From: James Morse <james.morse@arm.com> mainline inclusion from mainline-v6.15-rc1 commit 634ebb98b929443ea1a5502c93f26d01aedbd5c8 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IC35SV -------------------------------- __rdt_get_mem_config_amd() and __get_mem_config_intel() both use the default_ctrl property as a maximum value. This is because the MBA schema works differently between these platforms. Doing this complicates determining whether the default_ctrl property belongs to the arch code, or can be derived from the schema format. Deriving the maximum or default value from the schema format would avoid the architecture code having to tell resctrl such obvious things as the maximum percentage is 100, and the maximum bitmap is all ones. Maximum bandwidth is always going to vary per platform. Add max_bw as a special case. This is currently used for the maximum MBA percentage on Intel platforms, but can be removed from the architecture code if 'percentage' becomes a schema format resctrl supports directly. This value isn't needed for other schema formats. This will allow the default_ctrl to be generated from the schema properties when it is needed. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Fenghua Yu <fenghuay@nvidia.com> Reviewed-by: Babu Moger <babu.moger@amd.com> Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64 Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Amit Singh Tomar <amitsinght@marvell.com> # arm64 Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> # arm64 Tested-by: Babu Moger <babu.moger@amd.com> Link: https://lore.kernel.org/r/20250311183715.16445-8-james.morse@arm.com Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- arch/x86/kernel/cpu/resctrl/core.c | 2 ++ fs/resctrl/ctrlmondata.c | 4 ++-- include/linux/resctrl.h | 2 ++ 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 1454aa1a1f84..44379d4568b4 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -200,6 +200,7 @@ static __init bool __get_mem_config_intel(struct rdt_resource *r) hw_res->num_closid = edx.split.cos_max + 1; max_delay = eax.split.max_delay + 1; r->default_ctrl = MAX_MBA_BW; + r->membw.max_bw = MAX_MBA_BW; r->membw.arch_needs_linear = true; if (ecx & MBA_IS_LINEAR) { r->membw.delay_linear = true; @@ -236,6 +237,7 @@ static __init bool __rdt_get_mem_config_amd(struct rdt_resource *r) cpuid_count(0x80000020, subleaf, &eax, &ebx, &ecx, &edx); hw_res->num_closid = edx + 1; r->default_ctrl = 1 << eax; + r->membw.max_bw = 1 << eax; /* AMD does not use delay */ r->membw.delay_linear = false; diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index 025fbf91dfc6..0c7a6f37405d 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -62,10 +62,10 @@ static bool bw_validate(char *buf, u32 *data, struct rdt_resource *r) return true; } - if (bw < r->membw.min_bw || bw > r->default_ctrl) { + if (bw < r->membw.min_bw || bw > r->membw.max_bw) { rdt_last_cmd_printf("%s value %d out of range [%d,%d]\n", r->name, bw, r->membw.min_bw, - r->default_ctrl); + r->membw.max_bw); return false; } diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 3f73064769fa..7700f7019d77 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -163,6 +163,7 @@ enum membw_throttle_mode { /** * struct resctrl_membw - Memory bandwidth allocation related data * @min_bw: Minimum memory bandwidth percentage user can request + * @max_bw: Maximum memory bandwidth value, used as the reset value * @bw_gran: Granularity at which the memory bandwidth is allocated * @delay_linear: True if memory B/W delay is in linear scale * @arch_needs_linear: True if we can't configure non-linear resources @@ -175,6 +176,7 @@ enum membw_throttle_mode { */ struct resctrl_membw { u32 min_bw; + u32 max_bw; u32 bw_gran; u32 delay_linear; bool arch_needs_linear; -- 2.25.1