[PATCH 6/6] perf/x86/intel/uncore: Implement global init callback for GNR uncore

From: Zide Chen

Date: Mon May 11 2026 - 19:15:29 EST


On Sierra Forest and Clearwater Forest, the FRZ_ALL bit in the global
control register defaults to 0 at boot, but UBOX PMON units do not
work until the global control register is explicitly written with 0
to trigger hardware initialization properly.

Implement the generic uncore_msr_global_init() callback and add it to
gnr_uncore_init[], which is shared by GNR, GRR, SRF, and CWF.

Signed-off-by: Zide Chen <zide.chen@xxxxxxxxx>
---
arch/x86/events/intel/uncore.c | 14 +++++++++++++-
arch/x86/events/intel/uncore.h | 2 +-
arch/x86/events/intel/uncore_discovery.c | 2 +-
3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 19056514b081..a7780c5cd419 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1716,7 +1716,7 @@ static int __init uncore_mmio_init(void)
return ret;
}

-static int uncore_mmio_global_init(u64 ctl)
+static int uncore_mmio_global_init(int die, u64 ctl)
{
void __iomem *io_addr;

@@ -1731,6 +1731,17 @@ static int uncore_mmio_global_init(u64 ctl)
return 0;
}

+static int uncore_msr_global_init(int die, u64 msr)
+{
+ int cpu = uncore_die_to_cpu(die);
+
+ if (cpu == -1)
+ return -ENODEV;
+
+ wrmsrq_on_cpu(cpu, msr, 0);
+ return 0;
+}
+
static const struct uncore_plat_init nhm_uncore_init __initconst = {
.cpu_init = nhm_uncore_cpu_init,
};
@@ -1871,6 +1882,7 @@ static const struct uncore_plat_init gnr_uncore_init __initconst = {
.domain[0].base_is_pci = true,
.domain[0].discovery_base = UNCORE_DISCOVERY_TABLE_DEVICE,
.domain[0].units_ignore = gnr_uncore_units_ignore,
+ .domain[0].global_init = uncore_msr_global_init,
};

static const struct uncore_plat_init dmr_uncore_init __initconst = {
diff --git a/arch/x86/events/intel/uncore.h b/arch/x86/events/intel/uncore.h
index 94c68e3417b6..c2e5ccb1d72c 100644
--- a/arch/x86/events/intel/uncore.h
+++ b/arch/x86/events/intel/uncore.h
@@ -53,7 +53,7 @@ struct uncore_discovery_domain {
/* MSR address or PCI device used as the discovery base */
u32 discovery_base;
bool base_is_pci;
- int (*global_init)(u64 ctl);
+ int (*global_init)(int die, u64 ctl);

/* The units in the discovery table should be ignored. */
int *units_ignore;
diff --git a/arch/x86/events/intel/uncore_discovery.c b/arch/x86/events/intel/uncore_discovery.c
index 1d22d7c00ee0..49183d607a34 100644
--- a/arch/x86/events/intel/uncore_discovery.c
+++ b/arch/x86/events/intel/uncore_discovery.c
@@ -287,7 +287,7 @@ static int __parse_discovery_table(struct uncore_discovery_domain *domain,
if (!io_addr)
return -ENOMEM;

- if (domain->global_init && domain->global_init(global.ctl)) {
+ if (domain->global_init && domain->global_init(die, global.ctl)) {
ret = -ENODEV;
goto out;
}
--
2.54.0