From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/video/fbdev/core/fb_defio.c | 246 +++++++++++++++++++++++++++++ 1 file changed, 246 insertions(+) create mode 100644 kernel/drivers/video/fbdev/core/fb_defio.c (limited to 'kernel/drivers/video/fbdev/core/fb_defio.c') diff --git a/kernel/drivers/video/fbdev/core/fb_defio.c b/kernel/drivers/video/fbdev/core/fb_defio.c new file mode 100644 index 000000000..d6cab1fd9 --- /dev/null +++ b/kernel/drivers/video/fbdev/core/fb_defio.c @@ -0,0 +1,246 @@ +/* + * linux/drivers/video/fb_defio.c + * + * Copyright (C) 2006 Jaya Kumar + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* to support deferred IO */ +#include +#include + +static struct page *fb_deferred_io_page(struct fb_info *info, unsigned long offs) +{ + void *screen_base = (void __force *) info->screen_base; + struct page *page; + + if (is_vmalloc_addr(screen_base + offs)) + page = vmalloc_to_page(screen_base + offs); + else + page = pfn_to_page((info->fix.smem_start + offs) >> PAGE_SHIFT); + + return page; +} + +/* this is to find and return the vmalloc-ed fb pages */ +static int fb_deferred_io_fault(struct vm_area_struct *vma, + struct vm_fault *vmf) +{ + unsigned long offset; + struct page *page; + struct fb_info *info = vma->vm_private_data; + + offset = vmf->pgoff << PAGE_SHIFT; + if (offset >= info->fix.smem_len) + return VM_FAULT_SIGBUS; + + page = fb_deferred_io_page(info, offset); + if (!page) + return VM_FAULT_SIGBUS; + + get_page(page); + + if (vma->vm_file) + page->mapping = vma->vm_file->f_mapping; + else + printk(KERN_ERR "no mapping available\n"); + + BUG_ON(!page->mapping); + page->index = vmf->pgoff; + + vmf->page = page; + return 0; +} + +int fb_deferred_io_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct fb_info *info = file->private_data; + struct inode *inode = file_inode(file); + int err = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (err) + return err; + + /* Skip if deferred io is compiled-in but disabled on this fbdev */ + if (!info->fbdefio) + return 0; + + mutex_lock(&inode->i_mutex); + /* Kill off the delayed work */ + cancel_delayed_work_sync(&info->deferred_work); + + /* Run it immediately */ + schedule_delayed_work(&info->deferred_work, 0); + mutex_unlock(&inode->i_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(fb_deferred_io_fsync); + +/* vm_ops->page_mkwrite handler */ +static int fb_deferred_io_mkwrite(struct vm_area_struct *vma, + struct vm_fault *vmf) +{ + struct page *page = vmf->page; + struct fb_info *info = vma->vm_private_data; + struct fb_deferred_io *fbdefio = info->fbdefio; + struct page *cur; + + /* this is a callback we get when userspace first tries to + write to the page. we schedule a workqueue. that workqueue + will eventually mkclean the touched pages and execute the + deferred framebuffer IO. then if userspace touches a page + again, we repeat the same scheme */ + + file_update_time(vma->vm_file); + + /* protect against the workqueue changing the page list */ + mutex_lock(&fbdefio->lock); + + /* first write in this cycle, notify the driver */ + if (fbdefio->first_io && list_empty(&fbdefio->pagelist)) + fbdefio->first_io(info); + + /* + * We want the page to remain locked from ->page_mkwrite until + * the PTE is marked dirty to avoid page_mkclean() being called + * before the PTE is updated, which would leave the page ignored + * by defio. + * Do this by locking the page here and informing the caller + * about it with VM_FAULT_LOCKED. + */ + lock_page(page); + + /* we loop through the pagelist before adding in order + to keep the pagelist sorted */ + list_for_each_entry(cur, &fbdefio->pagelist, lru) { + /* this check is to catch the case where a new + process could start writing to the same page + through a new pte. this new access can cause the + mkwrite even when the original ps's pte is marked + writable */ + if (unlikely(cur == page)) + goto page_already_added; + else if (cur->index > page->index) + break; + } + + list_add_tail(&page->lru, &cur->lru); + +page_already_added: + mutex_unlock(&fbdefio->lock); + + /* come back after delay to process the deferred IO */ + schedule_delayed_work(&info->deferred_work, fbdefio->delay); + return VM_FAULT_LOCKED; +} + +static const struct vm_operations_struct fb_deferred_io_vm_ops = { + .fault = fb_deferred_io_fault, + .page_mkwrite = fb_deferred_io_mkwrite, +}; + +static int fb_deferred_io_set_page_dirty(struct page *page) +{ + if (!PageDirty(page)) + SetPageDirty(page); + return 0; +} + +static const struct address_space_operations fb_deferred_io_aops = { + .set_page_dirty = fb_deferred_io_set_page_dirty, +}; + +static int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma) +{ + vma->vm_ops = &fb_deferred_io_vm_ops; + vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; + if (!(info->flags & FBINFO_VIRTFB)) + vma->vm_flags |= VM_IO; + vma->vm_private_data = info; + return 0; +} + +/* workqueue callback */ +static void fb_deferred_io_work(struct work_struct *work) +{ + struct fb_info *info = container_of(work, struct fb_info, + deferred_work.work); + struct list_head *node, *next; + struct page *cur; + struct fb_deferred_io *fbdefio = info->fbdefio; + + /* here we mkclean the pages, then do all deferred IO */ + mutex_lock(&fbdefio->lock); + list_for_each_entry(cur, &fbdefio->pagelist, lru) { + lock_page(cur); + page_mkclean(cur); + unlock_page(cur); + } + + /* driver's callback with pagelist */ + fbdefio->deferred_io(info, &fbdefio->pagelist); + + /* clear the list */ + list_for_each_safe(node, next, &fbdefio->pagelist) { + list_del(node); + } + mutex_unlock(&fbdefio->lock); +} + +void fb_deferred_io_init(struct fb_info *info) +{ + struct fb_deferred_io *fbdefio = info->fbdefio; + + BUG_ON(!fbdefio); + mutex_init(&fbdefio->lock); + info->fbops->fb_mmap = fb_deferred_io_mmap; + INIT_DELAYED_WORK(&info->deferred_work, fb_deferred_io_work); + INIT_LIST_HEAD(&fbdefio->pagelist); + if (fbdefio->delay == 0) /* set a default of 1 s */ + fbdefio->delay = HZ; +} +EXPORT_SYMBOL_GPL(fb_deferred_io_init); + +void fb_deferred_io_open(struct fb_info *info, + struct inode *inode, + struct file *file) +{ + file->f_mapping->a_ops = &fb_deferred_io_aops; +} +EXPORT_SYMBOL_GPL(fb_deferred_io_open); + +void fb_deferred_io_cleanup(struct fb_info *info) +{ + struct fb_deferred_io *fbdefio = info->fbdefio; + struct page *page; + int i; + + BUG_ON(!fbdefio); + cancel_delayed_work_sync(&info->deferred_work); + + /* clear out the mapping that we setup */ + for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) { + page = fb_deferred_io_page(info, i); + page->mapping = NULL; + } + + info->fbops->fb_mmap = NULL; + mutex_destroy(&fbdefio->lock); +} +EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup); + +MODULE_LICENSE("GPL"); -- cgit 1.2.3-korg