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/export.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/string.h>
20 #include <linux/gfp.h>
21 #include <linux/types.h>
23 #include <linux/stddef.h>
24 #include <linux/init.h>
25 #include <linux/memblock.h>
26 #include <linux/highmem.h>
27 #include <linux/initrd.h>
28 #include <linux/pagemap.h>
29 #include <linux/suspend.h>
30 #include <linux/hugetlb.h>
31 #include <linux/slab.h>
32 #include <linux/vmalloc.h>
33 #include <linux/memremap.h>
34 #include <linux/dma-direct.h>
36 #include <asm/pgalloc.h>
39 #include <asm/mmu_context.h>
40 #include <asm/pgtable.h>
43 #include <asm/machdep.h>
44 #include <asm/btext.h>
46 #include <asm/sections.h>
47 #include <asm/sparsemem.h>
49 #include <asm/fixmap.h>
50 #include <asm/swiotlb.h>
53 #include <mm/mmu_decl.h>
55 #ifndef CPU_FTR_COHERENT_ICACHE
56 #define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */
57 #define CPU_FTR_NOEXECUTE 0
60 unsigned long long memory_limit;
61 bool init_mem_is_free;
65 EXPORT_SYMBOL(kmap_pte);
67 EXPORT_SYMBOL(kmap_prot);
69 static inline pte_t *virt_to_kpte(unsigned long vaddr)
71 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
72 vaddr), vaddr), vaddr);
76 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
77 unsigned long size, pgprot_t vma_prot)
79 if (ppc_md.phys_mem_access_prot)
80 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
82 if (!page_is_ram(pfn))
83 vma_prot = pgprot_noncached(vma_prot);
87 EXPORT_SYMBOL(phys_mem_access_prot);
89 #ifdef CONFIG_MEMORY_HOTPLUG
92 int memory_add_physaddr_to_nid(u64 start)
94 return hot_add_scn_to_nid(start);
98 int __weak create_section_mapping(unsigned long start, unsigned long end, int nid)
103 int __weak remove_section_mapping(unsigned long start, unsigned long end)
108 int __ref arch_add_memory(int nid, u64 start, u64 size,
109 struct mhp_restrictions *restrictions)
111 unsigned long start_pfn = start >> PAGE_SHIFT;
112 unsigned long nr_pages = size >> PAGE_SHIFT;
115 resize_hpt_for_hotplug(memblock_phys_mem_size());
117 start = (unsigned long)__va(start);
118 rc = create_section_mapping(start, start + size, nid);
120 pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
121 start, start + size, rc);
124 flush_dcache_range(start, start + size);
126 return __add_pages(nid, start_pfn, nr_pages, restrictions);
129 void __ref arch_remove_memory(int nid, u64 start, u64 size,
130 struct vmem_altmap *altmap)
132 unsigned long start_pfn = start >> PAGE_SHIFT;
133 unsigned long nr_pages = size >> PAGE_SHIFT;
134 struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
137 __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
139 /* Remove htab bolted mappings for this section of memory */
140 start = (unsigned long)__va(start);
141 flush_dcache_range(start, start + size);
142 ret = remove_section_mapping(start, start + size);
145 /* Ensure all vmalloc mappings are flushed in case they also
146 * hit that section of memory
150 if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
151 pr_warn("Hash collision while resizing HPT\n");
155 #ifndef CONFIG_NEED_MULTIPLE_NODES
156 void __init mem_topology_setup(void)
158 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
159 min_low_pfn = MEMORY_START >> PAGE_SHIFT;
160 #ifdef CONFIG_HIGHMEM
161 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
164 /* Place all memblock_regions in the same node and merge contiguous
167 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
170 void __init initmem_init(void)
172 /* XXX need to clip this if using highmem? */
173 sparse_memory_present_with_active_regions(0);
177 /* mark pages that don't exist as nosave */
178 static int __init mark_nonram_nosave(void)
180 struct memblock_region *reg, *prev = NULL;
182 for_each_memblock(memory, reg) {
184 memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
185 register_nosave_region(memblock_region_memory_end_pfn(prev),
186 memblock_region_memory_base_pfn(reg));
191 #else /* CONFIG_NEED_MULTIPLE_NODES */
192 static int __init mark_nonram_nosave(void)
201 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
202 * everything else. GFP_DMA32 page allocations automatically fall back to
205 * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
206 * generic DMA mapping code. 32-bit only devices (if not handled by an IOMMU
207 * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
210 static unsigned long max_zone_pfns[MAX_NR_ZONES];
213 * paging_init() sets up the page tables - in fact we've already done this.
215 void __init paging_init(void)
217 unsigned long long total_ram = memblock_phys_mem_size();
218 phys_addr_t top_of_ram = memblock_end_of_DRAM();
221 unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
222 unsigned long end = __fix_to_virt(FIX_HOLE);
224 for (; v < end; v += PAGE_SIZE)
225 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
228 #ifdef CONFIG_HIGHMEM
229 map_kernel_page(PKMAP_BASE, 0, __pgprot(0)); /* XXX gross */
230 pkmap_page_table = virt_to_kpte(PKMAP_BASE);
232 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
233 kmap_prot = PAGE_KERNEL;
234 #endif /* CONFIG_HIGHMEM */
236 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
237 (unsigned long long)top_of_ram, total_ram);
238 printk(KERN_DEBUG "Memory hole size: %ldMB\n",
239 (long int)((top_of_ram - total_ram) >> 20));
242 * Allow 30-bit DMA for very limited Broadcom wifi chips on many
245 if (IS_ENABLED(CONFIG_PPC32))
250 #ifdef CONFIG_ZONE_DMA
251 max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
252 1UL << (zone_dma_bits - PAGE_SHIFT));
254 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
255 #ifdef CONFIG_HIGHMEM
256 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
259 free_area_init_nodes(max_zone_pfns);
261 mark_nonram_nosave();
264 void __init mem_init(void)
267 * book3s is limited to 16 page sizes due to encoding this in
268 * a 4-bit field for slices.
270 BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
272 #ifdef CONFIG_SWIOTLB
276 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
277 set_max_mapnr(max_pfn);
280 #ifdef CONFIG_HIGHMEM
282 unsigned long pfn, highmem_mapnr;
284 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
285 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
286 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
287 struct page *page = pfn_to_page(pfn);
288 if (!memblock_is_reserved(paddr))
289 free_highmem_page(page);
292 #endif /* CONFIG_HIGHMEM */
294 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
296 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
297 * functions.... do it here for the non-smp case.
299 per_cpu(next_tlbcam_idx, smp_processor_id()) =
300 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
303 mem_init_print_info(NULL);
305 pr_info("Kernel virtual memory layout:\n");
307 pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n",
308 KASAN_SHADOW_START, KASAN_SHADOW_END);
310 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
311 #ifdef CONFIG_HIGHMEM
312 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
313 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
314 #endif /* CONFIG_HIGHMEM */
315 if (ioremap_bot != IOREMAP_TOP)
316 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
317 ioremap_bot, IOREMAP_TOP);
318 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
319 VMALLOC_START, VMALLOC_END);
320 #endif /* CONFIG_PPC32 */
323 void free_initmem(void)
325 ppc_md.progress = ppc_printk_progress;
327 init_mem_is_free = true;
328 free_initmem_default(POISON_FREE_INITMEM);
332 * This is called when a page has been modified by the kernel.
333 * It just marks the page as not i-cache clean. We do the i-cache
334 * flush later when the page is given to a user process, if necessary.
336 void flush_dcache_page(struct page *page)
338 if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
340 /* avoid an atomic op if possible */
341 if (test_bit(PG_arch_1, &page->flags))
342 clear_bit(PG_arch_1, &page->flags);
344 EXPORT_SYMBOL(flush_dcache_page);
346 void flush_dcache_icache_page(struct page *page)
348 #ifdef CONFIG_HUGETLB_PAGE
349 if (PageCompound(page)) {
350 flush_dcache_icache_hugepage(page);
354 #if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64)
355 /* On 8xx there is no need to kmap since highmem is not supported */
356 __flush_dcache_icache(page_address(page));
358 if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
359 void *start = kmap_atomic(page);
360 __flush_dcache_icache(start);
361 kunmap_atomic(start);
363 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
367 EXPORT_SYMBOL(flush_dcache_icache_page);
369 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
374 * We shouldn't have to do this, but some versions of glibc
375 * require it (ld.so assumes zero filled pages are icache clean)
378 flush_dcache_page(pg);
380 EXPORT_SYMBOL(clear_user_page);
382 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
385 copy_page(vto, vfrom);
388 * We should be able to use the following optimisation, however
389 * there are two problems.
390 * Firstly a bug in some versions of binutils meant PLT sections
391 * were not marked executable.
392 * Secondly the first word in the GOT section is blrl, used
393 * to establish the GOT address. Until recently the GOT was
394 * not marked executable.
398 if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
402 flush_dcache_page(pg);
405 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
406 unsigned long addr, int len)
410 maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
411 flush_icache_range(maddr, maddr + len);
414 EXPORT_SYMBOL(flush_icache_user_range);
417 * System memory should not be in /proc/iomem but various tools expect it
420 static int __init add_system_ram_resources(void)
422 struct memblock_region *reg;
424 for_each_memblock(memory, reg) {
425 struct resource *res;
426 unsigned long base = reg->base;
427 unsigned long size = reg->size;
429 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
433 res->name = "System RAM";
435 res->end = base + size - 1;
436 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
437 WARN_ON(request_resource(&iomem_resource, res) < 0);
443 subsys_initcall(add_system_ram_resources);
445 #ifdef CONFIG_STRICT_DEVMEM
447 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
448 * is valid. The argument is a physical page number.
450 * Access has to be given to non-kernel-ram areas as well, these contain the
451 * PCI mmio resources as well as potential bios/acpi data regions.
453 int devmem_is_allowed(unsigned long pfn)
455 if (page_is_rtas_user_buf(pfn))
457 if (iomem_is_exclusive(PFN_PHYS(pfn)))
459 if (!page_is_ram(pfn))
463 #endif /* CONFIG_STRICT_DEVMEM */
466 * This is defined in kernel/resource.c but only powerpc needs to export it, for
467 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
469 EXPORT_SYMBOL_GPL(walk_system_ram_range);