[v4,09/13] riscv: switch to relative alternative entries

Message ID	20230115154953.831-10-jszhang@kernel.org
State	Accepted
Headers	show Return-Path: <kvm-riscv-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org> From: Jisheng Zhang <jszhang@kernel.org> To: Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Anup Patel <anup@brainfault.org>, Atish Patra <atishp@atishpatra.org>, Heiko Stuebner <heiko@sntech.de>, Conor Dooley <conor.dooley@microchip.com>, Andrew Jones <ajones@ventanamicro.com> Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org Subject: [PATCH v4 09/13] riscv: switch to relative alternative entries Date: Sun, 15 Jan 2023 23:49:49 +0800 Message-Id: <20230115154953.831-10-jszhang@kernel.org> In-Reply-To: <20230115154953.831-1-jszhang@kernel.org> References: <20230115154953.831-1-jszhang@kernel.org> MIME-Version: 1.0 preview: 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 [...] Content analysis details: (-5.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [2604:1380:40e1:4800:0:0:0:1 listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.2 DKIMWL_WL_HIGH DKIMwl.org - High trust sender Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kvm-riscv" <kvm-riscv-bounces@lists.infradead.org> Errors-To: kvm-riscv-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org
Series	riscv: improve boot time isa extensions handling \| expand [v4,00/13] riscv: improve boot time isa extensions handling [v4,01/13] riscv: fix jal offsets in patched alternatives [v4,02/13] riscv: move riscv_noncoherent_supported() out of ZICBOM probe [v4,03/13] riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier [v4,04/13] riscv: hwcap: make ISA extension ids can be used in asm [v4,05/13] riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions [v4,06/13] riscv: introduce riscv_has_extension_[un]likely() [v4,07/13] riscv: fpu: switch has_fpu() to riscv_has_extension_likely() [v4,08/13] riscv: module: move find_section to module.h [v4,09/13] riscv: switch to relative alternative entries [v4,10/13] riscv: alternative: patch alternatives in the vDSO [v4,11/13] riscv: cpu_relax: switch to riscv_has_extension_likely() [v4,12/13] riscv: KVM: Switch has_svinval() to riscv_has_extension_unlikely() [v4,13/13] riscv: remove riscv_isa_ext_keys[] array and related usage

diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c index 1031038423e7..ef9a4eec0dba 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 fac5742d1c1e..c0bea5c94128 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 7226e2462584..cc6a81c00f2f 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 <linux/stringify.h> #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 1bd4027d34ca..b8648d4f2ac1 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 6db8b31d9149..50cfbbbecaa7 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -280,6 +280,7 @@ 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; @@ -293,12 +294,13 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin, continue; } + oldptr = ALT_OLD_PTR(alt); + altptr = ALT_ALT_PTR(alt); 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); + patch_text_nosync(oldptr, altptr, alt->alt_len); + riscv_alternative_fix_offsets(oldptr, alt->alt_len, oldptr - altptr); } } #endif

[v4,09/13] riscv: switch to relative alternative entries

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