[PATCH v2 3/7] x86/resctrl: Detect Smart Data Cache Injection Allocation Enforcement

From: Babu Moger
Date: Wed Dec 18 2024 - 16:40:03 EST


Introduce io_alloc_capable in struct resctrl_cache to detect SDCIAE
(L3 Smart Data Cache Injection Allocation Enforcement) feature.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v2: Changed sdciae_capable to io_alloc_capable to make it generic feature.
Also moved the io_alloc_capable in struct resctrl_cache.
---
arch/x86/kernel/cpu/resctrl/core.c | 7 +++++++
include/linux/resctrl.h | 4 ++++
2 files changed, 11 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index c2450cd52511..39e110033d96 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -306,6 +306,11 @@ static void rdt_get_cdp_config(int level)
rdt_resources_all[level].r_resctrl.cdp_capable = true;
}

+static void rdt_get_sdciae_alloc_cfg(struct rdt_resource *r)
+{
+ r->cache.io_alloc_capable = true;
+}
+
static void rdt_get_cdp_l3_config(void)
{
rdt_get_cdp_config(RDT_RESOURCE_L3);
@@ -931,6 +936,8 @@ static __init bool get_rdt_alloc_resources(void)
rdt_get_cache_alloc_cfg(1, r);
if (rdt_cpu_has(X86_FEATURE_CDP_L3))
rdt_get_cdp_l3_config();
+ if (rdt_cpu_has(X86_FEATURE_SDCIAE))
+ rdt_get_sdciae_alloc_cfg(r);
ret = true;
}
if (rdt_cpu_has(X86_FEATURE_CAT_L2)) {
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index d94abba1c716..5837acff7442 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -129,6 +129,8 @@ struct rdt_mon_domain {
* @arch_has_sparse_bitmasks: True if a bitmask like f00f is valid.
* @arch_has_per_cpu_cfg: True if QOS_CFG register for this cache
* level has CPU scope.
+ * @io_alloc_capable: Smart Data Cache Injection Allocation Enforcement
+ * capable (SDCIAE).
*/
struct resctrl_cache {
unsigned int cbm_len;
@@ -136,6 +138,7 @@ struct resctrl_cache {
unsigned int shareable_bits;
bool arch_has_sparse_bitmasks;
bool arch_has_per_cpu_cfg;
+ bool io_alloc_capable;
};

/**
@@ -202,6 +205,7 @@ enum resctrl_scope {
* @evt_list: List of monitoring events
* @fflags: flags to choose base and info files
* @cdp_capable: Is the CDP feature available on this resource
+ * @sdciae_capable: Is SDCIAE feature available on this resource
*/
struct rdt_resource {
int rid;
--
2.34.1