[PATCH v2 3/6] lib/pmu: reimplement per-arch ops as callbacks

[Tomasz Duszynski]

Replace static per-architecture ops with a callback-based ops
structure. This makes architecture-specific PMU implementations more
modular and easier to extend.

Signed-off-by: Tomasz Duszynski <tduszyn...@marvell.com>
---
 lib/pmu/pmu.c         | 17 +----------------
 lib/pmu/pmu_arm64.c   | 19 +++++++++++++------
 lib/pmu/pmu_private.h | 43 +++++++++++++++++++++++++++++++++++++------
 3 files changed, 51 insertions(+), 28 deletions(-)

diff --git a/lib/pmu/pmu.c b/lib/pmu/pmu.c
index 46b0b450ac..0709f5e58c 100644
--- a/lib/pmu/pmu.c
+++ b/lib/pmu/pmu.c
@@ -40,22 +40,7 @@ struct rte_pmu_event {
 RTE_EXPORT_INTERNAL_SYMBOL(rte_pmu)
 struct rte_pmu rte_pmu;
 
-/* Stubs for arch-specific functions */
-#if !defined(RTE_PMU_SUPPORTED) || defined(RTE_ARCH_X86_64)
-int
-pmu_arch_init(void)
-{
-       return 0;
-}
-void
-pmu_arch_fini(void)
-{
-}
-void
-pmu_arch_fixup_config(uint64_t __rte_unused config[3])
-{
-}
-#endif
+const struct pmu_arch_ops *arch_ops;
 
 static int
 get_term_format(const char *name, int *num, uint64_t *mask)
diff --git a/lib/pmu/pmu_arm64.c b/lib/pmu/pmu_arm64.c
index a23f1864df..3f4f5fa297 100644
--- a/lib/pmu/pmu_arm64.c
+++ b/lib/pmu/pmu_arm64.c
@@ -62,8 +62,8 @@ write_attr_int(const char *path, int val)
        return 0;
 }
 
-int
-pmu_arch_init(void)
+static int
+pmu_arm64_init(void)
 {
        int ret;
 
@@ -78,17 +78,24 @@ pmu_arch_init(void)
        return write_attr_int(PERF_USER_ACCESS_PATH, 1);
 }
 
-void
-pmu_arch_fini(void)
+static void
+pmu_arm64_fini(void)
 {
        write_attr_int(PERF_USER_ACCESS_PATH, restore_uaccess);
 }
 
-void
-pmu_arch_fixup_config(uint64_t config[3])
+static void
+pmu_arm64_fixup_config(uint64_t config[3])
 {
        /* select 64 bit counters */
        config[1] |= RTE_BIT64(0);
        /* enable userspace access */
        config[1] |= RTE_BIT64(1);
 }
+
+static const struct pmu_arch_ops arm64_ops = {
+       .init = pmu_arm64_init,
+       .fini = pmu_arm64_fini,
+       .fixup_config = pmu_arm64_fixup_config,
+};
+PMU_SET_ARCH_OPS(arm64_ops)
diff --git a/lib/pmu/pmu_private.h b/lib/pmu/pmu_private.h
index 3db1cb242b..d74f7f4092 100644
--- a/lib/pmu/pmu_private.h
+++ b/lib/pmu/pmu_private.h
@@ -5,20 +5,47 @@
 #ifndef PMU_PRIVATE_H
 #define PMU_PRIVATE_H
 
+/**
+ * Structure describing architecture specific PMU operations.
+ */
+struct pmu_arch_ops {
+       int (*init)(void);
+       void (*fini)(void);
+       void (*fixup_config)(uint64_t config[3]);
+};
+
+extern const struct pmu_arch_ops *arch_ops;
+
+#define PMU_SET_ARCH_OPS(ops) \
+       RTE_INIT(libpmu_set_arch_ops) \
+       { \
+               arch_ops = &(ops); \
+       }
+
 /**
  * Architecture-specific PMU init callback.
  *
  * @return
  *   0 in case of success, negative value otherwise.
  */
-int
-pmu_arch_init(void);
+static inline int
+pmu_arch_init(void)
+{
+       if (arch_ops != NULL && arch_ops->init != NULL)
+               return arch_ops->init();
+
+       return 0;
+}
 
 /**
  * Architecture-specific PMU cleanup callback.
  */
-void
-pmu_arch_fini(void);
+static inline void
+pmu_arch_fini(void)
+{
+       if (arch_ops != NULL && arch_ops->fini != NULL)
+               arch_ops->fini();
+}
 
 /**
  * Apply architecture-specific settings to config before passing it to syscall.
@@ -27,7 +54,11 @@ pmu_arch_fini(void);
  *   Architecture-specific event configuration.
  *   Consult kernel sources for available options.
  */
-void
-pmu_arch_fixup_config(uint64_t config[3]);
+static inline void
+pmu_arch_fixup_config(uint64_t config[3])
+{
+       if (arch_ops != NULL && arch_ops->fixup_config != NULL)
+               arch_ops->fixup_config(config);
+}
 
 #endif /* PMU_PRIVATE_H */
-- 
2.34.1