From abcc445acdbeb561e881fcbd8e1dc4684628cc9b Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:44 +0800 Subject: [PATCH 01/13] riscv: move riscv_noncoherent_supported() out of ZICBOM probe It's a bit weird to call riscv_noncoherent_supported() each time when insmoding a module. Move the calling out of feature patch func. Signed-off-by: Jisheng Zhang Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-2-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpufeature.c | 1 - arch/riscv/kernel/setup.c | 3 +++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index dde0e91d76688..62443fd32fa74 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -298,7 +298,6 @@ static bool __init_or_module cpufeature_probe_zicbom(unsigned int stage) if (!riscv_isa_extension_available(NULL, ZICBOM)) return false; - riscv_noncoherent_supported(); return true; } diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 86acd690d5293..376d2827e7365 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -300,6 +300,9 @@ void __init setup_arch(char **cmdline_p) riscv_init_cbom_blocksize(); riscv_fill_hwcap(); apply_boot_alternatives(); + if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) && + riscv_isa_extension_available(NULL, ZICBOM)) + riscv_noncoherent_supported(); } static int __init topology_init(void) From 191b27c7c0e8c1a587832f8680132564743af76c Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:45 +0800 Subject: [PATCH 02/13] riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier Currently riscv_cpufeature_patch_func() does nothing at the RISCV_ALTERNATIVES_EARLY_BOOT stage. Add a check to detect whether we are in this stage and exit early. This will allow us to use riscv_cpufeature_patch_func() for scanning of all ISA extensions. Signed-off-by: Jisheng Zhang Reviewed-by: Andrew Jones Reviewed-by: Heiko Stuebner Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-3-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpufeature.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 62443fd32fa74..59e20cad1b3dc 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -330,6 +330,9 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *alt; u32 tmp; + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) + return; + for (alt = begin; alt < end; alt++) { if (alt->vendor_id != 0) continue; From d8a3d8a75206d3dfba64b6d4468b7cf44d4eb4d7 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:46 +0800 Subject: [PATCH 03/13] riscv: hwcap: make ISA extension ids can be used in asm So that ISA extensions can be used in assembly files, convert the multi-letter RISC-V ISA extension IDs enums to macros. In order to make them visible, move the #ifndef __ASSEMBLY__ guard to a later point in the header Signed-off-by: Jisheng Zhang Reviewed-by: Heiko Stuebner Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-4-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 45 ++++++++++++++++------------------ 1 file changed, 21 insertions(+), 24 deletions(-) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 57439da71c775..8e0ee841fa778 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -12,20 +12,6 @@ #include #include -#ifndef __ASSEMBLY__ -#include -/* - * This yields a mask that user programs can use to figure out what - * instruction set this cpu supports. - */ -#define ELF_HWCAP (elf_hwcap) - -enum { - CAP_HWCAP = 1, -}; - -extern unsigned long elf_hwcap; - #define RISCV_ISA_EXT_a ('a' - 'a') #define RISCV_ISA_EXT_c ('c' - 'a') #define RISCV_ISA_EXT_d ('d' - 'a') @@ -46,23 +32,34 @@ extern unsigned long elf_hwcap; #define RISCV_ISA_EXT_BASE 26 /* - * This enum represent the logical ID for each multi-letter RISC-V ISA extension. + * These macros represent the logical ID for each multi-letter RISC-V ISA extension. * The logical ID should start from RISCV_ISA_EXT_BASE and must not exceed * RISCV_ISA_EXT_MAX. 0-25 range is reserved for single letter * extensions while all the multi-letter extensions should define the next * available logical extension id. * Entries are sorted alphabetically. */ -enum riscv_isa_ext_id { - RISCV_ISA_EXT_SSCOFPMF = RISCV_ISA_EXT_BASE, - RISCV_ISA_EXT_SSTC, - RISCV_ISA_EXT_SVINVAL, - RISCV_ISA_EXT_SVPBMT, - RISCV_ISA_EXT_ZICBOM, - RISCV_ISA_EXT_ZIHINTPAUSE, - RISCV_ISA_EXT_ID_MAX +#define RISCV_ISA_EXT_SSCOFPMF 26 +#define RISCV_ISA_EXT_SSTC 27 +#define RISCV_ISA_EXT_SVINVAL 28 +#define RISCV_ISA_EXT_SVPBMT 29 +#define RISCV_ISA_EXT_ZICBOM 30 +#define RISCV_ISA_EXT_ZIHINTPAUSE 31 + +#ifndef __ASSEMBLY__ +#include +/* + * This yields a mask that user programs can use to figure out what + * instruction set this cpu supports. + */ +#define ELF_HWCAP (elf_hwcap) + +enum { + CAP_HWCAP = 1, }; -static_assert(RISCV_ISA_EXT_ID_MAX <= RISCV_ISA_EXT_MAX); + +extern unsigned long elf_hwcap; + /* * This enum represents the logical ID for each RISC-V ISA extension static From 4bf8860760d9930019e4839fb4e8adc1e0bf1f91 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:47 +0800 Subject: [PATCH 04/13] riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions riscv_cpufeature_patch_func() currently only scans a limited set of cpufeatures, explicitly defined with macros. Extend it to probe for all ISA extensions. Signed-off-by: Jisheng Zhang Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-5-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/errata_list.h | 9 ++-- arch/riscv/kernel/cpufeature.c | 64 ++++------------------------ 2 files changed, 11 insertions(+), 62 deletions(-) diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h index 4180312d2a701..274c6f8896020 100644 --- a/arch/riscv/include/asm/errata_list.h +++ b/arch/riscv/include/asm/errata_list.h @@ -7,6 +7,7 @@ #include #include +#include #include #ifdef CONFIG_ERRATA_SIFIVE @@ -22,10 +23,6 @@ #define ERRATA_THEAD_NUMBER 3 #endif -#define CPUFEATURE_SVPBMT 0 -#define CPUFEATURE_ZICBOM 1 -#define CPUFEATURE_NUMBER 2 - #ifdef __ASSEMBLY__ #define ALT_INSN_FAULT(x) \ @@ -55,7 +52,7 @@ asm(ALTERNATIVE("sfence.vma %0", "sfence.vma", SIFIVE_VENDOR_ID, \ #define ALT_SVPBMT(_val, prot) \ asm(ALTERNATIVE_2("li %0, 0\t\nnop", \ "li %0, %1\t\nslli %0,%0,%3", 0, \ - CPUFEATURE_SVPBMT, CONFIG_RISCV_ISA_SVPBMT, \ + RISCV_ISA_EXT_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) \ @@ -129,7 +126,7 @@ asm volatile(ALTERNATIVE_2( \ "add a0, a0, %0\n\t" \ "2:\n\t" \ "bltu a0, %2, 3b\n\t" \ - "nop", 0, CPUFEATURE_ZICBOM, CONFIG_RISCV_ISA_ZICBOM, \ + "nop", 0, RISCV_ISA_EXT_ZICBOM, CONFIG_RISCV_ISA_ZICBOM, \ "mv a0, %1\n\t" \ "j 2f\n\t" \ "3:\n\t" \ diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 59e20cad1b3dc..6193f401f0c54 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -276,59 +276,11 @@ void __init riscv_fill_hwcap(void) } #ifdef CONFIG_RISCV_ALTERNATIVE -static bool __init_or_module cpufeature_probe_svpbmt(unsigned int stage) -{ - if (!IS_ENABLED(CONFIG_RISCV_ISA_SVPBMT)) - return false; - - if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) - return false; - - return riscv_isa_extension_available(NULL, SVPBMT); -} - -static bool __init_or_module cpufeature_probe_zicbom(unsigned int stage) -{ - if (!IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM)) - return false; - - if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) - return false; - - if (!riscv_isa_extension_available(NULL, ZICBOM)) - return false; - - return true; -} - -/* - * Probe presence of individual extensions. - * - * This code may also be executed before kernel relocation, so we cannot use - * addresses generated by the address-of operator as they won't be valid in - * this context. - * Tests, unless otherwise required, are to be added in alphabetical order. - */ -static u32 __init_or_module cpufeature_probe(unsigned int stage) -{ - u32 cpu_req_feature = 0; - - if (cpufeature_probe_svpbmt(stage)) - cpu_req_feature |= BIT(CPUFEATURE_SVPBMT); - - if (cpufeature_probe_zicbom(stage)) - cpu_req_feature |= BIT(CPUFEATURE_ZICBOM); - - return cpu_req_feature; -} - void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, struct alt_entry *end, unsigned int stage) { - u32 cpu_req_feature = cpufeature_probe(stage); struct alt_entry *alt; - u32 tmp; if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) return; @@ -336,18 +288,18 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, for (alt = begin; alt < end; alt++) { if (alt->vendor_id != 0) continue; - if (alt->errata_id >= CPUFEATURE_NUMBER) { - WARN(1, "This feature id:%d is not in kernel cpufeature list", + if (alt->errata_id >= RISCV_ISA_EXT_MAX) { + WARN(1, "This extension id:%d is not in ISA extension list", alt->errata_id); continue; } - tmp = (1U << alt->errata_id); - if (cpu_req_feature & tmp) { - patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); - riscv_alternative_fix_offsets(alt->old_ptr, alt->alt_len, - alt->old_ptr - alt->alt_ptr); - } + if (!__riscv_isa_extension_available(NULL, alt->errata_id)) + continue; + + patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); + riscv_alternative_fix_offsets(alt->old_ptr, alt->alt_len, + alt->old_ptr - alt->alt_ptr); } } #endif From bdda5d554e43f21d06e0b7485e6241ca46c26b99 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:48 +0800 Subject: [PATCH 05/13] riscv: introduce riscv_has_extension_[un]likely() Generally, riscv ISA extensions are fixed for any specific hardware platform, so a hart's features won't change after booting. This chacteristic makes it straightforward to use a static branch to check if a specific ISA extension is supported or not to optimize performance. However, some ISA extensions such as SVPBMT and ZICBOM are handled via. the alternative sequences. Basically, for ease of maintenance, we prefer to use static branches in C code, but recently, Samuel found that the static branch usage in cpu_relax() breaks building with CONFIG_CC_OPTIMIZE_FOR_SIZE[1]. As Samuel pointed out, "Having a static branch in cpu_relax() is problematic because that function is widely inlined, including in some quite complex functions like in the VDSO. A quick measurement shows this static branch is responsible by itself for around 40% of the jump table." Samuel's findings pointed out one of a few downsides of static branches usage in C code to handle ISA extensions detected at boot time: static branch's metadata in the __jump_table section, which is not discarded after ISA extensions are finalized, wastes some space. I want to try to solve the issue for all possible dynamic handling of ISA extensions at boot time. Inspired by Mark[2], this patch introduces riscv_has_extension_*() helpers, which work like static branches but are patched using alternatives, thus the metadata can be freed after patching. Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ [1] Link: https://lore.kernel.org/linux-arm-kernel/20220912162210.3626215-8-mark.rutland@arm.com/ [2] Signed-off-by: Jisheng Zhang Reviewed-by: Andrew Jones Acked-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-6-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 37 ++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 8e0ee841fa778..411ef0fb5c4b6 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -8,6 +8,7 @@ #ifndef _ASM_RISCV_HWCAP_H #define _ASM_RISCV_HWCAP_H +#include #include #include #include @@ -99,6 +100,42 @@ static __always_inline int riscv_isa_ext2key(int num) } } +static __always_inline bool +riscv_has_extension_likely(const unsigned long ext) +{ + compiletime_assert(ext < RISCV_ISA_EXT_MAX, + "ext must be < RISCV_ISA_EXT_MAX"); + + asm_volatile_goto( + ALTERNATIVE("j %l[l_no]", "nop", 0, %[ext], 1) + : + : [ext] "i" (ext) + : + : l_no); + + return true; +l_no: + return false; +} + +static __always_inline bool +riscv_has_extension_unlikely(const unsigned long ext) +{ + compiletime_assert(ext < RISCV_ISA_EXT_MAX, + "ext must be < RISCV_ISA_EXT_MAX"); + + asm_volatile_goto( + ALTERNATIVE("nop", "j %l[l_yes]", 0, %[ext], 1) + : + : [ext] "i" (ext) + : + : l_yes); + + return false; +l_yes: + return true; +} + unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap); #define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext) From 702e64550b12cf36089672af8f110660da7f847e Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:49 +0800 Subject: [PATCH 06/13] riscv: fpu: switch has_fpu() to riscv_has_extension_likely() Switch has_fpu() from static branch to the new helper riscv_has_extension_likely(). Signed-off-by: Jisheng Zhang Reviewed-by: Andrew Jones Reviewed-by: Heiko Stuebner Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-7-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/switch_to.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h index 11463489fec67..60f8ca01d36e4 100644 --- a/arch/riscv/include/asm/switch_to.h +++ b/arch/riscv/include/asm/switch_to.h @@ -59,7 +59,8 @@ static inline void __switch_to_aux(struct task_struct *prev, static __always_inline bool has_fpu(void) { - return static_branch_likely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_FPU]); + return riscv_has_extension_likely(RISCV_ISA_EXT_f) || + riscv_has_extension_likely(RISCV_ISA_EXT_d); } #else static __always_inline bool has_fpu(void) { return false; } From e0c267e03b0c77c9ac79ac08eada41ba8eb1b95f Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:50 +0800 Subject: [PATCH 07/13] riscv: module: move find_section to module.h Move find_section() to module.h so that the implementation can be shared by the alternatives code. This will allow us to use alternatives in the vdso. Reviewed-by: Conor Dooley Reviewed-by: Andrew Jones Signed-off-by: Jisheng Zhang Link: https://lore.kernel.org/r/20230128172856.3814-8-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/module.h | 16 ++++++++++++++++ arch/riscv/kernel/module.c | 15 --------------- 2 files changed, 16 insertions(+), 15 deletions(-) diff --git a/arch/riscv/include/asm/module.h b/arch/riscv/include/asm/module.h index 76aa96a9fc081..0f3baaa6a9a85 100644 --- a/arch/riscv/include/asm/module.h +++ b/arch/riscv/include/asm/module.h @@ -5,6 +5,7 @@ #define _ASM_RISCV_MODULE_H #include +#include struct module; unsigned long module_emit_got_entry(struct module *mod, unsigned long val); @@ -111,4 +112,19 @@ static inline struct plt_entry *get_plt_entry(unsigned long val, #endif /* CONFIG_MODULE_SECTIONS */ +static inline const Elf_Shdr *find_section(const Elf_Ehdr *hdr, + const Elf_Shdr *sechdrs, + const char *name) +{ + const Elf_Shdr *s, *se; + const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; + + for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) { + if (strcmp(name, secstrs + s->sh_name) == 0) + return s; + } + + return NULL; +} + #endif /* _ASM_RISCV_MODULE_H */ diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 91fe16bfaa07c..76f4b9c2ec5b6 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -429,21 +429,6 @@ void *module_alloc(unsigned long size) } #endif -static const Elf_Shdr *find_section(const Elf_Ehdr *hdr, - const Elf_Shdr *sechdrs, - const char *name) -{ - const Elf_Shdr *s, *se; - const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - - for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) { - if (strcmp(name, secstrs + s->sh_name) == 0) - return s; - } - - return NULL; -} - int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) From 1bc400ffb52b460eedc51ebd9b7753b7f2314878 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Sun, 29 Jan 2023 01:28:51 +0800 Subject: [PATCH 08/13] riscv: module: Add ADD16 and SUB16 rela types To prepare for 16-bit relocation types to be emitted in alternatives add support for ADD16 and SUB16. Signed-off-by: Andrew Jones Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-9-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/module.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 76f4b9c2ec5b6..7c651d55fcbd2 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -268,6 +268,13 @@ static int apply_r_riscv_align_rela(struct module *me, u32 *location, return -EINVAL; } +static int apply_r_riscv_add16_rela(struct module *me, u32 *location, + Elf_Addr v) +{ + *(u16 *)location += (u16)v; + return 0; +} + static int apply_r_riscv_add32_rela(struct module *me, u32 *location, Elf_Addr v) { @@ -282,6 +289,13 @@ static int apply_r_riscv_add64_rela(struct module *me, u32 *location, return 0; } +static int apply_r_riscv_sub16_rela(struct module *me, u32 *location, + Elf_Addr v) +{ + *(u16 *)location -= (u16)v; + return 0; +} + static int apply_r_riscv_sub32_rela(struct module *me, u32 *location, Elf_Addr v) { @@ -315,8 +329,10 @@ static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, [R_RISCV_CALL] = apply_r_riscv_call_rela, [R_RISCV_RELAX] = apply_r_riscv_relax_rela, [R_RISCV_ALIGN] = apply_r_riscv_align_rela, + [R_RISCV_ADD16] = apply_r_riscv_add16_rela, [R_RISCV_ADD32] = apply_r_riscv_add32_rela, [R_RISCV_ADD64] = apply_r_riscv_add64_rela, + [R_RISCV_SUB16] = apply_r_riscv_sub16_rela, [R_RISCV_SUB32] = apply_r_riscv_sub32_rela, [R_RISCV_SUB64] = apply_r_riscv_sub64_rela, }; From 8d23e94a443388e81c42ea7e476a5d79c1c795c9 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:52 +0800 Subject: [PATCH 09/13] riscv: switch to relative alternative entries Instead of using absolute addresses for both the old instrucions and the alternative instructions, use offsets relative to the alt_entry values. So this not only cuts the size of the alternative entry, but also meets the prerequisite for patching alternatives in the vDSO, since absolute alternative entries are subject to dynamic relocation, which is incompatible with the vDSO building. Signed-off-by: Jisheng Zhang Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-10-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/errata/sifive/errata.c | 3 ++- arch/riscv/errata/thead/errata.c | 11 ++++++++--- arch/riscv/include/asm/alternative-macros.h | 20 ++++++++++---------- arch/riscv/include/asm/alternative.h | 17 +++++++++++------ arch/riscv/kernel/cpufeature.c | 8 +++++--- 5 files changed, 36 insertions(+), 23 deletions(-) diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c index 1031038423e74..ef9a4eec0dba6 100644 --- a/arch/riscv/errata/sifive/errata.c +++ b/arch/riscv/errata/sifive/errata.c @@ -107,7 +107,8 @@ void __init_or_module sifive_errata_patch_func(struct alt_entry *begin, tmp = (1U << alt->errata_id); if (cpu_req_errata & tmp) { - patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); + patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt), + alt->alt_len); cpu_apply_errata |= tmp; } } diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c index fac5742d1c1e6..c0bea5c94128a 100644 --- a/arch/riscv/errata/thead/errata.c +++ b/arch/riscv/errata/thead/errata.c @@ -87,6 +87,7 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al struct alt_entry *alt; u32 cpu_req_errata = thead_errata_probe(stage, archid, impid); u32 tmp; + void *oldptr, *altptr; for (alt = begin; alt < end; alt++) { if (alt->vendor_id != THEAD_VENDOR_ID) @@ -96,12 +97,16 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al tmp = (1U << alt->errata_id); if (cpu_req_errata & tmp) { + oldptr = ALT_OLD_PTR(alt); + altptr = ALT_ALT_PTR(alt); + /* 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); + memcpy((void *)__pa_symbol(oldptr), + (void *)__pa_symbol(altptr), + alt->alt_len); else - patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); + patch_text_nosync(oldptr, altptr, alt->alt_len); } } diff --git a/arch/riscv/include/asm/alternative-macros.h b/arch/riscv/include/asm/alternative-macros.h index 7226e2462584b..cc6a81c00f2f0 100644 --- a/arch/riscv/include/asm/alternative-macros.h +++ b/arch/riscv/include/asm/alternative-macros.h @@ -7,11 +7,11 @@ #ifdef __ASSEMBLY__ .macro ALT_ENTRY oldptr newptr vendor_id errata_id new_len - RISCV_PTR \oldptr - RISCV_PTR \newptr - REG_ASM \vendor_id - REG_ASM \new_len - .word \errata_id + .4byte \oldptr - . + .4byte \newptr - . + .2byte \vendor_id + .2byte \new_len + .4byte \errata_id .endm .macro ALT_NEW_CONTENT vendor_id, errata_id, enable = 1, new_c : vararg @@ -59,11 +59,11 @@ #include #define ALT_ENTRY(oldptr, newptr, vendor_id, errata_id, newlen) \ - RISCV_PTR " " oldptr "\n" \ - RISCV_PTR " " newptr "\n" \ - REG_ASM " " vendor_id "\n" \ - REG_ASM " " newlen "\n" \ - ".word " errata_id "\n" + ".4byte ((" oldptr ") - .) \n" \ + ".4byte ((" newptr ") - .) \n" \ + ".2byte " vendor_id "\n" \ + ".2byte " newlen "\n" \ + ".4byte " errata_id "\n" #define ALT_NEW_CONTENT(vendor_id, errata_id, enable, new_c) \ ".if " __stringify(enable) " == 1\n" \ diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h index 1bd4027d34caa..b8648d4f2ac1a 100644 --- a/arch/riscv/include/asm/alternative.h +++ b/arch/riscv/include/asm/alternative.h @@ -23,6 +23,11 @@ #define RISCV_ALTERNATIVES_MODULE 1 /* alternatives applied during module-init */ #define RISCV_ALTERNATIVES_EARLY_BOOT 2 /* alternatives applied before mmu start */ +/* add the relative offset to the address of the offset to get the absolute address */ +#define __ALT_PTR(a, f) ((void *)&(a)->f + (a)->f) +#define ALT_OLD_PTR(a) __ALT_PTR(a, old_offset) +#define ALT_ALT_PTR(a) __ALT_PTR(a, alt_offset) + void __init apply_boot_alternatives(void); void __init apply_early_boot_alternatives(void); void apply_module_alternatives(void *start, size_t length); @@ -31,12 +36,12 @@ void riscv_alternative_fix_offsets(void *alt_ptr, unsigned int len, int patch_offset); struct alt_entry { - void *old_ptr; /* address of original instruciton or data */ - void *alt_ptr; /* address of replacement instruction or data */ - unsigned long vendor_id; /* cpu vendor id */ - unsigned long alt_len; /* The replacement size */ - unsigned int errata_id; /* The errata id */ -} __packed; + s32 old_offset; /* offset relative to original instruction or data */ + s32 alt_offset; /* offset relative to replacement instruction or data */ + u16 vendor_id; /* cpu vendor id */ + u16 alt_len; /* The replacement size */ + u32 errata_id; /* The errata id */ +}; struct errata_checkfunc_id { unsigned long vendor_id; diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 6193f401f0c54..18ea518f9e68d 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -281,6 +281,7 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, unsigned int stage) { struct alt_entry *alt; + void *oldptr, *altptr; if (stage == RISCV_ALTERNATIVES_EARLY_BOOT) return; @@ -297,9 +298,10 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, if (!__riscv_isa_extension_available(NULL, alt->errata_id)) continue; - patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len); - riscv_alternative_fix_offsets(alt->old_ptr, alt->alt_len, - alt->old_ptr - alt->alt_ptr); + oldptr = ALT_OLD_PTR(alt); + altptr = ALT_ALT_PTR(alt); + patch_text_nosync(oldptr, altptr, alt->alt_len); + riscv_alternative_fix_offsets(oldptr, alt->alt_len, oldptr - altptr); } } #endif From cabfd146b371462ed480a968f98eb0c2c80e3c8a Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:53 +0800 Subject: [PATCH 10/13] riscv: alternative: patch alternatives in the vDSO Make it possible to use alternatives in the vDSO, so that better implementations can be used if possible. Signed-off-by: Jisheng Zhang Reviewed-by: Guo Ren Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20230128172856.3814-11-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/vdso.h | 4 ++++ arch/riscv/kernel/alternative.c | 29 +++++++++++++++++++++++++++++ arch/riscv/kernel/vdso.c | 5 ----- arch/riscv/kernel/vdso/vdso.lds.S | 7 +++++++ 4 files changed, 40 insertions(+), 5 deletions(-) diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h index a7644f46d0e56..f891478829a52 100644 --- a/arch/riscv/include/asm/vdso.h +++ b/arch/riscv/include/asm/vdso.h @@ -28,8 +28,12 @@ #define COMPAT_VDSO_SYMBOL(base, name) \ (void __user *)((unsigned long)(base) + compat__vdso_##name##_offset) +extern char compat_vdso_start[], compat_vdso_end[]; + #endif /* CONFIG_COMPAT */ +extern char vdso_start[], vdso_end[]; + #endif /* !__ASSEMBLY__ */ #endif /* CONFIG_MMU */ diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c index 3d4f1f32c7f6c..fc341b69bf620 100644 --- a/arch/riscv/kernel/alternative.c +++ b/arch/riscv/kernel/alternative.c @@ -11,7 +11,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -160,6 +162,31 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin, stage); } +#ifdef CONFIG_MMU +static void __init apply_vdso_alternatives(void) +{ + const Elf_Ehdr *hdr; + const Elf_Shdr *shdr; + const Elf_Shdr *alt; + struct alt_entry *begin, *end; + + hdr = (Elf_Ehdr *)vdso_start; + shdr = (void *)hdr + hdr->e_shoff; + alt = find_section(hdr, shdr, ".alternative"); + if (!alt) + return; + + begin = (void *)hdr + alt->sh_offset, + end = (void *)hdr + alt->sh_offset + alt->sh_size, + + _apply_alternatives((struct alt_entry *)begin, + (struct alt_entry *)end, + RISCV_ALTERNATIVES_BOOT); +} +#else +static void __init apply_vdso_alternatives(void) { } +#endif + void __init apply_boot_alternatives(void) { /* If called on non-boot cpu things could go wrong */ @@ -168,6 +195,8 @@ void __init apply_boot_alternatives(void) _apply_alternatives((struct alt_entry *)__alt_start, (struct alt_entry *)__alt_end, RISCV_ALTERNATIVES_BOOT); + + apply_vdso_alternatives(); } /* diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c index e410275918ac4..4e631c098f4d2 100644 --- a/arch/riscv/kernel/vdso.c +++ b/arch/riscv/kernel/vdso.c @@ -22,11 +22,6 @@ struct vdso_data { }; #endif -extern char vdso_start[], vdso_end[]; -#ifdef CONFIG_COMPAT -extern char compat_vdso_start[], compat_vdso_end[]; -#endif - enum vvar_pages { VVAR_DATA_PAGE_OFFSET, VVAR_TIMENS_PAGE_OFFSET, diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S index 150b1a572e619..4a06066332902 100644 --- a/arch/riscv/kernel/vdso/vdso.lds.S +++ b/arch/riscv/kernel/vdso/vdso.lds.S @@ -40,6 +40,13 @@ SECTIONS . = 0x800; .text : { *(.text .text.*) } :text + . = ALIGN(4); + .alternative : { + __alt_start = .; + *(.alternative) + __alt_end = .; + } + .data : { *(.got.plt) *(.got) *(.data .data.* .gnu.linkonce.d.*) From 95bc69a47be2d5cdccf40ba3f23c99e9a6c57597 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:54 +0800 Subject: [PATCH 11/13] riscv: cpu_relax: switch to riscv_has_extension_likely() Switch cpu_relax() from static branch to the new helper riscv_has_extension_likely() Signed-off-by: Jisheng Zhang Reviewed-by: Andrew Jones Reviewed-by: Heiko Stuebner Reviewed-by: Guo Ren Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230128172856.3814-12-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/vdso/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/vdso/processor.h b/arch/riscv/include/asm/vdso/processor.h index fa70cfe507aa1..edf0e25e43d1b 100644 --- a/arch/riscv/include/asm/vdso/processor.h +++ b/arch/riscv/include/asm/vdso/processor.h @@ -10,7 +10,7 @@ static inline void cpu_relax(void) { - if (!static_branch_likely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_ZIHINTPAUSE])) { + if (!riscv_has_extension_likely(RISCV_ISA_EXT_ZIHINTPAUSE)) { #ifdef __riscv_muldiv int dummy; /* In lieu of a halt instruction, induce a long-latency stall. */ From e8ad17d2b5f38e595d597a3e2419d6d7cc727b17 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Sun, 29 Jan 2023 01:28:55 +0800 Subject: [PATCH 12/13] riscv: KVM: Switch has_svinval() to riscv_has_extension_unlikely() Switch has_svinval() from static branch to the new helper riscv_has_extension_unlikely(). Signed-off-by: Andrew Jones Reviewed-by: Guo Ren Acked-by: Anup Patel Link: https://lore.kernel.org/r/20230128172856.3814-13-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kvm/tlb.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/riscv/kvm/tlb.c b/arch/riscv/kvm/tlb.c index 309d79b3e5cd5..aa3da18ad8733 100644 --- a/arch/riscv/kvm/tlb.c +++ b/arch/riscv/kvm/tlb.c @@ -15,8 +15,7 @@ #include #include -#define has_svinval() \ - static_branch_unlikely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_SVINVAL]) +#define has_svinval() riscv_has_extension_unlikely(RISCV_ISA_EXT_SVINVAL) void kvm_riscv_local_hfence_gvma_vmid_gpa(unsigned long vmid, gpa_t gpa, gpa_t gpsz, From 03966594e1170303c037b0cded35c464a13a4a45 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 29 Jan 2023 01:28:56 +0800 Subject: [PATCH 13/13] riscv: remove riscv_isa_ext_keys[] array and related usage All users have switched to riscv_has_extension_*, remove unused definitions, vars and related setting code. Signed-off-by: Jisheng Zhang Reviewed-by: Andrew Jones Reviewed-by: Heiko Stuebner Reviewed-by: Conor Dooley Reviewed-by: Guo Ren Link: https://lore.kernel.org/r/20230128172856.3814-14-jszhang@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 32 -------------------------------- arch/riscv/kernel/cpufeature.c | 9 --------- 2 files changed, 41 deletions(-) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 411ef0fb5c4b6..7936ae6f7bdfb 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -61,20 +61,6 @@ enum { extern unsigned long elf_hwcap; - -/* - * This enum represents the logical ID for each RISC-V ISA extension static - * keys. We can use static key to optimize code path if some ISA extensions - * are available. - * Entries are sorted alphabetically. - */ -enum riscv_isa_ext_key { - RISCV_ISA_EXT_KEY_FPU, /* For 'F' and 'D' */ - RISCV_ISA_EXT_KEY_SVINVAL, - RISCV_ISA_EXT_KEY_ZIHINTPAUSE, - RISCV_ISA_EXT_KEY_MAX, -}; - struct riscv_isa_ext_data { /* Name of the extension displayed to userspace via /proc/cpuinfo */ char uprop[RISCV_ISA_EXT_NAME_LEN_MAX]; @@ -82,24 +68,6 @@ struct riscv_isa_ext_data { unsigned int isa_ext_id; }; -extern struct static_key_false riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_MAX]; - -static __always_inline int riscv_isa_ext2key(int num) -{ - switch (num) { - case RISCV_ISA_EXT_f: - return RISCV_ISA_EXT_KEY_FPU; - case RISCV_ISA_EXT_d: - return RISCV_ISA_EXT_KEY_FPU; - case RISCV_ISA_EXT_SVINVAL: - return RISCV_ISA_EXT_KEY_SVINVAL; - case RISCV_ISA_EXT_ZIHINTPAUSE: - return RISCV_ISA_EXT_KEY_ZIHINTPAUSE; - default: - return -EINVAL; - } -} - static __always_inline bool riscv_has_extension_likely(const unsigned long ext) { diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 18ea518f9e68d..a4f737bc75304 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -29,9 +29,6 @@ unsigned long elf_hwcap __read_mostly; /* Host ISA bitmap */ static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly; -DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX); -EXPORT_SYMBOL(riscv_isa_ext_keys); - /** * riscv_isa_extension_base() - Get base extension word * @@ -267,12 +264,6 @@ void __init riscv_fill_hwcap(void) if (elf_hwcap & BIT_MASK(i)) print_str[j++] = (char)('a' + i); pr_info("riscv: ELF capabilities %s\n", print_str); - - for_each_set_bit(i, riscv_isa, RISCV_ISA_EXT_MAX) { - j = riscv_isa_ext2key(i); - if (j >= 0) - static_branch_enable(&riscv_isa_ext_keys[j]); - } } #ifdef CONFIG_RISCV_ALTERNATIVE