* [PATCH] drm/imagination: On device loss, handle unplug after critical section
@ 2024-01-23 13:04 Matt Coster
2024-01-25 18:44 ` Daniel Vetter
0 siblings, 1 reply; 4+ messages in thread
From: Matt Coster @ 2024-01-23 13:04 UTC (permalink / raw)
To: dri-devel, Steven Price
Cc: Thomas Zimmermann, Maxime Ripard, Daniel Vetter, David Airlie
[-- Attachment #1.1.1: Type: text/plain, Size: 25222 bytes --]
From: Donald Robson <donald.robson@imgtec.com>
When the kernel driver 'loses' the device, for instance if the firmware
stops communicating, the driver calls drm_dev_unplug(). This is
currently done inside the drm_dev_enter() critical section, which isn't
permitted. In addition, the bool that marks the device as lost is not
atomic or protected by a lock.
This fix replaces the bool with an atomic that also acts as a mechanism
to ensure the device is unplugged after drm_dev_exit(), preventing a
concurrent call to drm_dev_enter() from succeeding in a race between it
and drm_dev_unplug().
Reported-by: Steven Price <steven.price@arm.com>
Closes: https://lore.kernel.org/dri-devel/1b957ca4-71cf-42fd-ac81-1920592b952d@arm.com/
Fixes: cc1aeedb98ad ("drm/imagination: Implement firmware infrastructure and META FW support")
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
---
drivers/gpu/drm/imagination/pvr_ccb.c | 2 +-
drivers/gpu/drm/imagination/pvr_device.c | 98 +++++++++++++++++++++-
drivers/gpu/drm/imagination/pvr_device.h | 72 +++++++++++++---
drivers/gpu/drm/imagination/pvr_drv.c | 87 ++++++++++---------
drivers/gpu/drm/imagination/pvr_fw.c | 12 +--
drivers/gpu/drm/imagination/pvr_fw_trace.c | 4 +-
drivers/gpu/drm/imagination/pvr_mmu.c | 20 ++---
drivers/gpu/drm/imagination/pvr_power.c | 42 +++-------
drivers/gpu/drm/imagination/pvr_power.h | 2 -
9 files changed, 237 insertions(+), 102 deletions(-)
diff --git a/drivers/gpu/drm/imagination/pvr_ccb.c b/drivers/gpu/drm/imagination/pvr_ccb.c
index 4deeac7ed40a..1fe64adc0c2c 100644
--- a/drivers/gpu/drm/imagination/pvr_ccb.c
+++ b/drivers/gpu/drm/imagination/pvr_ccb.c
@@ -247,7 +247,7 @@ pvr_kccb_send_cmd_reserved_powered(struct pvr_device *pvr_dev,
u32 old_write_offset;
u32 new_write_offset;
- WARN_ON(pvr_dev->lost);
+ WARN_ON(pvr_device_is_lost(pvr_dev));
mutex_lock(&pvr_ccb->lock);
diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c
index 1704c0268589..397491375b7d 100644
--- a/drivers/gpu/drm/imagination/pvr_device.c
+++ b/drivers/gpu/drm/imagination/pvr_device.c
@@ -6,14 +6,15 @@
#include "pvr_fw.h"
#include "pvr_params.h"
-#include "pvr_power.h"
#include "pvr_queue.h"
#include "pvr_rogue_cr_defs.h"
#include "pvr_stream.h"
#include "pvr_vm.h"
+#include <drm/drm_drv.h>
#include <drm/drm_print.h>
+#include <linux/atomic.h>
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/compiler_attributes.h>
@@ -556,6 +557,101 @@ pvr_device_fini(struct pvr_device *pvr_dev)
pvr_device_gpu_fini(pvr_dev);
}
+/**
+ * pvr_device_enter() - Try to enter device critical section.
+ * @pvr_dev: Target PowerVR device.
+ * @idx: Pointer to index that will be passed to the matching pvr_device_exit().
+ *
+ * Use this in place of drm_dev_enter() within this driver.
+ *
+ * Returns:
+ * * %true if the critical section was entered, or
+ * * %false otherwise.
+ */
+bool pvr_device_enter(struct pvr_device *pvr_dev, int *idx)
+{
+ const enum pvr_device_state old_state =
+ atomic_cmpxchg(&pvr_dev->state,
+ PVR_DEVICE_STATE_PRESENT,
+ PVR_DEVICE_STATE_ENTERED);
+
+ switch (old_state) {
+ case PVR_DEVICE_STATE_PRESENT:
+ case PVR_DEVICE_STATE_ENTERED:
+ return drm_dev_enter(from_pvr_device(pvr_dev), idx);
+
+ case PVR_DEVICE_STATE_LOST:
+ case PVR_DEVICE_STATE_LOST_UNPLUGGED:
+ WARN_ONCE(1, "Attempt to use GPU after becoming lost.");
+ break;
+ }
+
+ return false;
+}
+
+/**
+ * pvr_device_exit() - Exit a device critical section.
+ * @pvr_dev: Target PowerVR device.
+ * @idx: Index given by matching pvr_device_enter().
+ *
+ * Use this in place of drm_dev_exit() within this driver.
+ */
+void pvr_device_exit(struct pvr_device *pvr_dev, int idx)
+{
+ const enum pvr_device_state old_state =
+ atomic_cmpxchg(&pvr_dev->state,
+ PVR_DEVICE_STATE_ENTERED,
+ PVR_DEVICE_STATE_PRESENT);
+
+ switch (old_state) {
+ case PVR_DEVICE_STATE_PRESENT:
+ case PVR_DEVICE_STATE_ENTERED:
+ drm_dev_exit(idx);
+ return;
+
+ case PVR_DEVICE_STATE_LOST:
+ /* Unplug the device if it was lost during the critical section. */
+ atomic_set(&pvr_dev->state, PVR_DEVICE_STATE_LOST_UNPLUGGED);
+
+ drm_dev_exit(idx);
+
+ WARN_ONCE(1, "GPU lost and now unplugged.");
+ drm_dev_unplug(from_pvr_device(pvr_dev));
+
+ return;
+
+ case PVR_DEVICE_STATE_LOST_UNPLUGGED:
+ WARN_ONCE(1, "GPU unplugged during critical section.");
+ drm_dev_exit(idx);
+ return;
+ }
+}
+
+/**
+ * pvr_device_set_lost() - Mark GPU device as lost.
+ * @pvr_dev: Target PowerVR device.
+ *
+ * This will cause the DRM device to be unplugged at the next call to
+ * pvr_device_exit().
+ */
+void pvr_device_set_lost(struct pvr_device *pvr_dev)
+{
+ /*
+ * Unplug the device immediately if the device is not in a critical
+ * section.
+ */
+ const bool unplug = atomic_cmpxchg(&pvr_dev->state,
+ PVR_DEVICE_STATE_PRESENT,
+ PVR_DEVICE_STATE_LOST_UNPLUGGED) ==
+ PVR_DEVICE_STATE_PRESENT;
+
+ if (unplug)
+ drm_dev_unplug(from_pvr_device(pvr_dev));
+ else
+ atomic_cmpxchg(&pvr_dev->state, PVR_DEVICE_STATE_ENTERED,
+ PVR_DEVICE_STATE_LOST);
+}
+
bool
pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk)
{
diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h
index ecdd5767d8ef..7c08b2bda395 100644
--- a/drivers/gpu/drm/imagination/pvr_device.h
+++ b/drivers/gpu/drm/imagination/pvr_device.h
@@ -274,20 +274,19 @@ struct pvr_device {
} kccb;
/**
- * @lost: %true if the device has been lost.
- *
- * This variable is set if the device has become irretrievably unavailable, e.g. if the
- * firmware processor has stopped responding and can not be revived via a hard reset.
+ * @state: Indicates whether the device is present and in use. One of
+ * &enum pvr_device_state.
*/
- bool lost;
+ atomic_t state;
/**
* @reset_sem: Reset semaphore.
*
- * GPU reset code will lock this for writing. Any code that submits commands to the firmware
- * that isn't in an IRQ handler or on the scheduler workqueue must lock this for reading.
- * Once this has been successfully locked, &pvr_dev->lost _must_ be checked, and -%EIO must
- * be returned if it is set.
+ * GPU reset code will lock this for writing. Any code that submits
+ * commands to the firmware that isn't in an IRQ handler or on the
+ * scheduler workqueue must lock this for reading.
+ * Once this has been successfully locked, pvr_device_is_lost() _must_
+ * be checked, and -%EIO must be returned if it is.
*/
struct rw_semaphore reset_sem;
@@ -487,7 +486,60 @@ packed_bvnc_to_pvr_gpu_id(u64 bvnc, struct pvr_gpu_id *gpu_id)
int pvr_device_init(struct pvr_device *pvr_dev);
void pvr_device_fini(struct pvr_device *pvr_dev);
-void pvr_device_reset(struct pvr_device *pvr_dev);
+
+/**
+ * enum pvr_device_state - States used by &struct pvr_device.state.
+ */
+enum pvr_device_state {
+ /** @PVR_DEVICE_STATE_PRESENT: The device is available for use. */
+ PVR_DEVICE_STATE_PRESENT,
+
+ /** @PVR_DEVICE_STATE_ENTERED: The device is in a critical section. */
+ PVR_DEVICE_STATE_ENTERED,
+
+ /**
+ * @PVR_DEVICE_STATE_LOST: The device was lost during the current device
+ * critical section and will be unplugged once the section exits.
+ */
+ PVR_DEVICE_STATE_LOST,
+
+ /**
+ * @PVR_DEVICE_STATE_LOST_UNPLUGGED: The device was lost and
+ * subsequently unplugged.
+ *
+ * The device may become irretrievably unavailable, e.g. if the firmware
+ * processor has stopped responding and can not be revived via a hard
+ * reset.
+ */
+ PVR_DEVICE_STATE_LOST_UNPLUGGED,
+};
+
+/**
+ * pvr_device_is_lost() - Check if GPU device has been marked lost.
+ * @pvr_dev: Target PowerVR device.
+ *
+ * Returns:
+ * * %true if device is lost, or
+ * * %false otherwise.
+ */
+static __always_inline bool pvr_device_is_lost(struct pvr_device *pvr_dev)
+{
+ switch ((enum pvr_device_state)atomic_read(&pvr_dev->state)) {
+ case PVR_DEVICE_STATE_PRESENT:
+ case PVR_DEVICE_STATE_ENTERED:
+ return false;
+
+ case PVR_DEVICE_STATE_LOST:
+ case PVR_DEVICE_STATE_LOST_UNPLUGGED:
+ break;
+ }
+
+ return true;
+}
+
+bool pvr_device_enter(struct pvr_device *pvr_dev, int *idx);
+void pvr_device_exit(struct pvr_device *pvr_dev, int idx);
+void pvr_device_set_lost(struct pvr_device *pvr_dev);
bool
pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk);
diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c
index 5c3b2d58d766..55bea656a40f 100644
--- a/drivers/gpu/drm/imagination/pvr_drv.c
+++ b/drivers/gpu/drm/imagination/pvr_drv.c
@@ -81,13 +81,13 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
int idx;
int err;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
/* All padding fields must be zeroed. */
if (args->_padding_c != 0) {
err = -EINVAL;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
/*
@@ -101,7 +101,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
if (args->size > SIZE_MAX || args->size == 0 || args->flags &
~DRM_PVR_BO_FLAGS_MASK || args->size & (PVR_DEVICE_PAGE_SIZE - 1)) {
err = -EINVAL;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
sanitized_size = (size_t)args->size;
@@ -113,7 +113,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
pvr_obj = pvr_gem_object_create(pvr_dev, sanitized_size, args->flags);
if (IS_ERR(pvr_obj)) {
err = PTR_ERR(pvr_obj);
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
/* This function will not modify &args->handle unless it succeeds. */
@@ -121,7 +121,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
if (err)
goto err_destroy_obj;
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return 0;
@@ -133,8 +133,8 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
*/
pvr_gem_object_put(pvr_obj);
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return err;
}
@@ -164,19 +164,20 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
struct drm_file *file)
{
struct drm_pvr_ioctl_get_bo_mmap_offset_args *args = raw_args;
+ struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
struct pvr_file *pvr_file = to_pvr_file(file);
struct pvr_gem_object *pvr_obj;
struct drm_gem_object *gem_obj;
int idx;
int ret;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
/* All padding fields must be zeroed. */
if (args->_padding_4 != 0) {
ret = -EINVAL;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
/*
@@ -188,7 +189,7 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
pvr_obj = pvr_gem_object_from_handle(pvr_file, args->handle);
if (!pvr_obj) {
ret = -ENOENT;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
gem_obj = gem_from_pvr_gem(pvr_obj);
@@ -202,7 +203,7 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
if (ret != 0) {
/* Drop our reference to the buffer object. */
drm_gem_object_put(gem_obj);
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
/*
@@ -214,8 +215,8 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
/* Drop our reference to the buffer object. */
pvr_gem_object_put(pvr_obj);
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return ret;
}
@@ -626,7 +627,7 @@ pvr_ioctl_dev_query(struct drm_device *drm_dev, void *raw_args,
int idx;
int ret = -EINVAL;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
switch ((enum drm_pvr_dev_query)args->type) {
@@ -655,7 +656,7 @@ pvr_ioctl_dev_query(struct drm_device *drm_dev, void *raw_args,
break;
}
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return ret;
}
@@ -680,16 +681,17 @@ pvr_ioctl_create_context(struct drm_device *drm_dev, void *raw_args,
struct drm_file *file)
{
struct drm_pvr_ioctl_create_context_args *args = raw_args;
+ struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
struct pvr_file *pvr_file = file->driver_priv;
int idx;
int ret;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
ret = pvr_context_create(pvr_file, args);
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return ret;
}
@@ -738,18 +740,19 @@ pvr_ioctl_create_free_list(struct drm_device *drm_dev, void *raw_args,
struct drm_file *file)
{
struct drm_pvr_ioctl_create_free_list_args *args = raw_args;
+ struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
struct pvr_file *pvr_file = to_pvr_file(file);
struct pvr_free_list *free_list;
int idx;
int err;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
free_list = pvr_free_list_create(pvr_file, args);
if (IS_ERR(free_list)) {
err = PTR_ERR(free_list);
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
/* Allocate object handle for userspace. */
@@ -761,15 +764,15 @@ pvr_ioctl_create_free_list(struct drm_device *drm_dev, void *raw_args,
if (err < 0)
goto err_cleanup;
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return 0;
err_cleanup:
pvr_free_list_put(free_list);
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return err;
}
@@ -824,18 +827,19 @@ pvr_ioctl_create_hwrt_dataset(struct drm_device *drm_dev, void *raw_args,
struct drm_file *file)
{
struct drm_pvr_ioctl_create_hwrt_dataset_args *args = raw_args;
+ struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
struct pvr_file *pvr_file = to_pvr_file(file);
struct pvr_hwrt_dataset *hwrt;
int idx;
int err;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
hwrt = pvr_hwrt_dataset_create(pvr_file, args);
if (IS_ERR(hwrt)) {
err = PTR_ERR(hwrt);
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
/* Allocate object handle for userspace. */
@@ -847,15 +851,15 @@ pvr_ioctl_create_hwrt_dataset(struct drm_device *drm_dev, void *raw_args,
if (err < 0)
goto err_cleanup;
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return 0;
err_cleanup:
pvr_hwrt_dataset_put(hwrt);
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return err;
}
@@ -910,23 +914,24 @@ pvr_ioctl_create_vm_context(struct drm_device *drm_dev, void *raw_args,
struct drm_file *file)
{
struct drm_pvr_ioctl_create_vm_context_args *args = raw_args;
+ struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
struct pvr_file *pvr_file = to_pvr_file(file);
struct pvr_vm_context *vm_ctx;
int idx;
int err;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
if (args->_padding_4) {
err = -EINVAL;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
vm_ctx = pvr_vm_create_context(pvr_file->pvr_dev, true);
if (IS_ERR(vm_ctx)) {
err = PTR_ERR(vm_ctx);
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
/* Allocate object handle for userspace. */
@@ -938,15 +943,15 @@ pvr_ioctl_create_vm_context(struct drm_device *drm_dev, void *raw_args,
if (err < 0)
goto err_cleanup;
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return 0;
err_cleanup:
pvr_vm_context_put(vm_ctx);
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return err;
}
@@ -1022,26 +1027,26 @@ pvr_ioctl_vm_map(struct drm_device *drm_dev, void *raw_args,
int idx;
int err;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
/* Initial validation of args. */
if (args->_padding_14) {
err = -EINVAL;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
if (args->flags != 0 ||
check_add_overflow(args->offset, args->size, &offset_plus_size) ||
!pvr_find_heap_containing(pvr_dev, args->device_addr, args->size)) {
err = -EINVAL;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
vm_ctx = pvr_vm_context_lookup(pvr_file, args->vm_context_handle);
if (!vm_ctx) {
err = -EINVAL;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
pvr_obj = pvr_gem_object_from_handle(pvr_file, args->handle);
@@ -1079,8 +1084,8 @@ pvr_ioctl_vm_map(struct drm_device *drm_dev, void *raw_args,
err_put_vm_context:
pvr_vm_context_put(vm_ctx);
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return err;
}
@@ -1148,12 +1153,12 @@ pvr_ioctl_submit_jobs(struct drm_device *drm_dev, void *raw_args,
int idx;
int err;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
err = pvr_submit_jobs(pvr_dev, pvr_file, args);
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return err;
}
diff --git a/drivers/gpu/drm/imagination/pvr_fw.c b/drivers/gpu/drm/imagination/pvr_fw.c
index 3debc9870a82..07547e167963 100644
--- a/drivers/gpu/drm/imagination/pvr_fw.c
+++ b/drivers/gpu/drm/imagination/pvr_fw.c
@@ -1094,7 +1094,7 @@ pvr_fw_structure_cleanup(struct pvr_device *pvr_dev, u32 type, struct pvr_fw_obj
down_read(&pvr_dev->reset_sem);
- if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx)) {
+ if (!pvr_device_enter(pvr_dev, &idx)) {
err = -EIO;
goto err_up_read;
}
@@ -1118,22 +1118,22 @@ pvr_fw_structure_cleanup(struct pvr_device *pvr_dev, u32 type, struct pvr_fw_obj
break;
default:
err = -EINVAL;
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
err = pvr_kccb_send_cmd(pvr_dev, &cmd, &slot_nr);
if (err)
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
err = pvr_kccb_wait_for_completion(pvr_dev, slot_nr, HZ, &rtn);
if (err)
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
if (rtn & ROGUE_FWIF_KCCB_RTN_SLOT_CLEANUP_BUSY)
err = -EBUSY;
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
err_up_read:
up_read(&pvr_dev->reset_sem);
diff --git a/drivers/gpu/drm/imagination/pvr_fw_trace.c b/drivers/gpu/drm/imagination/pvr_fw_trace.c
index 31199e45b72e..26d67483eac2 100644
--- a/drivers/gpu/drm/imagination/pvr_fw_trace.c
+++ b/drivers/gpu/drm/imagination/pvr_fw_trace.c
@@ -149,7 +149,7 @@ update_logtype(struct pvr_device *pvr_dev, u32 group_mask)
fw_trace->group_mask = group_mask;
down_read(&pvr_dev->reset_sem);
- if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx)) {
+ if (!pvr_device_enter(pvr_dev, &idx)) {
err = -EIO;
goto err_up_read;
}
@@ -159,7 +159,7 @@ update_logtype(struct pvr_device *pvr_dev, u32 group_mask)
err = pvr_kccb_send_cmd(pvr_dev, &cmd, NULL);
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
err_up_read:
up_read(&pvr_dev->reset_sem);
diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c b/drivers/gpu/drm/imagination/pvr_mmu.c
index 4fe70610ed94..59911f70e9ca 100644
--- a/drivers/gpu/drm/imagination/pvr_mmu.c
+++ b/drivers/gpu/drm/imagination/pvr_mmu.c
@@ -129,18 +129,18 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
u32 slot;
int idx;
- if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
/* Can't flush MMU if the firmware hasn't booted yet. */
if (!pvr_dev->fw_dev.booted)
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
cmd_mmu_cache_data->cache_flags =
atomic_xchg(&pvr_dev->mmu_flush_cache_flags, 0);
if (!cmd_mmu_cache_data->cache_flags)
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
cmd_mmu_cache.cmd_type = ROGUE_FWIF_KCCB_CMD_MMUCACHE;
@@ -156,7 +156,7 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
if (err)
goto err_reset_and_retry;
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return 0;
@@ -167,23 +167,23 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
*/
err = pvr_power_reset(pvr_dev, true);
if (err)
- goto err_drm_dev_exit; /* Device is lost. */
+ goto err_pvr_device_exit; /* Device is lost. */
/* Retry sending flush request. */
err = pvr_kccb_send_cmd(pvr_dev, &cmd_mmu_cache, &slot);
if (err) {
- pvr_device_lost(pvr_dev);
- goto err_drm_dev_exit;
+ pvr_device_set_lost(pvr_dev);
+ goto err_pvr_device_exit;
}
if (wait) {
err = pvr_kccb_wait_for_completion(pvr_dev, slot, HZ, NULL);
if (err)
- pvr_device_lost(pvr_dev);
+ pvr_device_set_lost(pvr_dev);
}
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return err;
}
diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
index ba7816fd28ec..c927def3d3f3 100644
--- a/drivers/gpu/drm/imagination/pvr_power.c
+++ b/drivers/gpu/drm/imagination/pvr_power.c
@@ -23,21 +23,6 @@
#define WATCHDOG_TIME_MS (500)
-/**
- * pvr_device_lost() - Mark GPU device as lost
- * @pvr_dev: Target PowerVR device.
- *
- * This will cause the DRM device to be unplugged.
- */
-void
-pvr_device_lost(struct pvr_device *pvr_dev)
-{
- if (!pvr_dev->lost) {
- pvr_dev->lost = true;
- drm_dev_unplug(from_pvr_device(pvr_dev));
- }
-}
-
static int
pvr_power_send_command(struct pvr_device *pvr_dev, struct rogue_fwif_kccb_cmd *pow_cmd)
{
@@ -186,7 +171,7 @@ pvr_watchdog_worker(struct work_struct *work)
watchdog.work.work);
bool stalled;
- if (pvr_dev->lost)
+ if (pvr_device_is_lost(pvr_dev))
return;
if (pm_runtime_get_if_in_use(from_pvr_device(pvr_dev)->dev) <= 0)
@@ -208,10 +193,9 @@ pvr_watchdog_worker(struct work_struct *work)
pm_runtime_put(from_pvr_device(pvr_dev)->dev);
out_requeue:
- if (!pvr_dev->lost) {
+ if (!pvr_device_is_lost(pvr_dev))
queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,
msecs_to_jiffies(WATCHDOG_TIME_MS));
- }
}
/**
@@ -239,21 +223,21 @@ pvr_power_device_suspend(struct device *dev)
int err = 0;
int idx;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
if (pvr_dev->fw_dev.booted) {
err = pvr_power_fw_disable(pvr_dev, false);
if (err)
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
}
clk_disable_unprepare(pvr_dev->mem_clk);
clk_disable_unprepare(pvr_dev->sys_clk);
clk_disable_unprepare(pvr_dev->core_clk);
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return err;
}
@@ -267,12 +251,12 @@ pvr_power_device_resume(struct device *dev)
int idx;
int err;
- if (!drm_dev_enter(drm_dev, &idx))
+ if (!pvr_device_enter(pvr_dev, &idx))
return -EIO;
err = clk_prepare_enable(pvr_dev->core_clk);
if (err)
- goto err_drm_dev_exit;
+ goto err_pvr_device_exit;
err = clk_prepare_enable(pvr_dev->sys_clk);
if (err)
@@ -288,7 +272,7 @@ pvr_power_device_resume(struct device *dev)
goto err_mem_clk_disable;
}
- drm_dev_exit(idx);
+ pvr_device_exit(pvr_dev, idx);
return 0;
@@ -301,8 +285,8 @@ pvr_power_device_resume(struct device *dev)
err_core_clk_disable:
clk_disable_unprepare(pvr_dev->core_clk);
-err_drm_dev_exit:
- drm_dev_exit(idx);
+err_pvr_device_exit:
+ pvr_device_exit(pvr_dev, idx);
return err;
}
@@ -345,7 +329,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
down_write(&pvr_dev->reset_sem);
- if (pvr_dev->lost) {
+ if (pvr_device_is_lost(pvr_dev)) {
err = -EIO;
goto err_up_write;
}
@@ -407,7 +391,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
err_device_lost:
drm_err(from_pvr_device(pvr_dev), "GPU device lost");
- pvr_device_lost(pvr_dev);
+ pvr_device_set_lost(pvr_dev);
/* Leave IRQs disabled if the device is lost. */
diff --git a/drivers/gpu/drm/imagination/pvr_power.h b/drivers/gpu/drm/imagination/pvr_power.h
index 9a9312dcb2da..360980f454d7 100644
--- a/drivers/gpu/drm/imagination/pvr_power.h
+++ b/drivers/gpu/drm/imagination/pvr_power.h
@@ -12,8 +12,6 @@
int pvr_watchdog_init(struct pvr_device *pvr_dev);
[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 1817 bytes --]
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 236 bytes --]
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] drm/imagination: On device loss, handle unplug after critical section
2024-01-23 13:04 [PATCH] drm/imagination: On device loss, handle unplug after critical section Matt Coster
@ 2024-01-25 18:44 ` Daniel Vetter
2024-01-31 17:22 ` Matt Coster
0 siblings, 1 reply; 4+ messages in thread
From: Daniel Vetter @ 2024-01-25 18:44 UTC (permalink / raw)
To: Matt Coster
Cc: Daniel Vetter, Maxime Ripard, Steven Price, dri-devel,
Thomas Zimmermann, David Airlie
On Tue, Jan 23, 2024 at 01:04:24PM +0000, Matt Coster wrote:
> From: Donald Robson <donald.robson@imgtec.com>
>
> When the kernel driver 'loses' the device, for instance if the firmware
> stops communicating, the driver calls drm_dev_unplug(). This is
> currently done inside the drm_dev_enter() critical section, which isn't
> permitted. In addition, the bool that marks the device as lost is not
> atomic or protected by a lock.
>
> This fix replaces the bool with an atomic that also acts as a mechanism
> to ensure the device is unplugged after drm_dev_exit(), preventing a
> concurrent call to drm_dev_enter() from succeeding in a race between it
> and drm_dev_unplug().
Uh ... atomic_t does not make locking.
From a quick look this entire thing smells a bit like bad design overall,
and my gut feeling is that you probably want to rip out pvr_dev->lost
outright. Or alternatively, explain what exactly this does beyond
drm_dev_enter/exit, and then probably add that functionality there instead
of hand-roll lockless trickery in drivers.
From a quick look keeping track of where you realize the device is lost
and then calling drm_dev_unplug after the drm_dev_exit is probably the
clean solution. That also means the drm_dev_unplug() is not delayed due to
a drm_dev_enter/exit section on a different thread, which is probably a
good thing.
Cheers, Sima
>
> Reported-by: Steven Price <steven.price@arm.com>
> Closes: https://lore.kernel.org/dri-devel/1b957ca4-71cf-42fd-ac81-1920592b952d@arm.com/
> Fixes: cc1aeedb98ad ("drm/imagination: Implement firmware infrastructure and META FW support")
> Signed-off-by: Donald Robson <donald.robson@imgtec.com>
> Signed-off-by: Matt Coster <matt.coster@imgtec.com>
> ---
> drivers/gpu/drm/imagination/pvr_ccb.c | 2 +-
> drivers/gpu/drm/imagination/pvr_device.c | 98 +++++++++++++++++++++-
> drivers/gpu/drm/imagination/pvr_device.h | 72 +++++++++++++---
> drivers/gpu/drm/imagination/pvr_drv.c | 87 ++++++++++---------
> drivers/gpu/drm/imagination/pvr_fw.c | 12 +--
> drivers/gpu/drm/imagination/pvr_fw_trace.c | 4 +-
> drivers/gpu/drm/imagination/pvr_mmu.c | 20 ++---
> drivers/gpu/drm/imagination/pvr_power.c | 42 +++-------
> drivers/gpu/drm/imagination/pvr_power.h | 2 -
> 9 files changed, 237 insertions(+), 102 deletions(-)
>
> diff --git a/drivers/gpu/drm/imagination/pvr_ccb.c b/drivers/gpu/drm/imagination/pvr_ccb.c
> index 4deeac7ed40a..1fe64adc0c2c 100644
> --- a/drivers/gpu/drm/imagination/pvr_ccb.c
> +++ b/drivers/gpu/drm/imagination/pvr_ccb.c
> @@ -247,7 +247,7 @@ pvr_kccb_send_cmd_reserved_powered(struct pvr_device *pvr_dev,
> u32 old_write_offset;
> u32 new_write_offset;
>
> - WARN_ON(pvr_dev->lost);
> + WARN_ON(pvr_device_is_lost(pvr_dev));
>
> mutex_lock(&pvr_ccb->lock);
>
> diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c
> index 1704c0268589..397491375b7d 100644
> --- a/drivers/gpu/drm/imagination/pvr_device.c
> +++ b/drivers/gpu/drm/imagination/pvr_device.c
> @@ -6,14 +6,15 @@
>
> #include "pvr_fw.h"
> #include "pvr_params.h"
> -#include "pvr_power.h"
> #include "pvr_queue.h"
> #include "pvr_rogue_cr_defs.h"
> #include "pvr_stream.h"
> #include "pvr_vm.h"
>
> +#include <drm/drm_drv.h>
> #include <drm/drm_print.h>
>
> +#include <linux/atomic.h>
> #include <linux/bitfield.h>
> #include <linux/clk.h>
> #include <linux/compiler_attributes.h>
> @@ -556,6 +557,101 @@ pvr_device_fini(struct pvr_device *pvr_dev)
> pvr_device_gpu_fini(pvr_dev);
> }
>
> +/**
> + * pvr_device_enter() - Try to enter device critical section.
> + * @pvr_dev: Target PowerVR device.
> + * @idx: Pointer to index that will be passed to the matching pvr_device_exit().
> + *
> + * Use this in place of drm_dev_enter() within this driver.
> + *
> + * Returns:
> + * * %true if the critical section was entered, or
> + * * %false otherwise.
> + */
> +bool pvr_device_enter(struct pvr_device *pvr_dev, int *idx)
> +{
> + const enum pvr_device_state old_state =
> + atomic_cmpxchg(&pvr_dev->state,
> + PVR_DEVICE_STATE_PRESENT,
> + PVR_DEVICE_STATE_ENTERED);
> +
> + switch (old_state) {
> + case PVR_DEVICE_STATE_PRESENT:
> + case PVR_DEVICE_STATE_ENTERED:
> + return drm_dev_enter(from_pvr_device(pvr_dev), idx);
> +
> + case PVR_DEVICE_STATE_LOST:
> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
> + WARN_ONCE(1, "Attempt to use GPU after becoming lost.");
> + break;
> + }
> +
> + return false;
> +}
> +
> +/**
> + * pvr_device_exit() - Exit a device critical section.
> + * @pvr_dev: Target PowerVR device.
> + * @idx: Index given by matching pvr_device_enter().
> + *
> + * Use this in place of drm_dev_exit() within this driver.
> + */
> +void pvr_device_exit(struct pvr_device *pvr_dev, int idx)
> +{
> + const enum pvr_device_state old_state =
> + atomic_cmpxchg(&pvr_dev->state,
> + PVR_DEVICE_STATE_ENTERED,
> + PVR_DEVICE_STATE_PRESENT);
> +
> + switch (old_state) {
> + case PVR_DEVICE_STATE_PRESENT:
> + case PVR_DEVICE_STATE_ENTERED:
> + drm_dev_exit(idx);
> + return;
> +
> + case PVR_DEVICE_STATE_LOST:
> + /* Unplug the device if it was lost during the critical section. */
> + atomic_set(&pvr_dev->state, PVR_DEVICE_STATE_LOST_UNPLUGGED);
> +
> + drm_dev_exit(idx);
> +
> + WARN_ONCE(1, "GPU lost and now unplugged.");
> + drm_dev_unplug(from_pvr_device(pvr_dev));
> +
> + return;
> +
> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
> + WARN_ONCE(1, "GPU unplugged during critical section.");
> + drm_dev_exit(idx);
> + return;
> + }
> +}
> +
> +/**
> + * pvr_device_set_lost() - Mark GPU device as lost.
> + * @pvr_dev: Target PowerVR device.
> + *
> + * This will cause the DRM device to be unplugged at the next call to
> + * pvr_device_exit().
> + */
> +void pvr_device_set_lost(struct pvr_device *pvr_dev)
> +{
> + /*
> + * Unplug the device immediately if the device is not in a critical
> + * section.
> + */
> + const bool unplug = atomic_cmpxchg(&pvr_dev->state,
> + PVR_DEVICE_STATE_PRESENT,
> + PVR_DEVICE_STATE_LOST_UNPLUGGED) ==
> + PVR_DEVICE_STATE_PRESENT;
> +
> + if (unplug)
> + drm_dev_unplug(from_pvr_device(pvr_dev));
> + else
> + atomic_cmpxchg(&pvr_dev->state, PVR_DEVICE_STATE_ENTERED,
> + PVR_DEVICE_STATE_LOST);
> +}
> +
> bool
> pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk)
> {
> diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h
> index ecdd5767d8ef..7c08b2bda395 100644
> --- a/drivers/gpu/drm/imagination/pvr_device.h
> +++ b/drivers/gpu/drm/imagination/pvr_device.h
> @@ -274,20 +274,19 @@ struct pvr_device {
> } kccb;
>
> /**
> - * @lost: %true if the device has been lost.
> - *
> - * This variable is set if the device has become irretrievably unavailable, e.g. if the
> - * firmware processor has stopped responding and can not be revived via a hard reset.
> + * @state: Indicates whether the device is present and in use. One of
> + * &enum pvr_device_state.
> */
> - bool lost;
> + atomic_t state;
>
> /**
> * @reset_sem: Reset semaphore.
> *
> - * GPU reset code will lock this for writing. Any code that submits commands to the firmware
> - * that isn't in an IRQ handler or on the scheduler workqueue must lock this for reading.
> - * Once this has been successfully locked, &pvr_dev->lost _must_ be checked, and -%EIO must
> - * be returned if it is set.
> + * GPU reset code will lock this for writing. Any code that submits
> + * commands to the firmware that isn't in an IRQ handler or on the
> + * scheduler workqueue must lock this for reading.
> + * Once this has been successfully locked, pvr_device_is_lost() _must_
> + * be checked, and -%EIO must be returned if it is.
> */
> struct rw_semaphore reset_sem;
>
> @@ -487,7 +486,60 @@ packed_bvnc_to_pvr_gpu_id(u64 bvnc, struct pvr_gpu_id *gpu_id)
>
> int pvr_device_init(struct pvr_device *pvr_dev);
> void pvr_device_fini(struct pvr_device *pvr_dev);
> -void pvr_device_reset(struct pvr_device *pvr_dev);
> +
> +/**
> + * enum pvr_device_state - States used by &struct pvr_device.state.
> + */
> +enum pvr_device_state {
> + /** @PVR_DEVICE_STATE_PRESENT: The device is available for use. */
> + PVR_DEVICE_STATE_PRESENT,
> +
> + /** @PVR_DEVICE_STATE_ENTERED: The device is in a critical section. */
> + PVR_DEVICE_STATE_ENTERED,
> +
> + /**
> + * @PVR_DEVICE_STATE_LOST: The device was lost during the current device
> + * critical section and will be unplugged once the section exits.
> + */
> + PVR_DEVICE_STATE_LOST,
> +
> + /**
> + * @PVR_DEVICE_STATE_LOST_UNPLUGGED: The device was lost and
> + * subsequently unplugged.
> + *
> + * The device may become irretrievably unavailable, e.g. if the firmware
> + * processor has stopped responding and can not be revived via a hard
> + * reset.
> + */
> + PVR_DEVICE_STATE_LOST_UNPLUGGED,
> +};
> +
> +/**
> + * pvr_device_is_lost() - Check if GPU device has been marked lost.
> + * @pvr_dev: Target PowerVR device.
> + *
> + * Returns:
> + * * %true if device is lost, or
> + * * %false otherwise.
> + */
> +static __always_inline bool pvr_device_is_lost(struct pvr_device *pvr_dev)
> +{
> + switch ((enum pvr_device_state)atomic_read(&pvr_dev->state)) {
> + case PVR_DEVICE_STATE_PRESENT:
> + case PVR_DEVICE_STATE_ENTERED:
> + return false;
> +
> + case PVR_DEVICE_STATE_LOST:
> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
> + break;
> + }
> +
> + return true;
> +}
> +
> +bool pvr_device_enter(struct pvr_device *pvr_dev, int *idx);
> +void pvr_device_exit(struct pvr_device *pvr_dev, int idx);
> +void pvr_device_set_lost(struct pvr_device *pvr_dev);
>
> bool
> pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk);
> diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c
> index 5c3b2d58d766..55bea656a40f 100644
> --- a/drivers/gpu/drm/imagination/pvr_drv.c
> +++ b/drivers/gpu/drm/imagination/pvr_drv.c
> @@ -81,13 +81,13 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> int idx;
> int err;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> /* All padding fields must be zeroed. */
> if (args->_padding_c != 0) {
> err = -EINVAL;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> /*
> @@ -101,7 +101,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> if (args->size > SIZE_MAX || args->size == 0 || args->flags &
> ~DRM_PVR_BO_FLAGS_MASK || args->size & (PVR_DEVICE_PAGE_SIZE - 1)) {
> err = -EINVAL;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> sanitized_size = (size_t)args->size;
> @@ -113,7 +113,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> pvr_obj = pvr_gem_object_create(pvr_dev, sanitized_size, args->flags);
> if (IS_ERR(pvr_obj)) {
> err = PTR_ERR(pvr_obj);
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> /* This function will not modify &args->handle unless it succeeds. */
> @@ -121,7 +121,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> if (err)
> goto err_destroy_obj;
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return 0;
>
> @@ -133,8 +133,8 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> */
> pvr_gem_object_put(pvr_obj);
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> @@ -164,19 +164,20 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
> struct drm_file *file)
> {
> struct drm_pvr_ioctl_get_bo_mmap_offset_args *args = raw_args;
> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> struct pvr_file *pvr_file = to_pvr_file(file);
> struct pvr_gem_object *pvr_obj;
> struct drm_gem_object *gem_obj;
> int idx;
> int ret;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> /* All padding fields must be zeroed. */
> if (args->_padding_4 != 0) {
> ret = -EINVAL;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> /*
> @@ -188,7 +189,7 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
> pvr_obj = pvr_gem_object_from_handle(pvr_file, args->handle);
> if (!pvr_obj) {
> ret = -ENOENT;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> gem_obj = gem_from_pvr_gem(pvr_obj);
> @@ -202,7 +203,7 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
> if (ret != 0) {
> /* Drop our reference to the buffer object. */
> drm_gem_object_put(gem_obj);
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> /*
> @@ -214,8 +215,8 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
> /* Drop our reference to the buffer object. */
> pvr_gem_object_put(pvr_obj);
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return ret;
> }
> @@ -626,7 +627,7 @@ pvr_ioctl_dev_query(struct drm_device *drm_dev, void *raw_args,
> int idx;
> int ret = -EINVAL;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> switch ((enum drm_pvr_dev_query)args->type) {
> @@ -655,7 +656,7 @@ pvr_ioctl_dev_query(struct drm_device *drm_dev, void *raw_args,
> break;
> }
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return ret;
> }
> @@ -680,16 +681,17 @@ pvr_ioctl_create_context(struct drm_device *drm_dev, void *raw_args,
> struct drm_file *file)
> {
> struct drm_pvr_ioctl_create_context_args *args = raw_args;
> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> struct pvr_file *pvr_file = file->driver_priv;
> int idx;
> int ret;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> ret = pvr_context_create(pvr_file, args);
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return ret;
> }
> @@ -738,18 +740,19 @@ pvr_ioctl_create_free_list(struct drm_device *drm_dev, void *raw_args,
> struct drm_file *file)
> {
> struct drm_pvr_ioctl_create_free_list_args *args = raw_args;
> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> struct pvr_file *pvr_file = to_pvr_file(file);
> struct pvr_free_list *free_list;
> int idx;
> int err;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> free_list = pvr_free_list_create(pvr_file, args);
> if (IS_ERR(free_list)) {
> err = PTR_ERR(free_list);
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> /* Allocate object handle for userspace. */
> @@ -761,15 +764,15 @@ pvr_ioctl_create_free_list(struct drm_device *drm_dev, void *raw_args,
> if (err < 0)
> goto err_cleanup;
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return 0;
>
> err_cleanup:
> pvr_free_list_put(free_list);
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> @@ -824,18 +827,19 @@ pvr_ioctl_create_hwrt_dataset(struct drm_device *drm_dev, void *raw_args,
> struct drm_file *file)
> {
> struct drm_pvr_ioctl_create_hwrt_dataset_args *args = raw_args;
> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> struct pvr_file *pvr_file = to_pvr_file(file);
> struct pvr_hwrt_dataset *hwrt;
> int idx;
> int err;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> hwrt = pvr_hwrt_dataset_create(pvr_file, args);
> if (IS_ERR(hwrt)) {
> err = PTR_ERR(hwrt);
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> /* Allocate object handle for userspace. */
> @@ -847,15 +851,15 @@ pvr_ioctl_create_hwrt_dataset(struct drm_device *drm_dev, void *raw_args,
> if (err < 0)
> goto err_cleanup;
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return 0;
>
> err_cleanup:
> pvr_hwrt_dataset_put(hwrt);
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> @@ -910,23 +914,24 @@ pvr_ioctl_create_vm_context(struct drm_device *drm_dev, void *raw_args,
> struct drm_file *file)
> {
> struct drm_pvr_ioctl_create_vm_context_args *args = raw_args;
> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> struct pvr_file *pvr_file = to_pvr_file(file);
> struct pvr_vm_context *vm_ctx;
> int idx;
> int err;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> if (args->_padding_4) {
> err = -EINVAL;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> vm_ctx = pvr_vm_create_context(pvr_file->pvr_dev, true);
> if (IS_ERR(vm_ctx)) {
> err = PTR_ERR(vm_ctx);
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> /* Allocate object handle for userspace. */
> @@ -938,15 +943,15 @@ pvr_ioctl_create_vm_context(struct drm_device *drm_dev, void *raw_args,
> if (err < 0)
> goto err_cleanup;
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return 0;
>
> err_cleanup:
> pvr_vm_context_put(vm_ctx);
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> @@ -1022,26 +1027,26 @@ pvr_ioctl_vm_map(struct drm_device *drm_dev, void *raw_args,
> int idx;
> int err;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> /* Initial validation of args. */
> if (args->_padding_14) {
> err = -EINVAL;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> if (args->flags != 0 ||
> check_add_overflow(args->offset, args->size, &offset_plus_size) ||
> !pvr_find_heap_containing(pvr_dev, args->device_addr, args->size)) {
> err = -EINVAL;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> vm_ctx = pvr_vm_context_lookup(pvr_file, args->vm_context_handle);
> if (!vm_ctx) {
> err = -EINVAL;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> pvr_obj = pvr_gem_object_from_handle(pvr_file, args->handle);
> @@ -1079,8 +1084,8 @@ pvr_ioctl_vm_map(struct drm_device *drm_dev, void *raw_args,
> err_put_vm_context:
> pvr_vm_context_put(vm_ctx);
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> @@ -1148,12 +1153,12 @@ pvr_ioctl_submit_jobs(struct drm_device *drm_dev, void *raw_args,
> int idx;
> int err;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> err = pvr_submit_jobs(pvr_dev, pvr_file, args);
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> diff --git a/drivers/gpu/drm/imagination/pvr_fw.c b/drivers/gpu/drm/imagination/pvr_fw.c
> index 3debc9870a82..07547e167963 100644
> --- a/drivers/gpu/drm/imagination/pvr_fw.c
> +++ b/drivers/gpu/drm/imagination/pvr_fw.c
> @@ -1094,7 +1094,7 @@ pvr_fw_structure_cleanup(struct pvr_device *pvr_dev, u32 type, struct pvr_fw_obj
>
> down_read(&pvr_dev->reset_sem);
>
> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx)) {
> + if (!pvr_device_enter(pvr_dev, &idx)) {
> err = -EIO;
> goto err_up_read;
> }
> @@ -1118,22 +1118,22 @@ pvr_fw_structure_cleanup(struct pvr_device *pvr_dev, u32 type, struct pvr_fw_obj
> break;
> default:
> err = -EINVAL;
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> err = pvr_kccb_send_cmd(pvr_dev, &cmd, &slot_nr);
> if (err)
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
>
> err = pvr_kccb_wait_for_completion(pvr_dev, slot_nr, HZ, &rtn);
> if (err)
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
>
> if (rtn & ROGUE_FWIF_KCCB_RTN_SLOT_CLEANUP_BUSY)
> err = -EBUSY;
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> err_up_read:
> up_read(&pvr_dev->reset_sem);
> diff --git a/drivers/gpu/drm/imagination/pvr_fw_trace.c b/drivers/gpu/drm/imagination/pvr_fw_trace.c
> index 31199e45b72e..26d67483eac2 100644
> --- a/drivers/gpu/drm/imagination/pvr_fw_trace.c
> +++ b/drivers/gpu/drm/imagination/pvr_fw_trace.c
> @@ -149,7 +149,7 @@ update_logtype(struct pvr_device *pvr_dev, u32 group_mask)
> fw_trace->group_mask = group_mask;
>
> down_read(&pvr_dev->reset_sem);
> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx)) {
> + if (!pvr_device_enter(pvr_dev, &idx)) {
> err = -EIO;
> goto err_up_read;
> }
> @@ -159,7 +159,7 @@ update_logtype(struct pvr_device *pvr_dev, u32 group_mask)
>
> err = pvr_kccb_send_cmd(pvr_dev, &cmd, NULL);
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> err_up_read:
> up_read(&pvr_dev->reset_sem);
> diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c b/drivers/gpu/drm/imagination/pvr_mmu.c
> index 4fe70610ed94..59911f70e9ca 100644
> --- a/drivers/gpu/drm/imagination/pvr_mmu.c
> +++ b/drivers/gpu/drm/imagination/pvr_mmu.c
> @@ -129,18 +129,18 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
> u32 slot;
> int idx;
>
> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> /* Can't flush MMU if the firmware hasn't booted yet. */
> if (!pvr_dev->fw_dev.booted)
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
>
> cmd_mmu_cache_data->cache_flags =
> atomic_xchg(&pvr_dev->mmu_flush_cache_flags, 0);
>
> if (!cmd_mmu_cache_data->cache_flags)
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
>
> cmd_mmu_cache.cmd_type = ROGUE_FWIF_KCCB_CMD_MMUCACHE;
>
> @@ -156,7 +156,7 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
> if (err)
> goto err_reset_and_retry;
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return 0;
>
> @@ -167,23 +167,23 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
> */
> err = pvr_power_reset(pvr_dev, true);
> if (err)
> - goto err_drm_dev_exit; /* Device is lost. */
> + goto err_pvr_device_exit; /* Device is lost. */
>
> /* Retry sending flush request. */
> err = pvr_kccb_send_cmd(pvr_dev, &cmd_mmu_cache, &slot);
> if (err) {
> - pvr_device_lost(pvr_dev);
> - goto err_drm_dev_exit;
> + pvr_device_set_lost(pvr_dev);
> + goto err_pvr_device_exit;
> }
>
> if (wait) {
> err = pvr_kccb_wait_for_completion(pvr_dev, slot, HZ, NULL);
> if (err)
> - pvr_device_lost(pvr_dev);
> + pvr_device_set_lost(pvr_dev);
> }
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
> index ba7816fd28ec..c927def3d3f3 100644
> --- a/drivers/gpu/drm/imagination/pvr_power.c
> +++ b/drivers/gpu/drm/imagination/pvr_power.c
> @@ -23,21 +23,6 @@
>
> #define WATCHDOG_TIME_MS (500)
>
> -/**
> - * pvr_device_lost() - Mark GPU device as lost
> - * @pvr_dev: Target PowerVR device.
> - *
> - * This will cause the DRM device to be unplugged.
> - */
> -void
> -pvr_device_lost(struct pvr_device *pvr_dev)
> -{
> - if (!pvr_dev->lost) {
> - pvr_dev->lost = true;
> - drm_dev_unplug(from_pvr_device(pvr_dev));
> - }
> -}
> -
> static int
> pvr_power_send_command(struct pvr_device *pvr_dev, struct rogue_fwif_kccb_cmd *pow_cmd)
> {
> @@ -186,7 +171,7 @@ pvr_watchdog_worker(struct work_struct *work)
> watchdog.work.work);
> bool stalled;
>
> - if (pvr_dev->lost)
> + if (pvr_device_is_lost(pvr_dev))
> return;
>
> if (pm_runtime_get_if_in_use(from_pvr_device(pvr_dev)->dev) <= 0)
> @@ -208,10 +193,9 @@ pvr_watchdog_worker(struct work_struct *work)
> pm_runtime_put(from_pvr_device(pvr_dev)->dev);
>
> out_requeue:
> - if (!pvr_dev->lost) {
> + if (!pvr_device_is_lost(pvr_dev))
> queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,
> msecs_to_jiffies(WATCHDOG_TIME_MS));
> - }
> }
>
> /**
> @@ -239,21 +223,21 @@ pvr_power_device_suspend(struct device *dev)
> int err = 0;
> int idx;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> if (pvr_dev->fw_dev.booted) {
> err = pvr_power_fw_disable(pvr_dev, false);
> if (err)
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
> }
>
> clk_disable_unprepare(pvr_dev->mem_clk);
> clk_disable_unprepare(pvr_dev->sys_clk);
> clk_disable_unprepare(pvr_dev->core_clk);
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> @@ -267,12 +251,12 @@ pvr_power_device_resume(struct device *dev)
> int idx;
> int err;
>
> - if (!drm_dev_enter(drm_dev, &idx))
> + if (!pvr_device_enter(pvr_dev, &idx))
> return -EIO;
>
> err = clk_prepare_enable(pvr_dev->core_clk);
> if (err)
> - goto err_drm_dev_exit;
> + goto err_pvr_device_exit;
>
> err = clk_prepare_enable(pvr_dev->sys_clk);
> if (err)
> @@ -288,7 +272,7 @@ pvr_power_device_resume(struct device *dev)
> goto err_mem_clk_disable;
> }
>
> - drm_dev_exit(idx);
> + pvr_device_exit(pvr_dev, idx);
>
> return 0;
>
> @@ -301,8 +285,8 @@ pvr_power_device_resume(struct device *dev)
> err_core_clk_disable:
> clk_disable_unprepare(pvr_dev->core_clk);
>
> -err_drm_dev_exit:
> - drm_dev_exit(idx);
> +err_pvr_device_exit:
> + pvr_device_exit(pvr_dev, idx);
>
> return err;
> }
> @@ -345,7 +329,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
>
> down_write(&pvr_dev->reset_sem);
>
> - if (pvr_dev->lost) {
> + if (pvr_device_is_lost(pvr_dev)) {
> err = -EIO;
> goto err_up_write;
> }
> @@ -407,7 +391,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
>
> err_device_lost:
> drm_err(from_pvr_device(pvr_dev), "GPU device lost");
> - pvr_device_lost(pvr_dev);
> + pvr_device_set_lost(pvr_dev);
>
> /* Leave IRQs disabled if the device is lost. */
>
> diff --git a/drivers/gpu/drm/imagination/pvr_power.h b/drivers/gpu/drm/imagination/pvr_power.h
> index 9a9312dcb2da..360980f454d7 100644
> --- a/drivers/gpu/drm/imagination/pvr_power.h
> +++ b/drivers/gpu/drm/imagination/pvr_power.h
> @@ -12,8 +12,6 @@
> int pvr_watchdog_init(struct pvr_device *pvr_dev);
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] drm/imagination: On device loss, handle unplug after critical section
2024-01-25 18:44 ` Daniel Vetter
@ 2024-01-31 17:22 ` Matt Coster
2024-02-01 11:09 ` Daniel Vetter
0 siblings, 1 reply; 4+ messages in thread
From: Matt Coster @ 2024-01-31 17:22 UTC (permalink / raw)
To: Daniel Vetter; +Cc: Maxime Ripard, Steven Price, dri-devel, Thomas Zimmermann
[-- Attachment #1.1: Type: text/plain, Size: 29020 bytes --]
On 25/01/2024 18:44, Daniel Vetter wrote:
> On Tue, Jan 23, 2024 at 01:04:24PM +0000, Matt Coster wrote:
>> From: Donald Robson <donald.robson@imgtec.com>
>>
>> When the kernel driver 'loses' the device, for instance if the firmware
>> stops communicating, the driver calls drm_dev_unplug(). This is
>> currently done inside the drm_dev_enter() critical section, which isn't
>> permitted. In addition, the bool that marks the device as lost is not
>> atomic or protected by a lock.
>>
>> This fix replaces the bool with an atomic that also acts as a mechanism
>> to ensure the device is unplugged after drm_dev_exit(), preventing a
>> concurrent call to drm_dev_enter() from succeeding in a race between it
>> and drm_dev_unplug().
>
> Uh ... atomic_t does not make locking.
>
> From a quick look this entire thing smells a bit like bad design overall,
> and my gut feeling is that you probably want to rip out pvr_dev->lost
> outright. Or alternatively, explain what exactly this does beyond
> drm_dev_enter/exit, and then probably add that functionality there instead
> of hand-roll lockless trickery in drivers.
>
> From a quick look keeping track of where you realize the device is lost
> and then calling drm_dev_unplug after the drm_dev_exit is probably the
> clean solution. That also means the drm_dev_unplug() is not delayed due to
> a drm_dev_enter/exit section on a different thread, which is probably a
> good thing.
>
> Cheers, Sima
Hi Sima,
Thanks for taking the time to look over this patch.
This was the last piece of work Donald did for us at Imagination but he
never got a chance to send it out himself.
I'll put it on my list to try a new, more minimal, approach before
sending a v2. Your suggestion sounds very promising – that's probably
the first thing I'll try.
Cheers,
Matt
>> Reported-by: Steven Price <steven.price@arm.com>
>> Closes: https://lore.kernel.org/dri-devel/1b957ca4-71cf-42fd-ac81-1920592b952d@arm.com/
>> Fixes: cc1aeedb98ad ("drm/imagination: Implement firmware infrastructure and META FW support")
>> Signed-off-by: Donald Robson <donald.robson@imgtec.com>
>> Signed-off-by: Matt Coster <matt.coster@imgtec.com>
>> ---
>> drivers/gpu/drm/imagination/pvr_ccb.c | 2 +-
>> drivers/gpu/drm/imagination/pvr_device.c | 98 +++++++++++++++++++++-
>> drivers/gpu/drm/imagination/pvr_device.h | 72 +++++++++++++---
>> drivers/gpu/drm/imagination/pvr_drv.c | 87 ++++++++++---------
>> drivers/gpu/drm/imagination/pvr_fw.c | 12 +--
>> drivers/gpu/drm/imagination/pvr_fw_trace.c | 4 +-
>> drivers/gpu/drm/imagination/pvr_mmu.c | 20 ++---
>> drivers/gpu/drm/imagination/pvr_power.c | 42 +++-------
>> drivers/gpu/drm/imagination/pvr_power.h | 2 -
>> 9 files changed, 237 insertions(+), 102 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/imagination/pvr_ccb.c b/drivers/gpu/drm/imagination/pvr_ccb.c
>> index 4deeac7ed40a..1fe64adc0c2c 100644
>> --- a/drivers/gpu/drm/imagination/pvr_ccb.c
>> +++ b/drivers/gpu/drm/imagination/pvr_ccb.c
>> @@ -247,7 +247,7 @@ pvr_kccb_send_cmd_reserved_powered(struct pvr_device *pvr_dev,
>> u32 old_write_offset;
>> u32 new_write_offset;
>>
>> - WARN_ON(pvr_dev->lost);
>> + WARN_ON(pvr_device_is_lost(pvr_dev));
>>
>> mutex_lock(&pvr_ccb->lock);
>>
>> diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c
>> index 1704c0268589..397491375b7d 100644
>> --- a/drivers/gpu/drm/imagination/pvr_device.c
>> +++ b/drivers/gpu/drm/imagination/pvr_device.c
>> @@ -6,14 +6,15 @@
>>
>> #include "pvr_fw.h"
>> #include "pvr_params.h"
>> -#include "pvr_power.h"
>> #include "pvr_queue.h"
>> #include "pvr_rogue_cr_defs.h"
>> #include "pvr_stream.h"
>> #include "pvr_vm.h"
>>
>> +#include <drm/drm_drv.h>
>> #include <drm/drm_print.h>
>>
>> +#include <linux/atomic.h>
>> #include <linux/bitfield.h>
>> #include <linux/clk.h>
>> #include <linux/compiler_attributes.h>
>> @@ -556,6 +557,101 @@ pvr_device_fini(struct pvr_device *pvr_dev)
>> pvr_device_gpu_fini(pvr_dev);
>> }
>>
>> +/**
>> + * pvr_device_enter() - Try to enter device critical section.
>> + * @pvr_dev: Target PowerVR device.
>> + * @idx: Pointer to index that will be passed to the matching pvr_device_exit().
>> + *
>> + * Use this in place of drm_dev_enter() within this driver.
>> + *
>> + * Returns:
>> + * * %true if the critical section was entered, or
>> + * * %false otherwise.
>> + */
>> +bool pvr_device_enter(struct pvr_device *pvr_dev, int *idx)
>> +{
>> + const enum pvr_device_state old_state =
>> + atomic_cmpxchg(&pvr_dev->state,
>> + PVR_DEVICE_STATE_PRESENT,
>> + PVR_DEVICE_STATE_ENTERED);
>> +
>> + switch (old_state) {
>> + case PVR_DEVICE_STATE_PRESENT:
>> + case PVR_DEVICE_STATE_ENTERED:
>> + return drm_dev_enter(from_pvr_device(pvr_dev), idx);
>> +
>> + case PVR_DEVICE_STATE_LOST:
>> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
>> + WARN_ONCE(1, "Attempt to use GPU after becoming lost.");
>> + break;
>> + }
>> +
>> + return false;
>> +}
>> +
>> +/**
>> + * pvr_device_exit() - Exit a device critical section.
>> + * @pvr_dev: Target PowerVR device.
>> + * @idx: Index given by matching pvr_device_enter().
>> + *
>> + * Use this in place of drm_dev_exit() within this driver.
>> + */
>> +void pvr_device_exit(struct pvr_device *pvr_dev, int idx)
>> +{
>> + const enum pvr_device_state old_state =
>> + atomic_cmpxchg(&pvr_dev->state,
>> + PVR_DEVICE_STATE_ENTERED,
>> + PVR_DEVICE_STATE_PRESENT);
>> +
>> + switch (old_state) {
>> + case PVR_DEVICE_STATE_PRESENT:
>> + case PVR_DEVICE_STATE_ENTERED:
>> + drm_dev_exit(idx);
>> + return;
>> +
>> + case PVR_DEVICE_STATE_LOST:
>> + /* Unplug the device if it was lost during the critical section. */
>> + atomic_set(&pvr_dev->state, PVR_DEVICE_STATE_LOST_UNPLUGGED);
>> +
>> + drm_dev_exit(idx);
>> +
>> + WARN_ONCE(1, "GPU lost and now unplugged.");
>> + drm_dev_unplug(from_pvr_device(pvr_dev));
>> +
>> + return;
>> +
>> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
>> + WARN_ONCE(1, "GPU unplugged during critical section.");
>> + drm_dev_exit(idx);
>> + return;
>> + }
>> +}
>> +
>> +/**
>> + * pvr_device_set_lost() - Mark GPU device as lost.
>> + * @pvr_dev: Target PowerVR device.
>> + *
>> + * This will cause the DRM device to be unplugged at the next call to
>> + * pvr_device_exit().
>> + */
>> +void pvr_device_set_lost(struct pvr_device *pvr_dev)
>> +{
>> + /*
>> + * Unplug the device immediately if the device is not in a critical
>> + * section.
>> + */
>> + const bool unplug = atomic_cmpxchg(&pvr_dev->state,
>> + PVR_DEVICE_STATE_PRESENT,
>> + PVR_DEVICE_STATE_LOST_UNPLUGGED) ==
>> + PVR_DEVICE_STATE_PRESENT;
>> +
>> + if (unplug)
>> + drm_dev_unplug(from_pvr_device(pvr_dev));
>> + else
>> + atomic_cmpxchg(&pvr_dev->state, PVR_DEVICE_STATE_ENTERED,
>> + PVR_DEVICE_STATE_LOST);
>> +}
>> +
>> bool
>> pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk)
>> {
>> diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h
>> index ecdd5767d8ef..7c08b2bda395 100644
>> --- a/drivers/gpu/drm/imagination/pvr_device.h
>> +++ b/drivers/gpu/drm/imagination/pvr_device.h
>> @@ -274,20 +274,19 @@ struct pvr_device {
>> } kccb;
>>
>> /**
>> - * @lost: %true if the device has been lost.
>> - *
>> - * This variable is set if the device has become irretrievably unavailable, e.g. if the
>> - * firmware processor has stopped responding and can not be revived via a hard reset.
>> + * @state: Indicates whether the device is present and in use. One of
>> + * &enum pvr_device_state.
>> */
>> - bool lost;
>> + atomic_t state;
>>
>> /**
>> * @reset_sem: Reset semaphore.
>> *
>> - * GPU reset code will lock this for writing. Any code that submits commands to the firmware
>> - * that isn't in an IRQ handler or on the scheduler workqueue must lock this for reading.
>> - * Once this has been successfully locked, &pvr_dev->lost _must_ be checked, and -%EIO must
>> - * be returned if it is set.
>> + * GPU reset code will lock this for writing. Any code that submits
>> + * commands to the firmware that isn't in an IRQ handler or on the
>> + * scheduler workqueue must lock this for reading.
>> + * Once this has been successfully locked, pvr_device_is_lost() _must_
>> + * be checked, and -%EIO must be returned if it is.
>> */
>> struct rw_semaphore reset_sem;
>>
>> @@ -487,7 +486,60 @@ packed_bvnc_to_pvr_gpu_id(u64 bvnc, struct pvr_gpu_id *gpu_id)
>>
>> int pvr_device_init(struct pvr_device *pvr_dev);
>> void pvr_device_fini(struct pvr_device *pvr_dev);
>> -void pvr_device_reset(struct pvr_device *pvr_dev);
>> +
>> +/**
>> + * enum pvr_device_state - States used by &struct pvr_device.state.
>> + */
>> +enum pvr_device_state {
>> + /** @PVR_DEVICE_STATE_PRESENT: The device is available for use. */
>> + PVR_DEVICE_STATE_PRESENT,
>> +
>> + /** @PVR_DEVICE_STATE_ENTERED: The device is in a critical section. */
>> + PVR_DEVICE_STATE_ENTERED,
>> +
>> + /**
>> + * @PVR_DEVICE_STATE_LOST: The device was lost during the current device
>> + * critical section and will be unplugged once the section exits.
>> + */
>> + PVR_DEVICE_STATE_LOST,
>> +
>> + /**
>> + * @PVR_DEVICE_STATE_LOST_UNPLUGGED: The device was lost and
>> + * subsequently unplugged.
>> + *
>> + * The device may become irretrievably unavailable, e.g. if the firmware
>> + * processor has stopped responding and can not be revived via a hard
>> + * reset.
>> + */
>> + PVR_DEVICE_STATE_LOST_UNPLUGGED,
>> +};
>> +
>> +/**
>> + * pvr_device_is_lost() - Check if GPU device has been marked lost.
>> + * @pvr_dev: Target PowerVR device.
>> + *
>> + * Returns:
>> + * * %true if device is lost, or
>> + * * %false otherwise.
>> + */
>> +static __always_inline bool pvr_device_is_lost(struct pvr_device *pvr_dev)
>> +{
>> + switch ((enum pvr_device_state)atomic_read(&pvr_dev->state)) {
>> + case PVR_DEVICE_STATE_PRESENT:
>> + case PVR_DEVICE_STATE_ENTERED:
>> + return false;
>> +
>> + case PVR_DEVICE_STATE_LOST:
>> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
>> + break;
>> + }
>> +
>> + return true;
>> +}
>> +
>> +bool pvr_device_enter(struct pvr_device *pvr_dev, int *idx);
>> +void pvr_device_exit(struct pvr_device *pvr_dev, int idx);
>> +void pvr_device_set_lost(struct pvr_device *pvr_dev);
>>
>> bool
>> pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk);
>> diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c
>> index 5c3b2d58d766..55bea656a40f 100644
>> --- a/drivers/gpu/drm/imagination/pvr_drv.c
>> +++ b/drivers/gpu/drm/imagination/pvr_drv.c
>> @@ -81,13 +81,13 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
>> int idx;
>> int err;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> /* All padding fields must be zeroed. */
>> if (args->_padding_c != 0) {
>> err = -EINVAL;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> /*
>> @@ -101,7 +101,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
>> if (args->size > SIZE_MAX || args->size == 0 || args->flags &
>> ~DRM_PVR_BO_FLAGS_MASK || args->size & (PVR_DEVICE_PAGE_SIZE - 1)) {
>> err = -EINVAL;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> sanitized_size = (size_t)args->size;
>> @@ -113,7 +113,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
>> pvr_obj = pvr_gem_object_create(pvr_dev, sanitized_size, args->flags);
>> if (IS_ERR(pvr_obj)) {
>> err = PTR_ERR(pvr_obj);
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> /* This function will not modify &args->handle unless it succeeds. */
>> @@ -121,7 +121,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
>> if (err)
>> goto err_destroy_obj;
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return 0;
>>
>> @@ -133,8 +133,8 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
>> */
>> pvr_gem_object_put(pvr_obj);
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> @@ -164,19 +164,20 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
>> struct drm_file *file)
>> {
>> struct drm_pvr_ioctl_get_bo_mmap_offset_args *args = raw_args;
>> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
>> struct pvr_file *pvr_file = to_pvr_file(file);
>> struct pvr_gem_object *pvr_obj;
>> struct drm_gem_object *gem_obj;
>> int idx;
>> int ret;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> /* All padding fields must be zeroed. */
>> if (args->_padding_4 != 0) {
>> ret = -EINVAL;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> /*
>> @@ -188,7 +189,7 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
>> pvr_obj = pvr_gem_object_from_handle(pvr_file, args->handle);
>> if (!pvr_obj) {
>> ret = -ENOENT;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> gem_obj = gem_from_pvr_gem(pvr_obj);
>> @@ -202,7 +203,7 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
>> if (ret != 0) {
>> /* Drop our reference to the buffer object. */
>> drm_gem_object_put(gem_obj);
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> /*
>> @@ -214,8 +215,8 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
>> /* Drop our reference to the buffer object. */
>> pvr_gem_object_put(pvr_obj);
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return ret;
>> }
>> @@ -626,7 +627,7 @@ pvr_ioctl_dev_query(struct drm_device *drm_dev, void *raw_args,
>> int idx;
>> int ret = -EINVAL;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> switch ((enum drm_pvr_dev_query)args->type) {
>> @@ -655,7 +656,7 @@ pvr_ioctl_dev_query(struct drm_device *drm_dev, void *raw_args,
>> break;
>> }
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return ret;
>> }
>> @@ -680,16 +681,17 @@ pvr_ioctl_create_context(struct drm_device *drm_dev, void *raw_args,
>> struct drm_file *file)
>> {
>> struct drm_pvr_ioctl_create_context_args *args = raw_args;
>> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
>> struct pvr_file *pvr_file = file->driver_priv;
>> int idx;
>> int ret;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> ret = pvr_context_create(pvr_file, args);
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return ret;
>> }
>> @@ -738,18 +740,19 @@ pvr_ioctl_create_free_list(struct drm_device *drm_dev, void *raw_args,
>> struct drm_file *file)
>> {
>> struct drm_pvr_ioctl_create_free_list_args *args = raw_args;
>> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
>> struct pvr_file *pvr_file = to_pvr_file(file);
>> struct pvr_free_list *free_list;
>> int idx;
>> int err;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> free_list = pvr_free_list_create(pvr_file, args);
>> if (IS_ERR(free_list)) {
>> err = PTR_ERR(free_list);
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> /* Allocate object handle for userspace. */
>> @@ -761,15 +764,15 @@ pvr_ioctl_create_free_list(struct drm_device *drm_dev, void *raw_args,
>> if (err < 0)
>> goto err_cleanup;
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return 0;
>>
>> err_cleanup:
>> pvr_free_list_put(free_list);
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> @@ -824,18 +827,19 @@ pvr_ioctl_create_hwrt_dataset(struct drm_device *drm_dev, void *raw_args,
>> struct drm_file *file)
>> {
>> struct drm_pvr_ioctl_create_hwrt_dataset_args *args = raw_args;
>> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
>> struct pvr_file *pvr_file = to_pvr_file(file);
>> struct pvr_hwrt_dataset *hwrt;
>> int idx;
>> int err;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> hwrt = pvr_hwrt_dataset_create(pvr_file, args);
>> if (IS_ERR(hwrt)) {
>> err = PTR_ERR(hwrt);
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> /* Allocate object handle for userspace. */
>> @@ -847,15 +851,15 @@ pvr_ioctl_create_hwrt_dataset(struct drm_device *drm_dev, void *raw_args,
>> if (err < 0)
>> goto err_cleanup;
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return 0;
>>
>> err_cleanup:
>> pvr_hwrt_dataset_put(hwrt);
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> @@ -910,23 +914,24 @@ pvr_ioctl_create_vm_context(struct drm_device *drm_dev, void *raw_args,
>> struct drm_file *file)
>> {
>> struct drm_pvr_ioctl_create_vm_context_args *args = raw_args;
>> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
>> struct pvr_file *pvr_file = to_pvr_file(file);
>> struct pvr_vm_context *vm_ctx;
>> int idx;
>> int err;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> if (args->_padding_4) {
>> err = -EINVAL;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> vm_ctx = pvr_vm_create_context(pvr_file->pvr_dev, true);
>> if (IS_ERR(vm_ctx)) {
>> err = PTR_ERR(vm_ctx);
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> /* Allocate object handle for userspace. */
>> @@ -938,15 +943,15 @@ pvr_ioctl_create_vm_context(struct drm_device *drm_dev, void *raw_args,
>> if (err < 0)
>> goto err_cleanup;
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return 0;
>>
>> err_cleanup:
>> pvr_vm_context_put(vm_ctx);
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> @@ -1022,26 +1027,26 @@ pvr_ioctl_vm_map(struct drm_device *drm_dev, void *raw_args,
>> int idx;
>> int err;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> /* Initial validation of args. */
>> if (args->_padding_14) {
>> err = -EINVAL;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> if (args->flags != 0 ||
>> check_add_overflow(args->offset, args->size, &offset_plus_size) ||
>> !pvr_find_heap_containing(pvr_dev, args->device_addr, args->size)) {
>> err = -EINVAL;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> vm_ctx = pvr_vm_context_lookup(pvr_file, args->vm_context_handle);
>> if (!vm_ctx) {
>> err = -EINVAL;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> pvr_obj = pvr_gem_object_from_handle(pvr_file, args->handle);
>> @@ -1079,8 +1084,8 @@ pvr_ioctl_vm_map(struct drm_device *drm_dev, void *raw_args,
>> err_put_vm_context:
>> pvr_vm_context_put(vm_ctx);
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> @@ -1148,12 +1153,12 @@ pvr_ioctl_submit_jobs(struct drm_device *drm_dev, void *raw_args,
>> int idx;
>> int err;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> err = pvr_submit_jobs(pvr_dev, pvr_file, args);
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> diff --git a/drivers/gpu/drm/imagination/pvr_fw.c b/drivers/gpu/drm/imagination/pvr_fw.c
>> index 3debc9870a82..07547e167963 100644
>> --- a/drivers/gpu/drm/imagination/pvr_fw.c
>> +++ b/drivers/gpu/drm/imagination/pvr_fw.c
>> @@ -1094,7 +1094,7 @@ pvr_fw_structure_cleanup(struct pvr_device *pvr_dev, u32 type, struct pvr_fw_obj
>>
>> down_read(&pvr_dev->reset_sem);
>>
>> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx)) {
>> + if (!pvr_device_enter(pvr_dev, &idx)) {
>> err = -EIO;
>> goto err_up_read;
>> }
>> @@ -1118,22 +1118,22 @@ pvr_fw_structure_cleanup(struct pvr_device *pvr_dev, u32 type, struct pvr_fw_obj
>> break;
>> default:
>> err = -EINVAL;
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> err = pvr_kccb_send_cmd(pvr_dev, &cmd, &slot_nr);
>> if (err)
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>>
>> err = pvr_kccb_wait_for_completion(pvr_dev, slot_nr, HZ, &rtn);
>> if (err)
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>>
>> if (rtn & ROGUE_FWIF_KCCB_RTN_SLOT_CLEANUP_BUSY)
>> err = -EBUSY;
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> err_up_read:
>> up_read(&pvr_dev->reset_sem);
>> diff --git a/drivers/gpu/drm/imagination/pvr_fw_trace.c b/drivers/gpu/drm/imagination/pvr_fw_trace.c
>> index 31199e45b72e..26d67483eac2 100644
>> --- a/drivers/gpu/drm/imagination/pvr_fw_trace.c
>> +++ b/drivers/gpu/drm/imagination/pvr_fw_trace.c
>> @@ -149,7 +149,7 @@ update_logtype(struct pvr_device *pvr_dev, u32 group_mask)
>> fw_trace->group_mask = group_mask;
>>
>> down_read(&pvr_dev->reset_sem);
>> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx)) {
>> + if (!pvr_device_enter(pvr_dev, &idx)) {
>> err = -EIO;
>> goto err_up_read;
>> }
>> @@ -159,7 +159,7 @@ update_logtype(struct pvr_device *pvr_dev, u32 group_mask)
>>
>> err = pvr_kccb_send_cmd(pvr_dev, &cmd, NULL);
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> err_up_read:
>> up_read(&pvr_dev->reset_sem);
>> diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c b/drivers/gpu/drm/imagination/pvr_mmu.c
>> index 4fe70610ed94..59911f70e9ca 100644
>> --- a/drivers/gpu/drm/imagination/pvr_mmu.c
>> +++ b/drivers/gpu/drm/imagination/pvr_mmu.c
>> @@ -129,18 +129,18 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
>> u32 slot;
>> int idx;
>>
>> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> /* Can't flush MMU if the firmware hasn't booted yet. */
>> if (!pvr_dev->fw_dev.booted)
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>>
>> cmd_mmu_cache_data->cache_flags =
>> atomic_xchg(&pvr_dev->mmu_flush_cache_flags, 0);
>>
>> if (!cmd_mmu_cache_data->cache_flags)
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>>
>> cmd_mmu_cache.cmd_type = ROGUE_FWIF_KCCB_CMD_MMUCACHE;
>>
>> @@ -156,7 +156,7 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
>> if (err)
>> goto err_reset_and_retry;
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return 0;
>>
>> @@ -167,23 +167,23 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
>> */
>> err = pvr_power_reset(pvr_dev, true);
>> if (err)
>> - goto err_drm_dev_exit; /* Device is lost. */
>> + goto err_pvr_device_exit; /* Device is lost. */
>>
>> /* Retry sending flush request. */
>> err = pvr_kccb_send_cmd(pvr_dev, &cmd_mmu_cache, &slot);
>> if (err) {
>> - pvr_device_lost(pvr_dev);
>> - goto err_drm_dev_exit;
>> + pvr_device_set_lost(pvr_dev);
>> + goto err_pvr_device_exit;
>> }
>>
>> if (wait) {
>> err = pvr_kccb_wait_for_completion(pvr_dev, slot, HZ, NULL);
>> if (err)
>> - pvr_device_lost(pvr_dev);
>> + pvr_device_set_lost(pvr_dev);
>> }
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
>> index ba7816fd28ec..c927def3d3f3 100644
>> --- a/drivers/gpu/drm/imagination/pvr_power.c
>> +++ b/drivers/gpu/drm/imagination/pvr_power.c
>> @@ -23,21 +23,6 @@
>>
>> #define WATCHDOG_TIME_MS (500)
>>
>> -/**
>> - * pvr_device_lost() - Mark GPU device as lost
>> - * @pvr_dev: Target PowerVR device.
>> - *
>> - * This will cause the DRM device to be unplugged.
>> - */
>> -void
>> -pvr_device_lost(struct pvr_device *pvr_dev)
>> -{
>> - if (!pvr_dev->lost) {
>> - pvr_dev->lost = true;
>> - drm_dev_unplug(from_pvr_device(pvr_dev));
>> - }
>> -}
>> -
>> static int
>> pvr_power_send_command(struct pvr_device *pvr_dev, struct rogue_fwif_kccb_cmd *pow_cmd)
>> {
>> @@ -186,7 +171,7 @@ pvr_watchdog_worker(struct work_struct *work)
>> watchdog.work.work);
>> bool stalled;
>>
>> - if (pvr_dev->lost)
>> + if (pvr_device_is_lost(pvr_dev))
>> return;
>>
>> if (pm_runtime_get_if_in_use(from_pvr_device(pvr_dev)->dev) <= 0)
>> @@ -208,10 +193,9 @@ pvr_watchdog_worker(struct work_struct *work)
>> pm_runtime_put(from_pvr_device(pvr_dev)->dev);
>>
>> out_requeue:
>> - if (!pvr_dev->lost) {
>> + if (!pvr_device_is_lost(pvr_dev))
>> queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,
>> msecs_to_jiffies(WATCHDOG_TIME_MS));
>> - }
>> }
>>
>> /**
>> @@ -239,21 +223,21 @@ pvr_power_device_suspend(struct device *dev)
>> int err = 0;
>> int idx;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> if (pvr_dev->fw_dev.booted) {
>> err = pvr_power_fw_disable(pvr_dev, false);
>> if (err)
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>> }
>>
>> clk_disable_unprepare(pvr_dev->mem_clk);
>> clk_disable_unprepare(pvr_dev->sys_clk);
>> clk_disable_unprepare(pvr_dev->core_clk);
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> @@ -267,12 +251,12 @@ pvr_power_device_resume(struct device *dev)
>> int idx;
>> int err;
>>
>> - if (!drm_dev_enter(drm_dev, &idx))
>> + if (!pvr_device_enter(pvr_dev, &idx))
>> return -EIO;
>>
>> err = clk_prepare_enable(pvr_dev->core_clk);
>> if (err)
>> - goto err_drm_dev_exit;
>> + goto err_pvr_device_exit;
>>
>> err = clk_prepare_enable(pvr_dev->sys_clk);
>> if (err)
>> @@ -288,7 +272,7 @@ pvr_power_device_resume(struct device *dev)
>> goto err_mem_clk_disable;
>> }
>>
>> - drm_dev_exit(idx);
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return 0;
>>
>> @@ -301,8 +285,8 @@ pvr_power_device_resume(struct device *dev)
>> err_core_clk_disable:
>> clk_disable_unprepare(pvr_dev->core_clk);
>>
>> -err_drm_dev_exit:
>> - drm_dev_exit(idx);
>> +err_pvr_device_exit:
>> + pvr_device_exit(pvr_dev, idx);
>>
>> return err;
>> }
>> @@ -345,7 +329,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
>>
>> down_write(&pvr_dev->reset_sem);
>>
>> - if (pvr_dev->lost) {
>> + if (pvr_device_is_lost(pvr_dev)) {
>> err = -EIO;
>> goto err_up_write;
>> }
>> @@ -407,7 +391,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
>>
>> err_device_lost:
>> drm_err(from_pvr_device(pvr_dev), "GPU device lost");
>> - pvr_device_lost(pvr_dev);
>> + pvr_device_set_lost(pvr_dev);
>>
>> /* Leave IRQs disabled if the device is lost. */
>>
>> diff --git a/drivers/gpu/drm/imagination/pvr_power.h b/drivers/gpu/drm/imagination/pvr_power.h
>> index 9a9312dcb2da..360980f454d7 100644
>> --- a/drivers/gpu/drm/imagination/pvr_power.h
>> +++ b/drivers/gpu/drm/imagination/pvr_power.h
>> @@ -12,8 +12,6 @@
>> int pvr_watchdog_init(struct pvr_device *pvr_dev);
>
>
>
>
>
>
[-- Attachment #2: OpenPGP digital signature --]
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] drm/imagination: On device loss, handle unplug after critical section
2024-01-31 17:22 ` Matt Coster
@ 2024-02-01 11:09 ` Daniel Vetter
0 siblings, 0 replies; 4+ messages in thread
From: Daniel Vetter @ 2024-02-01 11:09 UTC (permalink / raw)
To: Matt Coster
Cc: Thomas Zimmermann, Maxime Ripard, Steven Price, dri-devel, Daniel Vetter
On Wed, Jan 31, 2024 at 05:22:26PM +0000, Matt Coster wrote:
> On 25/01/2024 18:44, Daniel Vetter wrote:
> > On Tue, Jan 23, 2024 at 01:04:24PM +0000, Matt Coster wrote:
> >> From: Donald Robson <donald.robson@imgtec.com>
> >>
> >> When the kernel driver 'loses' the device, for instance if the firmware
> >> stops communicating, the driver calls drm_dev_unplug(). This is
> >> currently done inside the drm_dev_enter() critical section, which isn't
> >> permitted. In addition, the bool that marks the device as lost is not
> >> atomic or protected by a lock.
> >>
> >> This fix replaces the bool with an atomic that also acts as a mechanism
> >> to ensure the device is unplugged after drm_dev_exit(), preventing a
> >> concurrent call to drm_dev_enter() from succeeding in a race between it
> >> and drm_dev_unplug().
> >
> > Uh ... atomic_t does not make locking.
> >
> > From a quick look this entire thing smells a bit like bad design overall,
> > and my gut feeling is that you probably want to rip out pvr_dev->lost
> > outright. Or alternatively, explain what exactly this does beyond
> > drm_dev_enter/exit, and then probably add that functionality there instead
> > of hand-roll lockless trickery in drivers.
> >
> > From a quick look keeping track of where you realize the device is lost
> > and then calling drm_dev_unplug after the drm_dev_exit is probably the
> > clean solution. That also means the drm_dev_unplug() is not delayed due to
> > a drm_dev_enter/exit section on a different thread, which is probably a
> > good thing.
> >
> > Cheers, Sima
>
> Hi Sima,
>
> Thanks for taking the time to look over this patch.
>
> This was the last piece of work Donald did for us at Imagination but he
> never got a chance to send it out himself.
>
> I'll put it on my list to try a new, more minimal, approach before
> sending a v2. Your suggestion sounds very promising – that's probably
> the first thing I'll try.
If it turns out to not be enough, then I think adding some tracking for
delayed unplug to drm_dev_enter/exit might be a good addition. But it
should imo be done in core drm code, with some proper docs, explanations
and really clear comments about why the locking/atomics/barriers are
correct. Since that stuff is tricky and having drivers play atomic
trickery worries me a lot ..
Cheers, Sima
>
> Cheers,
> Matt
>
> >> Reported-by: Steven Price <steven.price@arm.com>
> >> Closes: https://lore.kernel.org/dri-devel/1b957ca4-71cf-42fd-ac81-1920592b952d@arm.com/
> >> Fixes: cc1aeedb98ad ("drm/imagination: Implement firmware infrastructure and META FW support")
> >> Signed-off-by: Donald Robson <donald.robson@imgtec.com>
> >> Signed-off-by: Matt Coster <matt.coster@imgtec.com>
> >> ---
> >> drivers/gpu/drm/imagination/pvr_ccb.c | 2 +-
> >> drivers/gpu/drm/imagination/pvr_device.c | 98 +++++++++++++++++++++-
> >> drivers/gpu/drm/imagination/pvr_device.h | 72 +++++++++++++---
> >> drivers/gpu/drm/imagination/pvr_drv.c | 87 ++++++++++---------
> >> drivers/gpu/drm/imagination/pvr_fw.c | 12 +--
> >> drivers/gpu/drm/imagination/pvr_fw_trace.c | 4 +-
> >> drivers/gpu/drm/imagination/pvr_mmu.c | 20 ++---
> >> drivers/gpu/drm/imagination/pvr_power.c | 42 +++-------
> >> drivers/gpu/drm/imagination/pvr_power.h | 2 -
> >> 9 files changed, 237 insertions(+), 102 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/imagination/pvr_ccb.c b/drivers/gpu/drm/imagination/pvr_ccb.c
> >> index 4deeac7ed40a..1fe64adc0c2c 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_ccb.c
> >> +++ b/drivers/gpu/drm/imagination/pvr_ccb.c
> >> @@ -247,7 +247,7 @@ pvr_kccb_send_cmd_reserved_powered(struct pvr_device *pvr_dev,
> >> u32 old_write_offset;
> >> u32 new_write_offset;
> >>
> >> - WARN_ON(pvr_dev->lost);
> >> + WARN_ON(pvr_device_is_lost(pvr_dev));
> >>
> >> mutex_lock(&pvr_ccb->lock);
> >>
> >> diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c
> >> index 1704c0268589..397491375b7d 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_device.c
> >> +++ b/drivers/gpu/drm/imagination/pvr_device.c
> >> @@ -6,14 +6,15 @@
> >>
> >> #include "pvr_fw.h"
> >> #include "pvr_params.h"
> >> -#include "pvr_power.h"
> >> #include "pvr_queue.h"
> >> #include "pvr_rogue_cr_defs.h"
> >> #include "pvr_stream.h"
> >> #include "pvr_vm.h"
> >>
> >> +#include <drm/drm_drv.h>
> >> #include <drm/drm_print.h>
> >>
> >> +#include <linux/atomic.h>
> >> #include <linux/bitfield.h>
> >> #include <linux/clk.h>
> >> #include <linux/compiler_attributes.h>
> >> @@ -556,6 +557,101 @@ pvr_device_fini(struct pvr_device *pvr_dev)
> >> pvr_device_gpu_fini(pvr_dev);
> >> }
> >>
> >> +/**
> >> + * pvr_device_enter() - Try to enter device critical section.
> >> + * @pvr_dev: Target PowerVR device.
> >> + * @idx: Pointer to index that will be passed to the matching pvr_device_exit().
> >> + *
> >> + * Use this in place of drm_dev_enter() within this driver.
> >> + *
> >> + * Returns:
> >> + * * %true if the critical section was entered, or
> >> + * * %false otherwise.
> >> + */
> >> +bool pvr_device_enter(struct pvr_device *pvr_dev, int *idx)
> >> +{
> >> + const enum pvr_device_state old_state =
> >> + atomic_cmpxchg(&pvr_dev->state,
> >> + PVR_DEVICE_STATE_PRESENT,
> >> + PVR_DEVICE_STATE_ENTERED);
> >> +
> >> + switch (old_state) {
> >> + case PVR_DEVICE_STATE_PRESENT:
> >> + case PVR_DEVICE_STATE_ENTERED:
> >> + return drm_dev_enter(from_pvr_device(pvr_dev), idx);
> >> +
> >> + case PVR_DEVICE_STATE_LOST:
> >> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
> >> + WARN_ONCE(1, "Attempt to use GPU after becoming lost.");
> >> + break;
> >> + }
> >> +
> >> + return false;
> >> +}
> >> +
> >> +/**
> >> + * pvr_device_exit() - Exit a device critical section.
> >> + * @pvr_dev: Target PowerVR device.
> >> + * @idx: Index given by matching pvr_device_enter().
> >> + *
> >> + * Use this in place of drm_dev_exit() within this driver.
> >> + */
> >> +void pvr_device_exit(struct pvr_device *pvr_dev, int idx)
> >> +{
> >> + const enum pvr_device_state old_state =
> >> + atomic_cmpxchg(&pvr_dev->state,
> >> + PVR_DEVICE_STATE_ENTERED,
> >> + PVR_DEVICE_STATE_PRESENT);
> >> +
> >> + switch (old_state) {
> >> + case PVR_DEVICE_STATE_PRESENT:
> >> + case PVR_DEVICE_STATE_ENTERED:
> >> + drm_dev_exit(idx);
> >> + return;
> >> +
> >> + case PVR_DEVICE_STATE_LOST:
> >> + /* Unplug the device if it was lost during the critical section. */
> >> + atomic_set(&pvr_dev->state, PVR_DEVICE_STATE_LOST_UNPLUGGED);
> >> +
> >> + drm_dev_exit(idx);
> >> +
> >> + WARN_ONCE(1, "GPU lost and now unplugged.");
> >> + drm_dev_unplug(from_pvr_device(pvr_dev));
> >> +
> >> + return;
> >> +
> >> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
> >> + WARN_ONCE(1, "GPU unplugged during critical section.");
> >> + drm_dev_exit(idx);
> >> + return;
> >> + }
> >> +}
> >> +
> >> +/**
> >> + * pvr_device_set_lost() - Mark GPU device as lost.
> >> + * @pvr_dev: Target PowerVR device.
> >> + *
> >> + * This will cause the DRM device to be unplugged at the next call to
> >> + * pvr_device_exit().
> >> + */
> >> +void pvr_device_set_lost(struct pvr_device *pvr_dev)
> >> +{
> >> + /*
> >> + * Unplug the device immediately if the device is not in a critical
> >> + * section.
> >> + */
> >> + const bool unplug = atomic_cmpxchg(&pvr_dev->state,
> >> + PVR_DEVICE_STATE_PRESENT,
> >> + PVR_DEVICE_STATE_LOST_UNPLUGGED) ==
> >> + PVR_DEVICE_STATE_PRESENT;
> >> +
> >> + if (unplug)
> >> + drm_dev_unplug(from_pvr_device(pvr_dev));
> >> + else
> >> + atomic_cmpxchg(&pvr_dev->state, PVR_DEVICE_STATE_ENTERED,
> >> + PVR_DEVICE_STATE_LOST);
> >> +}
> >> +
> >> bool
> >> pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk)
> >> {
> >> diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h
> >> index ecdd5767d8ef..7c08b2bda395 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_device.h
> >> +++ b/drivers/gpu/drm/imagination/pvr_device.h
> >> @@ -274,20 +274,19 @@ struct pvr_device {
> >> } kccb;
> >>
> >> /**
> >> - * @lost: %true if the device has been lost.
> >> - *
> >> - * This variable is set if the device has become irretrievably unavailable, e.g. if the
> >> - * firmware processor has stopped responding and can not be revived via a hard reset.
> >> + * @state: Indicates whether the device is present and in use. One of
> >> + * &enum pvr_device_state.
> >> */
> >> - bool lost;
> >> + atomic_t state;
> >>
> >> /**
> >> * @reset_sem: Reset semaphore.
> >> *
> >> - * GPU reset code will lock this for writing. Any code that submits commands to the firmware
> >> - * that isn't in an IRQ handler or on the scheduler workqueue must lock this for reading.
> >> - * Once this has been successfully locked, &pvr_dev->lost _must_ be checked, and -%EIO must
> >> - * be returned if it is set.
> >> + * GPU reset code will lock this for writing. Any code that submits
> >> + * commands to the firmware that isn't in an IRQ handler or on the
> >> + * scheduler workqueue must lock this for reading.
> >> + * Once this has been successfully locked, pvr_device_is_lost() _must_
> >> + * be checked, and -%EIO must be returned if it is.
> >> */
> >> struct rw_semaphore reset_sem;
> >>
> >> @@ -487,7 +486,60 @@ packed_bvnc_to_pvr_gpu_id(u64 bvnc, struct pvr_gpu_id *gpu_id)
> >>
> >> int pvr_device_init(struct pvr_device *pvr_dev);
> >> void pvr_device_fini(struct pvr_device *pvr_dev);
> >> -void pvr_device_reset(struct pvr_device *pvr_dev);
> >> +
> >> +/**
> >> + * enum pvr_device_state - States used by &struct pvr_device.state.
> >> + */
> >> +enum pvr_device_state {
> >> + /** @PVR_DEVICE_STATE_PRESENT: The device is available for use. */
> >> + PVR_DEVICE_STATE_PRESENT,
> >> +
> >> + /** @PVR_DEVICE_STATE_ENTERED: The device is in a critical section. */
> >> + PVR_DEVICE_STATE_ENTERED,
> >> +
> >> + /**
> >> + * @PVR_DEVICE_STATE_LOST: The device was lost during the current device
> >> + * critical section and will be unplugged once the section exits.
> >> + */
> >> + PVR_DEVICE_STATE_LOST,
> >> +
> >> + /**
> >> + * @PVR_DEVICE_STATE_LOST_UNPLUGGED: The device was lost and
> >> + * subsequently unplugged.
> >> + *
> >> + * The device may become irretrievably unavailable, e.g. if the firmware
> >> + * processor has stopped responding and can not be revived via a hard
> >> + * reset.
> >> + */
> >> + PVR_DEVICE_STATE_LOST_UNPLUGGED,
> >> +};
> >> +
> >> +/**
> >> + * pvr_device_is_lost() - Check if GPU device has been marked lost.
> >> + * @pvr_dev: Target PowerVR device.
> >> + *
> >> + * Returns:
> >> + * * %true if device is lost, or
> >> + * * %false otherwise.
> >> + */
> >> +static __always_inline bool pvr_device_is_lost(struct pvr_device *pvr_dev)
> >> +{
> >> + switch ((enum pvr_device_state)atomic_read(&pvr_dev->state)) {
> >> + case PVR_DEVICE_STATE_PRESENT:
> >> + case PVR_DEVICE_STATE_ENTERED:
> >> + return false;
> >> +
> >> + case PVR_DEVICE_STATE_LOST:
> >> + case PVR_DEVICE_STATE_LOST_UNPLUGGED:
> >> + break;
> >> + }
> >> +
> >> + return true;
> >> +}
> >> +
> >> +bool pvr_device_enter(struct pvr_device *pvr_dev, int *idx);
> >> +void pvr_device_exit(struct pvr_device *pvr_dev, int idx);
> >> +void pvr_device_set_lost(struct pvr_device *pvr_dev);
> >>
> >> bool
> >> pvr_device_has_uapi_quirk(struct pvr_device *pvr_dev, u32 quirk);
> >> diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c
> >> index 5c3b2d58d766..55bea656a40f 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_drv.c
> >> +++ b/drivers/gpu/drm/imagination/pvr_drv.c
> >> @@ -81,13 +81,13 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> >> int idx;
> >> int err;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> /* All padding fields must be zeroed. */
> >> if (args->_padding_c != 0) {
> >> err = -EINVAL;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> /*
> >> @@ -101,7 +101,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> >> if (args->size > SIZE_MAX || args->size == 0 || args->flags &
> >> ~DRM_PVR_BO_FLAGS_MASK || args->size & (PVR_DEVICE_PAGE_SIZE - 1)) {
> >> err = -EINVAL;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> sanitized_size = (size_t)args->size;
> >> @@ -113,7 +113,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> >> pvr_obj = pvr_gem_object_create(pvr_dev, sanitized_size, args->flags);
> >> if (IS_ERR(pvr_obj)) {
> >> err = PTR_ERR(pvr_obj);
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> /* This function will not modify &args->handle unless it succeeds. */
> >> @@ -121,7 +121,7 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> >> if (err)
> >> goto err_destroy_obj;
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return 0;
> >>
> >> @@ -133,8 +133,8 @@ pvr_ioctl_create_bo(struct drm_device *drm_dev, void *raw_args,
> >> */
> >> pvr_gem_object_put(pvr_obj);
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> @@ -164,19 +164,20 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
> >> struct drm_file *file)
> >> {
> >> struct drm_pvr_ioctl_get_bo_mmap_offset_args *args = raw_args;
> >> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> >> struct pvr_file *pvr_file = to_pvr_file(file);
> >> struct pvr_gem_object *pvr_obj;
> >> struct drm_gem_object *gem_obj;
> >> int idx;
> >> int ret;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> /* All padding fields must be zeroed. */
> >> if (args->_padding_4 != 0) {
> >> ret = -EINVAL;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> /*
> >> @@ -188,7 +189,7 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
> >> pvr_obj = pvr_gem_object_from_handle(pvr_file, args->handle);
> >> if (!pvr_obj) {
> >> ret = -ENOENT;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> gem_obj = gem_from_pvr_gem(pvr_obj);
> >> @@ -202,7 +203,7 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
> >> if (ret != 0) {
> >> /* Drop our reference to the buffer object. */
> >> drm_gem_object_put(gem_obj);
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> /*
> >> @@ -214,8 +215,8 @@ pvr_ioctl_get_bo_mmap_offset(struct drm_device *drm_dev, void *raw_args,
> >> /* Drop our reference to the buffer object. */
> >> pvr_gem_object_put(pvr_obj);
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return ret;
> >> }
> >> @@ -626,7 +627,7 @@ pvr_ioctl_dev_query(struct drm_device *drm_dev, void *raw_args,
> >> int idx;
> >> int ret = -EINVAL;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> switch ((enum drm_pvr_dev_query)args->type) {
> >> @@ -655,7 +656,7 @@ pvr_ioctl_dev_query(struct drm_device *drm_dev, void *raw_args,
> >> break;
> >> }
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return ret;
> >> }
> >> @@ -680,16 +681,17 @@ pvr_ioctl_create_context(struct drm_device *drm_dev, void *raw_args,
> >> struct drm_file *file)
> >> {
> >> struct drm_pvr_ioctl_create_context_args *args = raw_args;
> >> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> >> struct pvr_file *pvr_file = file->driver_priv;
> >> int idx;
> >> int ret;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> ret = pvr_context_create(pvr_file, args);
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return ret;
> >> }
> >> @@ -738,18 +740,19 @@ pvr_ioctl_create_free_list(struct drm_device *drm_dev, void *raw_args,
> >> struct drm_file *file)
> >> {
> >> struct drm_pvr_ioctl_create_free_list_args *args = raw_args;
> >> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> >> struct pvr_file *pvr_file = to_pvr_file(file);
> >> struct pvr_free_list *free_list;
> >> int idx;
> >> int err;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> free_list = pvr_free_list_create(pvr_file, args);
> >> if (IS_ERR(free_list)) {
> >> err = PTR_ERR(free_list);
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> /* Allocate object handle for userspace. */
> >> @@ -761,15 +764,15 @@ pvr_ioctl_create_free_list(struct drm_device *drm_dev, void *raw_args,
> >> if (err < 0)
> >> goto err_cleanup;
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return 0;
> >>
> >> err_cleanup:
> >> pvr_free_list_put(free_list);
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> @@ -824,18 +827,19 @@ pvr_ioctl_create_hwrt_dataset(struct drm_device *drm_dev, void *raw_args,
> >> struct drm_file *file)
> >> {
> >> struct drm_pvr_ioctl_create_hwrt_dataset_args *args = raw_args;
> >> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> >> struct pvr_file *pvr_file = to_pvr_file(file);
> >> struct pvr_hwrt_dataset *hwrt;
> >> int idx;
> >> int err;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> hwrt = pvr_hwrt_dataset_create(pvr_file, args);
> >> if (IS_ERR(hwrt)) {
> >> err = PTR_ERR(hwrt);
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> /* Allocate object handle for userspace. */
> >> @@ -847,15 +851,15 @@ pvr_ioctl_create_hwrt_dataset(struct drm_device *drm_dev, void *raw_args,
> >> if (err < 0)
> >> goto err_cleanup;
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return 0;
> >>
> >> err_cleanup:
> >> pvr_hwrt_dataset_put(hwrt);
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> @@ -910,23 +914,24 @@ pvr_ioctl_create_vm_context(struct drm_device *drm_dev, void *raw_args,
> >> struct drm_file *file)
> >> {
> >> struct drm_pvr_ioctl_create_vm_context_args *args = raw_args;
> >> + struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
> >> struct pvr_file *pvr_file = to_pvr_file(file);
> >> struct pvr_vm_context *vm_ctx;
> >> int idx;
> >> int err;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> if (args->_padding_4) {
> >> err = -EINVAL;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> vm_ctx = pvr_vm_create_context(pvr_file->pvr_dev, true);
> >> if (IS_ERR(vm_ctx)) {
> >> err = PTR_ERR(vm_ctx);
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> /* Allocate object handle for userspace. */
> >> @@ -938,15 +943,15 @@ pvr_ioctl_create_vm_context(struct drm_device *drm_dev, void *raw_args,
> >> if (err < 0)
> >> goto err_cleanup;
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return 0;
> >>
> >> err_cleanup:
> >> pvr_vm_context_put(vm_ctx);
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> @@ -1022,26 +1027,26 @@ pvr_ioctl_vm_map(struct drm_device *drm_dev, void *raw_args,
> >> int idx;
> >> int err;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> /* Initial validation of args. */
> >> if (args->_padding_14) {
> >> err = -EINVAL;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> if (args->flags != 0 ||
> >> check_add_overflow(args->offset, args->size, &offset_plus_size) ||
> >> !pvr_find_heap_containing(pvr_dev, args->device_addr, args->size)) {
> >> err = -EINVAL;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> vm_ctx = pvr_vm_context_lookup(pvr_file, args->vm_context_handle);
> >> if (!vm_ctx) {
> >> err = -EINVAL;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> pvr_obj = pvr_gem_object_from_handle(pvr_file, args->handle);
> >> @@ -1079,8 +1084,8 @@ pvr_ioctl_vm_map(struct drm_device *drm_dev, void *raw_args,
> >> err_put_vm_context:
> >> pvr_vm_context_put(vm_ctx);
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> @@ -1148,12 +1153,12 @@ pvr_ioctl_submit_jobs(struct drm_device *drm_dev, void *raw_args,
> >> int idx;
> >> int err;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> err = pvr_submit_jobs(pvr_dev, pvr_file, args);
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> diff --git a/drivers/gpu/drm/imagination/pvr_fw.c b/drivers/gpu/drm/imagination/pvr_fw.c
> >> index 3debc9870a82..07547e167963 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_fw.c
> >> +++ b/drivers/gpu/drm/imagination/pvr_fw.c
> >> @@ -1094,7 +1094,7 @@ pvr_fw_structure_cleanup(struct pvr_device *pvr_dev, u32 type, struct pvr_fw_obj
> >>
> >> down_read(&pvr_dev->reset_sem);
> >>
> >> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx)) {
> >> + if (!pvr_device_enter(pvr_dev, &idx)) {
> >> err = -EIO;
> >> goto err_up_read;
> >> }
> >> @@ -1118,22 +1118,22 @@ pvr_fw_structure_cleanup(struct pvr_device *pvr_dev, u32 type, struct pvr_fw_obj
> >> break;
> >> default:
> >> err = -EINVAL;
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> err = pvr_kccb_send_cmd(pvr_dev, &cmd, &slot_nr);
> >> if (err)
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >>
> >> err = pvr_kccb_wait_for_completion(pvr_dev, slot_nr, HZ, &rtn);
> >> if (err)
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >>
> >> if (rtn & ROGUE_FWIF_KCCB_RTN_SLOT_CLEANUP_BUSY)
> >> err = -EBUSY;
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> err_up_read:
> >> up_read(&pvr_dev->reset_sem);
> >> diff --git a/drivers/gpu/drm/imagination/pvr_fw_trace.c b/drivers/gpu/drm/imagination/pvr_fw_trace.c
> >> index 31199e45b72e..26d67483eac2 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_fw_trace.c
> >> +++ b/drivers/gpu/drm/imagination/pvr_fw_trace.c
> >> @@ -149,7 +149,7 @@ update_logtype(struct pvr_device *pvr_dev, u32 group_mask)
> >> fw_trace->group_mask = group_mask;
> >>
> >> down_read(&pvr_dev->reset_sem);
> >> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx)) {
> >> + if (!pvr_device_enter(pvr_dev, &idx)) {
> >> err = -EIO;
> >> goto err_up_read;
> >> }
> >> @@ -159,7 +159,7 @@ update_logtype(struct pvr_device *pvr_dev, u32 group_mask)
> >>
> >> err = pvr_kccb_send_cmd(pvr_dev, &cmd, NULL);
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> err_up_read:
> >> up_read(&pvr_dev->reset_sem);
> >> diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c b/drivers/gpu/drm/imagination/pvr_mmu.c
> >> index 4fe70610ed94..59911f70e9ca 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_mmu.c
> >> +++ b/drivers/gpu/drm/imagination/pvr_mmu.c
> >> @@ -129,18 +129,18 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
> >> u32 slot;
> >> int idx;
> >>
> >> - if (!drm_dev_enter(from_pvr_device(pvr_dev), &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> /* Can't flush MMU if the firmware hasn't booted yet. */
> >> if (!pvr_dev->fw_dev.booted)
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >>
> >> cmd_mmu_cache_data->cache_flags =
> >> atomic_xchg(&pvr_dev->mmu_flush_cache_flags, 0);
> >>
> >> if (!cmd_mmu_cache_data->cache_flags)
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >>
> >> cmd_mmu_cache.cmd_type = ROGUE_FWIF_KCCB_CMD_MMUCACHE;
> >>
> >> @@ -156,7 +156,7 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
> >> if (err)
> >> goto err_reset_and_retry;
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return 0;
> >>
> >> @@ -167,23 +167,23 @@ int pvr_mmu_flush_exec(struct pvr_device *pvr_dev, bool wait)
> >> */
> >> err = pvr_power_reset(pvr_dev, true);
> >> if (err)
> >> - goto err_drm_dev_exit; /* Device is lost. */
> >> + goto err_pvr_device_exit; /* Device is lost. */
> >>
> >> /* Retry sending flush request. */
> >> err = pvr_kccb_send_cmd(pvr_dev, &cmd_mmu_cache, &slot);
> >> if (err) {
> >> - pvr_device_lost(pvr_dev);
> >> - goto err_drm_dev_exit;
> >> + pvr_device_set_lost(pvr_dev);
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> if (wait) {
> >> err = pvr_kccb_wait_for_completion(pvr_dev, slot, HZ, NULL);
> >> if (err)
> >> - pvr_device_lost(pvr_dev);
> >> + pvr_device_set_lost(pvr_dev);
> >> }
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
> >> index ba7816fd28ec..c927def3d3f3 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_power.c
> >> +++ b/drivers/gpu/drm/imagination/pvr_power.c
> >> @@ -23,21 +23,6 @@
> >>
> >> #define WATCHDOG_TIME_MS (500)
> >>
> >> -/**
> >> - * pvr_device_lost() - Mark GPU device as lost
> >> - * @pvr_dev: Target PowerVR device.
> >> - *
> >> - * This will cause the DRM device to be unplugged.
> >> - */
> >> -void
> >> -pvr_device_lost(struct pvr_device *pvr_dev)
> >> -{
> >> - if (!pvr_dev->lost) {
> >> - pvr_dev->lost = true;
> >> - drm_dev_unplug(from_pvr_device(pvr_dev));
> >> - }
> >> -}
> >> -
> >> static int
> >> pvr_power_send_command(struct pvr_device *pvr_dev, struct rogue_fwif_kccb_cmd *pow_cmd)
> >> {
> >> @@ -186,7 +171,7 @@ pvr_watchdog_worker(struct work_struct *work)
> >> watchdog.work.work);
> >> bool stalled;
> >>
> >> - if (pvr_dev->lost)
> >> + if (pvr_device_is_lost(pvr_dev))
> >> return;
> >>
> >> if (pm_runtime_get_if_in_use(from_pvr_device(pvr_dev)->dev) <= 0)
> >> @@ -208,10 +193,9 @@ pvr_watchdog_worker(struct work_struct *work)
> >> pm_runtime_put(from_pvr_device(pvr_dev)->dev);
> >>
> >> out_requeue:
> >> - if (!pvr_dev->lost) {
> >> + if (!pvr_device_is_lost(pvr_dev))
> >> queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,
> >> msecs_to_jiffies(WATCHDOG_TIME_MS));
> >> - }
> >> }
> >>
> >> /**
> >> @@ -239,21 +223,21 @@ pvr_power_device_suspend(struct device *dev)
> >> int err = 0;
> >> int idx;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> if (pvr_dev->fw_dev.booted) {
> >> err = pvr_power_fw_disable(pvr_dev, false);
> >> if (err)
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >> }
> >>
> >> clk_disable_unprepare(pvr_dev->mem_clk);
> >> clk_disable_unprepare(pvr_dev->sys_clk);
> >> clk_disable_unprepare(pvr_dev->core_clk);
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> @@ -267,12 +251,12 @@ pvr_power_device_resume(struct device *dev)
> >> int idx;
> >> int err;
> >>
> >> - if (!drm_dev_enter(drm_dev, &idx))
> >> + if (!pvr_device_enter(pvr_dev, &idx))
> >> return -EIO;
> >>
> >> err = clk_prepare_enable(pvr_dev->core_clk);
> >> if (err)
> >> - goto err_drm_dev_exit;
> >> + goto err_pvr_device_exit;
> >>
> >> err = clk_prepare_enable(pvr_dev->sys_clk);
> >> if (err)
> >> @@ -288,7 +272,7 @@ pvr_power_device_resume(struct device *dev)
> >> goto err_mem_clk_disable;
> >> }
> >>
> >> - drm_dev_exit(idx);
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return 0;
> >>
> >> @@ -301,8 +285,8 @@ pvr_power_device_resume(struct device *dev)
> >> err_core_clk_disable:
> >> clk_disable_unprepare(pvr_dev->core_clk);
> >>
> >> -err_drm_dev_exit:
> >> - drm_dev_exit(idx);
> >> +err_pvr_device_exit:
> >> + pvr_device_exit(pvr_dev, idx);
> >>
> >> return err;
> >> }
> >> @@ -345,7 +329,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
> >>
> >> down_write(&pvr_dev->reset_sem);
> >>
> >> - if (pvr_dev->lost) {
> >> + if (pvr_device_is_lost(pvr_dev)) {
> >> err = -EIO;
> >> goto err_up_write;
> >> }
> >> @@ -407,7 +391,7 @@ pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
> >>
> >> err_device_lost:
> >> drm_err(from_pvr_device(pvr_dev), "GPU device lost");
> >> - pvr_device_lost(pvr_dev);
> >> + pvr_device_set_lost(pvr_dev);
> >>
> >> /* Leave IRQs disabled if the device is lost. */
> >>
> >> diff --git a/drivers/gpu/drm/imagination/pvr_power.h b/drivers/gpu/drm/imagination/pvr_power.h
> >> index 9a9312dcb2da..360980f454d7 100644
> >> --- a/drivers/gpu/drm/imagination/pvr_power.h
> >> +++ b/drivers/gpu/drm/imagination/pvr_power.h
> >> @@ -12,8 +12,6 @@
> >> int pvr_watchdog_init(struct pvr_device *pvr_dev);
> >
> >
> >
> >
> >
> >
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-02-01 11:09 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-01-23 13:04 [PATCH] drm/imagination: On device loss, handle unplug after critical section Matt Coster
2024-01-25 18:44 ` Daniel Vetter
2024-01-31 17:22 ` Matt Coster
2024-02-01 11:09 ` Daniel Vetter
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