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drm/amd/display: Use atomic types for ref_count 

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@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Jerry Zuo 2017-07-31 17:10:44 -04:00 committed by Alex Deucher
parent f81483c4cc
commit e8cd26434d
8 changed files with 49 additions and 51 deletions
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24
drivers/gpu/drm/amd/display/dc/core/dc.c
View File

@ -454,7 +454,7 @@ static bool construct(struct core_dc *dc,
goto val_ctx_fail; 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->cgs_device = init_params->cgs_device;
dc_ctx->driver_context = init_params->driver; dc_ctx->driver_context = init_params->driver;
@ -704,7 +704,7 @@ struct validate_context *dc_get_validate_context(
if (context == NULL) if (context == NULL)
goto context_alloc_fail; goto context_alloc_fail;
++context->ref_count; atomic_inc(&context->ref_count);
if (!is_validation_required(core_dc, set, set_count)) { if (!is_validation_required(core_dc, set, set_count)) {
dc_resource_validate_ctx_copy_construct(core_dc->current_context, context); dc_resource_validate_ctx_copy_construct(core_dc->current_context, context);
@ -748,7 +748,7 @@ bool dc_validate_resources(
if (context == NULL) if (context == NULL)
goto context_alloc_fail; goto context_alloc_fail;
++context->ref_count; atomic_inc(&context->ref_count);
result = core_dc->res_pool->funcs->validate_with_context( result = core_dc->res_pool->funcs->validate_with_context(
core_dc, set, set_count, context, NULL); core_dc, set, set_count, context, NULL);
@ -782,7 +782,7 @@ bool dc_validate_guaranteed(
if (context == NULL) if (context == NULL)
goto context_alloc_fail; goto context_alloc_fail;
++context->ref_count; atomic_inc(&context->ref_count);
result = core_dc->res_pool->funcs->validate_guaranteed( result = core_dc->res_pool->funcs->validate_guaranteed(
core_dc, stream, context); core_dc, stream, context);
@ -1090,7 +1090,7 @@ bool dc_commit_streams(
if (context == NULL) if (context == NULL)
goto context_alloc_fail; goto context_alloc_fail;
++context->ref_count; atomic_inc(&context->ref_count);
result = core_dc->res_pool->funcs->validate_with_context( result = core_dc->res_pool->funcs->validate_with_context(
core_dc, set, stream_count, context, core_dc->current_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) void dc_retain_validate_context(struct validate_context *context)
{ {
ASSERT(context->ref_count > 0); ASSERT(atomic_read(&context->ref_count) > 0);
++context->ref_count; atomic_inc(&context->ref_count);
} }
void dc_release_validate_context(struct validate_context *context) void dc_release_validate_context(struct validate_context *context)
{ {
ASSERT(context->ref_count > 0); ASSERT(atomic_read(&context->ref_count) > 0);
--context->ref_count; atomic_dec(&context->ref_count);
if (context->ref_count == 0) { if (atomic_read(&context->ref_count) == 0) {
dc_resource_validate_ctx_destruct(context); dc_resource_validate_ctx_destruct(context);
dm_free(context); dm_free(context);
} }
@ -1485,7 +1485,7 @@ void dc_update_planes_and_stream(struct dc *dc,
if (context == NULL) if (context == NULL)
goto context_alloc_fail; goto context_alloc_fail;
++context->ref_count; atomic_inc(&context->ref_count);
dc_resource_validate_ctx_copy_construct( dc_resource_validate_ctx_copy_construct(
core_dc->current_context, context); core_dc->current_context, context);
@ -1800,7 +1800,7 @@ void dc_set_power_state(
enum dc_acpi_cm_power_state power_state) enum dc_acpi_cm_power_state power_state)
{ {
struct core_dc *core_dc = DC_TO_CORE(dc); struct core_dc *core_dc = DC_TO_CORE(dc);
int ref_count; atomic_t ref_count;
switch (power_state) { switch (power_state) {
case DC_ACPI_CM_POWER_STATE_D0: case DC_ACPI_CM_POWER_STATE_D0:

2
drivers/gpu/drm/amd/display/dc/core/dc_resource.c
View File

@ -2238,7 +2238,7 @@ void dc_resource_validate_ctx_copy_construct(
struct validate_context *dst_ctx) struct validate_context *dst_ctx)
{ {
int i, j; int i, j;
int ref_count = dst_ctx->ref_count; atomic_t ref_count = dst_ctx->ref_count;
*dst_ctx = *src_ctx; *dst_ctx = *src_ctx;

12
drivers/gpu/drm/amd/display/dc/core/dc_sink.c
View File

@ -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) void dc_sink_retain(struct dc_sink *sink)
{ {
ASSERT(sink->ref_count > 0); ASSERT(atomic_read(&sink->ref_count) > 0);
++sink->ref_count; atomic_inc(&sink->ref_count);
} }
void dc_sink_release(struct dc_sink *sink) void dc_sink_release(struct dc_sink *sink)
{ {
ASSERT(sink->ref_count > 0); ASSERT(atomic_read(&sink->ref_count) > 0);
--sink->ref_count; atomic_dec(&sink->ref_count);
if (sink->ref_count == 0) { if (atomic_read(&sink->ref_count) == 0) {
destruct(sink); destruct(sink);
dm_free(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)) if (false == construct(sink, init_params))
goto construct_fail; goto construct_fail;
++sink->ref_count; atomic_inc(&sink->ref_count);
return sink; return sink;

14
drivers/gpu/drm/amd/display/dc/core/dc_stream.c
View File

@ -96,19 +96,17 @@ static void destruct(struct dc_stream_state *stream)
void dc_stream_retain(struct dc_stream_state *stream) void dc_stream_retain(struct dc_stream_state *stream)
{ {
ASSERT(atomic_read(&stream->ref_count) > 0);
ASSERT(stream->ref_count > 0); atomic_inc(&stream->ref_count);
stream->ref_count++;
} }
void dc_stream_release(struct dc_stream_state *stream) void dc_stream_release(struct dc_stream_state *stream)
{ {
if (stream != NULL) { if (stream != NULL) {
ASSERT(stream->ref_count > 0); ASSERT(atomic_read(&stream->ref_count) > 0);
stream->ref_count--; atomic_dec(&stream->ref_count);
if (stream->ref_count == 0) { if (atomic_read(&stream->ref_count) == 0) {
destruct(stream); destruct(stream);
dm_free(stream); dm_free(stream);
} }
@ -131,7 +129,7 @@ struct dc_stream_state *dc_create_stream_for_sink(
if (false == construct(stream, sink)) if (false == construct(stream, sink))
goto construct_fail; goto construct_fail;
stream->ref_count++; atomic_inc(&stream->ref_count);
return stream; return stream;

36
drivers/gpu/drm/amd/display/dc/core/dc_surface.c
View File

@ -76,7 +76,7 @@ struct dc_plane_state *dc_create_plane_state(const struct dc *dc)
if (false == construct(core_dc->ctx, plane_state)) if (false == construct(core_dc->ctx, plane_state))
goto construct_fail; goto construct_fail;
++plane_state->ref_count; atomic_inc(&plane_state->ref_count);
return plane_state; 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) void dc_plane_state_retain(struct dc_plane_state *plane_state)
{ {
ASSERT(plane_state->ref_count > 0); ASSERT(atomic_read(&plane_state->ref_count) > 0);
++plane_state->ref_count; atomic_inc(&plane_state->ref_count);
} }
void dc_plane_state_release(struct dc_plane_state *plane_state) void dc_plane_state_release(struct dc_plane_state *plane_state)
{ {
ASSERT(plane_state->ref_count > 0); ASSERT(atomic_read(&plane_state->ref_count) > 0);
--plane_state->ref_count; atomic_dec(&plane_state->ref_count);
if (plane_state->ref_count == 0) { if (atomic_read(&plane_state->ref_count) == 0) {
destruct(plane_state); destruct(plane_state);
dm_free(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) void dc_gamma_retain(struct dc_gamma *gamma)
{ {
ASSERT(gamma->ref_count > 0); ASSERT(atomic_read(&gamma->ref_count) > 0);
++gamma->ref_count; atomic_inc(&gamma->ref_count);
} }
void dc_gamma_release(struct dc_gamma **gamma) void dc_gamma_release(struct dc_gamma **gamma)
{ {
ASSERT((*gamma)->ref_count > 0); ASSERT(atomic_read(&(*gamma)->ref_count) > 0);
--(*gamma)->ref_count; atomic_dec(&(*gamma)->ref_count);
if ((*gamma)->ref_count == 0) if (atomic_read(&(*gamma)->ref_count) == 0)
dm_free((*gamma)); dm_free((*gamma));
*gamma = NULL; *gamma = NULL;
@ -161,7 +161,7 @@ struct dc_gamma *dc_create_gamma()
if (gamma == NULL) if (gamma == NULL)
goto alloc_fail; goto alloc_fail;
++gamma->ref_count; atomic_inc(&gamma->ref_count);
return gamma; return gamma;
@ -171,16 +171,16 @@ alloc_fail:
void dc_transfer_func_retain(struct dc_transfer_func *tf) void dc_transfer_func_retain(struct dc_transfer_func *tf)
{ {
ASSERT(tf->ref_count > 0); ASSERT(atomic_read(&tf->ref_count) > 0);
++tf->ref_count; atomic_inc(&tf->ref_count);
} }
void dc_transfer_func_release(struct dc_transfer_func *tf) void dc_transfer_func_release(struct dc_transfer_func *tf)
{ {
ASSERT(tf->ref_count > 0); ASSERT(atomic_read(&tf->ref_count) > 0);
--tf->ref_count; atomic_dec(&tf->ref_count);
if (tf->ref_count == 0) if (atomic_read(&tf->ref_count) == 0)
dm_free(tf); dm_free(tf);
} }
@ -191,7 +191,7 @@ struct dc_transfer_func *dc_create_transfer_func()
if (tf == NULL) if (tf == NULL)
goto alloc_fail; goto alloc_fail;
++tf->ref_count; atomic_inc(&tf->ref_count);
return tf; return tf;

8
drivers/gpu/drm/amd/display/dc/dc.h
View File

@ -295,7 +295,7 @@ struct dc_transfer_func {
enum dc_transfer_func_type type; enum dc_transfer_func_type type;
enum dc_transfer_func_predefined tf; enum dc_transfer_func_predefined tf;
struct dc_context *ctx; struct dc_context *ctx;
int ref_count; atomic_t ref_count;
}; };
/* /*
@ -342,7 +342,7 @@ struct dc_plane_state {
/* private to dc_surface.c */ /* private to dc_surface.c */
enum dc_irq_source irq_source; enum dc_irq_source irq_source;
int ref_count; atomic_t ref_count;
}; };
struct dc_plane_info { struct dc_plane_info {
@ -518,7 +518,7 @@ struct dc_stream_state {
struct dc_stream_status status; struct dc_stream_status status;
/* from stream struct */ /* from stream struct */
int ref_count; atomic_t ref_count;
}; };
struct dc_stream_update { struct dc_stream_update {
@ -902,7 +902,7 @@ struct dc_sink {
struct dc_context *ctx; struct dc_context *ctx;
/* private to dc_sink.c */ /* private to dc_sink.c */
int ref_count; atomic_t ref_count;
}; };
void dc_sink_retain(struct dc_sink *sink); void dc_sink_retain(struct dc_sink *sink);

2
drivers/gpu/drm/amd/display/dc/dc_hw_types.h
View File

@ -433,7 +433,7 @@ struct dc_gamma {
struct dc_context *ctx; struct dc_context *ctx;
/* private to dc_surface.c */ /* private to dc_surface.c */
int ref_count; atomic_t ref_count;
}; };
/* Used by both ipp amd opp functions*/ /* Used by both ipp amd opp functions*/

2
drivers/gpu/drm/amd/display/dc/inc/core_types.h
View File

@ -260,7 +260,7 @@ struct validate_context {
struct dcn_bw_internal_vars dcn_bw_vars; struct dcn_bw_internal_vars dcn_bw_vars;
#endif #endif
int ref_count; atomic_t ref_count;
}; };
#endif /* _CORE_TYPES_H_ */ #endif /* _CORE_TYPES_H_ */