4  * SPDX-License-Identifier: Apache-2.0
17 #include <zephyr/linker/linker-defs.h>
31  * - A page frame is a page-sized physical memory region in RAM. It is a
37  * - A data page is a page-sized region of data. It may exist in a page frame,
86 		printk("-");  in page_frame_dump()
160  * +--------------+ <- K_MEM_VIRT_RAM_START
161  * | Undefined VM | <- May contain ancillary regions like x86_64's locore
162  * +--------------+ <- K_MEM_KERNEL_VIRT_START (often == K_MEM_VIRT_RAM_START)
168  * +--------------+ <- K_MEM_VM_FREE_START
173  * |..............| <- mapping_pos (grows downward as more mappings are made)
175  * +--------------+
177  * +--------------+
179  * +--------------+
181  * +--------------+ <- mappings start here
182  * | Reserved     | <- special purpose virtual page(s) of size K_MEM_VM_RESERVED
183  * +--------------+ <- K_MEM_VIRT_RAM_END
199 #define Z_VIRT_REGION_END_ADDR		(K_MEM_VIRT_RAM_END - K_MEM_VM_RESERVED)
204 	       - (offset * CONFIG_MMU_PAGE_SIZE) - size;  in virt_from_bitmap_offset()
210 		- POINTER_TO_UINT(vaddr) - size) / CONFIG_MMU_PAGE_SIZE;  in virt_to_bitmap_offset()
217 	/* There are regions where we should never map via  in virt_region_init()
231 		   - POINTER_TO_UINT(K_MEM_VIRT_RAM_START);  in virt_region_init()
256 		 && ((vaddr_u8 + size - 1) < Z_VIRT_REGION_END_ADDR),  in virt_region_free()
259 	      && ((vaddr_u8 + size - 1) < Z_VIRT_REGION_END_ADDR))) {  in virt_region_free()
274 	    (((vaddr_u8 + size - 1) >= Z_VIRT_REGION_START_ADDR) &&  in virt_region_free()
275 	     ((vaddr_u8 + size - 1) < Z_VIRT_REGION_END_ADDR))) {  in virt_region_free()
279 		size_t adjusted_sz = adjusted_end - adjusted_start;  in virt_region_free()
301 	num_bits = (size + align - CONFIG_MMU_PAGE_SIZE) / CONFIG_MMU_PAGE_SIZE;  in virt_region_alloc()
322 		 * +--------------+ <- K_MEM_VIRT_RAM_START  in virt_region_alloc()
324 		 * +--------------+ <- K_MEM_KERNEL_VIRT_START (often == K_MEM_VIRT_RAM_START)  in virt_region_alloc()
330 		 * +--------------+ <- K_MEM_VM_FREE_START  in virt_region_alloc()
332 		 * +==============+ <- dest_addr  in virt_region_alloc()
334 		 * |..............| <- aligned_dest_addr  in virt_region_alloc()
339 		 * |..............| <- aligned_dest_addr + size  in virt_region_alloc()
341 		 * +==============+ <- offset from K_MEM_VIRT_RAM_END == dest_addr + alloc_size  in virt_region_alloc()
343 		 * +--------------+  in virt_region_alloc()
345 		 * +--------------+  in virt_region_alloc()
347 		 * +--------------+ <- K_MEM_VIRT_RAM_END  in virt_region_alloc()
350 		/* Free the two unused regions */  in virt_region_alloc()
352 				 aligned_dest_addr - dest_addr);  in virt_region_alloc()
353 		if (((dest_addr + alloc_size) - (aligned_dest_addr + size)) > 0) {  in virt_region_alloc()
355 					 (dest_addr + alloc_size) - (aligned_dest_addr + size));  in virt_region_alloc()
379  * However, there are use-cases to consolidate free pages such that entire
406 		z_free_page_count--;  in free_page_frame_list_get()
410 		pf->va_and_flags = 0;  in free_page_frame_list_get()
422 	sys_sfnode_init(&pf->node, K_MEM_PAGE_FRAME_FREE);  in free_page_frame_list_put()
423 	sys_sflist_append(&free_page_frame_list, &pf->node);  in free_page_frame_list_put()
434 	pf->va_and_flags = 0;  in page_frame_free_locked()
454 	 * This is uncommon, use-cases are for things like the  in frame_mapped_set()
458 		 "non-pinned and already mapped to %p",  in frame_mapped_set()
461 	uintptr_t flags_mask = CONFIG_MMU_PAGE_SIZE - 1;  in frame_mapped_set()
464 	pf->va_and_flags &= flags_mask;  in frame_mapped_set()
465 	pf->va_and_flags |= va | K_MEM_PAGE_FRAME_MAPPED;  in frame_mapped_set()
477  * @retval -EFAULT if virtual address is not mapped
483 	int ret = -EFAULT;  in virt_to_page_frame()
513  * TODO: Add optional support for copy-on-write mappings to a zero page instead
516  * page-ins as memory is mapped and physical RAM or backing store storage will
524 	bool lock = (flags & K_MEM_MAP_LOCK) != 0U;  in map_anon_page()  local
540 			return -ENOMEM;  in map_anon_page()
545 		pf->va_and_flags = 0;  in map_anon_page()
547 		return -ENOMEM;  in map_anon_page()
554 	if (lock) {  in map_anon_page()
559 	if (IS_ENABLED(CONFIG_EVICTION_TRACKING) && (!lock)) {  in map_anon_page()
564 	LOG_DBG("memory mapping anon page %p -> 0x%lx", addr, phys);  in map_anon_page()
635 			LOG_DBG("memory mapping anon pages %p to %p unpaged", dst, pos-1);  in k_mem_map_phys_guard()
646 					 * call k_mem_unmap(dst, pos - dst)  in k_mem_map_phys_guard()
669 		/* If we later implement mappings to a copy-on-write  in k_mem_map_phys_guard()
693 	pos = (uint8_t *)addr - CONFIG_MMU_PAGE_SIZE;  in k_mem_unmap_phys_guard()
703 	ret = arch_page_phys_get(pos - CONFIG_MMU_PAGE_SIZE, NULL);  in k_mem_unmap_phys_guard()
801 		 * have been unmapped. We just need to unmapped the in-between  in k_mem_unmap_phys_guard()
810 	pos = (uint8_t *)addr - CONFIG_MMU_PAGE_SIZE;  in k_mem_unmap_phys_guard()
838 	/* TODO: detect and handle paged-out memory as well */  in k_mem_update_flags()
858 		ret = z_free_page_count - CONFIG_DEMAND_PAGING_PAGE_FRAMES_RESERVE;  in k_mem_free_get()
901 	__ASSERT(!(flags & K_MEM_DIRECT_MAP), "The direct-map is not enabled");  in k_mem_map_phys_bare()
906 	__ASSERT(aligned_size != 0U, "0-length mapping at 0x%lx", aligned_phys);  in k_mem_map_phys_bare()
907 	__ASSERT(aligned_phys < (aligned_phys + (aligned_size - 1)),  in k_mem_map_phys_bare()
928 			      (uintptr_t)(K_MEM_VIRT_RAM_END - 1)) ||  in k_mem_map_phys_bare()
929 		    IN_RANGE(aligned_phys + aligned_size - 1,  in k_mem_map_phys_bare()
931 			      (uintptr_t)(K_MEM_VIRT_RAM_END - 1))) {  in k_mem_map_phys_bare()
935 			size_t adjusted_sz = adjusted_end - adjusted_start;  in k_mem_map_phys_bare()
954 		 ((uintptr_t)dest_addr + (size - 1)),  in k_mem_map_phys_bare()
967 	/* May re-visit this in the future, but for now running out of  in k_mem_map_phys_bare()
988 	__ASSERT(aligned_size != 0U, "0-length mapping at 0x%lx", aligned_virt);  in k_mem_unmap_phys_bare()
989 	__ASSERT(aligned_virt < (aligned_virt + (aligned_size - 1)),  in k_mem_unmap_phys_bare()
1012 	/* The actual mapped region must be page-aligned. Round down the  in k_mem_region_align()
1016 	addr_offset = addr - *aligned_addr;  in k_mem_region_align()
1033 	size_t pinned_size = pinned_end - pinned_start;  in mark_linker_section_pinned()
1111 		 * currently tested with anonymously-mapped pages which are not  in z_mem_manage_init()
1114 		 * We will need to setup linker regions for a subset of kernel  in z_mem_manage_init()
1118 		 * handling, page-ins, etc.  in z_mem_manage_init()
1126 	 * boot process. Will be un-pinned once boot process completes.  in z_mem_manage_init()
1239 	time_diff = k_cycle_get_32() - time_start;  in do_backing_store_page_in()
1270 	time_diff = k_cycle_get_32() - time_start;  in do_backing_store_page_out()
1307  * - Map page frame to scratch area if requested. This always is true if we're
1310  * - If mapped:
1311  *    - obtain backing store location and populate location parameter
1312  *    - Update page tables with location
1313  * - Mark page frame as busy
1315  * Returns -ENOMEM if the backing store is full
1332 	 *    wasn't pre-populated with this data page.  in page_frame_prepare_locked()
1352 			return -ENOMEM;  in page_frame_prepare_locked()
1360 		/* Shouldn't happen unless this function is mis-used */  in page_frame_prepare_locked()
1361 		__ASSERT(!dirty, "un-mapped page determined to be dirty");  in page_frame_prepare_locked()
1401 		/* Un-mapped or already evicted. Nothing to do */  in do_mem_evict()
1469 	 * data page to page-in, see comments in that function.  in k_mem_page_frame_evict()
1535 	faulting_thread->paging_stats.pagefaults.cnt++;  in paging_stats_faults_inc()
1538 		faulting_thread->paging_stats.pagefaults.irq_unlocked++;  in paging_stats_faults_inc()
1540 		faulting_thread->paging_stats.pagefaults.irq_locked++;  in paging_stats_faults_inc()
1551 		faulting_thread->paging_stats.pagefaults.in_isr++;  in paging_stats_faults_inc()
1569 		faulting_thread->paging_stats.eviction.dirty++;  in paging_stats_eviction_inc()
1571 		faulting_thread->paging_stats.eviction.clean++;  in paging_stats_eviction_inc()
1604 	time_diff = k_cycle_get_32() - time_start;  in do_eviction_select()
1631 	 * - k_mem_paging_eviction_select() metrics  in do_page_fault()
1637 	 * We do re-enable interrupts during the page-in/page-out operation  in do_page_fault()
1650 	 * On UP we lock the scheduler so that other threads are never  in do_page_fault()
1651 	 * scheduled during the page-in/out operation. Support for  in do_page_fault()
1665 	 * and k_sched_lock()  is equivalent to a no-op on SMP anyway.  in do_page_fault()
1701 		/* This if-block is to pin the page if it is  in do_page_fault()