[PATCH V2 6/9] powerpc/pseries/htmdump: Add htm setup support to htmdump module

[Athira Rajeev]

Add htm setup support to htmdump module. To use the
HTM (Hardware Trace Macro), HTM buffer has to be allocated.
Support setup of HTM buffers via debugfs interface. Under
debugfs folder, "/sys/kernel/debug/powerpc/htmdump", add file
"htmsetup". The interface allows setup of HTM buffer by writing
size of HTM buffer in power of 2 to the "htmsetup" file

Signed-off-by: Athira Rajeev <atrajeev at linux.ibm.com>
---
 arch/powerpc/platforms/pseries/htmdump.c | 36 ++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/htmdump.c b/arch/powerpc/platforms/pseries/htmdump.c
index b387e46f2b8e..24e597fb85d8 100644
--- a/arch/powerpc/platforms/pseries/htmdump.c
+++ b/arch/powerpc/platforms/pseries/htmdump.c
@@ -20,6 +20,8 @@ static u32 coreindexonchip;
 static u32 htmtype;
 static u32 htmconfigure;
 static u32 htmstart;
+static u32 htmsetup;
+
 static struct dentry *htmdump_debugfs_dir;
 
 /*
@@ -284,8 +286,41 @@ static const struct file_operations htminfo_fops = {
 	.open   = simple_open,
 };
 
+static int  htmsetup_set(void *data, u64 val)
+{
+	long rc, ret;
+
+	/*
+	 * Input value: HTM buffer size in the power of 2
+	 * example: hex value 0x21 ( decimal: 33 ) is for
+	 * 8GB
+	 * Invoke H_HTM call with:
+	 * - operation as htm start (H_HTM_OP_SETUP)
+	 * - parameter 1 set to input value.
+	 * - last two values are unused, hence set to zero
+	 */
+	rc = htm_hcall_wrapper(nodeindex, nodalchipindex, coreindexonchip,
+			htmtype, H_HTM_OP_SETUP, val, 0, 0);
+
+	ret = htm_return_check(rc);
+	if (ret <= 0)
+		return ret;
+
+	/* Set htmsetup if H_HTM_OP_SETUP operation succeeds */
+	htmsetup = val;
+
+	return 0;
+}
+
+static int htmsetup_get(void *data, u64 *val)
+{
+	*val = htmsetup;
+	return 0;
+}
+
 DEFINE_SIMPLE_ATTRIBUTE(htmconfigure_fops, htmconfigure_get, htmconfigure_set, "%llu\n");
 DEFINE_SIMPLE_ATTRIBUTE(htmstart_fops, htmstart_get, htmstart_set, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(htmsetup_fops, htmsetup_get, htmsetup_set, "%llu\n");
 
 static int htmdump_init_debugfs(void)
 {
@@ -313,6 +348,7 @@ static int htmdump_init_debugfs(void)
 	 */
 	debugfs_create_file("htmconfigure", 0600, htmdump_debugfs_dir, NULL, &htmconfigure_fops);
 	debugfs_create_file("htmstart", 0600, htmdump_debugfs_dir, NULL, &htmstart_fops);
+	debugfs_create_file("htmsetup", 0600, htmdump_debugfs_dir, NULL, &htmsetup_fops);
 
 	/* Debugfs interface file to present status of HTM */
 	htm_status_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-- 
2.43.5