Newer versions of OPAL will provide this, so let's expose it to user
space so tools like perf can use it to properly decode samples in
firmware space.
Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
---
diff --git a/arch/powerpc/platforms/powernv/opal.c
b/arch/powerpc/platforms/powernv/opal.c
index 06d9076..6427959 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -61,6 +61,8 @@ static DEFINE_SPINLOCK(opal_notifier_lock);
static uint64_t last_notified_mask = 0x0ul;
static atomic_t opal_notifier_hold = ATOMIC_INIT(0);
static uint32_t opal_heartbeat;
+static void *opal_symmap;
+static uint64_t opal_symmap_size;
static void opal_reinit_cores(void)
{
@@ -604,10 +606,49 @@ static int opal_sysfs_init(void)
pr_warn("kobject_create_and_add opal failed\n");
return -ENOMEM;
}
-
return 0;
}
+static ssize_t symbol_map_read(struct file *fp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t off, size_t count)
+{
+ ssize_t chunk;
+
+ if (off >= opal_symmap_size)
+ return 0;
+ chunk = min_t(ssize_t, opal_symmap_size - off, count);
+ memcpy(buf, opal_symmap + off, chunk);
+
+ return chunk;
+}
+
+static BIN_ATTR_RO(symbol_map, 0);
+
+static void opal_export_symmap(void)
+{
+ const __be64 *syms;
+ unsigned int size;
+ struct device_node *fw;
+ int rc;
+
+ fw = of_find_node_by_path("/ibm,opal/firmware");
+ if (!fw)
+ return;
+ syms = of_get_property(fw, "symbol-map", &size);
+ if (!syms || size != 2 * sizeof(__be64))
+ return;
+
+ opal_symmap = __va(be64_to_cpu(syms[0]));
+ opal_symmap_size = be64_to_cpu(syms[1]);
+
+ /* Setup attributes */
+ bin_attr_symbol_map.size = opal_symmap_size;
+ rc = sysfs_create_bin_file(opal_kobj, &bin_attr_symbol_map);
+ if (rc)
+ pr_warn("Error %d creating OPAL symbols file\n", rc);
+}
+
static void __init opal_dump_region_init(void)
{
void *addr;
@@ -738,6 +779,8 @@ static int __init opal_init(void)
/* Create "opal" kobject under /sys/firmware */
rc = opal_sysfs_init();
if (rc == 0) {
+ /* Export symbol map to userspace */
+ opal_export_symmap();
/* Setup dump region interface */
opal_dump_region_init();
/* Setup error log interface */
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