[PATCH v4 3/5] lib: sbi_pmu: add override for counter data

[Heiko Stuebner]

In general counter-data is auto-detected but some platforms
may implement counters in a way that breaks this detection.

Implement an abstraction that those platforms can hook into
and override the counter-data.

Signed-off-by: Heiko Stuebner <heiko at sntech.de>
---
 include/sbi/sbi_pmu.h | 8 ++++++++
 lib/sbi/sbi_hart.c    | 7 +++++++
 lib/sbi/sbi_pmu.c     | 7 +++++++
 3 files changed, 22 insertions(+)

diff --git a/include/sbi/sbi_pmu.h b/include/sbi/sbi_pmu.h
index c365243..d257b14 100644
--- a/include/sbi/sbi_pmu.h
+++ b/include/sbi/sbi_pmu.h
@@ -78,6 +78,11 @@ struct sbi_pmu_device {
 	 * Custom function returning the machine-specific irq-bit.
 	 */
 	int (*hw_counter_irq_bit)(void);
+
+	/**
+	 * Override autodetected counter data.
+	 */
+	void (*hw_counter_data)(unsigned int *count, unsigned int *bits);
 };
 
 /** Get the PMU platform device */
@@ -95,6 +100,9 @@ void sbi_pmu_exit(struct sbi_scratch *scratch);
 /** Return the pmu irq bit depending on extension existence */
 int sbi_pmu_irq_bit(void);
 
+/** Allow non-standard platforms to override probed counter information */
+void sbi_pmu_override_counter_data(unsigned int *count, unsigned int *bits);
+
 /**
  * Add the hardware event to counter mapping information. This should be called
  * from the platform code to update the mapping table.
diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
index 45fbcde..6506a19 100644
--- a/lib/sbi/sbi_hart.c
+++ b/lib/sbi/sbi_hart.c
@@ -632,6 +632,13 @@ __mhpm_skip:
 #undef __check_csr_2
 #undef __check_csr
 
+	/**
+	 * Allow non-standard implementations to override the detected
+	 * values for number of counters and bits.
+	 */
+	sbi_pmu_override_counter_data(&hfeatures->mhpm_count,
+				      &hfeatures->mhpm_bits);
+
 	/* Detect if hart supports Priv v1.10 */
 	val = csr_read_allowed(CSR_MCOUNTEREN, (unsigned long)&trap);
 	if (!trap.cause)
diff --git a/lib/sbi/sbi_pmu.c b/lib/sbi/sbi_pmu.c
index 91d9ccc..c8becf3 100644
--- a/lib/sbi/sbi_pmu.c
+++ b/lib/sbi/sbi_pmu.c
@@ -852,3 +852,10 @@ int sbi_pmu_init(struct sbi_scratch *scratch, bool cold_boot)
 
 	return 0;
 }
+
+void sbi_pmu_override_counter_data(unsigned int *count,
+				   unsigned int *bits)
+{
+	if (pmu_dev && pmu_dev->hw_counter_data)
+		pmu_dev->hw_counter_data(count, bits);
+}
-- 
2.35.1