utils: fdt: Add fdt helper functions to parse PMU DT nodes

The PMU DT node bindings are defined in docs/pmu_support.md
Add few fdt helper functions to parse the DT node and update the
event-counter mapping tables.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

diff --git a/include/sbi_utils/fdt/fdt_pmu.h b/include/sbi_utils/fdt/fdt_pmu.h
new file mode 100644 (file)
index 0000000..2fa01ed
--- /dev/null
+++ b/include/sbi_utils/fdt/fdt_pmu.h
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * fdt_pmu.c - Flat Device Tree PMU helper routines
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Atish Patra <atish.patra@wdc.com>
+ */
+
+#ifndef __FDT_PMU_H__
+#define __FDT_PMU_H__
+
+#include <sbi/sbi_types.h>
+
+/**
+ * Fix up the PMU node in the device tree
+ *
+ * This routine:
+ * 1. Disables opensbi specific properties from the DT
+ *
+ * It is recommended that platform support call this function in
+ * their final_init() platform operation.
+ *
+ * @param fdt device tree blob
+ */
+void fdt_pmu_fixup(void *fdt);
+
+/**
+ * Setup PMU data from device tree
+ *
+ * @param fdt device tree blob
+ *
+ * @return 0 on success and negative error code on failure
+ */
+int fdt_pmu_setup(void *fdt);
+
+/**
+ * Get the mhpmevent select value read from DT for a given event
+ * @param event_idx Event ID of the given event
+ *
+ * @return The select value read from DT or 0 if given index was not found
+ */
+uint64_t fdt_pmu_get_select_value(uint32_t event_idx);
+
+#endif

diff --git a/lib/utils/fdt/fdt_fixup.c b/lib/utils/fdt/fdt_fixup.c
index 1465500..ac01ba3 100644 (file)
--- a/lib/utils/fdt/fdt_fixup.c
+++ b/lib/utils/fdt/fdt_fixup.c
@@ -15,6 +15,7 @@
 #include <sbi/sbi_scratch.h>
 #include <sbi/sbi_string.h>
 #include <sbi_utils/fdt/fdt_fixup.h>
+#include <sbi_utils/fdt/fdt_pmu.h>
 #include <sbi_utils/fdt/fdt_helper.h>
 
 void fdt_cpu_fixup(void *fdt)
@@ -263,6 +264,7 @@ void fdt_fixups(void *fdt)
        fdt_plic_fixup(fdt);
 
        fdt_reserved_memory_fixup(fdt);
+       fdt_pmu_fixup(fdt);
 }
 
 

diff --git a/lib/utils/fdt/fdt_pmu.c b/lib/utils/fdt/fdt_pmu.c
new file mode 100644 (file)
index 0000000..9ebf1c2
--- /dev/null
+++ b/lib/utils/fdt/fdt_pmu.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * fdt_pmu.c - Flat Device Tree PMU helper routines
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *     Atish Patra <atish.patra@wdc.com>
+ */
+
+#include <libfdt.h>
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_pmu.h>
+#include <sbi_utils/fdt/fdt_helper.h>
+
+#define FDT_PMU_HW_EVENT_MAX (SBI_PMU_HW_EVENT_MAX * 2)
+
+struct fdt_pmu_hw_event_select {
+       uint32_t eidx;
+       uint64_t select;
+};
+
+static struct fdt_pmu_hw_event_select fdt_pmu_evt_select[FDT_PMU_HW_EVENT_MAX] = {0};
+static uint32_t hw_event_count;
+
+uint64_t fdt_pmu_get_select_value(uint32_t event_idx)
+{
+       int i;
+       struct fdt_pmu_hw_event_select *event;
+
+       for (i = 0; i < SBI_PMU_HW_EVENT_MAX; i++) {
+               event = &fdt_pmu_evt_select[i];
+               if (event->eidx == event_idx)
+                       return event->select;
+       }
+
+       return 0;
+}
+
+int fdt_pmu_fixup(void *fdt)
+{
+       int pmu_offset;
+
+       if (!fdt)
+               return SBI_EINVAL;
+
+       pmu_offset = fdt_node_offset_by_compatible(fdt, -1, "riscv,pmu");
+       if (pmu_offset < 0)
+               return SBI_EFAIL;
+
+       fdt_delprop(fdt, pmu_offset, "pmu,event-to-mhpmcounters");
+       fdt_delprop(fdt, pmu_offset, "pmu,event-to-mhpmevent");
+       fdt_delprop(fdt, pmu_offset, "pmu,raw-event-to-mhpmcounters");
+
+       return 0;
+}
+
+int fdt_pmu_setup(void *fdt)
+{
+       int i, pmu_offset, len, result;
+       const u32 *event_val;
+       const u32 *event_ctr_map;
+       struct fdt_pmu_hw_event_select *event;
+       uint64_t raw_selector;
+       u32 event_idx_start, event_idx_end, ctr_map;
+
+       if (!fdt)
+               return SBI_EINVAL;
+
+       pmu_offset = fdt_node_offset_by_compatible(fdt, -1, "riscv,pmu");
+       if (pmu_offset < 0)
+               return SBI_EFAIL;
+
+       event_ctr_map = fdt_getprop(fdt, pmu_offset, "pmu,event-to-mhpmcounters", &len);
+       if (!event_ctr_map || len < 8)
+               return SBI_EFAIL;
+       len = len / (sizeof(u32) * 3);
+       for (i = 0; i < len; i++) {
+               event_idx_start = fdt32_to_cpu(event_ctr_map[3 * i]);
+               event_idx_end = fdt32_to_cpu(event_ctr_map[3 * i + 1]);
+               ctr_map = fdt32_to_cpu(event_ctr_map[3 * i + 2]);
+               sbi_pmu_add_hw_event_counter_map(event_idx_start, event_idx_end, ctr_map);
+       }
+
+       event_val = fdt_getprop(fdt, pmu_offset, "pmu,event-to-mhpmevent", &len);
+       if (!event_val || len < 8)
+               return SBI_EFAIL;
+       len = len / (sizeof(u32) * 3);
+       for (i = 0; i < len; i++) {
+               event = &fdt_pmu_evt_select[hw_event_count];
+               event->eidx = fdt32_to_cpu(event_val[3 * i]);
+               event->select = fdt32_to_cpu(event_val[3 * i + 1]);
+               event->select = (event->select << 32) | fdt32_to_cpu(event_val[3 * i + 2]);
+               hw_event_count++;
+       }
+
+       event_val = fdt_getprop(fdt, pmu_offset, "pmu,raw-event-to-mhpmcounters", &len);
+       if (!event_val || len < 8)
+               return SBI_EFAIL;
+       len = len / (sizeof(u32) * 3);
+       for (i = 0; i < len; i++) {
+               raw_selector = fdt32_to_cpu(event_val[3 * i]);
+               raw_selector = (raw_selector << 32) | fdt32_to_cpu(event_val[3 * i + 1]);
+               ctr_map = fdt32_to_cpu(event_val[3 * i + 2]);
+               result = sbi_pmu_add_raw_event_counter_map(raw_selector, ctr_map);
+               if (!result)
+                       hw_event_count++;
+       }
+
+       return 0;
+}

diff --git a/lib/utils/fdt/objects.mk b/lib/utils/fdt/objects.mk
index d9f1eae..03800f9 100644 (file)
--- a/lib/utils/fdt/objects.mk
+++ b/lib/utils/fdt/objects.mk
@@ -5,5 +5,6 @@
 #
 
 libsbiutils-objs-y += fdt/fdt_domain.o
+libsbiutils-objs-y += fdt/fdt_pmu.o
 libsbiutils-objs-y += fdt/fdt_helper.o
 libsbiutils-objs-y += fdt/fdt_fixup.o