From bfed6708d6c97406d14420f3288ee775c284ff8a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 17 Oct 2020 16:15:21 -0700 Subject: [PATCH] drm/i915: use vmap in shmem_pin_map shmem_pin_map somewhat awkwardly reimplements vmap using alloc_vm_area and manual pte setup. The only practical difference is that alloc_vm_area prefeaults the vmalloc area PTEs, which doesn't seem to be required here (and could be added to vmap using a flag if actually required). Switch to use vmap, and use vfree to free both the vmalloc mapping and the page array, as well as dropping the references to each page. Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Reviewed-by: Tvrtko Ursulin Cc: Boris Ostrovsky Cc: Chris Wilson Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Juergen Gross Cc: Matthew Auld Cc: "Matthew Wilcox (Oracle)" Cc: Minchan Kim Cc: Nitin Gupta Cc: Peter Zijlstra Cc: Rodrigo Vivi Cc: Stefano Stabellini Cc: Uladzislau Rezki (Sony) Link: https://lkml.kernel.org/r/20201002122204.1534411-7-hch@lst.de Signed-off-by: Linus Torvalds --- drivers/gpu/drm/i915/gt/shmem_utils.c | 76 +++++++++-------------------------- 1 file changed, 18 insertions(+), 58 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c index 43c7acb..f011ea4 100644 --- a/drivers/gpu/drm/i915/gt/shmem_utils.c +++ b/drivers/gpu/drm/i915/gt/shmem_utils.c @@ -49,80 +49,40 @@ struct file *shmem_create_from_object(struct drm_i915_gem_object *obj) return file; } -static size_t shmem_npte(struct file *file) -{ - return file->f_mapping->host->i_size >> PAGE_SHIFT; -} - -static void __shmem_unpin_map(struct file *file, void *ptr, size_t n_pte) -{ - unsigned long pfn; - - vunmap(ptr); - - for (pfn = 0; pfn < n_pte; pfn++) { - struct page *page; - - page = shmem_read_mapping_page_gfp(file->f_mapping, pfn, - GFP_KERNEL); - if (!WARN_ON(IS_ERR(page))) { - put_page(page); - put_page(page); - } - } -} - void *shmem_pin_map(struct file *file) { - const size_t n_pte = shmem_npte(file); - pte_t *stack[32], **ptes, **mem; - struct vm_struct *area; - unsigned long pfn; - - mem = stack; - if (n_pte > ARRAY_SIZE(stack)) { - mem = kvmalloc_array(n_pte, sizeof(*mem), GFP_KERNEL); - if (!mem) - return NULL; - } + struct page **pages; + size_t n_pages, i; + void *vaddr; - area = alloc_vm_area(n_pte << PAGE_SHIFT, mem); - if (!area) { - if (mem != stack) - kvfree(mem); + n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT; + pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL); + if (!pages) return NULL; - } - ptes = mem; - for (pfn = 0; pfn < n_pte; pfn++) { - struct page *page; - - page = shmem_read_mapping_page_gfp(file->f_mapping, pfn, - GFP_KERNEL); - if (IS_ERR(page)) + for (i = 0; i < n_pages; i++) { + pages[i] = shmem_read_mapping_page_gfp(file->f_mapping, i, + GFP_KERNEL); + if (IS_ERR(pages[i])) goto err_page; - - **ptes++ = mk_pte(page, PAGE_KERNEL); } - if (mem != stack) - kvfree(mem); - + vaddr = vmap(pages, n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL); + if (!vaddr) + goto err_page; mapping_set_unevictable(file->f_mapping); - return area->addr; - + return vaddr; err_page: - if (mem != stack) - kvfree(mem); - - __shmem_unpin_map(file, area->addr, pfn); + while (--i >= 0) + put_page(pages[i]); + kvfree(pages); return NULL; } void shmem_unpin_map(struct file *file, void *ptr) { mapping_clear_unevictable(file->f_mapping); - __shmem_unpin_map(file, ptr, shmem_npte(file)); + vfree(ptr); } static int __shmem_rw(struct file *file, loff_t off, -- 2.7.4