From 73a55431c8e517ea42b462fbf217e942e1e12614 Mon Sep 17 00:00:00 2001 From: YueHaibing Date: Sat, 26 Jan 2019 12:05:38 +0000 Subject: [PATCH 1/2] drm/xen-front: Drop pointless static qualifier in fb_destroy() [ Upstream commit 938010ab0722 ] There is no need to have the 'struct drm_framebuffer *fb' variable static since new value always be assigned before use it. Signed-off-by: YueHaibing Reviewed-by: Oleksandr Andrushchenko Signed-off-by: Oleksandr Andrushchenko Link: https://patchwork.freedesktop.org/patch/msgid/1548504338-114487-1-git-send-email-yuehaibing@huawei.com --- drivers/gpu/drm/xen/xen_drm_front_kms.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xen/xen_drm_front_kms.c b/drivers/gpu/drm/xen/xen_drm_front_kms.c index a3479eb72d7944..9b2eb6a747a37e 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_kms.c +++ b/drivers/gpu/drm/xen/xen_drm_front_kms.c @@ -54,7 +54,7 @@ fb_create(struct drm_device *dev, struct drm_file *filp, const struct drm_mode_fb_cmd2 *mode_cmd) { struct xen_drm_front_drm_info *drm_info = dev->dev_private; - static struct drm_framebuffer *fb; + struct drm_framebuffer *fb; struct drm_gem_object *gem_obj; int ret; From ab04a8a3d84c5aba235ff8340ff6792aa47db067 Mon Sep 17 00:00:00 2001 From: Oleksandr Andrushchenko Date: Tue, 29 Jan 2019 17:04:22 +0200 Subject: [PATCH 2/2] drm/xen-front: Fix mmap attributes for display buffers [ Upstream commit 24ded292a5c2 ] When GEM backing storage is allocated those are normal pages, so there is no point using pgprot_writecombine while mmaping. This fixes mismatch of buffer pages' memory attributes between the frontend and backend which may cause screen artifacts. Fixes: c575b7eeb89f ("drm/xen-front: Add support for Xen PV display frontend") Signed-off-by: Oleksandr Andrushchenko Suggested-by: Julien Grall Acked-by: Julien Grall Link: https://patchwork.freedesktop.org/patch/msgid/20190129150422.19867-1-andr2000@gmail.com --- drivers/gpu/drm/xen/xen_drm_front_gem.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c index c85bfe7571cbfc..802662839e7ede 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_gem.c +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c @@ -236,8 +236,14 @@ static int gem_mmap_obj(struct xen_gem_object *xen_obj, vma->vm_flags &= ~VM_PFNMAP; vma->vm_flags |= VM_MIXEDMAP; vma->vm_pgoff = 0; - vma->vm_page_prot = - pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + /* + * According to Xen on ARM ABI (xen/include/public/arch-arm.h): + * all memory which is shared with other entities in the system + * (including the hypervisor and other guests) must reside in memory + * which is mapped as Normal Inner Write-Back Outer Write-Back + * Inner-Shareable. + */ + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); /* * vm_operations_struct.fault handler will be called if CPU access @@ -283,8 +289,9 @@ void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj) if (!xen_obj->pages) return NULL; + /* Please see comment in gem_mmap_obj on mapping and attributes. */ return vmap(xen_obj->pages, xen_obj->num_pages, - VM_MAP, pgprot_writecombine(PAGE_KERNEL)); + VM_MAP, PAGE_KERNEL); } void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,