1 // SPDX-License-Identifier: GPL-2.0-only
5  * Copyright (C) 1995-2005 Russell King
23 #include <linux/dma-direct.h>
24 #include <linux/dma-map-ops.h>
38 #include <asm/kernel-pgtable.h>
47 #include <asm/xen/swiotlb-xen.h>
55 s64 memstart_addr __ro_after_init = -1;
60  * and ZONE_DMA32. By default ZONE_DMA covers the 32-bit addressable memory
61  * unless restricted on specific platforms (e.g. 30-bit on Raspberry Pi 4).
62  * In such case, ZONE_DMA32 covers the rest of the 32-bit addressable memory,
77  * To make optimal use of block mappings when laying out the linear
78  * mapping, round down the base of physical memory to a size that can
110 		return -ENOMEM;  in reserve_crashkernel_low()
113 	pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld MB)\n",  in reserve_crashkernel_low()
117 	crashk_low_res.end   = low_base + low_size - 1;  in reserve_crashkernel_low()
124  * reserve_crashkernel() - reserves memory for crash kernel
146 	if (ret == -ENOENT) {  in reserve_crashkernel()
156 		if (ret == -ENOENT)  in reserve_crashkernel()
187 			pr_warn("crashkernel reservation failed - memory is in use.\n");  in reserve_crashkernel()
223 	pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",  in reserve_crashkernel()
227 	 * The crashkernel memory will be removed from the kernel linear  in reserve_crashkernel()
235 	crashk_res.end = crash_base + crash_size - 1;  in reserve_crashkernel()
241  * limit. If DRAM starts above 32-bit, expand the zone to the maximum
242  * available memory, otherwise cap it at 32-bit.
254 	return min(zone_mask, memblock_end_of_DRAM() - 1) + 1;  in max_zone_phys()
314 	s64 linear_region_size = PAGE_END - _PAGE_OFFSET(vabits_actual);  in arm64_memblock_init()
317 	 * Corner case: 52-bit VA capable systems running KVM in nVHE mode may  in arm64_memblock_init()
318 	 * be limited in their ability to support a linear map that exceeds 51  in arm64_memblock_init()
321 	 * limit the kernel's linear map to 51 bits as well if we detect this  in arm64_memblock_init()
326 		pr_info("Capping linear region to 51 bits for KVM in nVHE mode on LVA capable hardware.\n");  in arm64_memblock_init()
339 	if ((memblock_end_of_DRAM() - memstart_addr) > linear_region_size)  in arm64_memblock_init()
340 		pr_warn("Memory doesn't fit in the linear mapping, VA_BITS too small\n");  in arm64_memblock_init()
344 	 * linear mapping. Take care not to clip the kernel which may be  in arm64_memblock_init()
351 		memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size,  in arm64_memblock_init()
357 	 * If we are running with a 52-bit kernel VA config on a system that  in arm64_memblock_init()
359 	 * memory in the 48-bit addressable part of the linear region, i.e.,  in arm64_memblock_init()
364 		memstart_addr -= _PAGE_OFFSET(48) - _PAGE_OFFSET(52);  in arm64_memblock_init()
369 	 * via the linear mapping.  in arm64_memblock_init()
373 		memblock_add(__pa_symbol(_text), (u64)(_end - _text));  in arm64_memblock_init()
379 		 * initrd to become inaccessible via the linear mapping.  in arm64_memblock_init()
380 		 * Otherwise, this is a no-op  in arm64_memblock_init()
383 		u64 size = PAGE_ALIGN(phys_initrd_start + phys_initrd_size) - base;  in arm64_memblock_init()
387 		 * with more memory than we can address via the linear mapping.  in arm64_memblock_init()
396 			"initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) {  in arm64_memblock_init()
410 		s64 range = linear_region_size -  in arm64_memblock_init()
414 		 * If the size of the linear region exceeds, by a sufficient  in arm64_memblock_init()
416 		 * span, randomize the linear region as well.  in arm64_memblock_init()
420 			memstart_addr -= ARM64_MEMSTART_ALIGN *  in arm64_memblock_init()
429 	memblock_reserve(__pa_symbol(_stext), _end - _stext);  in arm64_memblock_init()
438 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;  in arm64_memblock_init()