The QOS Memory Bandwidth Enforcement Limit is reported by
CPUID_Fn80000020_EAX_x01.
Bits Description
31:0 BW_LEN: Size of the QOS Memory Bandwidth Enforcement Limit.
Remove the hardcoded bandwidth limit value and detect using CPUID command.
The CPUID details are documentation in the PPR listed below [1].
[1] Processor Programming Reference (PPR) Vol 1.1 for AMD Family 19h Model
11h B1 - 55901 Rev 0.25.
Fixes: 4d05bf71f157 ("x86/resctrl: Introduce AMD QOS feature")
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
---
arch/x86/kernel/cpu/resctrl/core.c | 2 +-
arch/x86/kernel/cpu/resctrl/internal.h | 1 -
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 19e0681f0435..3fbae10b662d 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -243,7 +243,7 @@ static bool __rdt_get_mem_config_amd(struct rdt_resource *r)
cpuid_count(0x80000020, subleaf, &eax.full, &ebx, &ecx, &edx.full);
hw_res->num_closid = edx.split.cos_max + 1;
- r->default_ctrl = MAX_MBA_BW_AMD;
+ r->default_ctrl = 1 << eax.full;
/* AMD does not use delay */
r->membw.delay_linear = false;
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index a4f1aa15f0a2..d2979748fae4 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -18,7 +18,6 @@
#define MBM_OVERFLOW_INTERVAL 1000
#define MAX_MBA_BW 100u
#define MBA_IS_LINEAR 0x4
-#define MAX_MBA_BW_AMD 0x800
#define MBM_CNTR_WIDTH_OFFSET_AMD 20
#define RMID_VAL_ERROR BIT_ULL(63)
--
2.34.1
