From: James Morse <james.morse@arm.com> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/... --------------------------- prefetch_disable_bits is set by rdtgroup_locksetup_enter() from an arch code value, then read by the arch code. Instead of exporting this value, make resctrl_arch_get_prefetch_disable_bits() set it so that the other arch-code helpers can use the cached-value. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c index 09adf0e3e753..20e6c99db25b 100644 --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c @@ -85,6 +85,8 @@ static const struct class pseudo_lock_class = { */ u64 resctrl_arch_get_prefetch_disable_bits(void) { + prefetch_disable_bits = 0; + if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL || boot_cpu_data.x86 != 6) return 0; @@ -100,7 +102,8 @@ u64 resctrl_arch_get_prefetch_disable_bits(void) * 3 DCU IP Prefetcher Disable (R/W) * 63:4 Reserved */ - return 0xF; + prefetch_disable_bits = 0xF; + break; case INTEL_FAM6_ATOM_GOLDMONT: case INTEL_FAM6_ATOM_GOLDMONT_PLUS: /* @@ -111,10 +114,11 @@ u64 resctrl_arch_get_prefetch_disable_bits(void) * 2 DCU Hardware Prefetcher Disable (R/W) * 63:3 Reserved */ - return 0x5; + prefetch_disable_bits = 0x5; + break; } - return 0; + return prefetch_disable_bits; } /** @@ -715,8 +719,7 @@ int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp) * Not knowing the bits to disable prefetching implies that this * platform does not support Cache Pseudo-Locking. */ - prefetch_disable_bits = resctrl_arch_get_prefetch_disable_bits(); - if (prefetch_disable_bits == 0) { + if (resctrl_arch_get_prefetch_disable_bits() == 0) { rdt_last_cmd_puts("Pseudo-locking not supported\n"); return -EINVAL; } -- 2.25.1