On Fri, Nov 16, 2018 at 08:54:43PM +0000, Moger, Babu wrote: > Enables QOS feature on AMD. >From Documentation/process/submitting-patches.rst: "Describe your changes in imperative mood, e.g. "make xyzzy do frotz" instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy to do frotz", as if you are giving orders to the codebase to change its behaviour." > Following QoS sub-features are supported in AMD if the underlying > hardware supports it. > - L3 Cache allocation enforcement > - L3 Cache occupancy monitoring > - L3 Code-Data Prioritization support > - Memory Bandwidth Enforcement(Allocation) > > The specification for this feature is available at > https://developer.amd.com/wp-content/resources/56375.pdf I hope that URL is stable. > There are differences in the way some of the features are implemented. > Separate those functions and add those as vendor specific functions. > The major difference is in MBA feature. > - AMD uses CPUID leaf 0x80000020 to initialize the MBA features. > - AMD uses direct bandwidth value instead of delay based on bandwidth > values. > - MSR register base addresses are different for MBA. > - Also AMD allows non-contiguous L3 cache bit masks. > > Adds following functions to take care of the differences. > rdt_get_mem_config_amd : MBA initialization function > parse_bw_amd : Bandwidth parsing > mba_wrmsr_amd: Writes bandwidth value > cbm_validate_amd : L3 cache bitmask validation This paragraph is not needed - what you do is visible in the patch itself. > Signed-off-by: Babu Moger <babu.moger@xxxxxxx> > --- > arch/x86/kernel/cpu/resctrl.c | 68 +++++++++++++++++++++- > arch/x86/kernel/cpu/resctrl.h | 5 ++ > arch/x86/kernel/cpu/resctrl_ctrlmondata.c | 70 +++++++++++++++++++++++ > 3 files changed, 141 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/cpu/resctrl.c b/arch/x86/kernel/cpu/resctrl.c > index 3f26c7c114e7..0d700ab7fcf9 100644 > --- a/arch/x86/kernel/cpu/resctrl.c > +++ b/arch/x86/kernel/cpu/resctrl.c > @@ -61,6 +61,9 @@ mba_wrmsr_intel(struct rdt_domain *d, struct msr_param *m, > struct rdt_resource *r); > static void > cat_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r); > +static void > +mba_wrmsr_amd(struct rdt_domain *d, struct msr_param *m, > + struct rdt_resource *r); > > #define domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].domains) > > @@ -280,6 +283,31 @@ static bool rdt_get_mem_config(struct rdt_resource *r) > return true; > } > > +static bool rdt_get_mem_config_amd(struct rdt_resource *r) > +{ > + union cpuid_0x10_3_eax eax; > + union cpuid_0x10_x_edx edx; > + u32 ebx, ecx; > + > + cpuid_count(0x80000020, 1, &eax.full, &ebx, &ecx, &edx.full); > + r->num_closid = edx.split.cos_max + 1; > + r->default_ctrl = MAX_MBA_BW_AMD; > + > + /* AMD does not use delay. Set delay_linear to false by default */ You don't need to write in the comment *what* you do - that's obvious. "AMD does not use delay" is more than enough. > + r->membw.delay_linear = false; > + > + /* FIX ME - May need to be read from MSR */ FIX ME? > + r->membw.min_bw = 0; > + r->membw.bw_gran = 1; > + /* Max value is 2048, Data width should be 4 in decimal */ > + r->data_width = 4; > + > + r->alloc_capable = true; > + r->alloc_enabled = true; > + > + return true; > +} > + > static void rdt_get_cache_alloc_cfg(int idx, struct rdt_resource *r) > { > union cpuid_0x10_1_eax eax; > @@ -339,6 +367,16 @@ static int get_cache_id(int cpu, int level) > return -1; > } > > +static void > +mba_wrmsr_amd(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r) > +{ > + unsigned int i; > + > + /* Write the bw values for mba. */ That's an obvious comment. Drop it. > + for (i = m->low; i < m->high; i++) > + wrmsrl(r->msr_base + i, d->ctrl_val[i]); > +} > + > /* > * Map the memory b/w percentage value to delay values > * that can be written to QOS_MSRs. > @@ -792,8 +830,12 @@ static bool __init rdt_cpu_has(int flag) > > static __init bool rdt_mba_config(void) > { > - if (rdt_cpu_has(X86_FEATURE_MBA)) > - return rdt_get_mem_config(&rdt_resources_all[RDT_RESOURCE_MBA]); > + if (rdt_cpu_has(X86_FEATURE_MBA)) { Save yourself an indentation level: if (!rdt_cpu_has(X86_FEATURE_MBA)) return false; if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) ... > + return rdt_get_mem_config(&rdt_resources_all[RDT_RESOURCE_MBA]); > + else if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) > + return rdt_get_mem_config_amd(&rdt_resources_all[RDT_RESOURCE_MBA]); > + } > > return false; > } ... > diff --git a/arch/x86/kernel/cpu/resctrl.h b/arch/x86/kernel/cpu/resctrl.h > index 102bcffbefd7..54ba21b7de2c 100644 > --- a/arch/x86/kernel/cpu/resctrl.h > +++ b/arch/x86/kernel/cpu/resctrl.h > @@ -11,6 +11,7 @@ > #define IA32_L3_CBM_BASE 0xc90 > #define IA32_L2_CBM_BASE 0xd10 > #define IA32_MBA_THRTL_BASE 0xd50 > +#define IA32_MBA_BW_BASE 0xc0000200 MSR_... > > #define IA32_QM_CTR 0x0c8e > #define IA32_QM_EVTSEL 0x0c8d > @@ -34,6 +35,7 @@ > #define MAX_MBA_BW 100u > #define MBA_IS_LINEAR 0x4 > #define MBA_MAX_MBPS U32_MAX > +#define MAX_MBA_BW_AMD 0x800 > > #define RMID_VAL_ERROR BIT_ULL(63) > #define RMID_VAL_UNAVAIL BIT_ULL(62) > @@ -448,6 +450,8 @@ int parse_cbm(struct rdt_parse_data *data, struct rdt_resource *r, > struct rdt_domain *d); > int parse_bw_intel(struct rdt_parse_data *data, struct rdt_resource *r, > struct rdt_domain *d); > +int parse_bw_amd(struct rdt_parse_data *data, struct rdt_resource *r, > + struct rdt_domain *d); > > extern struct mutex rdtgroup_mutex; > > @@ -579,5 +583,6 @@ void cqm_handle_limbo(struct work_struct *work); > bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d); > void __check_limbo(struct rdt_domain *d, bool force_free); > bool cbm_validate_intel(char *buf, u32 *data, struct rdt_resource *r); > +bool cbm_validate_amd(char *buf, u32 *data, struct rdt_resource *r); > > #endif /* _ASM_X86_RESCTRL_H */ > diff --git a/arch/x86/kernel/cpu/resctrl_ctrlmondata.c b/arch/x86/kernel/cpu/resctrl_ctrlmondata.c > index 71aa1d971430..b6ceb4db9322 100644 > --- a/arch/x86/kernel/cpu/resctrl_ctrlmondata.c > +++ b/arch/x86/kernel/cpu/resctrl_ctrlmondata.c > @@ -28,6 +28,52 @@ > #include <linux/slab.h> > #include "resctrl.h" > > +/* > + * Check whether MBA bandwidth percentage value is correct. The value is > + * checked against the minimum and max bandwidth values specified by the Either write "min" and "max" or write them both out fully. > + * hardware. The allocated bandwidth percentage is rounded to the next > + * control step available on the hardware. > + */ > +static bool bw_validate_amd(char *buf, unsigned long *data, > + struct rdt_resource *r) > +{ > + unsigned long bw; > + int ret; > + > + ret = kstrtoul(buf, 10, &bw); > + if (ret) { > + rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf); > + return false; > + } > + > + if (bw < r->membw.min_bw || bw > r->default_ctrl) { > + rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw, > + r->membw.min_bw, r->default_ctrl); > + return false; > + } > + > + *data = roundup(bw, (unsigned long)r->membw.bw_gran); > + return true; > +} > + > +int parse_bw_amd(struct rdt_parse_data *data, struct rdt_resource *r, > + struct rdt_domain *d) > +{ > + unsigned long bw_val; > + > + if (d->have_new_ctrl) { > + rdt_last_cmd_printf("duplicate domain %d\n", d->id); Start with a capital letter: "Duplicate domain..." And looking at the rest, some of them start with a capital letter and some of them not. Please unify that in a separate patch. > + return -EINVAL; > + } > + > + if (!bw_validate_amd(data->buf, &bw_val, r)) > + return -EINVAL; <---- newline here. > + d->new_ctrl = bw_val; > + d->have_new_ctrl = true; > + > + return 0; > +} > + > /* > * Check whether MBA bandwidth percentage value is correct. The value is > * checked against the minimum and max bandwidth values specified by the -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.
