On Thu, May 24, 2012 at 10:43 AM, Andy Gross <andy.gross@xxxxxx> wrote:
> Failures during the dmm probe can cause the kernel to crash. Moved
> the spinlock to a global and moved list initializations immediately
> after the allocation of the dmm private structure.
>
> Signed-off-by: Andy Gross <andy.gross@xxxxxx>
Reviewed-by: Rob Clark <rob.clark@xxxxxxxxxx>
> ---
> drivers/staging/omapdrm/omap_dmm_priv.h | 1 -
> drivers/staging/omapdrm/omap_dmm_tiler.c | 44 ++++++++++++++++-------------
> 2 files changed, 24 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/staging/omapdrm/omap_dmm_priv.h b/drivers/staging/omapdrm/omap_dmm_priv.h
> index 2f529ab..08b22e9 100644
> --- a/drivers/staging/omapdrm/omap_dmm_priv.h
> +++ b/drivers/staging/omapdrm/omap_dmm_priv.h
> @@ -181,7 +181,6 @@ struct dmm {
>
> /* allocation list and lock */
> struct list_head alloc_head;
> - spinlock_t list_lock;
> };
>
> #endif
> diff --git a/drivers/staging/omapdrm/omap_dmm_tiler.c b/drivers/staging/omapdrm/omap_dmm_tiler.c
> index 1ecb6a7..3bc715d 100644
> --- a/drivers/staging/omapdrm/omap_dmm_tiler.c
> +++ b/drivers/staging/omapdrm/omap_dmm_tiler.c
> @@ -40,6 +40,9 @@
> static struct tcm *containers[TILFMT_NFORMATS];
> static struct dmm *omap_dmm;
>
> +/* global spinlock for protecting lists */
> +static DEFINE_SPINLOCK(list_lock);
> +
> /* Geometry table */
> #define GEOM(xshift, yshift, bytes_per_pixel) { \
> .x_shft = (xshift), \
> @@ -147,13 +150,13 @@ static struct dmm_txn *dmm_txn_init(struct dmm *dmm, struct tcm *tcm)
> down(&dmm->engine_sem);
>
> /* grab an idle engine */
> - spin_lock(&dmm->list_lock);
> + spin_lock(&list_lock);
> 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(&dmm->list_lock);
> + spin_unlock(&list_lock);
>
> BUG_ON(!engine);
>
> @@ -256,9 +259,9 @@ static int dmm_txn_commit(struct dmm_txn *txn, bool wait)
> }
>
> cleanup:
> - spin_lock(&dmm->list_lock);
> + spin_lock(&list_lock);
> list_add(&engine->idle_node, &dmm->idle_head);
> - spin_unlock(&dmm->list_lock);
> + spin_unlock(&list_lock);
>
> up(&omap_dmm->engine_sem);
> return ret;
> @@ -351,9 +354,9 @@ struct tiler_block *tiler_reserve_2d(enum tiler_fmt fmt, uint16_t w,
> }
>
> /* add to allocation list */
> - spin_lock(&omap_dmm->list_lock);
> + spin_lock(&list_lock);
> list_add(&block->alloc_node, &omap_dmm->alloc_head);
> - spin_unlock(&omap_dmm->list_lock);
> + spin_unlock(&list_lock);
>
> return block;
> }
> @@ -374,9 +377,9 @@ struct tiler_block *tiler_reserve_1d(size_t size)
> return 0;
> }
>
> - spin_lock(&omap_dmm->list_lock);
> + spin_lock(&list_lock);
> list_add(&block->alloc_node, &omap_dmm->alloc_head);
> - spin_unlock(&omap_dmm->list_lock);
> + spin_unlock(&list_lock);
>
> return block;
> }
> @@ -389,9 +392,9 @@ int tiler_release(struct tiler_block *block)
> if (block->area.tcm)
> dev_err(omap_dmm->dev, "failed to release block\n");
>
> - spin_lock(&omap_dmm->list_lock);
> + spin_lock(&list_lock);
> list_del(&block->alloc_node);
> - spin_unlock(&omap_dmm->list_lock);
> + spin_unlock(&list_lock);
>
> kfree(block);
> return ret;
> @@ -479,13 +482,13 @@ static int omap_dmm_remove(struct platform_device *dev)
>
> if (omap_dmm) {
> /* free all area regions */
> - spin_lock(&omap_dmm->list_lock);
> + spin_lock(&list_lock);
> list_for_each_entry_safe(block, _block, &omap_dmm->alloc_head,
> alloc_node) {
> list_del(&block->alloc_node);
> kfree(block);
> }
> - spin_unlock(&omap_dmm->list_lock);
> + spin_unlock(&list_lock);
>
> for (i = 0; i < omap_dmm->num_lut; i++)
> if (omap_dmm->tcm && omap_dmm->tcm[i])
> @@ -503,7 +506,7 @@ static int omap_dmm_remove(struct platform_device *dev)
>
> vfree(omap_dmm->lut);
>
> - if (omap_dmm->irq != -1)
> + if (omap_dmm->irq > 0)
> free_irq(omap_dmm->irq, omap_dmm);
>
> iounmap(omap_dmm->base);
> @@ -527,6 +530,10 @@ static int omap_dmm_probe(struct platform_device *dev)
> goto fail;
> }
>
> + /* initialize lists */
> + INIT_LIST_HEAD(&omap_dmm->alloc_head);
> + INIT_LIST_HEAD(&omap_dmm->idle_head);
> +
> /* lookup hwmod data - base address and irq */
> mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
> if (!mem) {
> @@ -629,7 +636,6 @@ static int omap_dmm_probe(struct platform_device *dev)
> }
>
> sema_init(&omap_dmm->engine_sem, omap_dmm->num_engines);
> - INIT_LIST_HEAD(&omap_dmm->idle_head);
> for (i = 0; i < omap_dmm->num_engines; i++) {
> omap_dmm->engines[i].id = i;
> omap_dmm->engines[i].dmm = omap_dmm;
> @@ -672,9 +678,6 @@ static int omap_dmm_probe(struct platform_device *dev)
> containers[TILFMT_32BIT] = omap_dmm->tcm[0];
> containers[TILFMT_PAGE] = omap_dmm->tcm[0];
>
> - INIT_LIST_HEAD(&omap_dmm->alloc_head);
> - spin_lock_init(&omap_dmm->list_lock);
> -
> area = (struct tcm_area) {
> .is2d = true,
> .tcm = NULL,
> @@ -697,7 +700,8 @@ static int omap_dmm_probe(struct platform_device *dev)
> return 0;
>
> fail:
> - omap_dmm_remove(dev);
> + if (omap_dmm_remove(dev))
> + dev_err(&dev->dev, "cleanup failed\n");
> return ret;
> }
>
> @@ -810,7 +814,7 @@ int tiler_map_show(struct seq_file *s, void *arg)
> map[i] = global_map + i * (w_adj + 1);
> map[i][w_adj] = 0;
> }
> - spin_lock_irqsave(&omap_dmm->list_lock, flags);
> + spin_lock_irqsave(&list_lock, flags);
>
> list_for_each_entry(block, &omap_dmm->alloc_head, alloc_node) {
> if (block->fmt != TILFMT_PAGE) {
> @@ -836,7 +840,7 @@ int tiler_map_show(struct seq_file *s, void *arg)
> }
> }
>
> - spin_unlock_irqrestore(&omap_dmm->list_lock, flags);
> + spin_unlock_irqrestore(&list_lock, flags);
>
> if (s) {
> seq_printf(s, "BEGIN DMM TILER MAP\n");
> --
> 1.7.5.4
>
> --
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