From: Benjamin Herrenschmidt <b...@kernel.crashing.org>
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>
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
---
arch/powerpc/platforms/powernv/opal.c | 38 ++++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)
v3. Use bin_attribute->private & size. Add pr_fmt().
v2. Use memory_read_from_buffer()
diff --git a/arch/powerpc/platforms/powernv/opal.c
b/arch/powerpc/platforms/powernv/opal.c
index d019b081df9d..8907ba039f1e 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -9,8 +9,9 @@
* 2 of the License, or (at your option) any later version.
*/
-#undef DEBUG
+#define pr_fmt(fmt) "opal: " fmt
+#include <linux/printk.h>
#include <linux/types.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
@@ -626,6 +627,39 @@ static int opal_sysfs_init(void)
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)
+{
+ return memory_read_from_buffer(buf, count, &off, bin_attr->private,
+ bin_attr->size);
+}
+
+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;
+
+ /* Setup attributes */
+ bin_attr_symbol_map.private = __va(be64_to_cpu(syms[0]));
+ bin_attr_symbol_map.size = be64_to_cpu(syms[1]);
+
+ 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;
@@ -693,6 +727,8 @@ 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 */
--
2.1.0
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