Support dumping HTM capabilities information from Hardware
Trace Macro (HTM) function via debugfs interface. Under
debugfs folder "/sys/kernel/debug/powerpc/htmdump", add
file "htmcaps".
The interface allows only read of this file which will present the
content of HTM buffer from the hcall.
Signed-off-by: Athira Rajeev <atraj...@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venka...@linux.ibm.com>
---
arch/powerpc/platforms/pseries/htmdump.c | 40 ++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/htmdump.c
b/arch/powerpc/platforms/pseries/htmdump.c
index dc5cdcd8c3c3..af15d50c924b 100644
--- a/arch/powerpc/platforms/pseries/htmdump.c
+++ b/arch/powerpc/platforms/pseries/htmdump.c
@@ -14,6 +14,7 @@
static void *htm_buf;
static void *htm_status_buf;
static void *htm_info_buf;
+static void *htm_caps_buf;
static u32 nodeindex;
static u32 nodalchipindex;
static u32 coreindexonchip;
@@ -304,12 +305,43 @@ static ssize_t htminfo_read(struct file *filp, char
__user *ubuf,
return simple_read_from_buffer(ubuf, count, ppos, htm_info_buf,
to_copy);
}
+static ssize_t htmcaps_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ void *htm_caps_buf = filp->private_data;
+ long rc, ret;
+
+ /*
+ * Invoke H_HTM call with:
+ * - operation as htm capabilities (H_HTM_OP_CAPABILITIES)
+ * - last three values as addr, size (0x80 for Capabilities Output
Buffer
+ * and zero
+ */
+ rc = htm_hcall_wrapper(htmflags, nodeindex, nodalchipindex,
coreindexonchip,
+ htmtype, H_HTM_OP_CAPABILITIES,
virt_to_phys(htm_caps_buf),
+ 0x80, 0);
+
+ ret = htm_return_check(rc);
+ if (ret <= 0) {
+ pr_debug("H_HTM hcall failed for op: H_HTM_OP_CAPABILITIES,
returning %ld\n", ret);
+ return ret;
+ }
+
+ return simple_read_from_buffer(ubuf, count, ppos, htm_caps_buf, 0x80);
+}
+
static const struct file_operations htminfo_fops = {
.llseek = NULL,
.read = htminfo_read,
.open = simple_open,
};
+static const struct file_operations htmcaps_fops = {
+ .llseek = NULL,
+ .read = htmcaps_read,
+ .open = simple_open,
+};
+
static int htmsetup_set(void *data, u64 val)
{
long rc, ret;
@@ -417,8 +449,16 @@ static int htmdump_init_debugfs(void)
return -ENOMEM;
}
+ /* Debugfs interface file to present HTM capabilities */
+ htm_caps_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!htm_caps_buf) {
+ pr_err("Failed to allocate htm caps buf\n");
+ return -ENOMEM;
+ }
+
debugfs_create_file("htmstatus", 0400, htmdump_debugfs_dir,
htm_status_buf, &htmstatus_fops);
debugfs_create_file("htminfo", 0400, htmdump_debugfs_dir, htm_info_buf,
&htminfo_fops);
+ debugfs_create_file("htmcaps", 0400, htmdump_debugfs_dir, htm_caps_buf,
&htmcaps_fops);
return 0;
}
--
2.43.0
