[PATCH v2] x86/resctrl: Fix unused variable warning in cache_alloc_hsw_probe()

From: Tony Luck
Date: Wed Nov 01 2023 - 17:26:32 EST


In a "W=1" build gcc throws a warning:

arch/x86/kernel/cpu/resctrl/core.c: In function ‘cache_alloc_hsw_probe’:
arch/x86/kernel/cpu/resctrl/core.c:139:16: warning: variable ‘h’ set but not used

Fix by switching from wrmsr_safe() to wrmsrl_safe(), and from rdmsr()
to rdmsrl() using a single u64 argument for the MSR value instead of
the pair of u32 for the high and low halves.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
Changes since v1 (suggested by Babu)

Switch both the wrmsr() and rdmsr() to the 64-bit versions.

arch/x86/kernel/cpu/resctrl/core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 19e0681f0435..d29ebe345de6 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -136,15 +136,15 @@ static inline void cache_alloc_hsw_probe(void)
{
struct rdt_hw_resource *hw_res = &rdt_resources_all[RDT_RESOURCE_L3];
struct rdt_resource *r = &hw_res->r_resctrl;
- u32 l, h, max_cbm = BIT_MASK(20) - 1;
+ u64 max_cbm = BIT_ULL_MASK(20) - 1, l3_cbm_0;

- if (wrmsr_safe(MSR_IA32_L3_CBM_BASE, max_cbm, 0))
+ if (wrmsrl_safe(MSR_IA32_L3_CBM_BASE, max_cbm))
return;

- rdmsr(MSR_IA32_L3_CBM_BASE, l, h);
+ rdmsrl(MSR_IA32_L3_CBM_BASE, l3_cbm_0);

/* If all the bits were set in MSR, return success */
- if (l != max_cbm)
+ if (l3_cbm_0 != max_cbm)
return;

hw_res->num_closid = 4;
--
2.41.0