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authorKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>2017-10-07 15:19:51 -0700
committerAndy Shevchenko <andriy.shevchenko@linux.intel.com>2017-10-23 20:16:36 +0300
commit6687aeb9cd3d40904d1f9e884d2145603c23adfa (patch)
tree22ff9a06a7b2be7f928cbeade5a25910350d3739 /drivers
parent83beee5c88a6c71ded70e2eef5ca7406a02605cc (diff)
platform/x86: intel_pmc_ipc: Use spin_lock to protect GCR updates
Currently, update_no_reboot_bit() function implemented in this driver uses mutex_lock() to protect its register updates. But this function is called with in atomic context in iTCO_wdt_start() and iTCO_wdt_stop() functions in iTCO_wdt.c driver, which in turn causes "sleeping into atomic context" issue. This patch fixes this issue by replacing the mutex_lock() with spin_lock() to protect the GCR read/write/update APIs. Fixes: 9d855d4 ("platform/x86: intel_pmc_ipc: Fix iTCO_wdt GCS memory mapping failure") Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kupuswamy@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/platform/x86/intel_pmc_ipc.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c
index 751b1212d01c..e03fa31446ca 100644
--- a/drivers/platform/x86/intel_pmc_ipc.c
+++ b/drivers/platform/x86/intel_pmc_ipc.c
@@ -33,6 +33,7 @@
#include <linux/suspend.h>
#include <linux/acpi.h>
#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/spinlock.h>
#include <asm/intel_pmc_ipc.h>
@@ -131,6 +132,7 @@ static struct intel_pmc_ipc_dev {
/* gcr */
void __iomem *gcr_mem_base;
bool has_gcr_regs;
+ spinlock_t gcr_lock;
/* punit */
struct platform_device *punit_dev;
@@ -225,17 +227,17 @@ int intel_pmc_gcr_read(u32 offset, u32 *data)
{
int ret;
- mutex_lock(&ipclock);
+ spin_lock(&ipcdev.gcr_lock);
ret = is_gcr_valid(offset);
if (ret < 0) {
- mutex_unlock(&ipclock);
+ spin_unlock(&ipcdev.gcr_lock);
return ret;
}
*data = readl(ipcdev.gcr_mem_base + offset);
- mutex_unlock(&ipclock);
+ spin_unlock(&ipcdev.gcr_lock);
return 0;
}
@@ -255,17 +257,17 @@ int intel_pmc_gcr_write(u32 offset, u32 data)
{
int ret;
- mutex_lock(&ipclock);
+ spin_lock(&ipcdev.gcr_lock);
ret = is_gcr_valid(offset);
if (ret < 0) {
- mutex_unlock(&ipclock);
+ spin_unlock(&ipcdev.gcr_lock);
return ret;
}
writel(data, ipcdev.gcr_mem_base + offset);
- mutex_unlock(&ipclock);
+ spin_unlock(&ipcdev.gcr_lock);
return 0;
}
@@ -287,7 +289,7 @@ int intel_pmc_gcr_update(u32 offset, u32 mask, u32 val)
u32 new_val;
int ret = 0;
- mutex_lock(&ipclock);
+ spin_lock(&ipcdev.gcr_lock);
ret = is_gcr_valid(offset);
if (ret < 0)
@@ -309,7 +311,7 @@ int intel_pmc_gcr_update(u32 offset, u32 mask, u32 val)
}
gcr_ipc_unlock:
- mutex_unlock(&ipclock);
+ spin_unlock(&ipcdev.gcr_lock);
return ret;
}
EXPORT_SYMBOL_GPL(intel_pmc_gcr_update);
@@ -489,6 +491,8 @@ static int ipc_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
pmc->irq_mode = IPC_TRIGGER_MODE_IRQ;
+ spin_lock_init(&ipcdev.gcr_lock);
+
ret = pcim_enable_device(pdev);
if (ret)
return ret;
@@ -903,6 +907,7 @@ static int ipc_plat_probe(struct platform_device *pdev)
ipcdev.dev = &pdev->dev;
ipcdev.irq_mode = IPC_TRIGGER_MODE_IRQ;
init_completion(&ipcdev.cmd_complete);
+ spin_lock_init(&ipcdev.gcr_lock);
ipcdev.irq = platform_get_irq(pdev, 0);
if (ipcdev.irq < 0) {