feat(amu): enable per-core AMU auxiliary counters
This change makes AMU auxiliary counters configurable on a per-core
basis, controlled by `ENABLE_AMU_AUXILIARY_COUNTERS`.
Auxiliary counters can be described via the `HW_CONFIG` device tree if
the `ENABLE_AMU_FCONF` build option is enabled, or the platform must
otherwise implement the `plat_amu_topology` function.
A new phandle property for `cpu` nodes (`amu`) has been introduced to
the `HW_CONFIG` specification to allow CPUs to describe the view of
their own AMU:
```
cpu0: cpu@0 {
...
amu = <&cpu0_amu>;
};
```
Multiple cores may share an `amu` handle if they implement the
same set of auxiliary counters.
AMU counters are described for one or more AMUs through the use of a new
`amus` node:
```
amus {
cpu0_amu: amu-0 {
#address-cells = <1>;
#size-cells = <0>;
counter@0 {
reg = <0>;
enable-at-el3;
};
counter@n {
reg = <n>;
...
};
};
};
```
This structure describes the **auxiliary** (group 1) AMU counters.
Architected counters have architecturally-defined behaviour, and as
such do not require DTB entries.
These `counter` nodes support two properties:
- The `reg` property represents the counter register index.
- The presence of the `enable-at-el3` property determines whether
the firmware should enable the counter prior to exiting EL3.
Change-Id: Ie43aee010518c5725a3b338a4899b0857caf4c28
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/include/lib/extensions/amu.h b/include/lib/extensions/amu.h
index 692d1ad..6452f7e 100644
--- a/include/lib/extensions/amu.h
+++ b/include/lib/extensions/amu.h
@@ -8,12 +8,40 @@
#define AMU_H
#include <stdbool.h>
+#include <stdint.h>
+
#include <context.h>
+#include <platform_def.h>
+
#if __aarch64__
void amu_enable(bool el2_unused, cpu_context_t *ctx);
#else
void amu_enable(bool el2_unused);
#endif
+#if ENABLE_AMU_AUXILIARY_COUNTERS
+/*
+ * AMU data for a single core.
+ */
+struct amu_core {
+ uint16_t enable; /* Mask of auxiliary counters to enable */
+};
+
+/*
+ * Topological platform data specific to the AMU.
+ */
+struct amu_topology {
+ struct amu_core cores[PLATFORM_CORE_COUNT]; /* Per-core data */
+};
+
+#if !ENABLE_AMU_FCONF
+/*
+ * Retrieve the platform's AMU topology. A `NULL` return value is treated as a
+ * non-fatal error, in which case no auxiliary counters will be enabled.
+ */
+const struct amu_topology *plat_amu_topology(void);
+#endif /* ENABLE_AMU_FCONF */
+#endif /* ENABLE_AMU_AUXILIARY_COUNTERS */
+
#endif /* AMU_H */
diff --git a/include/lib/fconf/fconf_amu_getter.h b/include/lib/fconf/fconf_amu_getter.h
new file mode 100644
index 0000000..2faee73
--- /dev/null
+++ b/include/lib/fconf/fconf_amu_getter.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef FCONF_AMU_GETTER_H
+#define FCONF_AMU_GETTER_H
+
+#include <lib/extensions/amu.h>
+
+#define amu__config_getter(id) fconf_amu_config.id
+
+struct fconf_amu_config {
+ const struct amu_topology *topology;
+};
+
+extern struct fconf_amu_config fconf_amu_config;
+
+#endif /* FCONF_AMU_GETTER_H */