| Message ID | 20220511192921.2223629-13-heiko@sntech.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv: support for Svpbmt and D1 memory types | expand |
Reviewed-by: Guo Ren <guoren@kernel.org> On Thu, May 12, 2022 at 3:33 AM Heiko Stuebner <heiko@sntech.de> wrote: > > Some current cpus based on T-Head cores implement memory-types > way different than described in the svpbmt spec even going > so far as using PTE bits marked as reserved. > > Add the T-Head vendor-id and necessary errata code to > replace the affected instructions. > > Signed-off-by: Heiko Stuebner <heiko@sntech.de> > Tested-by: Samuel Holland <samuel@sholland.org> > --- > arch/riscv/Kconfig | 6 ++ > arch/riscv/Kconfig.erratas | 21 +++++++ > arch/riscv/errata/Makefile | 1 + > arch/riscv/errata/sifive/errata.c | 7 ++- > arch/riscv/errata/thead/Makefile | 11 ++++ > arch/riscv/errata/thead/errata.c | 82 ++++++++++++++++++++++++++ > arch/riscv/include/asm/alternative.h | 6 ++ > arch/riscv/include/asm/errata_list.h | 50 +++++++++++++++- > arch/riscv/include/asm/pgtable-64.h | 18 +++++- > arch/riscv/include/asm/pgtable.h | 18 +++++- > arch/riscv/include/asm/vendorid_list.h | 1 + > arch/riscv/kernel/Makefile | 14 +++++ > arch/riscv/kernel/alternative.c | 26 ++++++++ > arch/riscv/kernel/cpufeature.c | 7 ++- > arch/riscv/mm/init.c | 1 + > 15 files changed, 260 insertions(+), 9 deletions(-) > create mode 100644 arch/riscv/errata/thead/Makefile > create mode 100644 arch/riscv/errata/thead/errata.c > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 90317a3d40a8..65285b980134 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -334,6 +334,12 @@ config RISCV_ALTERNATIVE > code patching is performed once in the boot stages. It means > that the overhead from this mechanism is just taken once. > > +config RISCV_ALTERNATIVE_EARLY > + bool > + depends on RISCV_ALTERNATIVE > + help > + Allows early patching of the kernel for special errata > + > config RISCV_ISA_C > bool "Emit compressed instructions when building Linux" > default y > diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas > index c521c2ae2de2..ebfcd5cc6eaf 100644 > --- a/arch/riscv/Kconfig.erratas > +++ b/arch/riscv/Kconfig.erratas > @@ -33,4 +33,25 @@ config ERRATA_SIFIVE_CIP_1200 > > If you don't know what to do here, say "Y". > > +config ERRATA_THEAD > + bool "T-HEAD errata" > + select RISCV_ALTERNATIVE > + help > + All T-HEAD errata Kconfig depend on this Kconfig. Disabling > + this Kconfig will disable all T-HEAD errata. Please say "Y" > + here if your platform uses T-HEAD CPU cores. > + > + Otherwise, please say "N" here to avoid unnecessary overhead. > + > +config ERRATA_THEAD_PBMT > + bool "Apply T-Head memory type errata" > + depends on ERRATA_THEAD && 64BIT > + select RISCV_ALTERNATIVE_EARLY > + default y > + help > + This will apply the memory type errata to handle the non-standard > + memory type bits in page-table-entries on T-Head SoCs. > + > + If you don't know what to do here, say "Y". > + > endmenu > diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile > index 0ca1c5281a2d..a1055965fbee 100644 > --- a/arch/riscv/errata/Makefile > +++ b/arch/riscv/errata/Makefile > @@ -1 +1,2 @@ > obj-$(CONFIG_ERRATA_SIFIVE) += sifive/ > +obj-$(CONFIG_ERRATA_THEAD) += thead/ > diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c > index 3e39587a49dc..672f02b21ce0 100644 > --- a/arch/riscv/errata/sifive/errata.c > +++ b/arch/riscv/errata/sifive/errata.c > @@ -88,10 +88,15 @@ void __init_or_module sifive_errata_patch_func(struct alt_entry *begin, > unsigned int stage) > { > struct alt_entry *alt; > - u32 cpu_req_errata = sifive_errata_probe(archid, impid); > + u32 cpu_req_errata; > u32 cpu_apply_errata = 0; > u32 tmp; > > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + return; > + > + cpu_req_errata = sifive_errata_probe(archid, impid); > + > for (alt = begin; alt < end; alt++) { > if (alt->vendor_id != SIFIVE_VENDOR_ID) > continue; > diff --git a/arch/riscv/errata/thead/Makefile b/arch/riscv/errata/thead/Makefile > new file mode 100644 > index 000000000000..137e700d9d3f > --- /dev/null > +++ b/arch/riscv/errata/thead/Makefile > @@ -0,0 +1,11 @@ > +ifdef CONFIG_RISCV_ALTERNATIVE_EARLY > +CFLAGS_errata.o := -mcmodel=medany > +ifdef CONFIG_FTRACE > +CFLAGS_REMOVE_errata.o = $(CC_FLAGS_FTRACE) > +endif > +ifdef CONFIG_KASAN > +KASAN_SANITIZE_errata.o := n > +endif > +endif > + > +obj-y += errata.o > diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c > new file mode 100644 > index 000000000000..e5d75270b99c > --- /dev/null > +++ b/arch/riscv/errata/thead/errata.c > @@ -0,0 +1,82 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2021 Heiko Stuebner <heiko@sntech.de> > + */ > + > +#include <linux/bug.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/string.h> > +#include <linux/uaccess.h> > +#include <asm/alternative.h> > +#include <asm/cacheflush.h> > +#include <asm/errata_list.h> > +#include <asm/patch.h> > +#include <asm/vendorid_list.h> > + > +struct errata_info { > + char name[ERRATA_STRING_LENGTH_MAX]; > + bool (*check_func)(unsigned long arch_id, unsigned long impid); > + unsigned int stage; > +}; > + > +static bool errata_mt_check_func(unsigned long arch_id, unsigned long impid) > +{ > + if (arch_id != 0 || impid != 0) > + return false; > + return true; > +} > + > +static const struct errata_info errata_list[ERRATA_THEAD_NUMBER] = { > + { > + .name = "memory-types", > + .stage = RISCV_ALTERNATIVES_EARLY_BOOT, > + .check_func = errata_mt_check_func > + }, > +}; > + > +static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid) > +{ > + const struct errata_info *info; > + u32 cpu_req_errata = 0; > + int idx; > + > + for (idx = 0; idx < ERRATA_THEAD_NUMBER; idx++) { > + info = &errata_list[idx]; > + > + if ((stage == RISCV_ALTERNATIVES_MODULE || > + info->stage == stage) && info->check_func(archid, impid)) > + cpu_req_errata |= (1U << idx); > + } > + > + return cpu_req_errata; > +} > + > +void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > + unsigned long archid, unsigned long impid, > + unsigned int stage) > +{ > + struct alt_entry *alt; > + u32 cpu_req_errata = thead_errata_probe(stage, archid, impid); > + u32 tmp; > + > + for (alt = begin; alt < end; alt++) { > + if (alt->vendor_id != THEAD_VENDOR_ID) > + continue; > + if (alt->errata_id >= ERRATA_THEAD_NUMBER) > + continue; > + > + tmp = (1U << alt->errata_id); > + if (cpu_req_errata & tmp) { > + /* On vm-alternatives, the mmu isn't running yet */ > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + memcpy((void *)__pa_symbol(alt->old_ptr), > + (void *)__pa_symbol(alt->alt_ptr), alt->alt_len); > + else > + patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); > + } > + } > + > + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) > + local_flush_icache_all(); > +} > diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h > index 64936356c37c..6511dd73e812 100644 > --- a/arch/riscv/include/asm/alternative.h > +++ b/arch/riscv/include/asm/alternative.h > @@ -21,8 +21,10 @@ > > #define RISCV_ALTERNATIVES_BOOT 0 /* alternatives applied during regular boot */ > #define RISCV_ALTERNATIVES_MODULE 1 /* alternatives applied during module-init */ > +#define RISCV_ALTERNATIVES_EARLY_BOOT 2 /* alternatives applied before mmu start */ > > void __init apply_boot_alternatives(void); > +void __init apply_early_boot_alternatives(void); > void apply_module_alternatives(void *start, size_t length); > > struct alt_entry { > @@ -41,6 +43,9 @@ struct errata_checkfunc_id { > void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > unsigned long archid, unsigned long impid, > unsigned int stage); > +void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, > + unsigned long archid, unsigned long impid, > + unsigned int stage); > > void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end, > unsigned int stage); > @@ -48,6 +53,7 @@ void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end, > #else /* CONFIG_RISCV_ALTERNATIVE */ > > static inline void apply_boot_alternatives(void) { } > +static inline void apply_early_boot_alternatives(void) { } > static inline void apply_module_alternatives(void *start, size_t length) { } > > #endif /* CONFIG_RISCV_ALTERNATIVE */ > diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h > index dbfcd9b72bd8..9e2888dbb5b1 100644 > --- a/arch/riscv/include/asm/errata_list.h > +++ b/arch/riscv/include/asm/errata_list.h > @@ -14,6 +14,11 @@ > #define ERRATA_SIFIVE_NUMBER 2 > #endif > > +#ifdef CONFIG_ERRATA_THEAD > +#define ERRATA_THEAD_PBMT 0 > +#define ERRATA_THEAD_NUMBER 1 > +#endif > + > #define CPUFEATURE_SVPBMT 0 > #define CPUFEATURE_NUMBER 1 > > @@ -42,12 +47,51 @@ asm(ALTERNATIVE("sfence.vma %0", "sfence.vma", SIFIVE_VENDOR_ID, \ > * in the default case. > */ > #define ALT_SVPBMT_SHIFT 61 > +#define ALT_THEAD_PBMT_SHIFT 59 > #define ALT_SVPBMT(_val, prot) \ > -asm(ALTERNATIVE("li %0, 0\t\nnop", "li %0, %1\t\nslli %0,%0,%2", 0, \ > - CPUFEATURE_SVPBMT, CONFIG_RISCV_ISA_SVPBMT) \ > +asm(ALTERNATIVE_2("li %0, 0\t\nnop", \ > + "li %0, %1\t\nslli %0,%0,%3", 0, \ > + CPUFEATURE_SVPBMT, CONFIG_RISCV_ISA_SVPBMT, \ > + "li %0, %2\t\nslli %0,%0,%4", THEAD_VENDOR_ID, \ > + ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \ > : "=r"(_val) \ > : "I"(prot##_SVPBMT >> ALT_SVPBMT_SHIFT), \ > - "I"(ALT_SVPBMT_SHIFT)) > + "I"(prot##_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > + "I"(ALT_SVPBMT_SHIFT), \ > + "I"(ALT_THEAD_PBMT_SHIFT)) > + > +#ifdef CONFIG_ERRATA_THEAD_PBMT > +/* > + * IO/NOCACHE memory types are handled together with svpbmt, > + * so on T-Head chips, check if no other memory type is set, > + * and set the non-0 PMA type if applicable. > + */ > +#define ALT_THEAD_PMA(_val) \ > +asm volatile(ALTERNATIVE( \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop\n\t" \ > + "nop", \ > + "li t3, %2\n\t" \ > + "slli t3, t3, %4\n\t" \ > + "and t3, %0, t3\n\t" \ > + "bne t3, zero, 2f\n\t" \ > + "li t3, %3\n\t" \ > + "slli t3, t3, %4\n\t" \ > + "or %0, %0, t3\n\t" \ > + "2:", THEAD_VENDOR_ID, \ > + ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \ > + : "+r"(_val) \ > + : "0"(_val), \ > + "I"(_PAGE_MTMASK_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > + "I"(_PAGE_PMA_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > + "I"(ALT_THEAD_PBMT_SHIFT)) > +#else > +#define ALT_THEAD_PMA(_val) > +#endif > > #endif /* __ASSEMBLY__ */ > > diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h > index 2354501f0203..e4ff3e0ab887 100644 > --- a/arch/riscv/include/asm/pgtable-64.h > +++ b/arch/riscv/include/asm/pgtable-64.h > @@ -86,6 +86,18 @@ typedef struct { > #define _PAGE_IO_SVPBMT (1UL << 62) > #define _PAGE_MTMASK_SVPBMT (_PAGE_NOCACHE_SVPBMT | _PAGE_IO_SVPBMT) > > +/* > + * [63:59] T-Head Memory Type definitions: > + * > + * 00000 - NC Weakly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable > + * 01110 - PMA Weakly-ordered, Cacheable, Bufferable, Shareable, Non-trustable > + * 10000 - IO Strongly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable > + */ > +#define _PAGE_PMA_THEAD ((1UL << 62) | (1UL << 61) | (1UL << 60)) > +#define _PAGE_NOCACHE_THEAD 0UL > +#define _PAGE_IO_THEAD (1UL << 63) > +#define _PAGE_MTMASK_THEAD (_PAGE_PMA_THEAD | _PAGE_IO_THEAD | (1UL << 59)) > + > static inline u64 riscv_page_mtmask(void) > { > u64 val; > @@ -193,7 +205,11 @@ static inline bool mm_pud_folded(struct mm_struct *mm) > > static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot) > { > - return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pmd((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > static inline unsigned long _pmd_pfn(pmd_t pmd) > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index c55341b72de1..6f0a260d3f2c 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -250,7 +250,11 @@ static inline void pmd_clear(pmd_t *pmdp) > > static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot) > { > - return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pgd((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > static inline unsigned long _pgd_pfn(pgd_t pgd) > @@ -289,7 +293,11 @@ static inline unsigned long pte_pfn(pte_t pte) > /* Constructs a page table entry */ > static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) > { > - return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); > + unsigned long prot_val = pgprot_val(prot); > + > + ALT_THEAD_PMA(prot_val); > + > + return __pte((pfn << _PAGE_PFN_SHIFT) | prot_val); > } > > #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) > @@ -398,7 +406,11 @@ static inline int pmd_protnone(pmd_t pmd) > /* Modify page protection bits */ > static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) > { > - return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); > + unsigned long newprot_val = pgprot_val(newprot); > + > + ALT_THEAD_PMA(newprot_val); > + > + return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val); > } > > #define pgd_ERROR(e) \ > diff --git a/arch/riscv/include/asm/vendorid_list.h b/arch/riscv/include/asm/vendorid_list.h > index 9d934215b3c8..cb89af3f0704 100644 > --- a/arch/riscv/include/asm/vendorid_list.h > +++ b/arch/riscv/include/asm/vendorid_list.h > @@ -6,5 +6,6 @@ > #define ASM_VENDOR_LIST_H > > #define SIFIVE_VENDOR_ID 0x489 > +#define THEAD_VENDOR_ID 0x5b7 > > #endif > diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile > index 0f8348ac30f1..bf3876a77ed7 100644 > --- a/arch/riscv/kernel/Makefile > +++ b/arch/riscv/kernel/Makefile > @@ -14,6 +14,20 @@ ifdef CONFIG_KEXEC > AFLAGS_kexec_relocate.o := -mcmodel=medany $(call cc-option,-mno-relax) > endif > > +# cmodel=medany and notrace when patching early > +ifdef CONFIG_RISCV_ALTERNATIVE_EARLY > +CFLAGS_alternative.o := -mcmodel=medany > +CFLAGS_cpufeature.o := -mcmodel=medany > +ifdef CONFIG_FTRACE > +CFLAGS_REMOVE_alternative.o = $(CC_FLAGS_FTRACE) > +CFLAGS_REMOVE_cpufeature.o = $(CC_FLAGS_FTRACE) > +endif > +ifdef CONFIG_KASAN > +KASAN_SANITIZE_alternative.o := n > +KASAN_SANITIZE_cpufeature.o := n > +endif > +endif > + > extra-y += head.o > extra-y += vmlinux.lds > > diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c > index 27f722ae452b..c9d0d3c53223 100644 > --- a/arch/riscv/kernel/alternative.c > +++ b/arch/riscv/kernel/alternative.c > @@ -42,6 +42,11 @@ static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_inf > case SIFIVE_VENDOR_ID: > cpu_mfr_info->vendor_patch_func = sifive_errata_patch_func; > break; > +#endif > +#ifdef CONFIG_ERRATA_THEAD > + case THEAD_VENDOR_ID: > + cpu_mfr_info->vendor_patch_func = thead_errata_patch_func; > + break; > #endif > default: > cpu_mfr_info->vendor_patch_func = NULL; > @@ -82,6 +87,27 @@ void __init apply_boot_alternatives(void) > RISCV_ALTERNATIVES_BOOT); > } > > +/* > + * apply_early_boot_alternatives() is called from setup_vm() with MMU-off. > + * > + * Following requirements should be honoured for it to work correctly: > + * 1) It should use PC-relative addressing for accessing kernel symbols. > + * To achieve this we always use GCC cmodel=medany. > + * 2) The compiler instrumentation for FTRACE will not work for setup_vm() > + * so disable compiler instrumentation when FTRACE is enabled. > + * > + * Currently, the above requirements are honoured by using custom CFLAGS > + * for alternative.o in kernel/Makefile. > + */ > +void __init apply_early_boot_alternatives(void) > +{ > +#ifdef CONFIG_RISCV_ALTERNATIVE_EARLY > + _apply_alternatives((struct alt_entry *)__alt_start, > + (struct alt_entry *)__alt_end, > + RISCV_ALTERNATIVES_EARLY_BOOT); > +#endif > +} > + > #ifdef CONFIG_MODULES > void apply_module_alternatives(void *start, size_t length) > { > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index f514b949c6a7..dea3ea19deee 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -254,7 +254,12 @@ struct cpufeature_info { > static bool __init_or_module cpufeature_svpbmt_check_func(unsigned int stage) > { > #ifdef CONFIG_RISCV_ISA_SVPBMT > - return riscv_isa_extension_available(NULL, SVPBMT); > + switch (stage) { > + case RISCV_ALTERNATIVES_EARLY_BOOT: > + return false; > + default: > + return riscv_isa_extension_available(NULL, SVPBMT); > + } > #endif > > return false; > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index b0793dc0c291..45a4bf107bd2 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -936,6 +936,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); > #endif > > + apply_early_boot_alternatives(); > pt_ops_set_early(); > > /* Setup early PGD for fixmap */ > -- > 2.35.1 >
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 90317a3d40a8..65285b980134 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -334,6 +334,12 @@ config RISCV_ALTERNATIVE code patching is performed once in the boot stages. It means that the overhead from this mechanism is just taken once. +config RISCV_ALTERNATIVE_EARLY + bool + depends on RISCV_ALTERNATIVE + help + Allows early patching of the kernel for special errata + config RISCV_ISA_C bool "Emit compressed instructions when building Linux" default y diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas index c521c2ae2de2..ebfcd5cc6eaf 100644 --- a/arch/riscv/Kconfig.erratas +++ b/arch/riscv/Kconfig.erratas @@ -33,4 +33,25 @@ config ERRATA_SIFIVE_CIP_1200 If you don't know what to do here, say "Y". +config ERRATA_THEAD + bool "T-HEAD errata" + select RISCV_ALTERNATIVE + help + All T-HEAD errata Kconfig depend on this Kconfig. Disabling + this Kconfig will disable all T-HEAD errata. Please say "Y" + here if your platform uses T-HEAD CPU cores. + + Otherwise, please say "N" here to avoid unnecessary overhead. + +config ERRATA_THEAD_PBMT + bool "Apply T-Head memory type errata" + depends on ERRATA_THEAD && 64BIT + select RISCV_ALTERNATIVE_EARLY + default y + help + This will apply the memory type errata to handle the non-standard + memory type bits in page-table-entries on T-Head SoCs. + + If you don't know what to do here, say "Y". + endmenu diff --git a/arch/riscv/errata/Makefile b/arch/riscv/errata/Makefile index 0ca1c5281a2d..a1055965fbee 100644 --- a/arch/riscv/errata/Makefile +++ b/arch/riscv/errata/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_ERRATA_SIFIVE) += sifive/ +obj-$(CONFIG_ERRATA_THEAD) += thead/ diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c index 3e39587a49dc..672f02b21ce0 100644 --- a/arch/riscv/errata/sifive/errata.c +++ b/arch/riscv/errata/sifive/errata.c @@ -88,10 +88,15 @@ void __init_or_module sifive_errata_patch_func(struct alt_entry *begin, unsigned int stage) { struct alt_entry *alt; - u32 cpu_req_errata = sifive_errata_probe(archid, impid); + u32 cpu_req_errata; u32 cpu_apply_errata = 0; u32 tmp; + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) + return; + + cpu_req_errata = sifive_errata_probe(archid, impid); + for (alt = begin; alt < end; alt++) { if (alt->vendor_id != SIFIVE_VENDOR_ID) continue; diff --git a/arch/riscv/errata/thead/Makefile b/arch/riscv/errata/thead/Makefile new file mode 100644 index 000000000000..137e700d9d3f --- /dev/null +++ b/arch/riscv/errata/thead/Makefile @@ -0,0 +1,11 @@ +ifdef CONFIG_RISCV_ALTERNATIVE_EARLY +CFLAGS_errata.o := -mcmodel=medany +ifdef CONFIG_FTRACE +CFLAGS_REMOVE_errata.o = $(CC_FLAGS_FTRACE) +endif +ifdef CONFIG_KASAN +KASAN_SANITIZE_errata.o := n +endif +endif + +obj-y += errata.o diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c new file mode 100644 index 000000000000..e5d75270b99c --- /dev/null +++ b/arch/riscv/errata/thead/errata.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Heiko Stuebner <heiko@sntech.de> + */ + +#include <linux/bug.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/uaccess.h> +#include <asm/alternative.h> +#include <asm/cacheflush.h> +#include <asm/errata_list.h> +#include <asm/patch.h> +#include <asm/vendorid_list.h> + +struct errata_info { + char name[ERRATA_STRING_LENGTH_MAX]; + bool (*check_func)(unsigned long arch_id, unsigned long impid); + unsigned int stage; +}; + +static bool errata_mt_check_func(unsigned long arch_id, unsigned long impid) +{ + if (arch_id != 0 || impid != 0) + return false; + return true; +} + +static const struct errata_info errata_list[ERRATA_THEAD_NUMBER] = { + { + .name = "memory-types", + .stage = RISCV_ALTERNATIVES_EARLY_BOOT, + .check_func = errata_mt_check_func + }, +}; + +static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid) +{ + const struct errata_info *info; + u32 cpu_req_errata = 0; + int idx; + + for (idx = 0; idx < ERRATA_THEAD_NUMBER; idx++) { + info = &errata_list[idx]; + + if ((stage == RISCV_ALTERNATIVES_MODULE || + info->stage == stage) && info->check_func(archid, impid)) + cpu_req_errata |= (1U << idx); + } + + return cpu_req_errata; +} + +void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, + unsigned long archid, unsigned long impid, + unsigned int stage) +{ + struct alt_entry *alt; + u32 cpu_req_errata = thead_errata_probe(stage, archid, impid); + u32 tmp; + + for (alt = begin; alt < end; alt++) { + if (alt->vendor_id != THEAD_VENDOR_ID) + continue; + if (alt->errata_id >= ERRATA_THEAD_NUMBER) + continue; + + tmp = (1U << alt->errata_id); + if (cpu_req_errata & tmp) { + /* On vm-alternatives, the mmu isn't running yet */ + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) + memcpy((void *)__pa_symbol(alt->old_ptr), + (void *)__pa_symbol(alt->alt_ptr), alt->alt_len); + else + patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); + } + } + + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) + local_flush_icache_all(); +} diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h index 64936356c37c..6511dd73e812 100644 --- a/arch/riscv/include/asm/alternative.h +++ b/arch/riscv/include/asm/alternative.h @@ -21,8 +21,10 @@ #define RISCV_ALTERNATIVES_BOOT 0 /* alternatives applied during regular boot */ #define RISCV_ALTERNATIVES_MODULE 1 /* alternatives applied during module-init */ +#define RISCV_ALTERNATIVES_EARLY_BOOT 2 /* alternatives applied before mmu start */ void __init apply_boot_alternatives(void); +void __init apply_early_boot_alternatives(void); void apply_module_alternatives(void *start, size_t length); struct alt_entry { @@ -41,6 +43,9 @@ struct errata_checkfunc_id { void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, unsigned long archid, unsigned long impid, unsigned int stage); +void thead_errata_patch_func(struct alt_entry *begin, struct alt_entry *end, + unsigned long archid, unsigned long impid, + unsigned int stage); void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end, unsigned int stage); @@ -48,6 +53,7 @@ void riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end, #else /* CONFIG_RISCV_ALTERNATIVE */ static inline void apply_boot_alternatives(void) { } +static inline void apply_early_boot_alternatives(void) { } static inline void apply_module_alternatives(void *start, size_t length) { } #endif /* CONFIG_RISCV_ALTERNATIVE */ diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h index dbfcd9b72bd8..9e2888dbb5b1 100644 --- a/arch/riscv/include/asm/errata_list.h +++ b/arch/riscv/include/asm/errata_list.h @@ -14,6 +14,11 @@ #define ERRATA_SIFIVE_NUMBER 2 #endif +#ifdef CONFIG_ERRATA_THEAD +#define ERRATA_THEAD_PBMT 0 +#define ERRATA_THEAD_NUMBER 1 +#endif + #define CPUFEATURE_SVPBMT 0 #define CPUFEATURE_NUMBER 1 @@ -42,12 +47,51 @@ asm(ALTERNATIVE("sfence.vma %0", "sfence.vma", SIFIVE_VENDOR_ID, \ * in the default case. */ #define ALT_SVPBMT_SHIFT 61 +#define ALT_THEAD_PBMT_SHIFT 59 #define ALT_SVPBMT(_val, prot) \ -asm(ALTERNATIVE("li %0, 0\t\nnop", "li %0, %1\t\nslli %0,%0,%2", 0, \ - CPUFEATURE_SVPBMT, CONFIG_RISCV_ISA_SVPBMT) \ +asm(ALTERNATIVE_2("li %0, 0\t\nnop", \ + "li %0, %1\t\nslli %0,%0,%3", 0, \ + CPUFEATURE_SVPBMT, CONFIG_RISCV_ISA_SVPBMT, \ + "li %0, %2\t\nslli %0,%0,%4", THEAD_VENDOR_ID, \ + ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \ : "=r"(_val) \ : "I"(prot##_SVPBMT >> ALT_SVPBMT_SHIFT), \ - "I"(ALT_SVPBMT_SHIFT)) + "I"(prot##_THEAD >> ALT_THEAD_PBMT_SHIFT), \ + "I"(ALT_SVPBMT_SHIFT), \ + "I"(ALT_THEAD_PBMT_SHIFT)) + +#ifdef CONFIG_ERRATA_THEAD_PBMT +/* + * IO/NOCACHE memory types are handled together with svpbmt, + * so on T-Head chips, check if no other memory type is set, + * and set the non-0 PMA type if applicable. + */ +#define ALT_THEAD_PMA(_val) \ +asm volatile(ALTERNATIVE( \ + "nop\n\t" \ + "nop\n\t" \ + "nop\n\t" \ + "nop\n\t" \ + "nop\n\t" \ + "nop\n\t" \ + "nop", \ + "li t3, %2\n\t" \ + "slli t3, t3, %4\n\t" \ + "and t3, %0, t3\n\t" \ + "bne t3, zero, 2f\n\t" \ + "li t3, %3\n\t" \ + "slli t3, t3, %4\n\t" \ + "or %0, %0, t3\n\t" \ + "2:", THEAD_VENDOR_ID, \ + ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \ + : "+r"(_val) \ + : "0"(_val), \ + "I"(_PAGE_MTMASK_THEAD >> ALT_THEAD_PBMT_SHIFT), \ + "I"(_PAGE_PMA_THEAD >> ALT_THEAD_PBMT_SHIFT), \ + "I"(ALT_THEAD_PBMT_SHIFT)) +#else +#define ALT_THEAD_PMA(_val) +#endif #endif /* __ASSEMBLY__ */ diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h index 2354501f0203..e4ff3e0ab887 100644 --- a/arch/riscv/include/asm/pgtable-64.h +++ b/arch/riscv/include/asm/pgtable-64.h @@ -86,6 +86,18 @@ typedef struct { #define _PAGE_IO_SVPBMT (1UL << 62) #define _PAGE_MTMASK_SVPBMT (_PAGE_NOCACHE_SVPBMT | _PAGE_IO_SVPBMT) +/* + * [63:59] T-Head Memory Type definitions: + * + * 00000 - NC Weakly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable + * 01110 - PMA Weakly-ordered, Cacheable, Bufferable, Shareable, Non-trustable + * 10000 - IO Strongly-ordered, Non-cacheable, Non-bufferable, Non-shareable, Non-trustable + */ +#define _PAGE_PMA_THEAD ((1UL << 62) | (1UL << 61) | (1UL << 60)) +#define _PAGE_NOCACHE_THEAD 0UL +#define _PAGE_IO_THEAD (1UL << 63) +#define _PAGE_MTMASK_THEAD (_PAGE_PMA_THEAD | _PAGE_IO_THEAD | (1UL << 59)) + static inline u64 riscv_page_mtmask(void) { u64 val; @@ -193,7 +205,11 @@ static inline bool mm_pud_folded(struct mm_struct *mm) static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot) { - return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); + unsigned long prot_val = pgprot_val(prot); + + ALT_THEAD_PMA(prot_val); + + return __pmd((pfn << _PAGE_PFN_SHIFT) | prot_val); } static inline unsigned long _pmd_pfn(pmd_t pmd) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index c55341b72de1..6f0a260d3f2c 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -250,7 +250,11 @@ static inline void pmd_clear(pmd_t *pmdp) static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot) { - return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); + unsigned long prot_val = pgprot_val(prot); + + ALT_THEAD_PMA(prot_val); + + return __pgd((pfn << _PAGE_PFN_SHIFT) | prot_val); } static inline unsigned long _pgd_pfn(pgd_t pgd) @@ -289,7 +293,11 @@ static inline unsigned long pte_pfn(pte_t pte) /* Constructs a page table entry */ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) { - return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); + unsigned long prot_val = pgprot_val(prot); + + ALT_THEAD_PMA(prot_val); + + return __pte((pfn << _PAGE_PFN_SHIFT) | prot_val); } #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) @@ -398,7 +406,11 @@ static inline int pmd_protnone(pmd_t pmd) /* Modify page protection bits */ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { - return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); + unsigned long newprot_val = pgprot_val(newprot); + + ALT_THEAD_PMA(newprot_val); + + return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val); } #define pgd_ERROR(e) \ diff --git a/arch/riscv/include/asm/vendorid_list.h b/arch/riscv/include/asm/vendorid_list.h index 9d934215b3c8..cb89af3f0704 100644 --- a/arch/riscv/include/asm/vendorid_list.h +++ b/arch/riscv/include/asm/vendorid_list.h @@ -6,5 +6,6 @@ #define ASM_VENDOR_LIST_H #define SIFIVE_VENDOR_ID 0x489 +#define THEAD_VENDOR_ID 0x5b7 #endif diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 0f8348ac30f1..bf3876a77ed7 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -14,6 +14,20 @@ ifdef CONFIG_KEXEC AFLAGS_kexec_relocate.o := -mcmodel=medany $(call cc-option,-mno-relax) endif +# cmodel=medany and notrace when patching early +ifdef CONFIG_RISCV_ALTERNATIVE_EARLY +CFLAGS_alternative.o := -mcmodel=medany +CFLAGS_cpufeature.o := -mcmodel=medany +ifdef CONFIG_FTRACE +CFLAGS_REMOVE_alternative.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_cpufeature.o = $(CC_FLAGS_FTRACE) +endif +ifdef CONFIG_KASAN +KASAN_SANITIZE_alternative.o := n +KASAN_SANITIZE_cpufeature.o := n +endif +endif + extra-y += head.o extra-y += vmlinux.lds diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c index 27f722ae452b..c9d0d3c53223 100644 --- a/arch/riscv/kernel/alternative.c +++ b/arch/riscv/kernel/alternative.c @@ -42,6 +42,11 @@ static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_inf case SIFIVE_VENDOR_ID: cpu_mfr_info->vendor_patch_func = sifive_errata_patch_func; break; +#endif +#ifdef CONFIG_ERRATA_THEAD + case THEAD_VENDOR_ID: + cpu_mfr_info->vendor_patch_func = thead_errata_patch_func; + break; #endif default: cpu_mfr_info->vendor_patch_func = NULL; @@ -82,6 +87,27 @@ void __init apply_boot_alternatives(void) RISCV_ALTERNATIVES_BOOT); } +/* + * apply_early_boot_alternatives() is called from setup_vm() with MMU-off. + * + * Following requirements should be honoured for it to work correctly: + * 1) It should use PC-relative addressing for accessing kernel symbols. + * To achieve this we always use GCC cmodel=medany. + * 2) The compiler instrumentation for FTRACE will not work for setup_vm() + * so disable compiler instrumentation when FTRACE is enabled. + * + * Currently, the above requirements are honoured by using custom CFLAGS + * for alternative.o in kernel/Makefile. + */ +void __init apply_early_boot_alternatives(void) +{ +#ifdef CONFIG_RISCV_ALTERNATIVE_EARLY + _apply_alternatives((struct alt_entry *)__alt_start, + (struct alt_entry *)__alt_end, + RISCV_ALTERNATIVES_EARLY_BOOT); +#endif +} + #ifdef CONFIG_MODULES void apply_module_alternatives(void *start, size_t length) { diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index f514b949c6a7..dea3ea19deee 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -254,7 +254,12 @@ struct cpufeature_info { static bool __init_or_module cpufeature_svpbmt_check_func(unsigned int stage) { #ifdef CONFIG_RISCV_ISA_SVPBMT - return riscv_isa_extension_available(NULL, SVPBMT); + switch (stage) { + case RISCV_ALTERNATIVES_EARLY_BOOT: + return false; + default: + return riscv_isa_extension_available(NULL, SVPBMT); + } #endif return false; diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index b0793dc0c291..45a4bf107bd2 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -936,6 +936,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); #endif + apply_early_boot_alternatives(); pt_ops_set_early(); /* Setup early PGD for fixmap */