[PATCH v2] platform/x86: ISST: Fix optimization with use of numa

From: Srinivas Pandruvada
Date: Tue Aug 10 2021 - 23:36:47 EST


When numa is used to map CPU to PCI device, the optimized path to read
from cached data is not working and still calls _isst_if_get_pci_dev().

The reason is that when caching the mapping, numa information is not
available as it is read later. So move the assignment of
isst_cpu_info[cpu].numa_node before calling _isst_if_get_pci_dev().

Fixes: aa2ddd242572 ("platform/x86: ISST: Use numa node id for cpu pci dev mapping")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
v2:
Fixed "Fixes tag" as suggested by Stephen Rothwell

Update:
The fixes tag was wrong
This patch can wait for next merge window as these systems are not
shipped.

drivers/platform/x86/intel_speed_select_if/isst_if_common.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_common.c b/drivers/platform/x86/intel_speed_select_if/isst_if_common.c
index 6f0cc679c8e5..8a4d52a9028d 100644
--- a/drivers/platform/x86/intel_speed_select_if/isst_if_common.c
+++ b/drivers/platform/x86/intel_speed_select_if/isst_if_common.c
@@ -379,6 +379,8 @@ static int isst_if_cpu_online(unsigned int cpu)
u64 data;
int ret;

+ isst_cpu_info[cpu].numa_node = cpu_to_node(cpu);
+
ret = rdmsrl_safe(MSR_CPU_BUS_NUMBER, &data);
if (ret) {
/* This is not a fatal error on MSR mailbox only I/F */
@@ -397,7 +399,6 @@ static int isst_if_cpu_online(unsigned int cpu)
return ret;
}
isst_cpu_info[cpu].punit_cpu_id = data;
- isst_cpu_info[cpu].numa_node = cpu_to_node(cpu);

isst_restore_msr_local(cpu);

--
2.31.1