1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
7 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
8 * Copyright (C) 1996 Paul Mackerras
9 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
11 * Derived from "arch/i386/mm/init.c"
12 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
15 #include <linux/memblock.h>
16 #include <linux/highmem.h>
17 #include <linux/suspend.h>
18 #include <linux/dma-direct.h>
20 #include <asm/swiotlb.h>
21 #include <asm/machdep.h>
23 #include <asm/kasan.h>
25 #include <asm/mmzone.h>
26 #include <asm/ftrace.h>
27 #include <asm/code-patching.h>
29 #include <mm/mmu_decl.h>
31 unsigned long long memory_limit;
33 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
34 EXPORT_SYMBOL(empty_zero_page);
36 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
37 unsigned long size, pgprot_t vma_prot)
39 if (ppc_md.phys_mem_access_prot)
40 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
42 if (!page_is_ram(pfn))
43 vma_prot = pgprot_noncached(vma_prot);
47 EXPORT_SYMBOL(phys_mem_access_prot);
49 #ifdef CONFIG_MEMORY_HOTPLUG
50 static DEFINE_MUTEX(linear_mapping_mutex);
53 int memory_add_physaddr_to_nid(u64 start)
55 return hot_add_scn_to_nid(start);
59 int __weak create_section_mapping(unsigned long start, unsigned long end,
60 int nid, pgprot_t prot)
65 int __weak remove_section_mapping(unsigned long start, unsigned long end)
70 int __ref arch_create_linear_mapping(int nid, u64 start, u64 size,
71 struct mhp_params *params)
75 start = (unsigned long)__va(start);
76 mutex_lock(&linear_mapping_mutex);
77 rc = create_section_mapping(start, start + size, nid,
79 mutex_unlock(&linear_mapping_mutex);
81 pr_warn("Unable to create linear mapping for 0x%llx..0x%llx: %d\n",
82 start, start + size, rc);
88 void __ref arch_remove_linear_mapping(u64 start, u64 size)
92 /* Remove htab bolted mappings for this section of memory */
93 start = (unsigned long)__va(start);
95 mutex_lock(&linear_mapping_mutex);
96 ret = remove_section_mapping(start, start + size);
97 mutex_unlock(&linear_mapping_mutex);
99 pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n",
100 start, start + size, ret);
102 /* Ensure all vmalloc mappings are flushed in case they also
103 * hit that section of memory
108 int __ref arch_add_memory(int nid, u64 start, u64 size,
109 struct mhp_params *params)
111 unsigned long start_pfn = start >> PAGE_SHIFT;
112 unsigned long nr_pages = size >> PAGE_SHIFT;
115 rc = arch_create_linear_mapping(nid, start, size, params);
118 rc = __add_pages(nid, start_pfn, nr_pages, params);
120 arch_remove_linear_mapping(start, size);
124 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
126 unsigned long start_pfn = start >> PAGE_SHIFT;
127 unsigned long nr_pages = size >> PAGE_SHIFT;
129 __remove_pages(start_pfn, nr_pages, altmap);
130 arch_remove_linear_mapping(start, size);
135 void __init mem_topology_setup(void)
137 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
138 min_low_pfn = MEMORY_START >> PAGE_SHIFT;
139 #ifdef CONFIG_HIGHMEM
140 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
143 /* Place all memblock_regions in the same node and merge contiguous
146 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
149 void __init initmem_init(void)
154 /* mark pages that don't exist as nosave */
155 static int __init mark_nonram_nosave(void)
157 unsigned long spfn, epfn, prev = 0;
160 for_each_mem_pfn_range(i, MAX_NUMNODES, &spfn, &epfn, NULL) {
161 if (prev && prev < spfn)
162 register_nosave_region(prev, spfn);
169 #else /* CONFIG_NUMA */
170 static int __init mark_nonram_nosave(void)
179 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
180 * everything else. GFP_DMA32 page allocations automatically fall back to
183 * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
184 * generic DMA mapping code. 32-bit only devices (if not handled by an IOMMU
185 * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
188 static unsigned long max_zone_pfns[MAX_NR_ZONES];
191 * paging_init() sets up the page tables - in fact we've already done this.
193 void __init paging_init(void)
195 unsigned long long total_ram = memblock_phys_mem_size();
196 phys_addr_t top_of_ram = memblock_end_of_DRAM();
198 #ifdef CONFIG_HIGHMEM
199 unsigned long v = __fix_to_virt(FIX_KMAP_END);
200 unsigned long end = __fix_to_virt(FIX_KMAP_BEGIN);
202 for (; v < end; v += PAGE_SIZE)
203 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
205 map_kernel_page(PKMAP_BASE, 0, __pgprot(0)); /* XXX gross */
206 pkmap_page_table = virt_to_kpte(PKMAP_BASE);
207 #endif /* CONFIG_HIGHMEM */
209 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
210 (unsigned long long)top_of_ram, total_ram);
211 printk(KERN_DEBUG "Memory hole size: %ldMB\n",
212 (long int)((top_of_ram - total_ram) >> 20));
215 * Allow 30-bit DMA for very limited Broadcom wifi chips on many
218 if (IS_ENABLED(CONFIG_PPC32))
223 #ifdef CONFIG_ZONE_DMA
224 max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
225 1UL << (zone_dma_bits - PAGE_SHIFT));
227 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
228 #ifdef CONFIG_HIGHMEM
229 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
232 free_area_init(max_zone_pfns);
234 mark_nonram_nosave();
237 void __init mem_init(void)
240 * book3s is limited to 16 page sizes due to encoding this in
241 * a 4-bit field for slices.
243 BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
245 #ifdef CONFIG_SWIOTLB
247 * Some platforms (e.g. 85xx) limit DMA-able memory way below
248 * 4G. We force memblock to bottom-up mode to ensure that the
249 * memory allocated in swiotlb_init() is DMA-able.
250 * As it's the last memblock allocation, no need to reset it
253 memblock_set_bottom_up(true);
254 swiotlb_init(ppc_swiotlb_enable, ppc_swiotlb_flags);
257 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
258 set_max_mapnr(max_pfn);
264 #ifdef CONFIG_HIGHMEM
266 unsigned long pfn, highmem_mapnr;
268 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
269 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
270 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
271 struct page *page = pfn_to_page(pfn);
272 if (!memblock_is_reserved(paddr))
273 free_highmem_page(page);
276 #endif /* CONFIG_HIGHMEM */
278 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
280 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
281 * functions.... do it here for the non-smp case.
283 per_cpu(next_tlbcam_idx, smp_processor_id()) =
284 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
288 pr_info("Kernel virtual memory layout:\n");
290 pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n",
291 KASAN_SHADOW_START, KASAN_SHADOW_END);
293 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
294 #ifdef CONFIG_HIGHMEM
295 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
296 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
297 #endif /* CONFIG_HIGHMEM */
298 if (ioremap_bot != IOREMAP_TOP)
299 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
300 ioremap_bot, IOREMAP_TOP);
301 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
302 VMALLOC_START, VMALLOC_END);
304 pr_info(" * 0x%08lx..0x%08lx : modules\n",
305 MODULES_VADDR, MODULES_END);
307 #endif /* CONFIG_PPC32 */
310 void free_initmem(void)
312 ppc_md.progress = ppc_printk_progress;
314 static_branch_enable(&init_mem_is_free);
315 free_initmem_default(POISON_FREE_INITMEM);
316 ftrace_free_init_tramp();
320 * System memory should not be in /proc/iomem but various tools expect it
323 static int __init add_system_ram_resources(void)
325 phys_addr_t start, end;
328 for_each_mem_range(i, &start, &end) {
329 struct resource *res;
331 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
335 res->name = "System RAM";
338 * In memblock, end points to the first byte after
339 * the range while in resourses, end points to the
340 * last byte in the range.
343 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
344 WARN_ON(request_resource(&iomem_resource, res) < 0);
350 subsys_initcall(add_system_ram_resources);
352 #ifdef CONFIG_STRICT_DEVMEM
354 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
355 * is valid. The argument is a physical page number.
357 * Access has to be given to non-kernel-ram areas as well, these contain the
358 * PCI mmio resources as well as potential bios/acpi data regions.
360 int devmem_is_allowed(unsigned long pfn)
362 if (page_is_rtas_user_buf(pfn))
364 if (iomem_is_exclusive(PFN_PHYS(pfn)))
366 if (!page_is_ram(pfn))
370 #endif /* CONFIG_STRICT_DEVMEM */
373 * This is defined in kernel/resource.c but only powerpc needs to export it, for
374 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
376 EXPORT_SYMBOL_GPL(walk_system_ram_range);