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b684001a5e
During review the naming of the function-pointer was called confusing as the vendor id is just one of three inputs for the patching and indeed it serves no real purpose, as with recent changes the function pointer is not a static global element anymore, so drop the "vendor_" prefix. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20220526205646.258337-4-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
118 lines
3.1 KiB
C
118 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* alternative runtime patching
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* inspired by the ARM64 and x86 version
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*
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* Copyright (C) 2021 Sifive.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/cpu.h>
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#include <linux/uaccess.h>
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#include <asm/alternative.h>
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#include <asm/sections.h>
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#include <asm/vendorid_list.h>
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#include <asm/sbi.h>
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#include <asm/csr.h>
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struct cpu_manufacturer_info_t {
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unsigned long vendor_id;
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unsigned long arch_id;
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unsigned long imp_id;
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void (*patch_func)(struct alt_entry *begin, struct alt_entry *end,
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unsigned long archid, unsigned long impid,
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unsigned int stage);
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};
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static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_info_t *cpu_mfr_info)
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{
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#ifdef CONFIG_RISCV_M_MODE
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cpu_mfr_info->vendor_id = csr_read(CSR_MVENDORID);
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cpu_mfr_info->arch_id = csr_read(CSR_MARCHID);
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cpu_mfr_info->imp_id = csr_read(CSR_MIMPID);
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#else
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cpu_mfr_info->vendor_id = sbi_get_mvendorid();
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cpu_mfr_info->arch_id = sbi_get_marchid();
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cpu_mfr_info->imp_id = sbi_get_mimpid();
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#endif
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switch (cpu_mfr_info->vendor_id) {
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#ifdef CONFIG_ERRATA_SIFIVE
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case SIFIVE_VENDOR_ID:
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cpu_mfr_info->patch_func = sifive_errata_patch_func;
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break;
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#endif
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#ifdef CONFIG_ERRATA_THEAD
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case THEAD_VENDOR_ID:
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cpu_mfr_info->patch_func = thead_errata_patch_func;
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break;
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#endif
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default:
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cpu_mfr_info->patch_func = NULL;
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}
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}
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/*
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* This is called very early in the boot process (directly after we run
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* a feature detect on the boot CPU). No need to worry about other CPUs
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* here.
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*/
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static void __init_or_module _apply_alternatives(struct alt_entry *begin,
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struct alt_entry *end,
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unsigned int stage)
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{
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struct cpu_manufacturer_info_t cpu_mfr_info;
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riscv_fill_cpu_mfr_info(&cpu_mfr_info);
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riscv_cpufeature_patch_func(begin, end, stage);
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if (!cpu_mfr_info.patch_func)
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return;
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cpu_mfr_info.patch_func(begin, end,
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cpu_mfr_info.arch_id,
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cpu_mfr_info.imp_id,
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stage);
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}
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void __init apply_boot_alternatives(void)
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{
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/* If called on non-boot cpu things could go wrong */
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WARN_ON(smp_processor_id() != 0);
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_apply_alternatives((struct alt_entry *)__alt_start,
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(struct alt_entry *)__alt_end,
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RISCV_ALTERNATIVES_BOOT);
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}
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/*
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* apply_early_boot_alternatives() is called from setup_vm() with MMU-off.
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*
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* Following requirements should be honoured for it to work correctly:
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* 1) It should use PC-relative addressing for accessing kernel symbols.
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* To achieve this we always use GCC cmodel=medany.
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* 2) The compiler instrumentation for FTRACE will not work for setup_vm()
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* so disable compiler instrumentation when FTRACE is enabled.
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*
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* Currently, the above requirements are honoured by using custom CFLAGS
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* for alternative.o in kernel/Makefile.
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*/
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void __init apply_early_boot_alternatives(void)
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{
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#ifdef CONFIG_RISCV_ALTERNATIVE_EARLY
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_apply_alternatives((struct alt_entry *)__alt_start,
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(struct alt_entry *)__alt_end,
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RISCV_ALTERNATIVES_EARLY_BOOT);
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#endif
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}
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#ifdef CONFIG_MODULES
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void apply_module_alternatives(void *start, size_t length)
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{
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_apply_alternatives((struct alt_entry *)start,
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(struct alt_entry *)(start + length),
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RISCV_ALTERNATIVES_MODULE);
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}
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#endif
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