Files
linux/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
Babu Moger 556d2892aa x86,fs/resctrl: Implement "io_alloc" enable/disable handlers
"io_alloc" is the generic name of the new resctrl feature that enables system
software to configure the portion of cache allocated for I/O traffic. On AMD
systems, "io_alloc" resctrl feature is backed by AMD's L3 Smart Data Cache
Injection Allocation Enforcement (SDCIAE).

Introduce the architecture-specific functions that resctrl fs should call to
enable, disable, or check status of the "io_alloc" feature. Change SDCIAE state
by setting (to enable) or clearing (to disable) bit 1 of
MSR_IA32_L3_QOS_EXT_CFG on all logical processors within the cache domain.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://patch.msgid.link/9e9070100c320eab5368e088a3642443dee95ed7.1762995456.git.babu.moger@amd.com
2025-11-21 22:35:22 +01:00

134 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Resource Director Technology(RDT)
* - Cache Allocation code.
*
* Copyright (C) 2016 Intel Corporation
*
* Authors:
* Fenghua Yu <fenghua.yu@intel.com>
* Tony Luck <tony.luck@intel.com>
*
* More information about RDT be found in the Intel (R) x86 Architecture
* Software Developer Manual June 2016, volume 3, section 17.17.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpu.h>
#include "internal.h"
int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d,
u32 closid, enum resctrl_conf_type t, u32 cfg_val)
{
struct rdt_hw_ctrl_domain *hw_dom = resctrl_to_arch_ctrl_dom(d);
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
u32 idx = resctrl_get_config_index(closid, t);
struct msr_param msr_param;
if (!cpumask_test_cpu(smp_processor_id(), &d->hdr.cpu_mask))
return -EINVAL;
hw_dom->ctrl_val[idx] = cfg_val;
msr_param.res = r;
msr_param.dom = d;
msr_param.low = idx;
msr_param.high = idx + 1;
hw_res->msr_update(&msr_param);
return 0;
}
int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
{
struct resctrl_staged_config *cfg;
struct rdt_hw_ctrl_domain *hw_dom;
struct msr_param msr_param;
struct rdt_ctrl_domain *d;
enum resctrl_conf_type t;
u32 idx;
/* Walking r->domains, ensure it can't race with cpuhp */
lockdep_assert_cpus_held();
list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
hw_dom = resctrl_to_arch_ctrl_dom(d);
msr_param.res = NULL;
for (t = 0; t < CDP_NUM_TYPES; t++) {
cfg = &hw_dom->d_resctrl.staged_config[t];
if (!cfg->have_new_ctrl)
continue;
idx = resctrl_get_config_index(closid, t);
if (cfg->new_ctrl == hw_dom->ctrl_val[idx])
continue;
hw_dom->ctrl_val[idx] = cfg->new_ctrl;
if (!msr_param.res) {
msr_param.low = idx;
msr_param.high = msr_param.low + 1;
msr_param.res = r;
msr_param.dom = d;
} else {
msr_param.low = min(msr_param.low, idx);
msr_param.high = max(msr_param.high, idx + 1);
}
}
if (msr_param.res)
smp_call_function_any(&d->hdr.cpu_mask, rdt_ctrl_update, &msr_param, 1);
}
return 0;
}
u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
u32 closid, enum resctrl_conf_type type)
{
struct rdt_hw_ctrl_domain *hw_dom = resctrl_to_arch_ctrl_dom(d);
u32 idx = resctrl_get_config_index(closid, type);
return hw_dom->ctrl_val[idx];
}
bool resctrl_arch_get_io_alloc_enabled(struct rdt_resource *r)
{
return resctrl_to_arch_res(r)->sdciae_enabled;
}
static void resctrl_sdciae_set_one_amd(void *arg)
{
bool *enable = arg;
if (*enable)
msr_set_bit(MSR_IA32_L3_QOS_EXT_CFG, SDCIAE_ENABLE_BIT);
else
msr_clear_bit(MSR_IA32_L3_QOS_EXT_CFG, SDCIAE_ENABLE_BIT);
}
static void _resctrl_sdciae_enable(struct rdt_resource *r, bool enable)
{
struct rdt_ctrl_domain *d;
/* Walking r->ctrl_domains, ensure it can't race with cpuhp */
lockdep_assert_cpus_held();
/* Update MSR_IA32_L3_QOS_EXT_CFG MSR on all the CPUs in all domains */
list_for_each_entry(d, &r->ctrl_domains, hdr.list)
on_each_cpu_mask(&d->hdr.cpu_mask, resctrl_sdciae_set_one_amd, &enable, 1);
}
int resctrl_arch_io_alloc_enable(struct rdt_resource *r, bool enable)
{
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
if (hw_res->r_resctrl.cache.io_alloc_capable &&
hw_res->sdciae_enabled != enable) {
_resctrl_sdciae_enable(r, enable);
hw_res->sdciae_enabled = enable;
}
return 0;
}