diff options
author | Dave Airlie <airlied@redhat.com> | 2025-03-07 02:55:33 +0300 |
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committer | Dave Airlie <airlied@redhat.com> | 2025-03-07 02:55:50 +0300 |
commit | d65a27f95f6ab236b1a788d9bc463d24a8b2aebe (patch) | |
tree | 45da6a037ca99ebec667e3057f3d973526510bc3 /drivers/gpu/drm/ttm/ttm_backup.c | |
parent | e21cba704714c301d04c5fd37a693734b623872a (diff) | |
parent | 4423e607ff50157aaf088854b145936cbab4d560 (diff) | |
download | linux-d65a27f95f6ab236b1a788d9bc463d24a8b2aebe.tar.xz |
Merge tag 'drm-misc-next-2025-03-06' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-next
drm-misc-next for v6.15:
Cross-subsystem Changes:
base:
- component: Provide helper to query bound status
fbdev:
- fbtft: Remove access to page->index
Core Changes:
- Fix usage of logging macros in several places
gem:
- Add test function for imported dma-bufs and use it in core and helpers
- Avoid struct drm_gem_object.import_attach
tests:
- Fix lockdep warnings
ttm:
- Add helpers for TTM shrinker
Driver Changes:
adp:
- Add support for Apple Touch Bar displays on M1/M2
amdxdna:
- Fix interrupt handling
appletbdrm:
- Add support for Apple Touch Bar displays on x86
bridge:
- synopsys: Add HDMI audio support
- ti-sn65dsi83: Support negative DE polarity
ipu-v3:
- Remove unused code
nouveau:
- Avoid multiple -Wflex-array-member-not-at-end warnings
panthor:
- Fix CS_STATUS_ defines
- Improve locking
rockchip:
- analogix_dp: Add eDP support
- lvds: Improve logging
- vop2: Improve HDMI mode handling; Add support for RK3576
- Fix shutdown
- Support rk3562-mali
xe:
- Use TTM shrinker
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306130700.GA485504@linux.fritz.box
Diffstat (limited to 'drivers/gpu/drm/ttm/ttm_backup.c')
-rw-r--r-- | drivers/gpu/drm/ttm/ttm_backup.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/gpu/drm/ttm/ttm_backup.c b/drivers/gpu/drm/ttm/ttm_backup.c new file mode 100644 index 000000000000..93c007f18855 --- /dev/null +++ b/drivers/gpu/drm/ttm/ttm_backup.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2024 Intel Corporation + */ + +#include <drm/ttm/ttm_backup.h> +#include <linux/page-flags.h> +#include <linux/swap.h> + +/* + * Casting from randomized struct file * to struct ttm_backup * is fine since + * struct ttm_backup is never defined nor dereferenced. + */ +static struct file *ttm_backup_to_file(struct ttm_backup *backup) +{ + return (void *)backup; +} + +static struct ttm_backup *ttm_file_to_backup(struct file *file) +{ + return (void *)file; +} + +/* + * Need to map shmem indices to handle since a handle value + * of 0 means error, following the swp_entry_t convention. + */ +static unsigned long ttm_backup_shmem_idx_to_handle(pgoff_t idx) +{ + return (unsigned long)idx + 1; +} + +static pgoff_t ttm_backup_handle_to_shmem_idx(pgoff_t handle) +{ + return handle - 1; +} + +/** + * ttm_backup_drop() - release memory associated with a handle + * @backup: The struct backup pointer used to obtain the handle + * @handle: The handle obtained from the @backup_page function. + */ +void ttm_backup_drop(struct ttm_backup *backup, pgoff_t handle) +{ + loff_t start = ttm_backup_handle_to_shmem_idx(handle); + + start <<= PAGE_SHIFT; + shmem_truncate_range(file_inode(ttm_backup_to_file(backup)), start, + start + PAGE_SIZE - 1); +} + +/** + * ttm_backup_copy_page() - Copy the contents of a previously backed + * up page + * @backup: The struct backup pointer used to back up the page. + * @dst: The struct page to copy into. + * @handle: The handle returned when the page was backed up. + * @intr: Try to perform waits interruptable or at least killable. + * + * Return: 0 on success, Negative error code on failure, notably + * -EINTR if @intr was set to true and a signal is pending. + */ +int ttm_backup_copy_page(struct ttm_backup *backup, struct page *dst, + pgoff_t handle, bool intr) +{ + struct file *filp = ttm_backup_to_file(backup); + struct address_space *mapping = filp->f_mapping; + struct folio *from_folio; + pgoff_t idx = ttm_backup_handle_to_shmem_idx(handle); + + from_folio = shmem_read_folio(mapping, idx); + if (IS_ERR(from_folio)) + return PTR_ERR(from_folio); + + copy_highpage(dst, folio_file_page(from_folio, idx)); + folio_put(from_folio); + + return 0; +} + +/** + * ttm_backup_backup_page() - Backup a page + * @backup: The struct backup pointer to use. + * @page: The page to back up. + * @writeback: Whether to perform immediate writeback of the page. + * This may have performance implications. + * @idx: A unique integer for each page and each struct backup. + * This allows the backup implementation to avoid managing + * its address space separately. + * @page_gfp: The gfp value used when the page was allocated. + * This is used for accounting purposes. + * @alloc_gfp: The gfp to be used when allocating memory. + * + * Context: If called from reclaim context, the caller needs to + * assert that the shrinker gfp has __GFP_FS set, to avoid + * deadlocking on lock_page(). If @writeback is set to true and + * called from reclaim context, the caller also needs to assert + * that the shrinker gfp has __GFP_IO set, since without it, + * we're not allowed to start backup IO. + * + * Return: A handle on success. Negative error code on failure. + * + * Note: This function could be extended to back up a folio and + * implementations would then split the folio internally if needed. + * Drawback is that the caller would then have to keep track of + * the folio size- and usage. + */ +s64 +ttm_backup_backup_page(struct ttm_backup *backup, struct page *page, + bool writeback, pgoff_t idx, gfp_t page_gfp, + gfp_t alloc_gfp) +{ + struct file *filp = ttm_backup_to_file(backup); + struct address_space *mapping = filp->f_mapping; + unsigned long handle = 0; + struct folio *to_folio; + int ret; + + to_folio = shmem_read_folio_gfp(mapping, idx, alloc_gfp); + if (IS_ERR(to_folio)) + return PTR_ERR(to_folio); + + folio_mark_accessed(to_folio); + folio_lock(to_folio); + folio_mark_dirty(to_folio); + copy_highpage(folio_file_page(to_folio, idx), page); + handle = ttm_backup_shmem_idx_to_handle(idx); + + if (writeback && !folio_mapped(to_folio) && + folio_clear_dirty_for_io(to_folio)) { + struct writeback_control wbc = { + .sync_mode = WB_SYNC_NONE, + .nr_to_write = SWAP_CLUSTER_MAX, + .range_start = 0, + .range_end = LLONG_MAX, + .for_reclaim = 1, + }; + folio_set_reclaim(to_folio); + ret = mapping->a_ops->writepage(folio_file_page(to_folio, idx), &wbc); + if (!folio_test_writeback(to_folio)) + folio_clear_reclaim(to_folio); + /* + * If writepage succeeds, it unlocks the folio. + * writepage() errors are otherwise dropped, since writepage() + * is only best effort here. + */ + if (ret) + folio_unlock(to_folio); + } else { + folio_unlock(to_folio); + } + + folio_put(to_folio); + + return handle; +} + +/** + * ttm_backup_fini() - Free the struct backup resources after last use. + * @backup: Pointer to the struct backup whose resources to free. + * + * After a call to this function, it's illegal to use the @backup pointer. + */ +void ttm_backup_fini(struct ttm_backup *backup) +{ + fput(ttm_backup_to_file(backup)); +} + +/** + * ttm_backup_bytes_avail() - Report the approximate number of bytes of backup space + * left for backup. + * + * This function is intended also for driver use to indicate whether a + * backup attempt is meaningful. + * + * Return: An approximate size of backup space available. + */ +u64 ttm_backup_bytes_avail(void) +{ + /* + * The idea behind backing up to shmem is that shmem objects may + * eventually be swapped out. So no point swapping out if there + * is no or low swap-space available. But the accuracy of this + * number also depends on shmem actually swapping out backed-up + * shmem objects without too much buffering. + */ + return (u64)get_nr_swap_pages() << PAGE_SHIFT; +} +EXPORT_SYMBOL_GPL(ttm_backup_bytes_avail); + +/** + * ttm_backup_shmem_create() - Create a shmem-based struct backup. + * @size: The maximum size (in bytes) to back up. + * + * Create a backup utilizing shmem objects. + * + * Return: A pointer to a struct ttm_backup on success, + * an error pointer on error. + */ +struct ttm_backup *ttm_backup_shmem_create(loff_t size) +{ + struct file *filp; + + filp = shmem_file_setup("ttm shmem backup", size, 0); + + return ttm_file_to_backup(filp); +} |