SPT LTR_IGN register provides a means to make the PMC ignore the LTR values
reported by the individual PCH devices.
echo <IP Offset> > /sys/kernel/debug/pmc_core/ltr_ignore.
When a particular IP Offset bit is set the PMC will ignore the LTR value
reported by the corresponding IP when the PMC performs the latency
coalescing.
IP Offset IP Name
0 SPA
1 SPB
2 SATA
3 GBE
4 XHCI
5 RSVD
6 ME
7 EVA
8 SPC
9 Azalia/ADSP
10 RSVD
11 LPSS
12 SPD
13 SPE
14 Camera
15 ESPI
16 SCC
17 ISH
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx>
---
drivers/platform/x86/intel_pmc_core.c | 57 ++++++++++++++++++++++++++++++++++-
drivers/platform/x86/intel_pmc_core.h | 2 ++
2 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index 4840158..5b867b7 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -19,11 +19,12 @@
*/
#include <linux/debugfs.h>
+#include <linux/delay.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/pci.h>
-#include <linux/delay.h>
+#include <linux/uaccess.h>
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
@@ -373,6 +374,53 @@ static const struct file_operations pmc_core_pll_ops = {
.release = single_release,
};
+static ssize_t pmc_core_ltr_ignore_write(struct file *file, const char __user
+*userbuf, size_t count, loff_t *ppos)
+{
+ u32 val, buf_size, fd;
+ int err = 0;
+ struct pmc_dev *pmcdev = &pmc;
+
+ buf_size = count < 64 ? count : 64;
+ mutex_lock(&pmcdev->lock);
+
+ if (kstrtou32_from_user(userbuf, buf_size, 10, &val)) {
+ err = -EFAULT;
+ goto out_unlock;
+ }
+
+ if (val > NUM_IP_IGN_ALLOWED) {
+ err = -EINVAL;
+ goto out_unlock;
+ }
+
+ fd = pmc_core_reg_read(pmcdev, SPT_PMC_LTR_IGNORE_OFFSET);
+ fd |= (1U << val);
+ pmc_core_reg_write(pmcdev, SPT_PMC_LTR_IGNORE_OFFSET, fd);
+
+out_unlock:
+ mutex_unlock(&pmcdev->lock);
+ return err == 0 ? count : err;
+}
+
+static int pmc_core_ltr_ignore_show(struct seq_file *s, void *unused)
+{
+ return 0;
+}
+
+static int pmc_core_ltr_ignore_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, pmc_core_ltr_ignore_show, inode->i_private);
+}
+
+static const struct file_operations pmc_core_ltr_ignore_ops = {
+ .open = pmc_core_ltr_ignore_open,
+ .read = seq_read,
+ .write = pmc_core_ltr_ignore_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
{
debugfs_remove_recursive(pmcdev->dbgfs_dir);
@@ -410,6 +458,13 @@ static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
if (!file)
goto err;
+ file = debugfs_create_file("ltr_ignore",
+ S_IFREG | S_IRUGO, dir, pmcdev,
+ &pmc_core_ltr_ignore_ops);
+
+ if (!file)
+ goto err;
+
return 0;
err:
pmc_core_dbgfs_unregister(pmcdev);
diff --git a/drivers/platform/x86/intel_pmc_core.h b/drivers/platform/x86/intel_pmc_core.h
index 07161fb..5a48e77 100644
--- a/drivers/platform/x86/intel_pmc_core.h
+++ b/drivers/platform/x86/intel_pmc_core.h
@@ -30,6 +30,7 @@
#define SPT_PMC_PM_STS_OFFSET 0x1c
#define SPT_PMC_MTPMC_OFFSET 0x20
#define SPT_PMC_MFPMC_OFFSET 0x38
+#define SPT_PMC_LTR_IGNORE_OFFSET 0x30C
#define SPT_PMC_MPHY_CORE_STS_0 0x1143
#define SPT_PMC_MPHY_CORE_STS_1 0x1142
#define SPT_PMC_MPHY_COM_STS_0 0x1155
@@ -41,6 +42,7 @@
#define SPT_PMC_READ_DISABLE_BIT 0x16
#define SPT_PMC_MSG_FULL_STS_BIT 0x18
#define NUM_RETRIES 100
+#define NUM_IP_IGN_ALLOWED 17
/* Sunrise Point: PGD PFET Enable Ack Status Registers */
enum ppfear_regs {
--
1.9.1
--
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