drivers/perf: apple_m1: Refactor event select/filter configuration

Supporting guest mode events will necessitate programming two event
filters. Prepare by splitting up the programming of the event selector +
event filter into separate headers.

Opportunistically replace RMW patterns with sysreg_clear_set_s().

Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305202641.428114-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/drivers/perf/apple_m1_cpu_pmu.c b/drivers/perf/apple_m1_cpu_pmu.c
index 06fd317529fcbab0f1485228efe8470be565407c..cea80afd12537b1efba3207b70b5f79d880aaa80 100644 (file)
--- a/drivers/perf/apple_m1_cpu_pmu.c
+++ b/drivers/perf/apple_m1_cpu_pmu.c
@@ -327,11 +327,10 @@ static void m1_pmu_disable_counter_interrupt(unsigned int index)
        __m1_pmu_enable_counter_interrupt(index, false);
 }
 
-static void m1_pmu_configure_counter(unsigned int index, u8 event,
-                                    bool user, bool kernel)
+static void __m1_pmu_configure_event_filter(unsigned int index, bool user,
+                                           bool kernel)
 {
-       u64 val, user_bit, kernel_bit;
-       int shift;
+       u64 clear, set, user_bit, kernel_bit;
 
        switch (index) {
        case 0 ... 7:
@@ -346,19 +345,24 @@ static void m1_pmu_configure_counter(unsigned int index, u8 event,
                BUG();
        }
 
-       val = read_sysreg_s(SYS_IMP_APL_PMCR1_EL1);
-
+       clear = set = 0;
        if (user)
-               val |= user_bit;
+               set |= user_bit;
        else
-               val &= ~user_bit;
+               clear |= user_bit;
 
        if (kernel)
-               val |= kernel_bit;
+               set |= kernel_bit;
        else
-               val &= ~kernel_bit;
+               clear |= kernel_bit;
 
-       write_sysreg_s(val, SYS_IMP_APL_PMCR1_EL1);
+       sysreg_clear_set_s(SYS_IMP_APL_PMCR1_EL1, clear, set);
+}
+
+static void __m1_pmu_configure_eventsel(unsigned int index, u8 event)
+{
+       u64 clear = 0, set = 0;
+       int shift;
 
        /*
         * Counters 0 and 1 have fixed events. For anything else,
@@ -371,21 +375,29 @@ static void m1_pmu_configure_counter(unsigned int index, u8 event,
                break;
        case 2 ... 5:
                shift = (index - 2) * 8;
-               val = read_sysreg_s(SYS_IMP_APL_PMESR0_EL1);
-               val &= ~((u64)0xff << shift);
-               val |= (u64)event << shift;
-               write_sysreg_s(val, SYS_IMP_APL_PMESR0_EL1);
+               clear |= (u64)0xff << shift;
+               set |= (u64)event << shift;
+               sysreg_clear_set_s(SYS_IMP_APL_PMESR0_EL1, clear, set);
                break;
        case 6 ... 9:
                shift = (index - 6) * 8;
-               val = read_sysreg_s(SYS_IMP_APL_PMESR1_EL1);
-               val &= ~((u64)0xff << shift);
-               val |= (u64)event << shift;
-               write_sysreg_s(val, SYS_IMP_APL_PMESR1_EL1);
+               clear |= (u64)0xff << shift;
+               set |= (u64)event << shift;
+               sysreg_clear_set_s(SYS_IMP_APL_PMESR1_EL1, clear, set);
                break;
        }
 }
 
+static void m1_pmu_configure_counter(unsigned int index, unsigned long config_base)
+{
+       bool kernel = config_base & M1_PMU_CFG_COUNT_KERNEL;
+       bool user = config_base & M1_PMU_CFG_COUNT_USER;
+       u8 evt = config_base & M1_PMU_CFG_EVENT;
+
+       __m1_pmu_configure_event_filter(index, user, kernel);
+       __m1_pmu_configure_eventsel(index, evt);
+}
+
 /* arm_pmu backend */
 static void m1_pmu_enable_event(struct perf_event *event)
 {
@@ -400,7 +412,7 @@ static void m1_pmu_enable_event(struct perf_event *event)
        m1_pmu_disable_counter(event->hw.idx);
        isb();
 
-       m1_pmu_configure_counter(event->hw.idx, evt, user, kernel);
+       m1_pmu_configure_counter(event->hw.idx, event->hw.config_base);
        m1_pmu_enable_counter(event->hw.idx);
        m1_pmu_enable_counter_interrupt(event->hw.idx);
        isb();