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 <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 7a04c16..9c4d3b2 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -332,9 +332,6 @@
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 @@
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 @@
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 @@
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 @@
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 @@
#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 @@
}
#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 @@
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 @@
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;