Re: [PATCH 9/9] ttm/dma: Implement set_page_caching implementationin the TTM DMA pool code.

From: Kevin Shanahan
Date: Thu Sep 29 2011 - 18:16:21 EST


On 2011-09-29 20:33:52, Konrad Rzeszutek Wilk wrote:
> . which is pretty much like the other TTM pool except it
> also handles moving the page to another pool list.
>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> ---
> drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 96 ++++++++++++++++++++++++++++++
> 1 files changed, 96 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> index 5909d28..cea031e 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> @@ -1307,11 +1307,107 @@ static int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
> mutex_unlock(&_manager->lock);
> return 0;
> }
> +#ifdef CONFIG_X86
> +static int ttm_dma_page_set_page_caching(struct page *p,
> + int flags,
> + enum ttm_caching_state c_old,
> + enum ttm_caching_state c_new,
> + struct device *dev)
> +{
> + struct dma_pool *src, *dst;
> + enum pool_type type;
> + struct dma_page *dma_p;
> + bool found = false;
> + unsigned long irq_flags;
> + int ret = 0;
> +
> + if (!p)
> + return 0;
> +
> + if (PageHighMem(p))
> + return 0;
> +
> + type = ttm_to_type(flags, c_old);
> + src = ttm_dma_find_pool(dev, type);
> + if (!src) {
> + WARN_ON(!src);
> + return -ENOMEM;
> + }
> + type = ttm_to_type(flags, c_new);
> + dst = ttm_dma_find_pool(dev, type);
> + if (!dst) {
> + gfp_t gfp_flags;
> + if (flags & TTM_PAGE_FLAG_DMA32)
> + gfp_flags = GFP_USER | GFP_DMA32;
> + else
> + gfp_flags = GFP_HIGHUSER;
> +
> + if (flags & TTM_PAGE_FLAG_ZERO_ALLOC)
> + gfp_flags |= __GFP_ZERO;
> +
> + dst = ttm_dma_pool_init(dev, gfp_flags, type);
> + if (IS_ERR_OR_NULL(dst))
> + return -ENOMEM;
> + }
> +
> + dev_dbg(dev, "(%d) Caching %p (%p) from %x to %x.\n", current->pid,
> + p, page_address(p), c_old, c_new);
> +
> + if (c_old != tt_cached) {
> + /* p isn't in the default caching state, set it to
> + * writeback first to free its current memtype. */
> +
> + ret = set_pages_wb(p, 1);
> + if (ret)
> + return ret;
> + }
>
> + if (c_new == tt_wc)
> + ret = set_memory_wc((unsigned long) page_address(p), 1);
> + else if (c_new == tt_uncached)
> + ret = set_pages_uc(p, 1);
> +
> + if (ret)
> + return ret;
> +
> + dev_dbg(src->dev, "(%s:%d) Moving %p (%p) to %s.\n", src->name,
> + current->pid, p, page_address(p), dst->name);
> +
> + /* To make it faster we only take the spinlock on list
> + * removal, and later on adding the page to the destination pool. */
> + spin_lock_irqsave(&src->lock, irq_flags);
> + list_for_each_entry(dma_p, &src->page_list, page_list) {
> + if (virt_to_page(dma_p->vaddr) != p) {
> + pr_debug("%s: (%s:%d) Skipping %p (%p) (DMA:0x%lx)\n",
> + src->dev_name, src->name, current->pid,
> + dma_p->vaddr,
> + virt_to_page(dma_p->vaddr),
> + (unsigned long)dma_p->dma);
> + continue;
> + }
> + list_del(&dma_p->page_list);
> + src->npages_in_use -= 1;
> + found = true;
> + break;
> + }
> + spin_lock_irqsave(&src->lock, irq_flags);
^^^^^^^^^^^^^^^^^

Was this meant to be spin_unlock_irqrestore?

Cheers,
Kevin.

> + if (!found)
> + return -ENODEV;
> +
> + spin_lock_irqsave(&dst->lock, irq_flags);
> + list_add(&dma_p->page_list, &dst->page_list);
> + dst->npages_in_use++;
> + spin_unlock_irqrestore(&dst->lock, irq_flags);
> + return 0;
> +};
> +#endif
> struct ttm_page_alloc_func ttm_page_alloc_dma = {
> .get_pages = ttm_dma_get_pages,
> .put_pages = ttm_dma_put_pages,
> .alloc_init = ttm_dma_page_alloc_init,
> .alloc_fini = ttm_dma_page_alloc_fini,
> .debugfs = ttm_dma_page_alloc_debugfs,
> +#ifdef CONFIG_X86
> + .set_caching = ttm_dma_page_set_page_caching,
> +#endif
> };
> --
> 1.7.4.1
>
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