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authorFenghua Yu <fenghua.yu@intel.com>2017-07-26 01:39:04 +0300
committerThomas Gleixner <tglx@linutronix.de>2017-08-01 23:41:30 +0300
commit0dd2d7494cd818d06a2ae1cd840cd62124a2d25e (patch)
tree9021ddec571d72febd154583ad8dee5d3f9adc6f /arch/x86/kernel/cpu
parente33026831bdb5f051499fec6a606f79fe1f94cc8 (diff)
downloadlinux-0dd2d7494cd818d06a2ae1cd840cd62124a2d25e.tar.xz
x86/intel_rdt: Show bitmask of shareable resource with other executing units
CPUID.(EAX=0x10, ECX=res#):EBX[31:0] reports a bit mask for a resource. Each set bit within the length of the CBM indicates the corresponding unit of the resource allocation may be used by other entities in the platform (e.g. an integrated graphics engine or hardware units outside the processor core and have direct access to the resource). Each cleared bit within the length of the CBM indicates the corresponding allocation unit can be configured to implement a priority-based allocation scheme without interference with other hardware agents in the system. Bits outside the length of the CBM are reserved. More details on the bit mask are described in x86 Software Developer's Manual. The bitmask is shown in "info" directory for each resource. It's up to user to decide how to use the bitmask within a CBM in a partition to share or isolate a resource with other executing units. Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: vikas.shivappa@linux.intel.com Link: http://lkml.kernel.org/r/20170725223904.12996-1-tony.luck@intel.com
Diffstat (limited to 'arch/x86/kernel/cpu')
-rw-r--r--arch/x86/kernel/cpu/intel_rdt.c2
-rw-r--r--arch/x86/kernel/cpu/intel_rdt.h3
-rw-r--r--arch/x86/kernel/cpu/intel_rdt_rdtgroup.c16
3 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index de26aa7971d4..da4f3898d517 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -193,6 +193,7 @@ static inline bool cache_alloc_hsw_probe(void)
r->num_closid = 4;
r->default_ctrl = max_cbm;
r->cache.cbm_len = 20;
+ r->cache.shareable_bits = 0xc0000;
r->cache.min_cbm_bits = 2;
r->alloc_capable = true;
r->alloc_enabled = true;
@@ -260,6 +261,7 @@ static void rdt_get_cache_alloc_cfg(int idx, struct rdt_resource *r)
r->num_closid = edx.split.cos_max + 1;
r->cache.cbm_len = eax.split.cbm_len + 1;
r->default_ctrl = BIT_MASK(eax.split.cbm_len + 1) - 1;
+ r->cache.shareable_bits = ebx & r->default_ctrl;
r->data_width = (r->cache.cbm_len + 3) / 4;
r->alloc_capable = true;
r->alloc_enabled = true;
diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 94e488af082e..4040bf1a075c 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -227,12 +227,15 @@ struct msr_param {
* @cbm_idx_offset: Offset of CBM index. CBM index is computed by:
* closid * cbm_idx_multi + cbm_idx_offset
* in a cache bit mask
+ * @shareable_bits: Bitmask of shareable resource with other
+ * executing entities
*/
struct rdt_cache {
unsigned int cbm_len;
unsigned int min_cbm_bits;
unsigned int cbm_idx_mult;
unsigned int cbm_idx_offset;
+ unsigned int shareable_bits;
};
/**
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index c24dd067b9c5..2621ae3f07fc 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -596,6 +596,15 @@ static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
return 0;
}
+static int rdt_shareable_bits_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ seq_printf(seq, "%x\n", r->cache.shareable_bits);
+ return 0;
+}
+
static int rdt_min_bw_show(struct kernfs_open_file *of,
struct seq_file *seq, void *v)
{
@@ -712,6 +721,13 @@ static struct rftype res_common_files[] = {
.fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
},
{
+ .name = "shareable_bits",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_shareable_bits_show,
+ .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
.name = "min_bandwidth",
.mode = 0444,
.kf_ops = &rdtgroup_kf_single_ops,