From: Alex Dai <yu....@intel.com> GuC client object is always pinned during its life cycle. We cache the kmap of its first page, which includes guc_process_desc and doorbell. By doing so, we can simplify the code where we read from this page to get where GuC is progressing on work queue; and the code where driver program doorbell to send work queue item to GuC.
As a result, this patch removes the kmap_atomic in wq_check_space, where usleep_range could be called while kmap_atomic is held. This fixes issue below. [ 34.098798] BUG: scheduling while atomic: gem_close_race/1941/0x00000002 [ 34.098822] Modules linked in: hid_generic usbhid i915 asix usbnet libphy mii i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea drm coretemp i2c_hid hid video pinctrl_sunrisepoint pinctrl_intel acpi_pad nls_iso8859_1 e1000e ptp psmouse pps_core ahci libahci [ 34.098824] CPU: 0 PID: 1941 Comm: gem_close_race Tainted: G U 4.4.0-160121+ #123 [ 34.098824] Hardware name: Intel Corporation Skylake Client platform/Skylake AIO DDR3L RVP10, BIOS SKLSE2R1.R00.X100.B01.1509220551 09/22/2015 [ 34.098825] 0000000000013e40 ffff880166c27a78 ffffffff81280d02 ffff880172c13e40 [ 34.098826] ffff880166c27a88 ffffffff810c203a ffff880166c27ac8 ffffffff814ec808 [ 34.098827] ffff88016b7c6000 ffff880166c28000 00000000000f4240 0000000000000001 [ 34.098827] Call Trace: [ 34.098831] [<ffffffff81280d02>] dump_stack+0x4b/0x79 [ 34.098833] [<ffffffff810c203a>] __schedule_bug+0x41/0x4f [ 34.098834] [<ffffffff814ec808>] __schedule+0x5a8/0x690 [ 34.098835] [<ffffffff814ec927>] schedule+0x37/0x80 [ 34.098836] [<ffffffff814ef3fd>] schedule_hrtimeout_range_clock+0xad/0x130 [ 34.098837] [<ffffffff81090be0>] ? hrtimer_init+0x10/0x10 [ 34.098838] [<ffffffff814ef3f1>] ? schedule_hrtimeout_range_clock+0xa1/0x130 [ 34.098839] [<ffffffff814ef48e>] schedule_hrtimeout_range+0xe/0x10 [ 34.098840] [<ffffffff814eef9b>] usleep_range+0x3b/0x40 [ 34.098853] [<ffffffffa01ec109>] i915_guc_wq_check_space+0x119/0x210 [i915] [ 34.098861] [<ffffffffa01da47c>] intel_logical_ring_alloc_request_extras+0x5c/0x70 [i915] [ 34.098869] [<ffffffffa01cdbf1>] i915_gem_request_alloc+0x91/0x170 [i915] [ 34.098875] [<ffffffffa01c1c07>] i915_gem_do_execbuffer.isra.25+0xbc7/0x12a0 [i915] [ 34.098882] [<ffffffffa01cb785>] ? i915_gem_object_get_pages_gtt+0x225/0x3c0 [i915] [ 34.098889] [<ffffffffa01d1fb6>] ? i915_gem_pwrite_ioctl+0xd6/0x9f0 [i915] [ 34.098895] [<ffffffffa01c2e68>] i915_gem_execbuffer2+0xa8/0x250 [i915] [ 34.098900] [<ffffffffa00f65d8>] drm_ioctl+0x258/0x4f0 [drm] [ 34.098906] [<ffffffffa01c2dc0>] ? i915_gem_execbuffer+0x340/0x340 [i915] [ 34.098908] [<ffffffff8111590d>] do_vfs_ioctl+0x2cd/0x4a0 [ 34.098909] [<ffffffff8111eac2>] ? __fget+0x72/0xb0 [ 34.098910] [<ffffffff81115b1c>] SyS_ioctl+0x3c/0x70 [ 34.098911] [<ffffffff814effd7>] entry_SYSCALL_64_fastpath+0x12/0x6a [ 34.100208] ------------[ cut here ]------------ Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93847 Cc: <daniel.vet...@ffwll.ch> Cc: <tvrtko.ursu...@intel.com> Signed-off-by: Alex Dai <yu....@intel.com> --- drivers/gpu/drm/i915/i915_guc_submission.c | 39 +++++++++--------------------- drivers/gpu/drm/i915/intel_guc.h | 3 ++- 2 files changed, 14 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index d7543ef..d51015e 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -195,11 +195,9 @@ static int guc_ring_doorbell(struct i915_guc_client *gc) struct guc_process_desc *desc; union guc_doorbell_qw db_cmp, db_exc, db_ret; union guc_doorbell_qw *db; - void *base; int attempt = 2, ret = -EAGAIN; - base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, 0)); - desc = base + gc->proc_desc_offset; + desc = gc->client_base + gc->proc_desc_offset; /* Update the tail so it is visible to GuC */ desc->tail = gc->wq_tail; @@ -215,7 +213,7 @@ static int guc_ring_doorbell(struct i915_guc_client *gc) db_exc.cookie = 1; /* pointer of current doorbell cacheline */ - db = base + gc->doorbell_offset; + db = gc->client_base + gc->doorbell_offset; while (attempt--) { /* lets ring the doorbell */ @@ -244,10 +242,6 @@ static int guc_ring_doorbell(struct i915_guc_client *gc) db_exc.cookie = 1; } - /* Finally, update the cached copy of the GuC's WQ head */ - gc->wq_head = desc->head; - - kunmap_atomic(base); return ret; } @@ -341,10 +335,8 @@ static void guc_init_proc_desc(struct intel_guc *guc, struct i915_guc_client *client) { struct guc_process_desc *desc; - void *base; - base = kmap_atomic(i915_gem_object_get_page(client->client_obj, 0)); - desc = base + client->proc_desc_offset; + desc = client->client_base + client->proc_desc_offset; memset(desc, 0, sizeof(*desc)); @@ -361,8 +353,6 @@ static void guc_init_proc_desc(struct intel_guc *guc, desc->wq_size_bytes = client->wq_size; desc->wq_status = WQ_STATUS_ACTIVE; desc->priority = client->priority; - - kunmap_atomic(base); } /* @@ -474,25 +464,16 @@ static void guc_fini_ctx_desc(struct intel_guc *guc, int i915_guc_wq_check_space(struct i915_guc_client *gc) { struct guc_process_desc *desc; - void *base; u32 size = sizeof(struct guc_wq_item); int ret = -ETIMEDOUT, timeout_counter = 200; if (!gc) return 0; - /* Quickly return if wq space is available since last time we cache the - * head position. */ - if (CIRC_SPACE(gc->wq_tail, gc->wq_head, gc->wq_size) >= size) - return 0; - - base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, 0)); - desc = base + gc->proc_desc_offset; + desc = gc->client_base + gc->proc_desc_offset; while (timeout_counter-- > 0) { - gc->wq_head = desc->head; - - if (CIRC_SPACE(gc->wq_tail, gc->wq_head, gc->wq_size) >= size) { + if (CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size) >= size) { ret = 0; break; } @@ -501,19 +482,19 @@ int i915_guc_wq_check_space(struct i915_guc_client *gc) usleep_range(1000, 2000); }; - kunmap_atomic(base); - return ret; } static int guc_add_workqueue_item(struct i915_guc_client *gc, struct drm_i915_gem_request *rq) { + struct guc_process_desc *desc; struct guc_wq_item *wqi; void *base; u32 tail, wq_len, wq_off, space; - space = CIRC_SPACE(gc->wq_tail, gc->wq_head, gc->wq_size); + desc = gc->client_base + gc->proc_desc_offset; + space = CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size); if (WARN_ON(space < sizeof(struct guc_wq_item))) return -ENOSPC; /* shouldn't happen */ @@ -675,6 +656,8 @@ static void guc_client_free(struct drm_device *dev, * Be sure to drop any locks */ + kunmap(kmap_to_page(client->client_base)); + gem_release_guc_obj(client->client_obj); if (client->ctx_index != GUC_INVALID_CTX_ID) { @@ -727,6 +710,8 @@ static struct i915_guc_client *guc_client_alloc(struct drm_device *dev, if (!obj) goto err; + client->client_base = kmap(i915_gem_object_get_dirty_page(obj, 0)); + client->client_obj = obj; client->wq_offset = GUC_DB_SIZE; client->wq_size = GUC_WQ_SIZE; diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h index 73002e9..9f08bd7 100644 --- a/drivers/gpu/drm/i915/intel_guc.h +++ b/drivers/gpu/drm/i915/intel_guc.h @@ -34,6 +34,8 @@ struct i915_guc_client { uint32_t priority; uint32_t ctx_index; + void *client_base; + uint32_t proc_desc_offset; uint32_t doorbell_offset; uint32_t cookie; @@ -43,7 +45,6 @@ struct i915_guc_client { uint32_t wq_offset; uint32_t wq_size; uint32_t wq_tail; - uint32_t wq_head; /* GuC submission statistics & status */ uint64_t submissions[GUC_MAX_ENGINES_NUM]; -- 2.5.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
