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/machdep.h>
22 #include <asm/kasan.h>
24 #include <asm/mmzone.h>
25 #include <asm/ftrace.h>
27 #include <mm/mmu_decl.h>
29 unsigned long long memory_limit;
30 bool init_mem_is_free;
32 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
33 EXPORT_SYMBOL(empty_zero_page);
35 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
36 unsigned long size, pgprot_t vma_prot)
38 if (ppc_md.phys_mem_access_prot)
39 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
41 if (!page_is_ram(pfn))
42 vma_prot = pgprot_noncached(vma_prot);
46 EXPORT_SYMBOL(phys_mem_access_prot);
48 #ifdef CONFIG_MEMORY_HOTPLUG
49 static DEFINE_MUTEX(linear_mapping_mutex);
52 int memory_add_physaddr_to_nid(u64 start)
54 return hot_add_scn_to_nid(start);
58 int __weak create_section_mapping(unsigned long start, unsigned long end,
59 int nid, pgprot_t prot)
64 int __weak remove_section_mapping(unsigned long start, unsigned long end)
69 int __ref arch_create_linear_mapping(int nid, u64 start, u64 size,
70 struct mhp_params *params)
74 start = (unsigned long)__va(start);
75 mutex_lock(&linear_mapping_mutex);
76 rc = create_section_mapping(start, start + size, nid,
78 mutex_unlock(&linear_mapping_mutex);
80 pr_warn("Unable to create linear mapping for 0x%llx..0x%llx: %d\n",
81 start, start + size, rc);
87 void __ref arch_remove_linear_mapping(u64 start, u64 size)
91 /* Remove htab bolted mappings for this section of memory */
92 start = (unsigned long)__va(start);
94 mutex_lock(&linear_mapping_mutex);
95 ret = remove_section_mapping(start, start + size);
96 mutex_unlock(&linear_mapping_mutex);
98 pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n",
99 start, start + size, ret);
101 /* Ensure all vmalloc mappings are flushed in case they also
102 * hit that section of memory
108 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
111 static void update_end_of_memory_vars(u64 start, u64 size)
113 unsigned long end_pfn = PFN_UP(start + size);
115 if (end_pfn > max_pfn) {
117 max_low_pfn = end_pfn;
118 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
122 int __ref add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
123 struct mhp_params *params)
127 ret = __add_pages(nid, start_pfn, nr_pages, params);
131 /* update max_pfn, max_low_pfn and high_memory */
132 update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
133 nr_pages << PAGE_SHIFT);
138 int __ref arch_add_memory(int nid, u64 start, u64 size,
139 struct mhp_params *params)
141 unsigned long start_pfn = start >> PAGE_SHIFT;
142 unsigned long nr_pages = size >> PAGE_SHIFT;
145 rc = arch_create_linear_mapping(nid, start, size, params);
148 rc = add_pages(nid, start_pfn, nr_pages, params);
150 arch_remove_linear_mapping(start, size);
154 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
156 unsigned long start_pfn = start >> PAGE_SHIFT;
157 unsigned long nr_pages = size >> PAGE_SHIFT;
159 __remove_pages(start_pfn, nr_pages, altmap);
160 arch_remove_linear_mapping(start, size);
165 void __init mem_topology_setup(void)
167 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
168 min_low_pfn = MEMORY_START >> PAGE_SHIFT;
169 #ifdef CONFIG_HIGHMEM
170 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
173 /* Place all memblock_regions in the same node and merge contiguous
176 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
179 void __init initmem_init(void)
184 /* mark pages that don't exist as nosave */
185 static int __init mark_nonram_nosave(void)
187 unsigned long spfn, epfn, prev = 0;
190 for_each_mem_pfn_range(i, MAX_NUMNODES, &spfn, &epfn, NULL) {
191 if (prev && prev < spfn)
192 register_nosave_region(prev, spfn);
199 #else /* CONFIG_NUMA */
200 static int __init mark_nonram_nosave(void)
209 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
210 * everything else. GFP_DMA32 page allocations automatically fall back to
213 * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
214 * generic DMA mapping code. 32-bit only devices (if not handled by an IOMMU
215 * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
218 static unsigned long max_zone_pfns[MAX_NR_ZONES];
221 * paging_init() sets up the page tables - in fact we've already done this.
223 void __init paging_init(void)
225 unsigned long long total_ram = memblock_phys_mem_size();
226 phys_addr_t top_of_ram = memblock_end_of_DRAM();
228 #ifdef CONFIG_HIGHMEM
229 unsigned long v = __fix_to_virt(FIX_KMAP_END);
230 unsigned long end = __fix_to_virt(FIX_KMAP_BEGIN);
232 for (; v < end; v += PAGE_SIZE)
233 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
235 map_kernel_page(PKMAP_BASE, 0, __pgprot(0)); /* XXX gross */
236 pkmap_page_table = virt_to_kpte(PKMAP_BASE);
237 #endif /* CONFIG_HIGHMEM */
239 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
240 (unsigned long long)top_of_ram, total_ram);
241 printk(KERN_DEBUG "Memory hole size: %ldMB\n",
242 (long int)((top_of_ram - total_ram) >> 20));
245 * Allow 30-bit DMA for very limited Broadcom wifi chips on many
248 if (IS_ENABLED(CONFIG_PPC32))
253 #ifdef CONFIG_ZONE_DMA
254 max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
255 1UL << (zone_dma_bits - PAGE_SHIFT));
257 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
258 #ifdef CONFIG_HIGHMEM
259 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
262 free_area_init(max_zone_pfns);
264 mark_nonram_nosave();
267 void __init mem_init(void)
270 * book3s is limited to 16 page sizes due to encoding this in
271 * a 4-bit field for slices.
273 BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
275 #ifdef CONFIG_SWIOTLB
277 * Some platforms (e.g. 85xx) limit DMA-able memory way below
278 * 4G. We force memblock to bottom-up mode to ensure that the
279 * memory allocated in swiotlb_init() is DMA-able.
280 * As it's the last memblock allocation, no need to reset it
283 memblock_set_bottom_up(true);
284 if (is_secure_guest())
290 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
291 set_max_mapnr(max_pfn);
297 #ifdef CONFIG_HIGHMEM
299 unsigned long pfn, highmem_mapnr;
301 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
302 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
303 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
304 struct page *page = pfn_to_page(pfn);
305 if (!memblock_is_reserved(paddr))
306 free_highmem_page(page);
309 #endif /* CONFIG_HIGHMEM */
311 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
313 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
314 * functions.... do it here for the non-smp case.
316 per_cpu(next_tlbcam_idx, smp_processor_id()) =
317 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
321 pr_info("Kernel virtual memory layout:\n");
323 pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n",
324 KASAN_SHADOW_START, KASAN_SHADOW_END);
326 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
327 #ifdef CONFIG_HIGHMEM
328 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
329 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
330 #endif /* CONFIG_HIGHMEM */
331 if (ioremap_bot != IOREMAP_TOP)
332 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
333 ioremap_bot, IOREMAP_TOP);
334 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
335 VMALLOC_START, VMALLOC_END);
337 pr_info(" * 0x%08lx..0x%08lx : modules\n",
338 MODULES_VADDR, MODULES_END);
340 #endif /* CONFIG_PPC32 */
343 void free_initmem(void)
345 ppc_md.progress = ppc_printk_progress;
347 init_mem_is_free = true;
348 free_initmem_default(POISON_FREE_INITMEM);
349 ftrace_free_init_tramp();
353 * System memory should not be in /proc/iomem but various tools expect it
356 static int __init add_system_ram_resources(void)
358 phys_addr_t start, end;
361 for_each_mem_range(i, &start, &end) {
362 struct resource *res;
364 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
368 res->name = "System RAM";
371 * In memblock, end points to the first byte after
372 * the range while in resourses, end points to the
373 * last byte in the range.
376 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
377 WARN_ON(request_resource(&iomem_resource, res) < 0);
383 subsys_initcall(add_system_ram_resources);
385 #ifdef CONFIG_STRICT_DEVMEM
387 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
388 * is valid. The argument is a physical page number.
390 * Access has to be given to non-kernel-ram areas as well, these contain the
391 * PCI mmio resources as well as potential bios/acpi data regions.
393 int devmem_is_allowed(unsigned long pfn)
395 if (page_is_rtas_user_buf(pfn))
397 if (iomem_is_exclusive(PFN_PHYS(pfn)))
399 if (!page_is_ram(pfn))
403 #endif /* CONFIG_STRICT_DEVMEM */
406 * This is defined in kernel/resource.c but only powerpc needs to export it, for
407 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
409 EXPORT_SYMBOL_GPL(walk_system_ram_range);