From: Jerry Zuo <Jerry.Zuo@xxxxxxx>
Current ref_count inc/dec is not guarded by locks which leads to
a raced condition where two threads try to access the variable
at the same time. In this case, both might act on the same cached
value and inc/dec from the same value, rather than inc/dec by 2.
Signed-off-by: Jerry Zuo <Jerry.Zuo at amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland at amd.com>
---
drivers/gpu/drm/amd/display/dc/core/dc.c | 24 +++++++--------
drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 2 +-
drivers/gpu/drm/amd/display/dc/core/dc_sink.c | 12 ++++----
drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 14 ++++-----
drivers/gpu/drm/amd/display/dc/core/dc_surface.c | 36 +++++++++++------------
drivers/gpu/drm/amd/display/dc/dc.h | 8 ++---
drivers/gpu/drm/amd/display/dc/dc_hw_types.h | 2 +-
drivers/gpu/drm/amd/display/dc/inc/core_types.h | 2 +-
8 files changed, 49 insertions(+), 51 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index b69a726717d9..8efdd05841e1 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -454,7 +454,7 @@ static bool construct(struct core_dc *dc,
goto val_ctx_fail;
}
- dc->current_context->ref_count++;
+ atomic_inc(&dc->current_context->ref_count);
dc_ctx->cgs_device = init_params->cgs_device;
dc_ctx->driver_context = init_params->driver;
@@ -704,7 +704,7 @@ struct validate_context *dc_get_validate_context(
if (context == NULL)
goto context_alloc_fail;
- ++context->ref_count;
+ atomic_inc(&context->ref_count);
if (!is_validation_required(core_dc, set, set_count)) {
dc_resource_validate_ctx_copy_construct(core_dc->current_context, context);
@@ -748,7 +748,7 @@ bool dc_validate_resources(
if (context == NULL)
goto context_alloc_fail;
- ++context->ref_count;
+ atomic_inc(&context->ref_count);
result = core_dc->res_pool->funcs->validate_with_context(
core_dc, set, set_count, context, NULL);
@@ -782,7 +782,7 @@ bool dc_validate_guaranteed(
if (context == NULL)
goto context_alloc_fail;
- ++context->ref_count;
+ atomic_inc(&context->ref_count);
result = core_dc->res_pool->funcs->validate_guaranteed(
core_dc, stream, context);
@@ -1090,7 +1090,7 @@ bool dc_commit_streams(
if (context == NULL)
goto context_alloc_fail;
- ++context->ref_count;
+ atomic_inc(&context->ref_count);
result = core_dc->res_pool->funcs->validate_with_context(
core_dc, set, stream_count, context, core_dc->current_context);
@@ -1203,16 +1203,16 @@ bool dc_commit_planes_to_stream(
void dc_retain_validate_context(struct validate_context *context)
{
- ASSERT(context->ref_count > 0);
- ++context->ref_count;
+ ASSERT(atomic_read(&context->ref_count) > 0);
+ atomic_inc(&context->ref_count);
}
void dc_release_validate_context(struct validate_context *context)
{
- ASSERT(context->ref_count > 0);
- --context->ref_count;
+ ASSERT(atomic_read(&context->ref_count) > 0);
+ atomic_dec(&context->ref_count);
- if (context->ref_count == 0) {
+ if (atomic_read(&context->ref_count) == 0) {
dc_resource_validate_ctx_destruct(context);
dm_free(context);
}
@@ -1485,7 +1485,7 @@ void dc_update_planes_and_stream(struct dc *dc,
if (context == NULL)
goto context_alloc_fail;
- ++context->ref_count;
+ atomic_inc(&context->ref_count);
dc_resource_validate_ctx_copy_construct(
core_dc->current_context, context);
@@ -1800,7 +1800,7 @@ void dc_set_power_state(
enum dc_acpi_cm_power_state power_state)
{
struct core_dc *core_dc = DC_TO_CORE(dc);
- int ref_count;
+ atomic_t ref_count;
switch (power_state) {
case DC_ACPI_CM_POWER_STATE_D0:
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index f0100396d870..6687baa3d8b8 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -2238,7 +2238,7 @@ void dc_resource_validate_ctx_copy_construct(
struct validate_context *dst_ctx)
{
int i, j;
- int ref_count = dst_ctx->ref_count;
+ atomic_t ref_count = dst_ctx->ref_count;
*dst_ctx = *src_ctx;
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_sink.c b/drivers/gpu/drm/amd/display/dc/core/dc_sink.c
index a83f1243a9d1..7717350297a5 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_sink.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_sink.c
@@ -63,16 +63,16 @@ static bool construct(struct dc_sink *sink, const struct dc_sink_init_data *init
void dc_sink_retain(struct dc_sink *sink)
{
- ASSERT(sink->ref_count > 0);
- ++sink->ref_count;
+ ASSERT(atomic_read(&sink->ref_count) > 0);
+ atomic_inc(&sink->ref_count);
}
void dc_sink_release(struct dc_sink *sink)
{
- ASSERT(sink->ref_count > 0);
- --sink->ref_count;
+ ASSERT(atomic_read(&sink->ref_count) > 0);
+ atomic_dec(&sink->ref_count);
- if (sink->ref_count == 0) {
+ if (atomic_read(&sink->ref_count) == 0) {
destruct(sink);
dm_free(sink);
}
@@ -88,7 +88,7 @@ struct dc_sink *dc_sink_create(const struct dc_sink_init_data *init_params)
if (false == construct(sink, init_params))
goto construct_fail;
- ++sink->ref_count;
+ atomic_inc(&sink->ref_count);
return sink;
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index 2de37fed12a5..47e407dab4a3 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -96,19 +96,17 @@ static void destruct(struct dc_stream_state *stream)
void dc_stream_retain(struct dc_stream_state *stream)
{
-
- ASSERT(stream->ref_count > 0);
- stream->ref_count++;
+ ASSERT(atomic_read(&stream->ref_count) > 0);
+ atomic_inc(&stream->ref_count);
}
void dc_stream_release(struct dc_stream_state *stream)
{
-
if (stream != NULL) {
- ASSERT(stream->ref_count > 0);
- stream->ref_count--;
+ ASSERT(atomic_read(&stream->ref_count) > 0);
+ atomic_dec(&stream->ref_count);
- if (stream->ref_count == 0) {
+ if (atomic_read(&stream->ref_count) == 0) {
destruct(stream);
dm_free(stream);
}
@@ -131,7 +129,7 @@ struct dc_stream_state *dc_create_stream_for_sink(
if (false == construct(stream, sink))
goto construct_fail;
- stream->ref_count++;
+ atomic_inc(&stream->ref_count);
return stream;
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_surface.c b/drivers/gpu/drm/amd/display/dc/core/dc_surface.c
index 3bcca2d1872b..da19c7fa5151 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_surface.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_surface.c
@@ -76,7 +76,7 @@ struct dc_plane_state *dc_create_plane_state(const struct dc *dc)
if (false == construct(core_dc->ctx, plane_state))
goto construct_fail;
- ++plane_state->ref_count;
+ atomic_inc(&plane_state->ref_count);
return plane_state;
@@ -122,16 +122,16 @@ const struct dc_plane_status *dc_plane_get_status(
void dc_plane_state_retain(struct dc_plane_state *plane_state)
{
- ASSERT(plane_state->ref_count > 0);
- ++plane_state->ref_count;
+ ASSERT(atomic_read(&plane_state->ref_count) > 0);
+ atomic_inc(&plane_state->ref_count);
}
void dc_plane_state_release(struct dc_plane_state *plane_state)
{
- ASSERT(plane_state->ref_count > 0);
- --plane_state->ref_count;
+ ASSERT(atomic_read(&plane_state->ref_count) > 0);
+ atomic_dec(&plane_state->ref_count);
- if (plane_state->ref_count == 0) {
+ if (atomic_read(&plane_state->ref_count) == 0) {
destruct(plane_state);
dm_free(plane_state);
}
@@ -139,16 +139,16 @@ void dc_plane_state_release(struct dc_plane_state *plane_state)
void dc_gamma_retain(struct dc_gamma *gamma)
{
- ASSERT(gamma->ref_count > 0);
- ++gamma->ref_count;
+ ASSERT(atomic_read(&gamma->ref_count) > 0);
+ atomic_inc(&gamma->ref_count);
}
void dc_gamma_release(struct dc_gamma **gamma)
{
- ASSERT((*gamma)->ref_count > 0);
- --(*gamma)->ref_count;
+ ASSERT(atomic_read(&(*gamma)->ref_count) > 0);
+ atomic_dec(&(*gamma)->ref_count);
- if ((*gamma)->ref_count == 0)
+ if (atomic_read(&(*gamma)->ref_count) == 0)
dm_free((*gamma));
*gamma = NULL;
@@ -161,7 +161,7 @@ struct dc_gamma *dc_create_gamma()
if (gamma == NULL)
goto alloc_fail;
- ++gamma->ref_count;
+ atomic_inc(&gamma->ref_count);
return gamma;
@@ -171,16 +171,16 @@ struct dc_gamma *dc_create_gamma()
void dc_transfer_func_retain(struct dc_transfer_func *tf)
{
- ASSERT(tf->ref_count > 0);
- ++tf->ref_count;
+ ASSERT(atomic_read(&tf->ref_count) > 0);
+ atomic_inc(&tf->ref_count);
}
void dc_transfer_func_release(struct dc_transfer_func *tf)
{
- ASSERT(tf->ref_count > 0);
- --tf->ref_count;
+ ASSERT(atomic_read(&tf->ref_count) > 0);
+ atomic_dec(&tf->ref_count);
- if (tf->ref_count == 0)
+ if (atomic_read(&tf->ref_count) == 0)
dm_free(tf);
}
@@ -191,7 +191,7 @@ struct dc_transfer_func *dc_create_transfer_func()
if (tf == NULL)
goto alloc_fail;
- ++tf->ref_count;
+ atomic_inc(&tf->ref_count);
return tf;
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index cac92bf91e4a..4e60adb981e1 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -295,7 +295,7 @@ struct dc_transfer_func {
enum dc_transfer_func_type type;
enum dc_transfer_func_predefined tf;
struct dc_context *ctx;
- int ref_count;
+ atomic_t ref_count;
};
/*
@@ -342,7 +342,7 @@ struct dc_plane_state {
/* private to dc_surface.c */
enum dc_irq_source irq_source;
- int ref_count;
+ atomic_t ref_count;
};
struct dc_plane_info {
@@ -518,7 +518,7 @@ struct dc_stream_state {
struct dc_stream_status status;
/* from stream struct */
- int ref_count;
+ atomic_t ref_count;
};
struct dc_stream_update {
@@ -902,7 +902,7 @@ struct dc_sink {
struct dc_context *ctx;
/* private to dc_sink.c */
- int ref_count;
+ atomic_t ref_count;
};
void dc_sink_retain(struct dc_sink *sink);
diff --git a/drivers/gpu/drm/amd/display/dc/dc_hw_types.h b/drivers/gpu/drm/amd/display/dc/dc_hw_types.h
index 8d1504668ec7..94f83cd9ab32 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_hw_types.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_hw_types.h
@@ -433,7 +433,7 @@ struct dc_gamma {
struct dc_context *ctx;
/* private to dc_surface.c */
- int ref_count;
+ atomic_t ref_count;
};
/* Used by both ipp amd opp functions*/
diff --git a/drivers/gpu/drm/amd/display/dc/inc/core_types.h b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
index b3005629ab21..5190901ea379 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/core_types.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
@@ -260,7 +260,7 @@ struct validate_context {
struct dcn_bw_internal_vars dcn_bw_vars;
#endif
- int ref_count;
+ atomic_t ref_count;
};
#endif /* _CORE_TYPES_H_ */
--
2.11.0
