6f4eea9046
Introduce the "alternative" mechanism from ARM64 and x86 to apply the CPU vendors' errata solution at runtime. The main purpose of this patch is to provide a framework. Therefore, the implementation is quite basic for now so that some scenarios could not use this schemei, such as patching code to a module, relocating the patching code and heterogeneous CPU topology. Users could use the macro ALTERNATIVE to apply an errata to the existing code flow. In the macro ALTERNATIVE, users need to specify the manufacturer information(vendorid, archid, and impid) for this errata. Therefore, kernel will know this errata is suitable for which CPU core. During the booting procedure, kernel will select the errata required by the CPU core and then patch it. It means that the kernel only applies the errata to the specified CPU core. In this case, the vendor's errata does not affect each other at runtime. The above patching procedure only occurs during the booting phase, so we only take the overhead of the "alternative" mechanism once. This "alternative" mechanism is enabled by default to ensure that all required errata will be applied. However, users can disable this feature by the Kconfig "CONFIG_RISCV_ERRATA_ALTERNATIVE". Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
71 lines
1.5 KiB
C
71 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2015 Regents of the University of California
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*/
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#ifndef _ASM_RISCV_ASM_H
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#define _ASM_RISCV_ASM_H
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#ifdef __ASSEMBLY__
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#define __ASM_STR(x) x
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#else
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#define __ASM_STR(x) #x
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#endif
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#if __riscv_xlen == 64
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#define __REG_SEL(a, b) __ASM_STR(a)
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#elif __riscv_xlen == 32
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#define __REG_SEL(a, b) __ASM_STR(b)
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#else
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#error "Unexpected __riscv_xlen"
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#endif
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#define REG_L __REG_SEL(ld, lw)
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#define REG_S __REG_SEL(sd, sw)
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#define REG_SC __REG_SEL(sc.d, sc.w)
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#define REG_ASM __REG_SEL(.dword, .word)
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#define SZREG __REG_SEL(8, 4)
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#define LGREG __REG_SEL(3, 2)
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#if __SIZEOF_POINTER__ == 8
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#ifdef __ASSEMBLY__
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#define RISCV_PTR .dword
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#define RISCV_SZPTR 8
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#define RISCV_LGPTR 3
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#else
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#define RISCV_PTR ".dword"
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#define RISCV_SZPTR "8"
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#define RISCV_LGPTR "3"
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#endif
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#elif __SIZEOF_POINTER__ == 4
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#ifdef __ASSEMBLY__
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#define RISCV_PTR .word
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#define RISCV_SZPTR 4
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#define RISCV_LGPTR 2
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#else
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#define RISCV_PTR ".word"
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#define RISCV_SZPTR "4"
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#define RISCV_LGPTR "2"
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#endif
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#else
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#error "Unexpected __SIZEOF_POINTER__"
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#endif
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#if (__SIZEOF_INT__ == 4)
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#define RISCV_INT __ASM_STR(.word)
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#define RISCV_SZINT __ASM_STR(4)
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#define RISCV_LGINT __ASM_STR(2)
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#else
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#error "Unexpected __SIZEOF_INT__"
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#endif
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#if (__SIZEOF_SHORT__ == 2)
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#define RISCV_SHORT __ASM_STR(.half)
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#define RISCV_SZSHORT __ASM_STR(2)
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#define RISCV_LGSHORT __ASM_STR(1)
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#else
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#error "Unexpected __SIZEOF_SHORT__"
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#endif
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#endif /* _ASM_RISCV_ASM_H */
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