| Message ID | 20210701171550.49353-5-matthew.brost@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | CT changes required for GuC submission | expand |
On 7/1/2021 10:15, Matthew Brost wrote: > Add non blocking CTB send function, intel_guc_send_nb. GuC submission > will send CTBs in the critical path and does not need to wait for these > CTBs to complete before moving on, hence the need for this new function. > > The non-blocking CTB now must have a flow control mechanism to ensure > the buffer isn't overrun. A lazy spin wait is used as we believe the > flow control condition should be rare with a properly sized buffer. > > The function, intel_guc_send_nb, is exported in this patch but unused. > Several patches later in the series make use of this function. > > v2: > (Michal) > - Use define for H2G room calculations > - Move INTEL_GUC_SEND_NB define > (Daniel Vetter) > - Use msleep_interruptible rather than cond_resched > v3: > (Michal) > - Move includes to following patch > - s/INTEL_GUC_SEND_NB/INTEL_GUC_CT_SEND_NB/g > > Signed-off-by: John Harrison <John.C.Harrison@Intel.com> > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > --- > .../gt/uc/abi/guc_communication_ctb_abi.h | 3 +- > drivers/gpu/drm/i915/gt/uc/intel_guc.h | 11 ++- > drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 87 +++++++++++++++++-- > drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h | 4 +- > 4 files changed, 91 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h > index e933ca02d0eb..99e1fad5ca20 100644 > --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h > +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h > @@ -79,7 +79,8 @@ static_assert(sizeof(struct guc_ct_buffer_desc) == 64); > * +---+-------+--------------------------------------------------------------+ > */ > > -#define GUC_CTB_MSG_MIN_LEN 1u > +#define GUC_CTB_HDR_LEN 1u > +#define GUC_CTB_MSG_MIN_LEN GUC_CTB_HDR_LEN > #define GUC_CTB_MSG_MAX_LEN 256u > #define GUC_CTB_MSG_0_FENCE (0xffff << 16) > #define GUC_CTB_MSG_0_FORMAT (0xf << 12) > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h > index 4abc59f6f3cd..72e4653222e2 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h > @@ -74,7 +74,14 @@ static inline struct intel_guc *log_to_guc(struct intel_guc_log *log) > static > inline int intel_guc_send(struct intel_guc *guc, const u32 *action, u32 len) > { > - return intel_guc_ct_send(&guc->ct, action, len, NULL, 0); > + return intel_guc_ct_send(&guc->ct, action, len, NULL, 0, 0); > +} > + > +static > +inline int intel_guc_send_nb(struct intel_guc *guc, const u32 *action, u32 len) > +{ > + return intel_guc_ct_send(&guc->ct, action, len, NULL, 0, > + INTEL_GUC_CT_SEND_NB); > } > > static inline int > @@ -82,7 +89,7 @@ intel_guc_send_and_receive(struct intel_guc *guc, const u32 *action, u32 len, > u32 *response_buf, u32 response_buf_size) > { > return intel_guc_ct_send(&guc->ct, action, len, > - response_buf, response_buf_size); > + response_buf, response_buf_size, 0); > } > > static inline void intel_guc_to_host_event_handler(struct intel_guc *guc) > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c > index 43e03aa2dde8..fb825cc1d090 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c > @@ -3,6 +3,8 @@ > * Copyright © 2016-2019 Intel Corporation > */ > > +#include <linux/circ_buf.h> > + > #include "i915_drv.h" > #include "intel_guc_ct.h" > #include "gt/intel_gt.h" > @@ -373,7 +375,7 @@ static void write_barrier(struct intel_guc_ct *ct) > static int ct_write(struct intel_guc_ct *ct, > const u32 *action, > u32 len /* in dwords */, > - u32 fence) > + u32 fence, u32 flags) > { > struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; > struct guc_ct_buffer_desc *desc = ctb->desc; > @@ -409,7 +411,7 @@ static int ct_write(struct intel_guc_ct *ct, > used = tail - head; > > /* make sure there is a space including extra dw for the fence */ > - if (unlikely(used + len + 1 >= size)) > + if (unlikely(used + len + GUC_CTB_HDR_LEN >= size)) I thought the plan was to update the comment? Given that the '+1' is now 'HDR_LEN' it would be good to update the comment to say 'header' instead of 'fence'. > return -ENOSPC; > > /* > @@ -421,9 +423,13 @@ static int ct_write(struct intel_guc_ct *ct, > FIELD_PREP(GUC_CTB_MSG_0_NUM_DWORDS, len) | > FIELD_PREP(GUC_CTB_MSG_0_FENCE, fence); > > - hxg = FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_REQUEST) | > - FIELD_PREP(GUC_HXG_REQUEST_MSG_0_ACTION | > - GUC_HXG_REQUEST_MSG_0_DATA0, action[0]); > + hxg = (flags & INTEL_GUC_CT_SEND_NB) ? > + (FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_EVENT) | > + FIELD_PREP(GUC_HXG_EVENT_MSG_0_ACTION | > + GUC_HXG_EVENT_MSG_0_DATA0, action[0])) : > + (FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_REQUEST) | > + FIELD_PREP(GUC_HXG_REQUEST_MSG_0_ACTION | > + GUC_HXG_REQUEST_MSG_0_DATA0, action[0])); If would be much easier to read if this used a proper 'if' rather than an inline '?'. Or maybe have something like: type = SEND_NB ? TYPE_EVENT : TYPE REQUEST; hxg = PREP(type) | ACTION ...; Neither issue above is a blocker but I think the comment at least should be fixed up when merging. With that: Reviewed-by: John Harrison <John.C.Harrison@Intel.com> > > CT_DEBUG(ct, "writing (tail %u) %*ph %*ph %*ph\n", > tail, 4, &header, 4, &hxg, 4 * (len - 1), &action[1]); > @@ -500,6 +506,48 @@ static int wait_for_ct_request_update(struct ct_request *req, u32 *status) > return err; > } > > +static inline bool h2g_has_room(struct intel_guc_ct_buffer *ctb, u32 len_dw) > +{ > + struct guc_ct_buffer_desc *desc = ctb->desc; > + u32 head = READ_ONCE(desc->head); > + u32 space; > + > + space = CIRC_SPACE(desc->tail, head, ctb->size); > + > + return space >= len_dw; > +} > + > +static int ct_send_nb(struct intel_guc_ct *ct, > + const u32 *action, > + u32 len, > + u32 flags) > +{ > + struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; > + unsigned long spin_flags; > + u32 fence; > + int ret; > + > + spin_lock_irqsave(&ctb->lock, spin_flags); > + > + ret = h2g_has_room(ctb, len + GUC_CTB_HDR_LEN); > + if (unlikely(!ret)) { > + ret = -EBUSY; > + goto out; > + } > + > + fence = ct_get_next_fence(ct); > + ret = ct_write(ct, action, len, fence, flags); > + if (unlikely(ret)) > + goto out; > + > + intel_guc_notify(ct_to_guc(ct)); > + > +out: > + spin_unlock_irqrestore(&ctb->lock, spin_flags); > + > + return ret; > +} > + > static int ct_send(struct intel_guc_ct *ct, > const u32 *action, > u32 len, > @@ -507,8 +555,10 @@ static int ct_send(struct intel_guc_ct *ct, > u32 response_buf_size, > u32 *status) > { > + struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; > struct ct_request request; > unsigned long flags; > + unsigned int sleep_period_ms = 1; > u32 fence; > int err; > > @@ -516,8 +566,24 @@ static int ct_send(struct intel_guc_ct *ct, > GEM_BUG_ON(!len); > GEM_BUG_ON(len & ~GUC_CT_MSG_LEN_MASK); > GEM_BUG_ON(!response_buf && response_buf_size); > + might_sleep(); > + > + /* > + * We use a lazy spin wait loop here as we believe that if the CT > + * buffers are sized correctly the flow control condition should be > + * rare. > + */ > +retry: > + spin_lock_irqsave(&ctb->lock, flags); > + if (unlikely(!h2g_has_room(ctb, len + GUC_CTB_HDR_LEN))) { > + spin_unlock_irqrestore(&ctb->lock, flags); > > - spin_lock_irqsave(&ct->ctbs.send.lock, flags); > + if (msleep_interruptible(sleep_period_ms)) > + return -EINTR; > + sleep_period_ms = sleep_period_ms << 1; > + > + goto retry; > + } > > fence = ct_get_next_fence(ct); > request.fence = fence; > @@ -529,9 +595,9 @@ static int ct_send(struct intel_guc_ct *ct, > list_add_tail(&request.link, &ct->requests.pending); > spin_unlock(&ct->requests.lock); > > - err = ct_write(ct, action, len, fence); > + err = ct_write(ct, action, len, fence, 0); > > - spin_unlock_irqrestore(&ct->ctbs.send.lock, flags); > + spin_unlock_irqrestore(&ctb->lock, flags); > > if (unlikely(err)) > goto unlink; > @@ -571,7 +637,7 @@ static int ct_send(struct intel_guc_ct *ct, > * Command Transport (CT) buffer based GuC send function. > */ > int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, > - u32 *response_buf, u32 response_buf_size) > + u32 *response_buf, u32 response_buf_size, u32 flags) > { > u32 status = ~0; /* undefined */ > int ret; > @@ -581,6 +647,9 @@ int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, > return -ENODEV; > } > > + if (flags & INTEL_GUC_CT_SEND_NB) > + return ct_send_nb(ct, action, len, flags); > + > ret = ct_send(ct, action, len, response_buf, response_buf_size, &status); > if (unlikely(ret < 0)) { > CT_ERROR(ct, "Sending action %#x failed (err=%d status=%#X)\n", > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h > index 1ae2dde6db93..5bb8bef024c8 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h > @@ -42,7 +42,6 @@ struct intel_guc_ct_buffer { > bool broken; > }; > > - > /** Top-level structure for Command Transport related data > * > * Includes a pair of CT buffers for bi-directional communication and tracking > @@ -87,8 +86,9 @@ static inline bool intel_guc_ct_enabled(struct intel_guc_ct *ct) > return ct->enabled; > } > > +#define INTEL_GUC_CT_SEND_NB BIT(31) > int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, > - u32 *response_buf, u32 response_buf_size); > + u32 *response_buf, u32 response_buf_size, u32 flags); > void intel_guc_ct_event_handler(struct intel_guc_ct *ct); > > #endif /* _INTEL_GUC_CT_H_ */
On Tue, Jul 06, 2021 at 11:12:21AM -0700, John Harrison wrote: > On 7/1/2021 10:15, Matthew Brost wrote: > > Add non blocking CTB send function, intel_guc_send_nb. GuC submission > will send CTBs in the critical path and does not need to wait for these > CTBs to complete before moving on, hence the need for this new function. > > The non-blocking CTB now must have a flow control mechanism to ensure > the buffer isn't overrun. A lazy spin wait is used as we believe the > flow control condition should be rare with a properly sized buffer. > > The function, intel_guc_send_nb, is exported in this patch but unused. > Several patches later in the series make use of this function. > > v2: > (Michal) > - Use define for H2G room calculations > - Move INTEL_GUC_SEND_NB define > (Daniel Vetter) > - Use msleep_interruptible rather than cond_resched > v3: > (Michal) > - Move includes to following patch > - s/INTEL_GUC_SEND_NB/INTEL_GUC_CT_SEND_NB/g > > Signed-off-by: John Harrison [1]<John.C.Harrison@Intel.com> > Signed-off-by: Matthew Brost [2]<matthew.brost@intel.com> > --- > .../gt/uc/abi/guc_communication_ctb_abi.h | 3 +- > drivers/gpu/drm/i915/gt/uc/intel_guc.h | 11 ++- > drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 87 +++++++++++++++++-- > drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h | 4 +- > 4 files changed, 91 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h b/driver > s/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h > index e933ca02d0eb..99e1fad5ca20 100644 > --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h > +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h > @@ -79,7 +79,8 @@ static_assert(sizeof(struct guc_ct_buffer_desc) == 64); > * +---+-------+-------------------------------------------------------------- > + > */ > > -#define GUC_CTB_MSG_MIN_LEN 1u > +#define GUC_CTB_HDR_LEN 1u > +#define GUC_CTB_MSG_MIN_LEN GUC_CTB_HDR_LEN > #define GUC_CTB_MSG_MAX_LEN 256u > #define GUC_CTB_MSG_0_FENCE (0xffff << 16) > #define GUC_CTB_MSG_0_FORMAT (0xf << 12) > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc > /intel_guc.h > index 4abc59f6f3cd..72e4653222e2 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h > @@ -74,7 +74,14 @@ static inline struct intel_guc *log_to_guc(struct intel_guc_l > og *log) > static > inline int intel_guc_send(struct intel_guc *guc, const u32 *action, u32 len) > { > - return intel_guc_ct_send(&guc->ct, action, len, NULL, 0); > + return intel_guc_ct_send(&guc->ct, action, len, NULL, 0, 0); > +} > + > +static > +inline int intel_guc_send_nb(struct intel_guc *guc, const u32 *action, u32 len) > +{ > + return intel_guc_ct_send(&guc->ct, action, len, NULL, 0, > + INTEL_GUC_CT_SEND_NB); > } > > static inline int > @@ -82,7 +89,7 @@ intel_guc_send_and_receive(struct intel_guc *guc, const u32 *a > ction, u32 len, > u32 *response_buf, u32 response_buf_size) > { > return intel_guc_ct_send(&guc->ct, action, len, > - response_buf, response_buf_size); > + response_buf, response_buf_size, 0); > } > > static inline void intel_guc_to_host_event_handler(struct intel_guc *guc) > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt > /uc/intel_guc_ct.c > index 43e03aa2dde8..fb825cc1d090 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c > @@ -3,6 +3,8 @@ > * Copyright © 2016-2019 Intel Corporation > */ > > +#include <linux/circ_buf.h> > + > #include "i915_drv.h" > #include "intel_guc_ct.h" > #include "gt/intel_gt.h" > @@ -373,7 +375,7 @@ static void write_barrier(struct intel_guc_ct *ct) > static int ct_write(struct intel_guc_ct *ct, > const u32 *action, > u32 len /* in dwords */, > - u32 fence) > + u32 fence, u32 flags) > { > struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; > struct guc_ct_buffer_desc *desc = ctb->desc; > @@ -409,7 +411,7 @@ static int ct_write(struct intel_guc_ct *ct, > used = tail - head; > > /* make sure there is a space including extra dw for the fence */ > - if (unlikely(used + len + 1 >= size)) > + if (unlikely(used + len + GUC_CTB_HDR_LEN >= size)) > > I thought the plan was to update the comment? Given that the '+1' is > now 'HDR_LEN' it would be good to update the comment to say 'header' > instead of 'fence'. > Yep, will fix. > return -ENOSPC; > > /* > @@ -421,9 +423,13 @@ static int ct_write(struct intel_guc_ct *ct, > FIELD_PREP(GUC_CTB_MSG_0_NUM_DWORDS, len) | > FIELD_PREP(GUC_CTB_MSG_0_FENCE, fence); > > - hxg = FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_REQUEST) | > - FIELD_PREP(GUC_HXG_REQUEST_MSG_0_ACTION | > - GUC_HXG_REQUEST_MSG_0_DATA0, action[0]); > + hxg = (flags & INTEL_GUC_CT_SEND_NB) ? > + (FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_EVENT) | > + FIELD_PREP(GUC_HXG_EVENT_MSG_0_ACTION | > + GUC_HXG_EVENT_MSG_0_DATA0, action[0])) : > + (FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_REQUEST) | > + FIELD_PREP(GUC_HXG_REQUEST_MSG_0_ACTION | > + GUC_HXG_REQUEST_MSG_0_DATA0, action[0])); > > If would be much easier to read if this used a proper 'if' rather than > an inline '?'. Or maybe have something like: > > type = SEND_NB ? TYPE_EVENT : TYPE REQUEST; > hxg = PREP(type) | ACTION ...; > > Neither issue above is a blocker but I think the comment at least > should be fixed up when merging. With that: Probably a bit cleaner. Will fix. Matt > Reviewed-by: John Harrison [3]<John.C.Harrison@Intel.com> > > > CT_DEBUG(ct, "writing (tail %u) %*ph %*ph %*ph\n", > tail, 4, &header, 4, &hxg, 4 * (len - 1), &action[1]); > @@ -500,6 +506,48 @@ static int wait_for_ct_request_update(struct ct_request *re > q, u32 *status) > return err; > } > > +static inline bool h2g_has_room(struct intel_guc_ct_buffer *ctb, u32 len_dw) > +{ > + struct guc_ct_buffer_desc *desc = ctb->desc; > + u32 head = READ_ONCE(desc->head); > + u32 space; > + > + space = CIRC_SPACE(desc->tail, head, ctb->size); > + > + return space >= len_dw; > +} > + > +static int ct_send_nb(struct intel_guc_ct *ct, > + const u32 *action, > + u32 len, > + u32 flags) > +{ > + struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; > + unsigned long spin_flags; > + u32 fence; > + int ret; > + > + spin_lock_irqsave(&ctb->lock, spin_flags); > + > + ret = h2g_has_room(ctb, len + GUC_CTB_HDR_LEN); > + if (unlikely(!ret)) { > + ret = -EBUSY; > + goto out; > + } > + > + fence = ct_get_next_fence(ct); > + ret = ct_write(ct, action, len, fence, flags); > + if (unlikely(ret)) > + goto out; > + > + intel_guc_notify(ct_to_guc(ct)); > + > +out: > + spin_unlock_irqrestore(&ctb->lock, spin_flags); > + > + return ret; > +} > + > static int ct_send(struct intel_guc_ct *ct, > const u32 *action, > u32 len, > @@ -507,8 +555,10 @@ static int ct_send(struct intel_guc_ct *ct, > u32 response_buf_size, > u32 *status) > { > + struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; > struct ct_request request; > unsigned long flags; > + unsigned int sleep_period_ms = 1; > u32 fence; > int err; > > @@ -516,8 +566,24 @@ static int ct_send(struct intel_guc_ct *ct, > GEM_BUG_ON(!len); > GEM_BUG_ON(len & ~GUC_CT_MSG_LEN_MASK); > GEM_BUG_ON(!response_buf && response_buf_size); > + might_sleep(); > + > + /* > + * We use a lazy spin wait loop here as we believe that if the CT > + * buffers are sized correctly the flow control condition should be > + * rare. > + */ > +retry: > + spin_lock_irqsave(&ctb->lock, flags); > + if (unlikely(!h2g_has_room(ctb, len + GUC_CTB_HDR_LEN))) { > + spin_unlock_irqrestore(&ctb->lock, flags); > > - spin_lock_irqsave(&ct->ctbs.send.lock, flags); > + if (msleep_interruptible(sleep_period_ms)) > + return -EINTR; > + sleep_period_ms = sleep_period_ms << 1; > + > + goto retry; > + } > > fence = ct_get_next_fence(ct); > request.fence = fence; > @@ -529,9 +595,9 @@ static int ct_send(struct intel_guc_ct *ct, > list_add_tail(&request.link, &ct->requests.pending); > spin_unlock(&ct->requests.lock); > > - err = ct_write(ct, action, len, fence); > + err = ct_write(ct, action, len, fence, 0); > > - spin_unlock_irqrestore(&ct->ctbs.send.lock, flags); > + spin_unlock_irqrestore(&ctb->lock, flags); > > if (unlikely(err)) > goto unlink; > @@ -571,7 +637,7 @@ static int ct_send(struct intel_guc_ct *ct, > * Command Transport (CT) buffer based GuC send function. > */ > int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, > - u32 *response_buf, u32 response_buf_size) > + u32 *response_buf, u32 response_buf_size, u32 flags) > { > u32 status = ~0; /* undefined */ > int ret; > @@ -581,6 +647,9 @@ int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *ac > tion, u32 len, > return -ENODEV; > } > > + if (flags & INTEL_GUC_CT_SEND_NB) > + return ct_send_nb(ct, action, len, flags); > + > ret = ct_send(ct, action, len, response_buf, response_buf_size, &status) > ; > if (unlikely(ret < 0)) { > CT_ERROR(ct, "Sending action %#x failed (err=%d status=%#X)\n", > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h b/drivers/gpu/drm/i915/gt > /uc/intel_guc_ct.h > index 1ae2dde6db93..5bb8bef024c8 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h > @@ -42,7 +42,6 @@ struct intel_guc_ct_buffer { > bool broken; > }; > > - > /** Top-level structure for Command Transport related data > * > * Includes a pair of CT buffers for bi-directional communication and tracking > @@ -87,8 +86,9 @@ static inline bool intel_guc_ct_enabled(struct intel_guc_ct *c > t) > return ct->enabled; > } > > +#define INTEL_GUC_CT_SEND_NB BIT(31) > int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, > - u32 *response_buf, u32 response_buf_size); > + u32 *response_buf, u32 response_buf_size, u32 flags); > void intel_guc_ct_event_handler(struct intel_guc_ct *ct); > > #endif /* _INTEL_GUC_CT_H_ */ > > References > > 1. mailto:John.C.Harrison@Intel.com > 2. mailto:matthew.brost@intel.com > 3. mailto:John.C.Harrison@Intel.com
diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h index e933ca02d0eb..99e1fad5ca20 100644 --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h @@ -79,7 +79,8 @@ static_assert(sizeof(struct guc_ct_buffer_desc) == 64); * +---+-------+--------------------------------------------------------------+ */ -#define GUC_CTB_MSG_MIN_LEN 1u +#define GUC_CTB_HDR_LEN 1u +#define GUC_CTB_MSG_MIN_LEN GUC_CTB_HDR_LEN #define GUC_CTB_MSG_MAX_LEN 256u #define GUC_CTB_MSG_0_FENCE (0xffff << 16) #define GUC_CTB_MSG_0_FORMAT (0xf << 12) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h index 4abc59f6f3cd..72e4653222e2 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h @@ -74,7 +74,14 @@ static inline struct intel_guc *log_to_guc(struct intel_guc_log *log) static inline int intel_guc_send(struct intel_guc *guc, const u32 *action, u32 len) { - return intel_guc_ct_send(&guc->ct, action, len, NULL, 0); + return intel_guc_ct_send(&guc->ct, action, len, NULL, 0, 0); +} + +static +inline int intel_guc_send_nb(struct intel_guc *guc, const u32 *action, u32 len) +{ + return intel_guc_ct_send(&guc->ct, action, len, NULL, 0, + INTEL_GUC_CT_SEND_NB); } static inline int @@ -82,7 +89,7 @@ intel_guc_send_and_receive(struct intel_guc *guc, const u32 *action, u32 len, u32 *response_buf, u32 response_buf_size) { return intel_guc_ct_send(&guc->ct, action, len, - response_buf, response_buf_size); + response_buf, response_buf_size, 0); } static inline void intel_guc_to_host_event_handler(struct intel_guc *guc) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c index 43e03aa2dde8..fb825cc1d090 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -3,6 +3,8 @@ * Copyright © 2016-2019 Intel Corporation */ +#include <linux/circ_buf.h> + #include "i915_drv.h" #include "intel_guc_ct.h" #include "gt/intel_gt.h" @@ -373,7 +375,7 @@ static void write_barrier(struct intel_guc_ct *ct) static int ct_write(struct intel_guc_ct *ct, const u32 *action, u32 len /* in dwords */, - u32 fence) + u32 fence, u32 flags) { struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; struct guc_ct_buffer_desc *desc = ctb->desc; @@ -409,7 +411,7 @@ static int ct_write(struct intel_guc_ct *ct, used = tail - head; /* make sure there is a space including extra dw for the fence */ - if (unlikely(used + len + 1 >= size)) + if (unlikely(used + len + GUC_CTB_HDR_LEN >= size)) return -ENOSPC; /* @@ -421,9 +423,13 @@ static int ct_write(struct intel_guc_ct *ct, FIELD_PREP(GUC_CTB_MSG_0_NUM_DWORDS, len) | FIELD_PREP(GUC_CTB_MSG_0_FENCE, fence); - hxg = FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_REQUEST) | - FIELD_PREP(GUC_HXG_REQUEST_MSG_0_ACTION | - GUC_HXG_REQUEST_MSG_0_DATA0, action[0]); + hxg = (flags & INTEL_GUC_CT_SEND_NB) ? + (FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_EVENT) | + FIELD_PREP(GUC_HXG_EVENT_MSG_0_ACTION | + GUC_HXG_EVENT_MSG_0_DATA0, action[0])) : + (FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_REQUEST) | + FIELD_PREP(GUC_HXG_REQUEST_MSG_0_ACTION | + GUC_HXG_REQUEST_MSG_0_DATA0, action[0])); CT_DEBUG(ct, "writing (tail %u) %*ph %*ph %*ph\n", tail, 4, &header, 4, &hxg, 4 * (len - 1), &action[1]); @@ -500,6 +506,48 @@ static int wait_for_ct_request_update(struct ct_request *req, u32 *status) return err; } +static inline bool h2g_has_room(struct intel_guc_ct_buffer *ctb, u32 len_dw) +{ + struct guc_ct_buffer_desc *desc = ctb->desc; + u32 head = READ_ONCE(desc->head); + u32 space; + + space = CIRC_SPACE(desc->tail, head, ctb->size); + + return space >= len_dw; +} + +static int ct_send_nb(struct intel_guc_ct *ct, + const u32 *action, + u32 len, + u32 flags) +{ + struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; + unsigned long spin_flags; + u32 fence; + int ret; + + spin_lock_irqsave(&ctb->lock, spin_flags); + + ret = h2g_has_room(ctb, len + GUC_CTB_HDR_LEN); + if (unlikely(!ret)) { + ret = -EBUSY; + goto out; + } + + fence = ct_get_next_fence(ct); + ret = ct_write(ct, action, len, fence, flags); + if (unlikely(ret)) + goto out; + + intel_guc_notify(ct_to_guc(ct)); + +out: + spin_unlock_irqrestore(&ctb->lock, spin_flags); + + return ret; +} + static int ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, @@ -507,8 +555,10 @@ static int ct_send(struct intel_guc_ct *ct, u32 response_buf_size, u32 *status) { + struct intel_guc_ct_buffer *ctb = &ct->ctbs.send; struct ct_request request; unsigned long flags; + unsigned int sleep_period_ms = 1; u32 fence; int err; @@ -516,8 +566,24 @@ static int ct_send(struct intel_guc_ct *ct, GEM_BUG_ON(!len); GEM_BUG_ON(len & ~GUC_CT_MSG_LEN_MASK); GEM_BUG_ON(!response_buf && response_buf_size); + might_sleep(); + + /* + * We use a lazy spin wait loop here as we believe that if the CT + * buffers are sized correctly the flow control condition should be + * rare. + */ +retry: + spin_lock_irqsave(&ctb->lock, flags); + if (unlikely(!h2g_has_room(ctb, len + GUC_CTB_HDR_LEN))) { + spin_unlock_irqrestore(&ctb->lock, flags); - spin_lock_irqsave(&ct->ctbs.send.lock, flags); + if (msleep_interruptible(sleep_period_ms)) + return -EINTR; + sleep_period_ms = sleep_period_ms << 1; + + goto retry; + } fence = ct_get_next_fence(ct); request.fence = fence; @@ -529,9 +595,9 @@ static int ct_send(struct intel_guc_ct *ct, list_add_tail(&request.link, &ct->requests.pending); spin_unlock(&ct->requests.lock); - err = ct_write(ct, action, len, fence); + err = ct_write(ct, action, len, fence, 0); - spin_unlock_irqrestore(&ct->ctbs.send.lock, flags); + spin_unlock_irqrestore(&ctb->lock, flags); if (unlikely(err)) goto unlink; @@ -571,7 +637,7 @@ static int ct_send(struct intel_guc_ct *ct, * Command Transport (CT) buffer based GuC send function. */ int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, - u32 *response_buf, u32 response_buf_size) + u32 *response_buf, u32 response_buf_size, u32 flags) { u32 status = ~0; /* undefined */ int ret; @@ -581,6 +647,9 @@ int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, return -ENODEV; } + if (flags & INTEL_GUC_CT_SEND_NB) + return ct_send_nb(ct, action, len, flags); + ret = ct_send(ct, action, len, response_buf, response_buf_size, &status); if (unlikely(ret < 0)) { CT_ERROR(ct, "Sending action %#x failed (err=%d status=%#X)\n", diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h index 1ae2dde6db93..5bb8bef024c8 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.h @@ -42,7 +42,6 @@ struct intel_guc_ct_buffer { bool broken; }; - /** Top-level structure for Command Transport related data * * Includes a pair of CT buffers for bi-directional communication and tracking @@ -87,8 +86,9 @@ static inline bool intel_guc_ct_enabled(struct intel_guc_ct *ct) return ct->enabled; } +#define INTEL_GUC_CT_SEND_NB BIT(31) int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len, - u32 *response_buf, u32 response_buf_size); + u32 *response_buf, u32 response_buf_size, u32 flags); void intel_guc_ct_event_handler(struct intel_guc_ct *ct); #endif /* _INTEL_GUC_CT_H_ */