[Xen-devel] [PATCH 9/9] ttm/dma: Implement set_page_caching implementation in the TTM DMA pool code.

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

. 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);
+       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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