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,
71  * To make optimal use of block mappings when laying out the linear
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()
193 	 * be limited in their ability to support a linear map that exceeds 51  in arm64_memblock_init()
196 	 * limit the kernel's linear map to 51 bits as well if we detect this  in arm64_memblock_init()
201 		pr_info("Capping linear region to 51 bits for KVM in nVHE mode on LVA capable hardware.\n");  in arm64_memblock_init()
214 	if ((memblock_end_of_DRAM() - memstart_addr) > linear_region_size)  in arm64_memblock_init()
215 		pr_warn("Memory doesn't fit in the linear mapping, VA_BITS too small\n");  in arm64_memblock_init()
219 	 * linear mapping. Take care not to clip the kernel which may be  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()
244 	 * via the linear mapping.  in arm64_memblock_init()
248 		memblock_add(__pa_symbol(_text), (u64)(_end - _text));  in arm64_memblock_init()
254 		 * initrd to become inaccessible via the linear mapping.  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()
262 		 * with more memory than we can address via the linear mapping.  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()
289 		 * If the size of the linear region exceeds, by a sufficient  in arm64_memblock_init()
291 		 * span, randomize the linear region as well.  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()
313 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;  in arm64_memblock_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
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()
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()