diff options
| author | Vincent Chen <vincent.chen@sifive.com> | 2021-03-22 22:26:03 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmerdabbelt@google.com> | 2021-04-26 08:24:55 -0700 |
| commit | 6f4eea90465ad0cd5f3d041b9b2c728426f2b8d4 (patch) | |
| tree | 7a7f210cfc5003dd70c0fba9e100cb7a8efea5df /arch/riscv/include/asm/csr.h | |
| parent | 183787c6fcc2c793ec96e946a4fdd8cd0e6d7aa0 (diff) | |
riscv: Introduce alternative mechanism to apply errata solution
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>
Diffstat (limited to 'arch/riscv/include/asm/csr.h')
| -rw-r--r-- | arch/riscv/include/asm/csr.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h index caadfc1d7487..87ac65696871 100644 --- a/arch/riscv/include/asm/csr.h +++ b/arch/riscv/include/asm/csr.h @@ -115,6 +115,9 @@ #define CSR_MIP 0x344 #define CSR_PMPCFG0 0x3a0 #define CSR_PMPADDR0 0x3b0 +#define CSR_MVENDORID 0xf11 +#define CSR_MARCHID 0xf12 +#define CSR_MIMPID 0xf13 #define CSR_MHARTID 0xf14 #ifdef CONFIG_RISCV_M_MODE |