On 22-Jul-2020, at 9:48 AM, Jordan Niethe <jniethe5@gmail.com> wrote:

On Sat, Jul 18, 2020 at 1:02 AM Athira Rajeev
<atrajeev@linux.vnet.ibm.com> wrote:

From: Madhavan Srinivasan <maddy@linux.ibm.com>

PowerISA v3.1 includes new performance monitoring unit(PMU)
special purpose registers (SPRs). They are

Monitor Mode Control Register 3 (MMCR3)
Sampled Instruction Event Register 2 (SIER2)
Sampled Instruction Event Register 3 (SIER3)

MMCR3 is added for further sampling related configuration
control. SIER2/SIER3 are added to provide additional
information about the sampled instruction.

Patch adds new PPMU flag called "PPMU_ARCH_310S" to support
handling of these new SPRs, updates the struct thread_struct
to include these new SPRs, include MMCR3 in struct mmcr_regs.
This is needed to support programming of MMCR3 SPR during
event_[enable/disable]. Patch also adds the sysfs support
for the MMCR3 SPR along with SPRN_ macros for these new pmu sprs.

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
---
arch/powerpc/include/asm/perf_event_server.h |  2 ++
arch/powerpc/include/asm/processor.h         |  4 ++++
arch/powerpc/include/asm/reg.h               |  6 ++++++
arch/powerpc/kernel/sysfs.c                  |  8 ++++++++
arch/powerpc/perf/core-book3s.c              | 29 ++++++++++++++++++++++++++++
5 files changed, 49 insertions(+)

diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
index 14b8dc1..832450a 100644
--- a/arch/powerpc/include/asm/perf_event_server.h
+++ b/arch/powerpc/include/asm/perf_event_server.h
@@ -22,6 +22,7 @@ struct mmcr_regs {
       unsigned long mmcr1;
       unsigned long mmcr2;
       unsigned long mmcra;
+       unsigned long mmcr3;
};
/*
 * This struct provides the constants and functions needed to
@@ -75,6 +76,7 @@ struct power_pmu {
#define PPMU_HAS_SIER          0x00000040 /* Has SIER */
#define PPMU_ARCH_207S         0x00000080 /* PMC is architecture v2.07S */
#define PPMU_NO_SIAR           0x00000100 /* Do not use SIAR */
+#define PPMU_ARCH_310S         0x00000200 /* Has MMCR3, SIER2 and SIER3 */
We elsewhere have CPU_FTR_ARCH_31, so should this be PPMU_ARCH_31S to
be consistent.


Ok,
This change will need to be done in all places which are currently using PPMU_ARCH_310S

/*
 * Values for flags to get_alternatives()
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 52a6783..a466e94 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -272,6 +272,10 @@ struct thread_struct {
       unsigned        mmcr0;

       unsigned        used_ebb;
+       unsigned long   mmcr3;
+       unsigned long   sier2;
+       unsigned long   sier3;
+
#endif
};

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 88e6c78..21a1b2d 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -876,7 +876,9 @@
#define   MMCR0_FCHV   0x00000001UL /* freeze conditions in hypervisor mode */
#define SPRN_MMCR1     798
#define SPRN_MMCR2     785
+#define SPRN_MMCR3     754
#define SPRN_UMMCR2    769
+#define SPRN_UMMCR3    738
#define SPRN_MMCRA     0x312
#define   MMCRA_SDSYNC 0x80000000UL /* SDAR synced with SIAR */
#define   MMCRA_SDAR_DCACHE_MISS 0x40000000UL
@@ -918,6 +920,10 @@
#define   SIER_SIHV            0x1000000       /* Sampled MSR_HV */
#define   SIER_SIAR_VALID      0x0400000       /* SIAR contents valid */
#define   SIER_SDAR_VALID      0x0200000       /* SDAR contents valid */
+#define SPRN_SIER2     752
+#define SPRN_SIER3     753
+#define SPRN_USIER2    736
+#define SPRN_USIER3    737
#define SPRN_SIAR      796
#define SPRN_SDAR      797
#define SPRN_TACR      888
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 571b325..46b4ebc 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -622,8 +622,10 @@ void ppc_enable_pmcs(void)
SYSFS_PMCSETUP(pmc8, SPRN_PMC8);

SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
+SYSFS_PMCSETUP(mmcr3, SPRN_MMCR3);

static DEVICE_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
+static DEVICE_ATTR(mmcr3, 0600, show_mmcr3, store_mmcr3);
#endif /* HAS_PPC_PMC56 */


@@ -886,6 +888,9 @@ static int register_cpu_online(unsigned int cpu)
#ifdef CONFIG_PMU_SYSFS
       if (cpu_has_feature(CPU_FTR_MMCRA))
               device_create_file(s, &dev_attr_mmcra);
+
+       if (cpu_has_feature(CPU_FTR_ARCH_31))
+               device_create_file(s, &dev_attr_mmcr3);
#endif /* CONFIG_PMU_SYSFS */

       if (cpu_has_feature(CPU_FTR_PURR)) {
@@ -980,6 +985,9 @@ static int unregister_cpu_online(unsigned int cpu)
#ifdef CONFIG_PMU_SYSFS
       if (cpu_has_feature(CPU_FTR_MMCRA))
               device_remove_file(s, &dev_attr_mmcra);
+
+       if (cpu_has_feature(CPU_FTR_ARCH_31))
+               device_remove_file(s, &dev_attr_mmcr3);
#endif /* CONFIG_PMU_SYSFS */

       if (cpu_has_feature(CPU_FTR_PURR)) {
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index f4d07b5..ca32fc0 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -72,6 +72,11 @@ struct cpu_hw_events {
/*
 * 32-bit doesn't have MMCRA but does have an MMCR2,
 * and a few other names are different.
+ * Also 32-bit doesn't have MMCR3, SIER2 and SIER3.
+ * Define them as zero knowing that any code path accessing
+ * these registers (via mtspr/mfspr) are done under ppmu flag
+ * check for PPMU_ARCH_310S and we will not enter that code path
+ * for 32-bit.
 */
#ifdef CONFIG_PPC32

@@ -85,6 +90,9 @@ struct cpu_hw_events {
#define MMCR0_PMCC_U6          0

#define SPRN_MMCRA             SPRN_MMCR2
+#define SPRN_MMCR3             0
+#define SPRN_SIER2             0
+#define SPRN_SIER3             0
#define MMCRA_SAMPLE_ENABLE    0

static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
@@ -581,6 +589,11 @@ static void ebb_switch_out(unsigned long mmcr0)
       current->thread.sdar  = mfspr(SPRN_SDAR);
       current->thread.mmcr0 = mmcr0 & MMCR0_USER_MASK;
       current->thread.mmcr2 = mfspr(SPRN_MMCR2) & MMCR2_USER_MASK;
+       if (ppmu->flags & PPMU_ARCH_310S) {
+               current->thread.mmcr3 = mfspr(SPRN_MMCR3);
Like MMCR0_USER_MASK and MMCR2_USER_MASK do we need a MMCR3_USER_MASK
here, or is there no need?

Jordan

We don’t need user mask for MMCR3 and other new SPRs ( SIER2/3) . Incase of MMCR3, we dont have any Freeze control bits and incase of SIER2/3, it is similar to SIER (where HW handles the masking of the bits), hence we didn't add any user_mask for these SPRs

Thanks
Athira

+               current->thread.sier2 = mfspr(SPRN_SIER2);
+               current->thread.sier3 = mfspr(SPRN_SIER3);
+       }
}

static unsigned long ebb_switch_in(bool ebb, struct cpu_hw_events *cpuhw)
@@ -620,6 +633,12 @@ static unsigned long ebb_switch_in(bool ebb, struct cpu_hw_events *cpuhw)
        * instead manage the MMCR2 entirely by itself.
        */
       mtspr(SPRN_MMCR2, cpuhw->mmcr.mmcr2 | current->thread.mmcr2);
+
+       if (ppmu->flags & PPMU_ARCH_310S) {
+               mtspr(SPRN_MMCR3, current->thread.mmcr3);
+               mtspr(SPRN_SIER2, current->thread.sier2);
+               mtspr(SPRN_SIER3, current->thread.sier3);
+       }
out:
       return mmcr0;
}
@@ -840,6 +859,11 @@ void perf_event_print_debug(void)
               pr_info("EBBRR: %016lx BESCR: %016lx\n",
                       mfspr(SPRN_EBBRR), mfspr(SPRN_BESCR));
       }
+
+       if (ppmu->flags & PPMU_ARCH_310S) {
+               pr_info("MMCR3: %016lx SIER2: %016lx SIER3: %016lx\n",
+                       mfspr(SPRN_MMCR3), mfspr(SPRN_SIER2), mfspr(SPRN_SIER3));
+       }
#endif
       pr_info("SIAR:  %016lx SDAR:  %016lx SIER:  %016lx\n",
               mfspr(SPRN_SIAR), sdar, sier);
@@ -1305,6 +1329,8 @@ static void power_pmu_enable(struct pmu *pmu)
       if (!cpuhw->n_added) {
               mtspr(SPRN_MMCRA, cpuhw->mmcr.mmcra & ~MMCRA_SAMPLE_ENABLE);
               mtspr(SPRN_MMCR1, cpuhw->mmcr.mmcr1);
+               if (ppmu->flags & PPMU_ARCH_310S)
+                       mtspr(SPRN_MMCR3, cpuhw->mmcr.mmcr3);
               goto out_enable;
       }

@@ -1348,6 +1374,9 @@ static void power_pmu_enable(struct pmu *pmu)
       if (ppmu->flags & PPMU_ARCH_207S)
               mtspr(SPRN_MMCR2, cpuhw->mmcr.mmcr2);

+       if (ppmu->flags & PPMU_ARCH_310S)
+               mtspr(SPRN_MMCR3, cpuhw->mmcr.mmcr3);
+
       /*
        * Read off any pre-existing events that need to move
        * to another PMC.
--
1.8.3.1