1 // SPDX-License-Identifier: GPL-2.0-only
5  * Copyright (C) 1995-2005 Russell King
24 #include <linux/dma-direct.h>
25 #include <linux/dma-map-ops.h>
40 #include <asm/kernel-pgtable.h>
50 #include <asm/xen/swiotlb-xen.h>
58 s64 memstart_addr __ro_after_init = -1;
63  * and ZONE_DMA32. By default ZONE_DMA covers the 32-bit addressable memory
64  * unless restricted on specific platforms (e.g. 30-bit on Raspberry Pi 4).
65  * In such case, ZONE_DMA32 covers the rest of the 32-bit addressable memory,
89  * in the virtual address space.
120 	return min(zone_limit, memblock_end_of_DRAM() - 1) + 1;  in max_zone_phys()
136 	 * Information we get from firmware (e.g. DT dma-ranges) describe DMA  in zone_sizes_init()
138 	 * Some of them rely on DMA zone in low 32-bit memory. Keep low RAM  in zone_sizes_init()
189 	s64 linear_region_size = PAGE_END - _PAGE_OFFSET(vabits_actual);  in arm64_memblock_init()
192 	 * Corner case: 52-bit VA capable systems running KVM in nVHE mode may  in arm64_memblock_init()
214 	if ((memblock_end_of_DRAM() - memstart_addr) > linear_region_size)  in arm64_memblock_init()
226 		memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size,  in arm64_memblock_init()
232 	 * If we are running with a 52-bit kernel VA config on a system that  in arm64_memblock_init()
234 	 * memory in the 48-bit addressable part of the linear region, i.e.,  in arm64_memblock_init()
239 		memstart_addr -= _PAGE_OFFSET(vabits_actual) - _PAGE_OFFSET(52);  in arm64_memblock_init()
248 		memblock_add(__pa_symbol(_text), (u64)(_end - _text));  in arm64_memblock_init()
255 		 * Otherwise, this is a no-op  in arm64_memblock_init()
258 		u64 size = PAGE_ALIGN(phys_initrd_start + phys_initrd_size) - base;  in arm64_memblock_init()
271 			"initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) {  in arm64_memblock_init()
285 		s64 range = linear_region_size -  in arm64_memblock_init()
295 			memstart_addr -= ARM64_MEMSTART_ALIGN *  in arm64_memblock_init()
304 	memblock_reserve(__pa_symbol(_stext), _end - _stext);  in arm64_memblock_init()
306 		/* the generic initrd code expects virtual addresses */  in arm64_memblock_init()
313 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;  in arm64_memblock_init()
318 	unsigned long min, max;  in bootmem_init()  local
321 	max = PFN_DOWN(memblock_end_of_DRAM());  in bootmem_init()
323 	early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);  in bootmem_init()
325 	max_pfn = max_low_pfn = max;  in bootmem_init()
404 	 * scratch using the virtual address range and page size.  in mem_init()
428 	memblock_free(lm_init_begin, lm_init_end - lm_init_begin);  in free_initmem()
454  * Choose a random page-aligned base address for a window of 'size' bytes which
455  * entirely contains the interval [start, end - 1].
461 	if ((end - start) >= size)  in random_bounding_box()
464 	max_pgoff = (size - (end - start)) / PAGE_SIZE;  in random_bounding_box()
467 	return start - pgoff * PAGE_SIZE;  in random_bounding_box()
472  * image and other modules. References using PREL32 relocations have a +/-2G
476  * Modules may directly branch to functions and code within the kernel text,
477  * and to functions and code within other modules. These branches will use
478  * CALL26/JUMP26 relocations with a +/-128M range. Without PLTs, we must ensure
494 	u64 kernel_size = kernel_end - kernel_start;  in module_init_limits()
505 			module_direct_base = kernel_end - SZ_128M;  in module_init_limits()
507 			module_plt_base = kernel_end - SZ_2G;  in module_init_limits()
510 		u64 max = kernel_end;  in module_init_limits()  local
515 			module_direct_base = random_bounding_box(SZ_128M, min, max);  in module_init_limits()
518 				max = module_direct_base + SZ_128M;  in module_init_limits()
522 		module_plt_base = random_bounding_box(SZ_2G, min, max);  in module_init_limits()
525 	pr_info("%llu pages in range for non-PLT usage",  in module_init_limits()
526 		module_direct_base ? (SZ_128M - kernel_size) / PAGE_SIZE : 0);  in module_init_limits()
528 		module_plt_base ? (SZ_2G - kernel_size) / PAGE_SIZE : 0);  in module_init_limits()