[PATCH v4 04/15] target/ppc: adding user read/write functions for PMCs

[Daniel Henrique Barboza]

Problem state needs to be able to read and write the PMU counters,
otherwise it won't be aware of any sampling result that the PMU produces
after a Perf run.

This patch does that in a similar fashion as already done in the
previous patches. PMCs 5 and 6 have a special condition, aside from the
constraints that are common with PMCs 1-4, where they are not part of the
PMU if MMCR0_PMCC is 0b11.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 target/ppc/cpu_init.c            | 12 +++---
 target/ppc/power8-pmu-regs.c.inc | 70 ++++++++++++++++++++++++++++++++
 target/ppc/spr_tcg.h             |  4 ++
 3 files changed, 80 insertions(+), 6 deletions(-)

diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index ad88e54950..65545ba9ca 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -6879,27 +6879,27 @@ static void register_book3s_pmu_user_sprs(CPUPPCState 
*env)
                  &spr_read_ureg, &spr_write_ureg,
                  0x00000000);
     spr_register(env, SPR_POWER_UPMC1, "UPMC1",
-                 &spr_read_ureg, SPR_NOACCESS,
+                 &spr_read_PMC14_ureg, &spr_write_PMC14_ureg,
                  &spr_read_ureg, &spr_write_ureg,
                  0x00000000);
     spr_register(env, SPR_POWER_UPMC2, "UPMC2",
-                 &spr_read_ureg, SPR_NOACCESS,
+                 &spr_read_PMC14_ureg, &spr_write_PMC14_ureg,
                  &spr_read_ureg, &spr_write_ureg,
                  0x00000000);
     spr_register(env, SPR_POWER_UPMC3, "UPMC3",
-                 &spr_read_ureg, SPR_NOACCESS,
+                 &spr_read_PMC14_ureg, &spr_write_PMC14_ureg,
                  &spr_read_ureg, &spr_write_ureg,
                  0x00000000);
     spr_register(env, SPR_POWER_UPMC4, "UPMC4",
-                 &spr_read_ureg, SPR_NOACCESS,
+                 &spr_read_PMC14_ureg, &spr_write_PMC14_ureg,
                  &spr_read_ureg, &spr_write_ureg,
                  0x00000000);
     spr_register(env, SPR_POWER_UPMC5, "UPMC5",
-                 &spr_read_ureg, SPR_NOACCESS,
+                 &spr_read_PMC56_ureg, &spr_write_PMC56_ureg,
                  &spr_read_ureg, &spr_write_ureg,
                  0x00000000);
     spr_register(env, SPR_POWER_UPMC6, "UPMC6",
-                 &spr_read_ureg, SPR_NOACCESS,
+                 &spr_read_PMC56_ureg, &spr_write_PMC56_ureg,
                  &spr_read_ureg, &spr_write_ureg,
                  0x00000000);
     spr_register(env, SPR_POWER_USIAR, "USIAR",
diff --git a/target/ppc/power8-pmu-regs.c.inc b/target/ppc/power8-pmu-regs.c.inc
index fb95175183..7391851238 100644
--- a/target/ppc/power8-pmu-regs.c.inc
+++ b/target/ppc/power8-pmu-regs.c.inc
@@ -169,6 +169,56 @@ void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int 
gprn)
 
     tcg_temp_free(masked_gprn);
 }
+
+void spr_read_PMC14_ureg(DisasContext *ctx, int gprn, int sprn)
+{
+    if (!spr_groupA_read_allowed(ctx)) {
+        return;
+    }
+
+    spr_read_ureg(ctx, gprn, sprn);
+}
+
+void spr_read_PMC56_ureg(DisasContext *ctx, int gprn, int sprn)
+{
+    /*
+     * If PMCC = 0b11, PMC5 and PMC6 aren't included in the Performance
+     * Monitor, and a read attempt results in a Facility Unavailable
+     * Interrupt.
+     */
+    if (ctx->mmcr0_pmcc0 && ctx->mmcr0_pmcc1) {
+        gen_hvpriv_exception(ctx, POWERPC_EXCP_FU);
+        return;
+    }
+
+    /* The remaining steps are similar to PMCs 1-4 userspace read */
+    spr_read_PMC14_ureg(ctx, gprn, sprn);
+}
+
+void spr_write_PMC14_ureg(DisasContext *ctx, int sprn, int gprn)
+{
+    if (!spr_groupA_write_allowed(ctx)) {
+        return;
+    }
+
+    spr_write_ureg(ctx, sprn, gprn);
+}
+
+void spr_write_PMC56_ureg(DisasContext *ctx, int sprn, int gprn)
+{
+    /*
+     * If PMCC = 0b11, PMC5 and PMC6 aren't included in the Performance
+     * Monitor, and a write attempt results in a Facility Unavailable
+     * Interrupt.
+     */
+    if (ctx->mmcr0_pmcc0 && ctx->mmcr0_pmcc1) {
+        gen_hvpriv_exception(ctx, POWERPC_EXCP_FU);
+        return;
+    }
+
+    /* The remaining steps are similar to PMCs 1-4 userspace write */
+    spr_write_PMC14_ureg(ctx, sprn, gprn);
+}
 #else
 void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn)
 {
@@ -189,4 +239,24 @@ void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int 
gprn)
 {
     spr_noaccess(ctx, gprn, sprn);
 }
+
+void spr_read_PMC14_ureg(DisasContext *ctx, int gprn, int sprn)
+{
+    spr_read_ureg(ctx, gprn, sprn);
+}
+
+void spr_read_PMC56_ureg(DisasContext *ctx, int gprn, int sprn)
+{
+    spr_read_ureg(ctx, gprn, sprn);
+}
+
+void spr_write_PMC14_ureg(DisasContext *ctx, int sprn, int gprn)
+{
+    spr_noaccess(ctx, gprn, sprn);
+}
+
+void spr_write_PMC56_ureg(DisasContext *ctx, int sprn, int gprn)
+{
+    spr_noaccess(ctx, gprn, sprn);
+}
 #endif /* defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY) */
diff --git a/target/ppc/spr_tcg.h b/target/ppc/spr_tcg.h
index cb7f40eedf..520f1ef233 100644
--- a/target/ppc/spr_tcg.h
+++ b/target/ppc/spr_tcg.h
@@ -34,6 +34,8 @@ void spr_write_ctr(DisasContext *ctx, int sprn, int gprn);
 void spr_read_ureg(DisasContext *ctx, int gprn, int sprn);
 void spr_read_MMCR0_ureg(DisasContext *ctx, int gprn, int sprn);
 void spr_read_MMCR2_ureg(DisasContext *ctx, int gprn, int sprn);
+void spr_read_PMC14_ureg(DisasContext *ctx, int gprn, int sprn);
+void spr_read_PMC56_ureg(DisasContext *ctx, int gprn, int sprn);
 void spr_read_tbl(DisasContext *ctx, int gprn, int sprn);
 void spr_read_tbu(DisasContext *ctx, int gprn, int sprn);
 void spr_read_atbl(DisasContext *ctx, int gprn, int sprn);
@@ -44,6 +46,8 @@ void spr_read_spefscr(DisasContext *ctx, int gprn, int sprn);
 void spr_write_spefscr(DisasContext *ctx, int sprn, int gprn);
 void spr_write_MMCR0_ureg(DisasContext *ctx, int sprn, int gprn);
 void spr_write_MMCR2_ureg(DisasContext *ctx, int sprn, int gprn);
+void spr_write_PMC14_ureg(DisasContext *ctx, int sprn, int gprn);
+void spr_write_PMC56_ureg(DisasContext *ctx, int sprn, int gprn);
 
 #ifndef CONFIG_USER_ONLY
 void spr_write_generic32(DisasContext *ctx, int sprn, int gprn);
-- 
2.31.1