From cd60cd96137f6cb3ea82cace9225626619e7a52d Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Wed, 10 Feb 2016 15:00:26 -0700 Subject: [PATCH] dmaengine: IOATDMA: Removing descriptor ring reshape Moving to contingous memory backed descriptor rings. This makes is really difficult and complex to do reshape. Going to remove this as I don't think we need to do it anymore. Signed-off-by: Dave Jiang Signed-off-by: Vinod Koul --- drivers/dma/ioat/dma.c | 143 ------------------------------------------------ drivers/dma/ioat/dma.h | 5 -- drivers/dma/ioat/init.c | 10 +--- 3 files changed, 1 insertion(+), 157 deletions(-) diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c index 7a04c16a..9c4d3b2 100644 --- a/drivers/dma/ioat/dma.c +++ b/drivers/dma/ioat/dma.c @@ -332,9 +332,6 @@ ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags) int descs = 1 << order; int i; - if (order > ioat_get_max_alloc_order()) - return NULL; - /* allocate the array to hold the software ring */ ring = kcalloc(descs, sizeof(*ring), flags); if (!ring) @@ -362,114 +359,6 @@ ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags) return ring; } -static bool reshape_ring(struct ioatdma_chan *ioat_chan, int order) -{ - /* reshape differs from normal ring allocation in that we want - * to allocate a new software ring while only - * extending/truncating the hardware ring - */ - struct dma_chan *c = &ioat_chan->dma_chan; - const u32 curr_size = ioat_ring_size(ioat_chan); - const u16 active = ioat_ring_active(ioat_chan); - const u32 new_size = 1 << order; - struct ioat_ring_ent **ring; - u32 i; - - if (order > ioat_get_max_alloc_order()) - return false; - - /* double check that we have at least 1 free descriptor */ - if (active == curr_size) - return false; - - /* when shrinking, verify that we can hold the current active - * set in the new ring - */ - if (active >= new_size) - return false; - - /* allocate the array to hold the software ring */ - ring = kcalloc(new_size, sizeof(*ring), GFP_NOWAIT); - if (!ring) - return false; - - /* allocate/trim descriptors as needed */ - if (new_size > curr_size) { - /* copy current descriptors to the new ring */ - for (i = 0; i < curr_size; i++) { - u16 curr_idx = (ioat_chan->tail+i) & (curr_size-1); - u16 new_idx = (ioat_chan->tail+i) & (new_size-1); - - ring[new_idx] = ioat_chan->ring[curr_idx]; - set_desc_id(ring[new_idx], new_idx); - } - - /* add new descriptors to the ring */ - for (i = curr_size; i < new_size; i++) { - u16 new_idx = (ioat_chan->tail+i) & (new_size-1); - - ring[new_idx] = ioat_alloc_ring_ent(c, GFP_NOWAIT); - if (!ring[new_idx]) { - while (i--) { - u16 new_idx = (ioat_chan->tail+i) & - (new_size-1); - - ioat_free_ring_ent(ring[new_idx], c); - } - kfree(ring); - return false; - } - set_desc_id(ring[new_idx], new_idx); - } - - /* hw link new descriptors */ - for (i = curr_size-1; i < new_size; i++) { - u16 new_idx = (ioat_chan->tail+i) & (new_size-1); - struct ioat_ring_ent *next = - ring[(new_idx+1) & (new_size-1)]; - struct ioat_dma_descriptor *hw = ring[new_idx]->hw; - - hw->next = next->txd.phys; - } - } else { - struct ioat_dma_descriptor *hw; - struct ioat_ring_ent *next; - - /* copy current descriptors to the new ring, dropping the - * removed descriptors - */ - for (i = 0; i < new_size; i++) { - u16 curr_idx = (ioat_chan->tail+i) & (curr_size-1); - u16 new_idx = (ioat_chan->tail+i) & (new_size-1); - - ring[new_idx] = ioat_chan->ring[curr_idx]; - set_desc_id(ring[new_idx], new_idx); - } - - /* free deleted descriptors */ - for (i = new_size; i < curr_size; i++) { - struct ioat_ring_ent *ent; - - ent = ioat_get_ring_ent(ioat_chan, ioat_chan->tail+i); - ioat_free_ring_ent(ent, c); - } - - /* fix up hardware ring */ - hw = ring[(ioat_chan->tail+new_size-1) & (new_size-1)]->hw; - next = ring[(ioat_chan->tail+new_size) & (new_size-1)]; - hw->next = next->txd.phys; - } - - dev_dbg(to_dev(ioat_chan), "%s: allocated %d descriptors\n", - __func__, new_size); - - kfree(ioat_chan->ring); - ioat_chan->ring = ring; - ioat_chan->alloc_order = order; - - return true; -} - /** * ioat_check_space_lock - verify space and grab ring producer lock * @ioat: ioat,3 channel (ring) to operate on @@ -478,9 +367,6 @@ static bool reshape_ring(struct ioatdma_chan *ioat_chan, int order) int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs) __acquires(&ioat_chan->prep_lock) { - bool retry; - - retry: spin_lock_bh(&ioat_chan->prep_lock); /* never allow the last descriptor to be consumed, we need at * least one free at all times to allow for on-the-fly ring @@ -493,24 +379,8 @@ int ioat_check_space_lock(struct ioatdma_chan *ioat_chan, int num_descs) ioat_chan->produce = num_descs; return 0; /* with ioat->prep_lock held */ } - retry = test_and_set_bit(IOAT_RESHAPE_PENDING, &ioat_chan->state); spin_unlock_bh(&ioat_chan->prep_lock); - /* is another cpu already trying to expand the ring? */ - if (retry) - goto retry; - - spin_lock_bh(&ioat_chan->cleanup_lock); - spin_lock_bh(&ioat_chan->prep_lock); - retry = reshape_ring(ioat_chan, ioat_chan->alloc_order + 1); - clear_bit(IOAT_RESHAPE_PENDING, &ioat_chan->state); - spin_unlock_bh(&ioat_chan->prep_lock); - spin_unlock_bh(&ioat_chan->cleanup_lock); - - /* if we were able to expand the ring retry the allocation */ - if (retry) - goto retry; - dev_dbg_ratelimited(to_dev(ioat_chan), "%s: ring full! num_descs: %d (%x:%x:%x)\n", __func__, num_descs, ioat_chan->head, @@ -823,19 +693,6 @@ static void check_active(struct ioatdma_chan *ioat_chan) if (test_and_clear_bit(IOAT_CHAN_ACTIVE, &ioat_chan->state)) mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT); - else if (ioat_chan->alloc_order > ioat_get_alloc_order()) { - /* if the ring is idle, empty, and oversized try to step - * down the size - */ - reshape_ring(ioat_chan, ioat_chan->alloc_order - 1); - - /* keep shrinking until we get back to our minimum - * default size - */ - if (ioat_chan->alloc_order > ioat_get_alloc_order()) - mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT); - } - } void ioat_timer_event(unsigned long data) diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h index f471092..5f2f9fb 100644 --- a/drivers/dma/ioat/dma.h +++ b/drivers/dma/ioat/dma.h @@ -100,7 +100,6 @@ struct ioatdma_chan { #define IOAT_COMPLETION_ACK 1 #define IOAT_RESET_PENDING 2 #define IOAT_KOBJ_INIT_FAIL 3 - #define IOAT_RESHAPE_PENDING 4 #define IOAT_RUN 5 #define IOAT_CHAN_ACTIVE 6 struct timer_list timer; @@ -302,10 +301,6 @@ static inline bool is_ioat_bug(unsigned long err) } #define IOAT_MAX_ORDER 16 -#define ioat_get_alloc_order() \ - (min(ioat_ring_alloc_order, IOAT_MAX_ORDER)) -#define ioat_get_max_alloc_order() \ - (min(ioat_ring_max_alloc_order, IOAT_MAX_ORDER)) static inline u32 ioat_ring_size(struct ioatdma_chan *ioat_chan) { diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c index b02b63b..6636920 100644 --- a/drivers/dma/ioat/init.c +++ b/drivers/dma/ioat/init.c @@ -136,14 +136,6 @@ int ioat_pending_level = 4; module_param(ioat_pending_level, int, 0644); MODULE_PARM_DESC(ioat_pending_level, "high-water mark for pushing ioat descriptors (default: 4)"); -int ioat_ring_alloc_order = 8; -module_param(ioat_ring_alloc_order, int, 0644); -MODULE_PARM_DESC(ioat_ring_alloc_order, - "ioat+: allocate 2^n descriptors per channel (default: 8 max: 16)"); -int ioat_ring_max_alloc_order = IOAT_MAX_ORDER; -module_param(ioat_ring_max_alloc_order, int, 0644); -MODULE_PARM_DESC(ioat_ring_max_alloc_order, - "ioat+: upper limit for ring size (default: 16)"); static char ioat_interrupt_style[32] = "msix"; module_param_string(ioat_interrupt_style, ioat_interrupt_style, sizeof(ioat_interrupt_style), 0644); @@ -712,7 +704,7 @@ static int ioat_alloc_chan_resources(struct dma_chan *c) writel(((u64)ioat_chan->completion_dma) >> 32, ioat_chan->reg_base + IOAT_CHANCMP_OFFSET_HIGH); - order = ioat_get_alloc_order(); + order = IOAT_MAX_ORDER; ring = ioat_alloc_ring(c, order, GFP_KERNEL); if (!ring) return -ENOMEM; -- 2.7.4