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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>
This commit is contained in:
Kuppuswamy Sathyanarayanan 2017-10-07 15:19:51 -07:00 committed by Andy Shevchenko
parent 83beee5c88
commit 6687aeb9cd
1 changed files with 13 additions and 8 deletions
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21
drivers/platform/x86/intel_pmc_ipc.c
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@ -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) {