From bff3ff525460b492dca1d1665e821d2b5816ebdb Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Mon, 22 Mar 2021 22:26:06 +0800 Subject: [PATCH] riscv: sifive: Apply errata "cip-1200" patch For certain SiFive CPUs, "sfence.vma addr" cannot exactly flush addr from TLB in the particular cases. The details could be found here: https://sifive.cdn.prismic.io/sifive/167a1a56-03f4-4615-a79e-b2a86153148f_FU740_errata_20210205.pdf In order to ensure the functionality, this patch uses the Alternative scheme to replace all "sfence.vma addr" with "sfence.vma" at runtime. Signed-off-by: Vincent Chen Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig.erratas | 11 +++++++++++ arch/riscv/errata/sifive/errata.c | 18 ++++++++++++++++++ arch/riscv/include/asm/errata_list.h | 10 +++++++++- arch/riscv/include/asm/tlbflush.h | 3 ++- 4 files changed, 40 insertions(+), 2 deletions(-) diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas index b4146dca50fc..d5d03ae8d685 100644 --- a/arch/riscv/Kconfig.erratas +++ b/arch/riscv/Kconfig.erratas @@ -30,4 +30,15 @@ config ERRATA_SIFIVE_CIP_453 If you don't know what to do here, say "Y". +config ERRATA_SIFIVE_CIP_1200 + bool "Apply SiFive errata CIP-1200" + depends on ERRATA_SIFIVE + default y + help + This will apply the SiFive CIP-1200 errata to repalce all + "sfence.vma addr" with "sfence.vma" to ensure that the addr + has been flushed from TLB. + + If you don't know what to do here, say "Y". + endmenu diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c index e27391823f0f..f5e5ae70e829 100644 --- a/arch/riscv/errata/sifive/errata.c +++ b/arch/riscv/errata/sifive/errata.c @@ -29,11 +29,29 @@ static bool errata_cip_453_check_func(unsigned long arch_id, unsigned long impi return true; } +static bool errata_cip_1200_check_func(unsigned long arch_id, unsigned long impid) +{ + /* + * Affected cores: + * Architecture ID: 0x8000000000000007 or 0x1 + * Implement ID: mimpid[23:0] <= 0x200630 and mimpid != 0x01200626 + */ + if (arch_id != 0x8000000000000007 && arch_id != 0x1) + return false; + if ((impid & 0xffffff) > 0x200630 || impid == 0x1200626) + return false; + return true; +} + static struct errata_info_t errata_list[ERRATA_SIFIVE_NUMBER] = { { .name = "cip-453", .check_func = errata_cip_453_check_func }, + { + .name = "cip-1200", + .check_func = errata_cip_1200_check_func + }, }; static u32 __init sifive_errata_probe(unsigned long archid, unsigned long impid) diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h index 6148d34d4245..5f1046e82d9f 100644 --- a/arch/riscv/include/asm/errata_list.h +++ b/arch/riscv/include/asm/errata_list.h @@ -10,7 +10,8 @@ #ifdef CONFIG_ERRATA_SIFIVE #define ERRATA_SIFIVE_CIP_453 0 -#define ERRATA_SIFIVE_NUMBER 1 +#define ERRATA_SIFIVE_CIP_1200 1 +#define ERRATA_SIFIVE_NUMBER 2 #endif #ifdef __ASSEMBLY__ @@ -26,6 +27,13 @@ ALTERNATIVE(__stringify(RISCV_PTR do_page_fault), \ __stringify(RISCV_PTR sifive_cip_453_page_fault_trp), \ SIFIVE_VENDOR_ID, ERRATA_SIFIVE_CIP_453, \ CONFIG_ERRATA_SIFIVE_CIP_453) +#else /* !__ASSEMBLY__ */ + +#define ALT_FLUSH_TLB_PAGE(x) \ +asm(ALTERNATIVE("sfence.vma %0", "sfence.vma", SIFIVE_VENDOR_ID, \ + ERRATA_SIFIVE_CIP_1200, CONFIG_ERRATA_SIFIVE_CIP_1200) \ + : : "r" (addr) : "memory") + #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h index 394cfbccdcd9..c84218ad7afc 100644 --- a/arch/riscv/include/asm/tlbflush.h +++ b/arch/riscv/include/asm/tlbflush.h @@ -9,6 +9,7 @@ #include #include +#include #ifdef CONFIG_MMU static inline void local_flush_tlb_all(void) @@ -19,7 +20,7 @@ static inline void local_flush_tlb_all(void) /* Flush one page from local TLB */ static inline void local_flush_tlb_page(unsigned long addr) { - __asm__ __volatile__ ("sfence.vma %0" : : "r" (addr) : "memory"); + ALT_FLUSH_TLB_PAGE(__asm__ __volatile__ ("sfence.vma %0" : : "r" (addr) : "memory")); } #else /* CONFIG_MMU */ #define local_flush_tlb_all() do { } while (0) -- 2.11.0