linux-kernel - [PATCH 9/9] platform/x86:intel/pmc: Add support to undo ltr

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Date: Mon, 24 Jun 2024 13:32:18 -0700
From: Xi Pardee <xi.pardee@...ux.intel.com>
To: xi.pardee@...ux.intel.com,
	irenic.rajneesh@...il.com,
	david.e.box@...ux.intel.com,
	hdegoede@...hat.com,
	ilpo.jarvinen@...ux.intel.com,
	platform-driver-x86@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 9/9] platform/x86:intel/pmc: Add support to undo ltr_ignore

Add ltr_restore support to undo the ltr_ignore action. It sets the
ltr_ignore bit of the corresponding IP to 0. Ltr_restore reuses some
functionality of pmc_core_ltr_ignore_write() so moved the common
functionality into a helper function.

Signed-off-by: Xi Pardee <xi.pardee@...ux.intel.com>
---
 drivers/platform/x86/intel/pmc/core.c | 38 ++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index cfdacb04ff8d..9dbd3a43ddad 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -507,12 +507,10 @@ int pmc_core_send_ltr_ignore(struct pmc_dev *pmcdev, u32 value, int ignore)
 	return 0;
 }
 
-static ssize_t pmc_core_ltr_ignore_write(struct file *file,
-					 const char __user *userbuf,
-					 size_t count, loff_t *ppos)
+static ssize_t pmc_core_ltr_write(struct pmc_dev *pmcdev,
+				  const char __user *userbuf,
+				  size_t count, int ignore)
 {
-	struct seq_file *s = file->private_data;
-	struct pmc_dev *pmcdev = s->private;
 	u32 value;
 	int err;
 
@@ -520,17 +518,43 @@ static ssize_t pmc_core_ltr_ignore_write(struct file *file,
 	if (err)
 		return err;
 
-	err = pmc_core_send_ltr_ignore(pmcdev, value, 1);
+	err = pmc_core_send_ltr_ignore(pmcdev, value, ignore);
 
 	return err ?: count;
 }
 
+static ssize_t pmc_core_ltr_ignore_write(struct file *file,
+					 const char __user *userbuf,
+					 size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct pmc_dev *pmcdev = s->private;
+
+	return pmc_core_ltr_write(pmcdev, userbuf, count, 1);
+}
+
 static int pmc_core_ltr_ignore_show(struct seq_file *s, void *unused)
 {
 	return 0;
 }
 DEFINE_SHOW_STORE_ATTRIBUTE(pmc_core_ltr_ignore);
 
+static ssize_t pmc_core_ltr_restore_write(struct file *file,
+					  const char __user *userbuf,
+					  size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct pmc_dev *pmcdev = s->private;
+
+	return pmc_core_ltr_write(pmcdev, userbuf, count, 0);
+}
+
+static int pmc_core_ltr_restore_show(struct seq_file *s, void *unused)
+{
+	return 0;
+}
+DEFINE_SHOW_STORE_ATTRIBUTE(pmc_core_ltr_restore);
+
 static void pmc_core_slps0_dbg_latch(struct pmc_dev *pmcdev, bool reset)
 {
 	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
@@ -1208,6 +1232,8 @@ static void pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
 	debugfs_create_file("ltr_ignore", 0644, dir, pmcdev,
 			    &pmc_core_ltr_ignore_fops);
 
+	debugfs_create_file("ltr_restore", 0200, dir, pmcdev, &pmc_core_ltr_restore_fops);
+
 	debugfs_create_file("ltr_show", 0444, dir, pmcdev, &pmc_core_ltr_fops);
 
 	if (primary_pmc->map->s0ix_blocker_maps)
-- 
2.34.1