do here, say "Y". +config ERRATA_THEAD_CMO + bool "Apply T-Head cache management errata" + depends on ERRATA_THEAD + select RISCV_DMA_NONCOHERENT + default y + help + This will apply the cache management errata to handle the + non-standard handling on non-coherent operations on T-Head SoCs. + + If you don't know what to do here, say "Y". + endmenu diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c index b37b6fedd53b..202c83f677b2 100644 --- a/arch/riscv/errata/thead/errata.c +++ b/arch/riscv/errata/thead/errata.c @@ -27,6 +27,23 @@ static bool errata_probe_pbmt(unsigned int stage, return false; } +static bool errata_probe_cmo(unsigned int stage, + unsigned long arch_id, unsigned long impid) +{ +#ifdef CONFIG_ERRATA_THEAD_CMO + if (arch_id != 0 || impid != 0) + return false; + + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) + return false; + + riscv_noncoherent_supported(); + return true; +#else + return false; +#endif +} + static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid) { @@ -35,6 +52,9 @@ static u32 thead_errata_probe(unsigned int stage, if (errata_probe_pbmt(stage, archid, impid)) cpu_req_errata |= (1U << ERRATA_THEAD_PBMT); + if (errata_probe_cmo(stage, archid, impid)) + cpu_req_errata |= (1U << ERRATA_THEAD_CMO); + return cpu_req_errata; } diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h index f7c015005847..0f66e368e351 100644 --- a/arch/riscv/include/asm/errata_list.h +++ b/arch/riscv/include/asm/errata_list.h @@ -16,7 +16,8 @@ #ifdef CONFIG_ERRATA_THEAD #define ERRATA_THEAD_PBMT 0 -#define ERRATA_THEAD_NUMBER 1 +#define ERRATA_THEAD_CMO 1 +#define ERRATA_THEAD_NUMBER 2 #endif #define CPUFEATURE_SVPBMT 0 @@ -94,17 +95,54 @@ asm volatile(ALTERNATIVE( \ #define ALT_THEAD_PMA(_val) #endif +/* + * dcache.ipa rs1 (invalidate, physical address) + * | 31 - 25 | 24 - 20 | 19 - 15 | 14 - 12 | 11 - 7 | 6 - 0 | + * 0000001 01010 rs1 000 00000 0001011 + * dache.iva rs1 (invalida, virtual address) + * 0000001 00110 rs1 000 00000 0001011 + * + * dcache.cpa rs1 (clean, physical address) + * | 31 - 25 | 24 - 20 | 19 - 15 | 14 - 12 | 11 - 7 | 6 - 0 | + * 0000001 01001 rs1 000 00000 0001011 + * dcache.cva rs1 (clean, virtual address) + * 0000001 00100 rs1 000 00000 0001011 + * + * dcache.cipa rs1 (clean then invalidate, physical address) + * | 31 - 25 | 24 - 20 | 19 - 15 | 14 - 12 | 11 - 7 | 6 - 0 | + * 0000001 01011 rs1 000 00000 0001011 + * dcache.civa rs1 (... virtual address) + * 0000001 00111 rs1 000 00000 0001011 + * + * sync.s (make sure all cache operations finished) + * | 31 - 25 | 24 - 20 | 19 - 15 | 14 - 12 | 11 - 7 | 6 - 0 | + * 0000000 11001 00000 000 00000 0001011 + */ +#define THEAD_inval_A0 ".long 0x0265000b" +#define THEAD_clean_A0 ".long 0x0245000b" +#define THEAD_flush_A0 ".long 0x0275000b" +#define THEAD_SYNC_S ".long 0x0190000b" + #define ALT_CMO_OP(_op, _start, _size, _cachesize) \ -asm volatile(ALTERNATIVE( \ - __nops(5), \ +asm volatile(ALTERNATIVE_2( \ + __nops(6), \ "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) \ + "bltu a0, %2, 3b\n\t" \ + "nop", 0, CPUFEATURE_ZICBOM, CONFIG_RISCV_ISA_ZICBOM, \ + "mv a0, %1\n\t" \ + "j 2f\n\t" \ + "3:\n\t" \ + THEAD_##_op##_A0 "\n\t" \ + "add a0, a0, %0\n\t" \ + "2:\n\t" \ + "bltu a0, %2, 3b\n\t" \ + THEAD_SYNC_S, THEAD_VENDOR_ID, \ + ERRATA_THEAD_CMO, CONFIG_ERRATA_THEAD_CMO) \ : : "r"(_cachesize), \ "r"((unsigned long)(_start) & ~((_cachesize) - 1UL)), \ "r"((unsigned long)(_start) + (_size)) \ |