Update FW initialised state shared resource access with READ/WRITE_ONCE
to prevent any complier optimization and ensure atomicity of operation.

Signed-off-by: Brajesh Gupta <[email protected]>
---
 drivers/gpu/drm/imagination/pvr_device.c |  2 +-
 drivers/gpu/drm/imagination/pvr_fw.c     |  4 ++--
 drivers/gpu/drm/imagination/pvr_mmu.c    |  2 +-
 drivers/gpu/drm/imagination/pvr_power.c  | 10 +++++-----
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/imagination/pvr_device.c 
b/drivers/gpu/drm/imagination/pvr_device.c
index 49696101b547..2691ef9af0ca 100644
--- a/drivers/gpu/drm/imagination/pvr_device.c
+++ b/drivers/gpu/drm/imagination/pvr_device.c
@@ -213,7 +213,7 @@ static irqreturn_t pvr_device_irq_thread_handler(int irq, 
void *data)
        while (pvr_fw_irq_pending(pvr_dev)) {
                pvr_fw_irq_clear(pvr_dev);
 
-               if (pvr_dev->fw_dev.initialised) {
+               if (READ_ONCE(pvr_dev->fw_dev.initialised)) {
                        pvr_fwccb_process(pvr_dev);
                        pvr_kccb_wake_up_waiters(pvr_dev);
                        pvr_device_process_active_queues(pvr_dev);
diff --git a/drivers/gpu/drm/imagination/pvr_fw.c 
b/drivers/gpu/drm/imagination/pvr_fw.c
index b8ad3f1d222c..850a3ec8e775 100644
--- a/drivers/gpu/drm/imagination/pvr_fw.c
+++ b/drivers/gpu/drm/imagination/pvr_fw.c
@@ -1004,7 +1004,7 @@ pvr_fw_init(struct pvr_device *pvr_dev)
                goto err_fw_stop;
        }
 
-       fw_dev->initialised = true;
+       WRITE_ONCE(fw_dev->initialised, true);
 
        return 0;
 
@@ -1044,7 +1044,7 @@ pvr_fw_fini(struct pvr_device *pvr_dev)
 {
        struct pvr_fw_device *fw_dev = &pvr_dev->fw_dev;
 
-       fw_dev->initialised = false;
+       WRITE_ONCE(fw_dev->initialised, false);
 
        pvr_fw_destroy_structures(pvr_dev);
        pvr_fw_object_unmap_and_destroy(pvr_dev->kccb.rtn_obj);
diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c 
b/drivers/gpu/drm/imagination/pvr_mmu.c
index e9fefcc4e234..3cac482e1034 100644
--- a/drivers/gpu/drm/imagination/pvr_mmu.c
+++ b/drivers/gpu/drm/imagination/pvr_mmu.c
@@ -134,7 +134,7 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool 
wait)
                return -EIO;
 
        /* Can't flush MMU if the firmware hasn't been initialised yet. */
-       if (!pvr_dev->fw_dev.initialised)
+       if (!READ_ONCE(pvr_dev->fw_dev.initialised))
                goto err_drm_dev_exit;
 
        cmd_mmu_cache_data->cache_flags =
diff --git a/drivers/gpu/drm/imagination/pvr_power.c 
b/drivers/gpu/drm/imagination/pvr_power.c
index a73a6815306b..0ed9e7be604b 100644
--- a/drivers/gpu/drm/imagination/pvr_power.c
+++ b/drivers/gpu/drm/imagination/pvr_power.c
@@ -216,7 +216,7 @@ pvr_watchdog_worker(struct work_struct *work)
        if (pm_runtime_get_if_in_use(from_pvr_device(pvr_dev)->dev) <= 0)
                goto out_requeue;
 
-       if (!pvr_dev->fw_dev.initialised)
+       if (!READ_ONCE(pvr_dev->fw_dev.initialised))
                goto out_pm_runtime_put;
 
        stalled = pvr_watchdog_kccb_stalled(pvr_dev);
@@ -378,7 +378,7 @@ pvr_power_device_suspend(struct device *dev)
        if (!drm_dev_enter(drm_dev, &idx))
                return -EIO;
 
-       if (pvr_dev->fw_dev.initialised) {
+       if (READ_ONCE(pvr_dev->fw_dev.initialised)) {
                err = pvr_power_fw_disable(pvr_dev, false);
                if (err)
                        goto err_drm_dev_exit;
@@ -408,7 +408,7 @@ pvr_power_device_resume(struct device *dev)
        if (err)
                goto err_drm_dev_exit;
 
-       if (pvr_dev->fw_dev.initialised) {
+       if (READ_ONCE(pvr_dev->fw_dev.initialised)) {
                err = pvr_power_fw_enable(pvr_dev);
                if (err)
                        goto err_power_off;
@@ -548,7 +548,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
                err = pvr_power_fw_disable(pvr_dev, hard_reset, false);
                if (!err) {
                        if (hard_reset) {
-                               pvr_dev->fw_dev.initialised = false;
+                               WRITE_ONCE(pvr_dev->fw_dev.initialised, false);
                                
WARN_ON(pvr_power_device_suspend(from_pvr_device(pvr_dev)->dev));
 
                                err = pvr_fw_hard_reset(pvr_dev);
@@ -556,7 +556,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
                                        goto err_device_lost;
 
                                err = 
pvr_power_device_resume(from_pvr_device(pvr_dev)->dev);
-                               pvr_dev->fw_dev.initialised = true;
+                               WRITE_ONCE(pvr_dev->fw_dev.initialised, true);
                                if (err)
                                        goto err_device_lost;
                        } else {

-- 
2.43.0

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