From: Dave Airlie airlied@redhat.com
While developing MST support I noticed I often got the wrong data back from a transaction, in a racy fashion. I noticed the scratch space wasn't locked against concurrent users.
Based on a patch by Alex, but I've made it a bit more obvious when things are locked.
Signed-off-by: Dave Airlie airlied@redhat.com --- drivers/gpu/drm/radeon/atom.c | 11 ++++++++++- drivers/gpu/drm/radeon/atom.h | 2 ++ drivers/gpu/drm/radeon/atombios_dp.c | 4 +++- drivers/gpu/drm/radeon/atombios_i2c.c | 4 +++- drivers/gpu/drm/radeon/radeon_device.c | 1 + 5 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c index 6f26eb7..bec41c4 100644 --- a/drivers/gpu/drm/radeon/atom.c +++ b/drivers/gpu/drm/radeon/atom.c @@ -1218,7 +1218,7 @@ free: return ret; }
-int atom_execute_table(struct atom_context *ctx, int index, uint32_t * params) +int atom_execute_table_scratch_unlocked(struct atom_context *ctx, int index, uint32_t * params) { int r;
@@ -1239,6 +1239,15 @@ int atom_execute_table(struct atom_context *ctx, int index, uint32_t * params) return r; }
+int atom_execute_table(struct atom_context *ctx, int index, uint32_t * params) +{ + int r; + mutex_lock(&ctx->scratch_mutex); + r = atom_execute_table_scratch_unlocked(ctx, index, params); + mutex_unlock(&ctx->scratch_mutex); + return r; +} + static int atom_iio_len[] = { 1, 2, 3, 3, 3, 3, 4, 4, 4, 3 };
static void atom_index_iio(struct atom_context *ctx, int base) diff --git a/drivers/gpu/drm/radeon/atom.h b/drivers/gpu/drm/radeon/atom.h index bf9e6f2..6dffe15 100644 --- a/drivers/gpu/drm/radeon/atom.h +++ b/drivers/gpu/drm/radeon/atom.h @@ -125,6 +125,7 @@ struct card_info { struct atom_context { struct card_info *card; struct mutex mutex; + struct mutex scratch_mutex; void *bios; uint32_t cmd_table, data_table; uint16_t *iio; @@ -146,6 +147,7 @@ extern int atom_reg_debug;
struct atom_context *atom_parse(struct card_info *, void *); int atom_execute_table(struct atom_context *, int, uint32_t *); +int atom_execute_table_scratch_unlocked(struct atom_context *, int, uint32_t *); int atom_asic_init(struct atom_context *); void atom_destroy(struct atom_context *); bool atom_parse_data_header(struct atom_context *ctx, int index, uint16_t *size, diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index bd96ae7..0f39d96 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -100,6 +100,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan, memset(&args, 0, sizeof(args));
mutex_lock(&chan->mutex); + mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);
base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1);
@@ -113,7 +114,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan, if (ASIC_IS_DCE4(rdev)) args.v2.ucHPD_ID = chan->rec.hpd;
- atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args); + atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);
*ack = args.v1.ucReplyStatus;
@@ -147,6 +148,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
r = recv_bytes; done: + mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex); mutex_unlock(&chan->mutex);
return r; diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c b/drivers/gpu/drm/radeon/atombios_i2c.c index 9c570fb..4157780 100644 --- a/drivers/gpu/drm/radeon/atombios_i2c.c +++ b/drivers/gpu/drm/radeon/atombios_i2c.c @@ -48,6 +48,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, memset(&args, 0, sizeof(args));
mutex_lock(&chan->mutex); + mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);
base = (unsigned char *)rdev->mode_info.atom_context->scratch;
@@ -82,7 +83,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, args.ucSlaveAddr = slave_addr << 1; args.ucLineNumber = chan->rec.i2c_id;
- atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args); + atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);
/* error */ if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) { @@ -95,6 +96,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, radeon_atom_copy_swap(buf, base, num, false);
done: + mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex); mutex_unlock(&chan->mutex);
return r; diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c index 0d77dce..e63c9a4 100644 --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -950,6 +950,7 @@ int radeon_atombios_init(struct radeon_device *rdev) }
mutex_init(&rdev->mode_info.atom_context->mutex); + mutex_init(&rdev->mode_info.atom_context->scratch_mutex); radeon_atom_initialize_bios_scratch_regs(rdev->ddev); atom_allocate_fb_scratch(rdev->mode_info.atom_context); return 0;
On Mon, Nov 10, 2014 at 6:16 PM, Dave Airlie airlied@gmail.com wrote:
From: Dave Airlie airlied@redhat.com
While developing MST support I noticed I often got the wrong data back from a transaction, in a racy fashion. I noticed the scratch space wasn't locked against concurrent users.
Based on a patch by Alex, but I've made it a bit more obvious when things are locked.
Signed-off-by: Dave Airlie airlied@redhat.com
Applied to my -fixes tree.
Alex
drivers/gpu/drm/radeon/atom.c | 11 ++++++++++- drivers/gpu/drm/radeon/atom.h | 2 ++ drivers/gpu/drm/radeon/atombios_dp.c | 4 +++- drivers/gpu/drm/radeon/atombios_i2c.c | 4 +++- drivers/gpu/drm/radeon/radeon_device.c | 1 + 5 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c index 6f26eb7..bec41c4 100644 --- a/drivers/gpu/drm/radeon/atom.c +++ b/drivers/gpu/drm/radeon/atom.c @@ -1218,7 +1218,7 @@ free: return ret; }
-int atom_execute_table(struct atom_context *ctx, int index, uint32_t * params) +int atom_execute_table_scratch_unlocked(struct atom_context *ctx, int index, uint32_t * params) { int r;
@@ -1239,6 +1239,15 @@ int atom_execute_table(struct atom_context *ctx, int index, uint32_t * params) return r; }
+int atom_execute_table(struct atom_context *ctx, int index, uint32_t * params) +{
int r;mutex_lock(&ctx->scratch_mutex);r = atom_execute_table_scratch_unlocked(ctx, index, params);mutex_unlock(&ctx->scratch_mutex);return r;+}
static int atom_iio_len[] = { 1, 2, 3, 3, 3, 3, 4, 4, 4, 3 };
static void atom_index_iio(struct atom_context *ctx, int base) diff --git a/drivers/gpu/drm/radeon/atom.h b/drivers/gpu/drm/radeon/atom.h index bf9e6f2..6dffe15 100644 --- a/drivers/gpu/drm/radeon/atom.h +++ b/drivers/gpu/drm/radeon/atom.h @@ -125,6 +125,7 @@ struct card_info { struct atom_context { struct card_info *card; struct mutex mutex;
struct mutex scratch_mutex; void *bios; uint32_t cmd_table, data_table; uint16_t *iio;@@ -146,6 +147,7 @@ extern int atom_reg_debug;
struct atom_context *atom_parse(struct card_info *, void *); int atom_execute_table(struct atom_context *, int, uint32_t *); +int atom_execute_table_scratch_unlocked(struct atom_context *, int, uint32_t *); int atom_asic_init(struct atom_context *); void atom_destroy(struct atom_context *); bool atom_parse_data_header(struct atom_context *ctx, int index, uint16_t *size, diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index bd96ae7..0f39d96 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -100,6 +100,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan, memset(&args, 0, sizeof(args));
mutex_lock(&chan->mutex);
mutex_lock(&rdev->mode_info.atom_context->scratch_mutex); base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1);@@ -113,7 +114,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan, if (ASIC_IS_DCE4(rdev)) args.v2.ucHPD_ID = chan->rec.hpd;
atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args); *ack = args.v1.ucReplyStatus;@@ -147,6 +148,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan,
r = recv_bytes;done:
mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex); mutex_unlock(&chan->mutex); return r;diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c b/drivers/gpu/drm/radeon/atombios_i2c.c index 9c570fb..4157780 100644 --- a/drivers/gpu/drm/radeon/atombios_i2c.c +++ b/drivers/gpu/drm/radeon/atombios_i2c.c @@ -48,6 +48,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, memset(&args, 0, sizeof(args));
mutex_lock(&chan->mutex);
mutex_lock(&rdev->mode_info.atom_context->scratch_mutex); base = (unsigned char *)rdev->mode_info.atom_context->scratch;@@ -82,7 +83,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, args.ucSlaveAddr = slave_addr << 1; args.ucLineNumber = chan->rec.i2c_id;
atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args); /* error */ if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {@@ -95,6 +96,7 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan, radeon_atom_copy_swap(buf, base, num, false);
done:
mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex); mutex_unlock(&chan->mutex); return r;diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c index 0d77dce..e63c9a4 100644 --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -950,6 +950,7 @@ int radeon_atombios_init(struct radeon_device *rdev) }
mutex_init(&rdev->mode_info.atom_context->mutex);
mutex_init(&rdev->mode_info.atom_context->scratch_mutex); radeon_atom_initialize_bios_scratch_regs(rdev->ddev); atom_allocate_fb_scratch(rdev->mode_info.atom_context); return 0;-- 1.9.3
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