[PATCH] drm/omap: Fix release of refill engine
Andy Gross
andy.gross at ti.com
Fri Oct 12 08:58:42 PDT 2012
Please disregard this mail. Wrong patch sent
On 10/12/2012 10:56 AM, Andy Gross wrote:
> During asynchronous refills, we don't wait for the refill to
> finish. However, we cannot release the engine back to the idle
> list until it has actually completed the refill operation. The
> engine release will now be done in the IRQ handler, but only
> for asynchronous refill operations.
>
> Synchronous refills will continue to release the engine after they
> unblock from waiting on the refill.
>
> Signed-off-by: Andy Gross <andy.gross at ti.com>
> ---
> drivers/staging/omapdrm/omap_dmm_priv.h | 5 ++-
> drivers/staging/omapdrm/omap_dmm_tiler.c | 77 ++++++++++++++++++++---------
> 2 files changed, 57 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/staging/omapdrm/omap_dmm_priv.h b/drivers/staging/omapdrm/omap_dmm_priv.h
> index 09ebc50..5ea73305 100644
> --- a/drivers/staging/omapdrm/omap_dmm_priv.h
> +++ b/drivers/staging/omapdrm/omap_dmm_priv.h
> @@ -141,6 +141,8 @@ struct refill_engine {
> /* only one trans per engine for now */
> struct dmm_txn txn;
>
> + unsigned int async;
> +
> wait_queue_head_t wait_for_refill;
>
> struct list_head idle_node;
> @@ -158,10 +160,11 @@ struct dmm {
> dma_addr_t refill_pa;
>
> /* refill engines */
> - struct semaphore engine_sem;
> + wait_queue_head_t engine_queue;
> struct list_head idle_head;
> struct refill_engine *engines;
> int num_engines;
> + atomic_t engine_counter;
>
> /* container information */
> int container_width;
> diff --git a/drivers/staging/omapdrm/omap_dmm_tiler.c b/drivers/staging/omapdrm/omap_dmm_tiler.c
> index fda9efc..eda2fce 100644
> --- a/drivers/staging/omapdrm/omap_dmm_tiler.c
> +++ b/drivers/staging/omapdrm/omap_dmm_tiler.c
> @@ -29,7 +29,6 @@
> #include <linux/mm.h>
> #include <linux/time.h>
> #include <linux/list.h>
> -#include <linux/semaphore.h>
>
> #include "omap_dmm_tiler.h"
> #include "omap_dmm_priv.h"
> @@ -120,6 +119,18 @@ static int wait_status(struct refill_engine *engine, uint32_t wait_mask)
> return 0;
> }
>
> +static void release_engine(struct refill_engine *engine)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&list_lock, flags);
> + list_add(&engine->idle_node, &omap_dmm->idle_head);
> + spin_unlock_irqrestore(&list_lock, flags);
> +
> + atomic_inc(&omap_dmm->engine_counter);
> + wake_up_interruptible(&omap_dmm->engine_queue);
> +}
> +
> static irqreturn_t omap_dmm_irq_handler(int irq, void *arg)
> {
> struct dmm *dmm = arg;
> @@ -130,9 +141,13 @@ static irqreturn_t omap_dmm_irq_handler(int irq, void *arg)
> writel(status, dmm->base + DMM_PAT_IRQSTATUS);
>
> for (i = 0; i < dmm->num_engines; i++) {
> - if (status & DMM_IRQSTAT_LST)
> + if (status & DMM_IRQSTAT_LST) {
> wake_up_interruptible(&dmm->engines[i].wait_for_refill);
>
> + if (&dmm->engines[i].async)
> + release_engine(&dmm->engines[i]);
> + }
> +
> status >>= 8;
> }
>
> @@ -146,17 +161,24 @@ static struct dmm_txn *dmm_txn_init(struct dmm *dmm, struct tcm *tcm)
> {
> struct dmm_txn *txn = NULL;
> struct refill_engine *engine = NULL;
> + int ret;
> + unsigned long flags;
> +
>
> - down(&dmm->engine_sem);
> + /* wait until an engine is available */
> + ret = wait_event_interruptible(omap_dmm->engine_queue,
> + atomic_add_unless(&omap_dmm->engine_counter, -1, 0));
> + if (ret)
> + return ERR_PTR(ret);
>
> /* grab an idle engine */
> - spin_lock(&list_lock);
> + spin_lock_irqsave(&list_lock, flags);
> if (!list_empty(&dmm->idle_head)) {
> engine = list_entry(dmm->idle_head.next, struct refill_engine,
> idle_node);
> list_del(&engine->idle_node);
> }
> - spin_unlock(&list_lock);
> + spin_unlock_irqrestore(&list_lock, flags);
>
> BUG_ON(!engine);
>
> @@ -174,7 +196,7 @@ static struct dmm_txn *dmm_txn_init(struct dmm *dmm, struct tcm *tcm)
> * Add region to DMM transaction. If pages or pages[i] is NULL, then the
> * corresponding slot is cleared (ie. dummy_pa is programmed)
> */
> -static int dmm_txn_append(struct dmm_txn *txn, struct pat_area *area,
> +static void dmm_txn_append(struct dmm_txn *txn, struct pat_area *area,
> struct page **pages, uint32_t npages, uint32_t roll)
> {
> dma_addr_t pat_pa = 0;
> @@ -208,7 +230,7 @@ static int dmm_txn_append(struct dmm_txn *txn, struct pat_area *area,
>
> txn->last_pat = pat;
>
> - return 0;
> + return;
> }
>
> /**
> @@ -238,6 +260,9 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait)
> goto cleanup;
> }
>
> + /* mark whether it is async to denote list management in IRQ handler */
> + engine->async = wait ? 0 : 1;
> +
> /* kick reload */
> writel(engine->refill_pa,
> dmm->base + reg[PAT_DESCR][engine->id]);
> @@ -252,11 +277,10 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait)
> }
>
> cleanup:
> - spin_lock(&list_lock);
> - list_add(&engine->idle_node, &dmm->idle_head);
> - spin_unlock(&list_lock);
> + /* only place engine back on list if we are done with it */
> + if (ret || wait)
> + release_engine(engine);
>
> - up(&omap_dmm->engine_sem);
> return ret;
> }
>
> @@ -270,6 +294,7 @@ static int fill(struct tcm_area *area, struct page **pages,
> struct tcm_area slice, area_s;
> struct dmm_txn *txn;
>
> +
> txn = dmm_txn_init(omap_dmm, area->tcm);
> if (IS_ERR_OR_NULL(txn))
> return PTR_ERR(txn);
> @@ -280,16 +305,13 @@ static int fill(struct tcm_area *area, struct page **pages,
> .x1 = slice.p1.x, .y1 = slice.p1.y,
> };
>
> - ret = dmm_txn_append(txn, &p_area, pages, npages, roll);
> - if (ret)
> - goto fail;
> + dmm_txn_append(txn, &p_area, pages, npages, roll);
>
> roll += tcm_sizeof(slice);
> }
>
> ret = dmm_txn_commit(txn, wait);
>
> -fail:
> return ret;
> }
>
> @@ -326,6 +348,7 @@ struct tiler_block *tiler_reserve_2d(enum tiler_fmt fmt, uint16_t w,
> struct tiler_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
> u32 min_align = 128;
> int ret;
> + unsigned long flags;
>
> BUG_ON(!validfmt(fmt));
>
> @@ -347,9 +370,9 @@ struct tiler_block *tiler_reserve_2d(enum tiler_fmt fmt, uint16_t w,
> }
>
> /* add to allocation list */
> - spin_lock(&list_lock);
> + spin_lock_irqsave(&list_lock, flags);
> list_add(&block->alloc_node, &omap_dmm->alloc_head);
> - spin_unlock(&list_lock);
> + spin_unlock_irqrestore(&list_lock, flags);
>
> return block;
> }
> @@ -358,6 +381,7 @@ struct tiler_block *tiler_reserve_1d(size_t size)
> {
> struct tiler_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
> int num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
> + unsigned long flags;
>
> if (!block)
> return ERR_PTR(-ENOMEM);
> @@ -370,9 +394,9 @@ struct tiler_block *tiler_reserve_1d(size_t size)
> return ERR_PTR(-ENOMEM);
> }
>
> - spin_lock(&list_lock);
> + spin_lock_irqsave(&list_lock, flags);
> list_add(&block->alloc_node, &omap_dmm->alloc_head);
> - spin_unlock(&list_lock);
> + spin_unlock_irqrestore(&list_lock, flags);
>
> return block;
> }
> @@ -381,13 +405,14 @@ struct tiler_block *tiler_reserve_1d(size_t size)
> int tiler_release(struct tiler_block *block)
> {
> int ret = tcm_free(&block->area);
> + unsigned long flags;
>
> if (block->area.tcm)
> dev_err(omap_dmm->dev, "failed to release block\n");
>
> - spin_lock(&list_lock);
> + spin_lock_irqsave(&list_lock, flags);
> list_del(&block->alloc_node);
> - spin_unlock(&list_lock);
> + spin_unlock_irqrestore(&list_lock, flags);
>
> kfree(block);
> return ret;
> @@ -507,16 +532,17 @@ static int omap_dmm_remove(struct platform_device *dev)
> {
> struct tiler_block *block, *_block;
> int i;
> + unsigned long flags;
>
> if (omap_dmm) {
> /* free all area regions */
> - spin_lock(&list_lock);
> + spin_lock_irqsave(&list_lock, flags);
> list_for_each_entry_safe(block, _block, &omap_dmm->alloc_head,
> alloc_node) {
> list_del(&block->alloc_node);
> kfree(block);
> }
> - spin_unlock(&list_lock);
> + spin_unlock_irqrestore(&list_lock, flags);
>
> for (i = 0; i < omap_dmm->num_lut; i++)
> if (omap_dmm->tcm && omap_dmm->tcm[i])
> @@ -560,6 +586,8 @@ static int omap_dmm_probe(struct platform_device *dev)
> INIT_LIST_HEAD(&omap_dmm->alloc_head);
> INIT_LIST_HEAD(&omap_dmm->idle_head);
>
> + init_waitqueue_head(&omap_dmm->engine_queue);
> +
> /* lookup hwmod data - base address and irq */
> mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
> if (!mem) {
> @@ -588,6 +616,8 @@ static int omap_dmm_probe(struct platform_device *dev)
> omap_dmm->container_width = 256;
> omap_dmm->container_height = 128;
>
> + atomic_set(&omap_dmm->engine_counter, omap_dmm->num_engines);
> +
> /* read out actual LUT width and height */
> pat_geom = readl(omap_dmm->base + DMM_PAT_GEOMETRY);
> omap_dmm->lut_width = ((pat_geom >> 16) & 0xF) << 5;
> @@ -651,7 +681,6 @@ static int omap_dmm_probe(struct platform_device *dev)
> goto fail;
> }
>
> - sema_init(&omap_dmm->engine_sem, omap_dmm->num_engines);
> for (i = 0; i < omap_dmm->num_engines; i++) {
> omap_dmm->engines[i].id = i;
> omap_dmm->engines[i].dmm = omap_dmm;
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