diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_ext.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/mm/page_ext.c b/mm/page_ext.c index d7396a8970e5..e2e92bd27ebd 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -11,6 +11,7 @@ #include <linux/page_table_check.h> #include <linux/rcupdate.h> #include <linux/pgalloc_tag.h> +#include <linux/iommu-debug-pagealloc.h> /* * struct page extension @@ -89,6 +90,9 @@ static struct page_ext_operations *page_ext_ops[] __initdata = { #ifdef CONFIG_PAGE_TABLE_CHECK &page_table_check_ops, #endif +#ifdef CONFIG_IOMMU_DEBUG_PAGEALLOC + &page_iommu_debug_ops, +#endif }; unsigned long page_ext_size; @@ -535,6 +539,29 @@ struct page_ext *page_ext_get(const struct page *page) } /** + * page_ext_from_phys() - Get the page_ext structure for a physical address. + * @phys: The physical address to query. + * + * This function safely gets the `struct page_ext` associated with a given + * physical address. It performs validation to ensure the address corresponds + * to a valid, online struct page before attempting to access it. + * It returns NULL for MMIO, ZONE_DEVICE, holes and offline memory. + * + * Return: NULL if no page_ext exists for this physical address. + * Context: Any context. Caller may not sleep until they have called + * page_ext_put(). + */ +struct page_ext *page_ext_from_phys(phys_addr_t phys) +{ + struct page *page = pfn_to_online_page(__phys_to_pfn(phys)); + + if (!page) + return NULL; + + return page_ext_get(page); +} + +/** * page_ext_put() - Working with page extended information is done. * @page_ext: Page extended information received from page_ext_get(). * |