Re: [PATCH v4 13/21] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2021-01-23 14:05:42
Also in:
kvmarm, lkml
On Mon, Jan 18, 2021 at 09:45:25AM +0000, Marc Zyngier wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index fe0130d6c0ff..80a5f423444e 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h@@ -814,6 +814,9 @@ static inline unsigned int get_vmid_bits(u64 mmfr1) return 8; } +extern u64 id_aa64mmfr1_val; +extern u64 id_aa64mmfr1_mask; + u32 get_kvm_ipa_limit(void); void dump_cpu_features(void);diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 48a011935d8c..5b9343d2e9f0 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c@@ -555,6 +555,9 @@ static const struct arm64_ftr_bits ftr_raz[] = { #define ARM64_FTR_REG(id, table) ARM64_FTR_REG_OVERRIDE(id, table, NULL, NULL) +u64 id_aa64mmfr1_val; +u64 id_aa64mmfr1_mask; + static const struct __ftr_reg_entry { u32 sys_id; struct arm64_ftr_reg *reg;@@ -602,7 +605,8 @@ static const struct __ftr_reg_entry { /* Op1 = 0, CRn = 0, CRm = 7 */ ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0), - ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1), + ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1, + &id_aa64mmfr1_val, &id_aa64mmfr1_mask), ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2), /* Op1 = 0, CRn = 1, CRm = 2 */diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c index 392f93b67103..75d9845f489b 100644 --- a/arch/arm64/kernel/idreg-override.c +++ b/arch/arm64/kernel/idreg-override.c@@ -10,6 +10,7 @@ #include <linux/libfdt.h> #include <asm/cacheflush.h> +#include <asm/cpufeature.h> #include <asm/setup.h> struct reg_desc {@@ -22,7 +23,18 @@ struct reg_desc { } fields[]; }; +static const struct reg_desc mmfr1 __initdata = { + .name = "id_aa64mmfr1", + .val = &id_aa64mmfr1_val, + .mask = &id_aa64mmfr1_mask, + .fields = { + { "vh", ID_AA64MMFR1_VHE_SHIFT }, + {} + }, +}; + static const struct reg_desc * const regs[] __initdata = { + &mmfr1, };
I'm ok in principle with how all these link together. I wonder however if we could skip the separate u64 variables and just have a struct reg_override with val and mask u64 rather than pointers. The ARM64_FTR_REG_OVERRIDE macro takes a pointer to this new struct reg_override and can access val/mask directly. Some 'const' may need to be dropped. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel