From 8dda2baa976a3b4caa9c6e52a861adb0431f7dbf Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Fri, 17 Jul 2020 08:48:26 -0600 Subject: [PATCH] x86: mtrr: Add support for writing to MTRRs on any CPU To enable support for the 'mtrr' command, add a way to perform MTRR operations on selected CPUs. This works by setting up a little 'operation' structure and sending it around the CPUs for action. Signed-off-by: Simon Glass Reviewed-by: Bin Meng Reviewed-by: Wolfgang Wallner --- arch/x86/cpu/mtrr.c | 81 +++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/mtrr.h | 21 ++++++++++ cmd/x86/mtrr.c | 6 +-- 3 files changed, 105 insertions(+), 3 deletions(-) diff --git a/arch/x86/cpu/mtrr.c b/arch/x86/cpu/mtrr.c index 5c567551e5..2468d88a80 100644 --- a/arch/x86/cpu/mtrr.c +++ b/arch/x86/cpu/mtrr.c @@ -221,3 +221,84 @@ int mtrr_set_next_var(uint type, uint64_t start, uint64_t size) return 0; } + +/** enum mtrr_opcode - supported operations for mtrr_do_oper() */ +enum mtrr_opcode { + MTRR_OP_SET, + MTRR_OP_SET_VALID, +}; + +/** + * struct mtrr_oper - An MTRR operation to perform on a CPU + * + * @opcode: Indicates operation to perform + * @reg: MTRR reg number to select (0-7, -1 = all) + * @valid: Valid value to write for MTRR_OP_SET_VALID + * @base: Base value to write for MTRR_OP_SET + * @mask: Mask value to write for MTRR_OP_SET + */ +struct mtrr_oper { + enum mtrr_opcode opcode; + int reg; + bool valid; + u64 base; + u64 mask; +}; + +static void mtrr_do_oper(void *arg) +{ + struct mtrr_oper *oper = arg; + u64 mask; + + switch (oper->opcode) { + case MTRR_OP_SET_VALID: + mask = native_read_msr(MTRR_PHYS_MASK_MSR(oper->reg)); + if (oper->valid) + mask |= MTRR_PHYS_MASK_VALID; + else + mask &= ~MTRR_PHYS_MASK_VALID; + wrmsrl(MTRR_PHYS_MASK_MSR(oper->reg), mask); + break; + case MTRR_OP_SET: + wrmsrl(MTRR_PHYS_BASE_MSR(oper->reg), oper->base); + wrmsrl(MTRR_PHYS_MASK_MSR(oper->reg), oper->mask); + break; + } +} + +static int mtrr_start_op(int cpu_select, struct mtrr_oper *oper) +{ + struct mtrr_state state; + int ret; + + mtrr_open(&state, true); + ret = mp_run_on_cpus(cpu_select, mtrr_do_oper, oper); + mtrr_close(&state, true); + if (ret) + return log_msg_ret("run", ret); + + return 0; +} + +int mtrr_set_valid(int cpu_select, int reg, bool valid) +{ + struct mtrr_oper oper; + + oper.opcode = MTRR_OP_SET_VALID; + oper.reg = reg; + oper.valid = valid; + + return mtrr_start_op(cpu_select, &oper); +} + +int mtrr_set(int cpu_select, int reg, u64 base, u64 mask) +{ + struct mtrr_oper oper; + + oper.opcode = MTRR_OP_SET; + oper.reg = reg; + oper.base = base; + oper.mask = mask; + + return mtrr_start_op(cpu_select, &oper); +} diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h index e1f1a44643..48db1dd82f 100644 --- a/arch/x86/include/asm/mtrr.h +++ b/arch/x86/include/asm/mtrr.h @@ -159,6 +159,27 @@ int mtrr_set_next_var(uint type, uint64_t base, uint64_t size); */ void mtrr_read_all(struct mtrr_info *info); +/** + * mtrr_set_valid() - Set the valid flag for a selected MTRR and CPU(s) + * + * @cpu_select: Selected CPUs (either a CPU number or MP_SELECT_...) + * @reg: MTRR register to write (0-7) + * @valid: Valid flag to write + * @return 0 on success, -ve on error + */ +int mtrr_set_valid(int cpu_select, int reg, bool valid); + +/** + * mtrr_set() - Set the valid flag for a selected MTRR and CPU(s) + * + * @cpu_select: Selected CPUs (either a CPU number or MP_SELECT_...) + * @reg: MTRR register to write (0-7) + * @base: Base address and MTRR_BASE_TYPE_MASK + * @mask: Mask and MTRR_PHYS_MASK_VALID + * @return 0 on success, -ve on error + */ +int mtrr_set(int cpu_select, int reg, u64 base, u64 mask); + #endif #if ((CONFIG_XIP_ROM_SIZE & (CONFIG_XIP_ROM_SIZE - 1)) != 0) diff --git a/cmd/x86/mtrr.c b/cmd/x86/mtrr.c index f357f58767..46ef6a2830 100644 --- a/cmd/x86/mtrr.c +++ b/cmd/x86/mtrr.c @@ -96,7 +96,7 @@ static int do_mtrr_set(uint reg, int argc, char *const argv[]) return 0; } -static int mtrr_set_valid(int reg, bool valid) +static int mtrr_set_valid_(int reg, bool valid) { struct mtrr_state state; uint64_t mask; @@ -134,9 +134,9 @@ static int do_mtrr(struct cmd_tbl *cmdtp, int flag, int argc, return CMD_RET_USAGE; } if (*cmd == 'e') - return mtrr_set_valid(reg, true); + return mtrr_set_valid_(reg, true); else if (*cmd == 'd') - return mtrr_set_valid(reg, false); + return mtrr_set_valid_(reg, false); else if (*cmd == 's') return do_mtrr_set(reg, argc - 1, argv + 1); else -- 2.39.5