Files
linux/arch/riscv/include/asm/errata_list.h
Jisheng Zhang a4ff64edf9 riscv: errata: thead: use riscv_nonstd_cache_ops for CMO
Previously, we use alternative mechanism to dynamically patch
the CMO operations for THEAD C906/C910 during boot for performance
reason. But as pointed out by Arnd, "there is already a significant
cost in accessing the invalidated cache lines afterwards, which is
likely going to be much higher than the cost of an indirect branch".
And indeed, there's no performance difference with GMAC and EMMC per
my test on Sipeed Lichee Pi 4A board.

Use riscv_nonstd_cache_ops for THEAD C906/C910 CMO to simplify
the alternative code, and to acchieve Arnd's goal -- "I think
moving the THEAD ops at the same level as all nonstandard operations
makes sense, but I'd still leave CMO as an explicit fast path that
avoids the indirect branch. This seems like the right thing to do both
for readability and for platforms on which the indirect branch has a
noticeable overhead."

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231114143338.2406-2-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-10 09:54:26 -08:00

127 lines
3.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2021 Sifive.
*/
#ifndef ASM_ERRATA_LIST_H
#define ASM_ERRATA_LIST_H
#include <asm/alternative.h>
#include <asm/csr.h>
#include <asm/insn-def.h>
#include <asm/hwcap.h>
#include <asm/vendorid_list.h>
#ifdef CONFIG_ERRATA_ANDES
#define ERRATA_ANDESTECH_NO_IOCP 0
#define ERRATA_ANDESTECH_NUMBER 1
#endif
#ifdef CONFIG_ERRATA_SIFIVE
#define ERRATA_SIFIVE_CIP_453 0
#define ERRATA_SIFIVE_CIP_1200 1
#define ERRATA_SIFIVE_NUMBER 2
#endif
#ifdef CONFIG_ERRATA_THEAD
#define ERRATA_THEAD_PBMT 0
#define ERRATA_THEAD_PMU 1
#define ERRATA_THEAD_NUMBER 2
#endif
#ifdef __ASSEMBLY__
#define ALT_INSN_FAULT(x) \
ALTERNATIVE(__stringify(RISCV_PTR do_trap_insn_fault), \
__stringify(RISCV_PTR sifive_cip_453_insn_fault_trp), \
SIFIVE_VENDOR_ID, ERRATA_SIFIVE_CIP_453, \
CONFIG_ERRATA_SIFIVE_CIP_453)
#define ALT_PAGE_FAULT(x) \
ALTERNATIVE(__stringify(RISCV_PTR do_page_fault), \
__stringify(RISCV_PTR sifive_cip_453_page_fault_trp), \
SIFIVE_VENDOR_ID, ERRATA_SIFIVE_CIP_453, \
CONFIG_ERRATA_SIFIVE_CIP_453)
#else /* !__ASSEMBLY__ */
#define ALT_FLUSH_TLB_PAGE(x) \
asm(ALTERNATIVE("sfence.vma %0", "sfence.vma", SIFIVE_VENDOR_ID, \
ERRATA_SIFIVE_CIP_1200, CONFIG_ERRATA_SIFIVE_CIP_1200) \
: : "r" (addr) : "memory")
/*
* _val is marked as "will be overwritten", so need to set it to 0
* in the default case.
*/
#define ALT_SVPBMT_SHIFT 61
#define ALT_THEAD_PBMT_SHIFT 59
#define ALT_SVPBMT(_val, prot) \
asm(ALTERNATIVE_2("li %0, 0\t\nnop", \
"li %0, %1\t\nslli %0,%0,%3", 0, \
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) \
: "I"(prot##_SVPBMT >> ALT_SVPBMT_SHIFT), \
"I"(prot##_THEAD >> ALT_THEAD_PBMT_SHIFT), \
"I"(ALT_SVPBMT_SHIFT), \
"I"(ALT_THEAD_PBMT_SHIFT))
#ifdef CONFIG_ERRATA_THEAD_PBMT
/*
* IO/NOCACHE memory types are handled together with svpbmt,
* so on T-Head chips, check if no other memory type is set,
* and set the non-0 PMA type if applicable.
*/
#define ALT_THEAD_PMA(_val) \
asm volatile(ALTERNATIVE( \
__nops(7), \
"li t3, %1\n\t" \
"slli t3, t3, %3\n\t" \
"and t3, %0, t3\n\t" \
"bne t3, zero, 2f\n\t" \
"li t3, %2\n\t" \
"slli t3, t3, %3\n\t" \
"or %0, %0, t3\n\t" \
"2:", THEAD_VENDOR_ID, \
ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \
: "+r"(_val) \
: "I"(_PAGE_MTMASK_THEAD >> ALT_THEAD_PBMT_SHIFT), \
"I"(_PAGE_PMA_THEAD >> ALT_THEAD_PBMT_SHIFT), \
"I"(ALT_THEAD_PBMT_SHIFT) \
: "t3")
#else
#define ALT_THEAD_PMA(_val)
#endif
#define ALT_CMO_OP(_op, _start, _size, _cachesize) \
asm volatile(ALTERNATIVE( \
__nops(5), \
"mv a0, %1\n\t" \
"j 2f\n\t" \
"3:\n\t" \
CBO_##_op(a0) \
"add a0, a0, %0\n\t" \
"2:\n\t" \
"bltu a0, %2, 3b\n\t", \
0, RISCV_ISA_EXT_ZICBOM, CONFIG_RISCV_ISA_ZICBOM) \
: : "r"(_cachesize), \
"r"((unsigned long)(_start) & ~((_cachesize) - 1UL)), \
"r"((unsigned long)(_start) + (_size)) \
: "a0")
#define THEAD_C9XX_RV_IRQ_PMU 17
#define THEAD_C9XX_CSR_SCOUNTEROF 0x5c5
#define ALT_SBI_PMU_OVERFLOW(__ovl) \
asm volatile(ALTERNATIVE( \
"csrr %0, " __stringify(CSR_SSCOUNTOVF), \
"csrr %0, " __stringify(THEAD_C9XX_CSR_SCOUNTEROF), \
THEAD_VENDOR_ID, ERRATA_THEAD_PMU, \
CONFIG_ERRATA_THEAD_PMU) \
: "=r" (__ovl) : \
: "memory")
#endif /* __ASSEMBLY__ */
#endif