| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * address space "slices" (meta-segments) support |
| * |
| * Copyright (C) 2007 Benjamin Herrenschmidt, IBM Corporation. |
| * |
| * Based on hugetlb implementation |
| * |
| * Copyright (C) 2003 David Gibson, IBM Corporation. |
| */ |
| |
| #undef DEBUG |
| |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/err.h> |
| #include <linux/spinlock.h> |
| #include <linux/export.h> |
| #include <linux/hugetlb.h> |
| #include <linux/sched/mm.h> |
| #include <linux/security.h> |
| #include <asm/mman.h> |
| #include <asm/mmu.h> |
| #include <asm/copro.h> |
| #include <asm/hugetlb.h> |
| #include <asm/mmu_context.h> |
| |
| static DEFINE_SPINLOCK(slice_convert_lock); |
| |
| #ifdef DEBUG |
| int _slice_debug = 1; |
| |
| static void slice_print_mask(const char *label, const struct slice_mask *mask) |
| { |
| if (!_slice_debug) |
| return; |
| pr_devel("%s low_slice: %*pbl\n", label, |
| (int)SLICE_NUM_LOW, &mask->low_slices); |
| pr_devel("%s high_slice: %*pbl\n", label, |
| (int)SLICE_NUM_HIGH, mask->high_slices); |
| } |
| |
| #define slice_dbg(fmt...) do { if (_slice_debug) pr_devel(fmt); } while (0) |
| |
| #else |
| |
| static void slice_print_mask(const char *label, const struct slice_mask *mask) {} |
| #define slice_dbg(fmt...) |
| |
| #endif |
| |
| static inline notrace bool slice_addr_is_low(unsigned long addr) |
| { |
| u64 tmp = (u64)addr; |
| |
| return tmp < SLICE_LOW_TOP; |
| } |
| |
| static void slice_range_to_mask(unsigned long start, unsigned long len, |
| struct slice_mask *ret) |
| { |
| unsigned long end = start + len - 1; |
| |
| ret->low_slices = 0; |
| if (SLICE_NUM_HIGH) |
| bitmap_zero(ret->high_slices, SLICE_NUM_HIGH); |
| |
| if (slice_addr_is_low(start)) { |
| unsigned long mend = min(end, |
| (unsigned long)(SLICE_LOW_TOP - 1)); |
| |
| ret->low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1)) |
| - (1u << GET_LOW_SLICE_INDEX(start)); |
| } |
| |
| if (SLICE_NUM_HIGH && !slice_addr_is_low(end)) { |
| unsigned long start_index = GET_HIGH_SLICE_INDEX(start); |
| unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT)); |
| unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index; |
| |
| bitmap_set(ret->high_slices, start_index, count); |
| } |
| } |
| |
| static int slice_area_is_free(struct mm_struct *mm, unsigned long addr, |
| unsigned long len) |
| { |
| struct vm_area_struct *vma; |
| |
| if ((mm_ctx_slb_addr_limit(&mm->context) - len) < addr) |
| return 0; |
| vma = find_vma(mm, addr); |
| return (!vma || (addr + len) <= vm_start_gap(vma)); |
| } |
| |
| static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice) |
| { |
| return !slice_area_is_free(mm, slice << SLICE_LOW_SHIFT, |
| 1ul << SLICE_LOW_SHIFT); |
| } |
| |
| static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice) |
| { |
| unsigned long start = slice << SLICE_HIGH_SHIFT; |
| unsigned long end = start + (1ul << SLICE_HIGH_SHIFT); |
| |
| /* Hack, so that each addresses is controlled by exactly one |
| * of the high or low area bitmaps, the first high area starts |
| * at 4GB, not 0 */ |
| if (start == 0) |
| start = (unsigned long)SLICE_LOW_TOP; |
| |
| return !slice_area_is_free(mm, start, end - start); |
| } |
| |
| static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret, |
| unsigned long high_limit) |
| { |
| unsigned long i; |
| |
| ret->low_slices = 0; |
| if (SLICE_NUM_HIGH) |
| bitmap_zero(ret->high_slices, SLICE_NUM_HIGH); |
| |
| for (i = 0; i < SLICE_NUM_LOW; i++) |
| if (!slice_low_has_vma(mm, i)) |
| ret->low_slices |= 1u << i; |
| |
| if (slice_addr_is_low(high_limit - 1)) |
| return; |
| |
| for (i = 0; i < GET_HIGH_SLICE_INDEX(high_limit); i++) |
| if (!slice_high_has_vma(mm, i)) |
| __set_bit(i, ret->high_slices); |
| } |
| |
| static bool slice_check_range_fits(struct mm_struct *mm, |
| const struct slice_mask *available, |
| unsigned long start, unsigned long len) |
| { |
| unsigned long end = start + len - 1; |
| u64 low_slices = 0; |
| |
| if (slice_addr_is_low(start)) { |
| unsigned long mend = min(end, |
| (unsigned long)(SLICE_LOW_TOP - 1)); |
| |
| low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1)) |
| - (1u << GET_LOW_SLICE_INDEX(start)); |
| } |
| if ((low_slices & available->low_slices) != low_slices) |
| return false; |
| |
| if (SLICE_NUM_HIGH && !slice_addr_is_low(end)) { |
| unsigned long start_index = GET_HIGH_SLICE_INDEX(start); |
| unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT)); |
| unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index; |
| unsigned long i; |
| |
| for (i = start_index; i < start_index + count; i++) { |
| if (!test_bit(i, available->high_slices)) |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| static void slice_flush_segments(void *parm) |
| { |
| #ifdef CONFIG_PPC64 |
| struct mm_struct *mm = parm; |
| unsigned long flags; |
| |
| if (mm != current->active_mm) |
| return; |
| |
| copy_mm_to_paca(current->active_mm); |
| |
| local_irq_save(flags); |
| slb_flush_and_restore_bolted(); |
| local_irq_restore(flags); |
| #endif |
| } |
| |
| static void slice_convert(struct mm_struct *mm, |
| const struct slice_mask *mask, int psize) |
| { |
| int index, mask_index; |
| /* Write the new slice psize bits */ |
| unsigned char *hpsizes, *lpsizes; |
| struct slice_mask *psize_mask, *old_mask; |
| unsigned long i, flags; |
| int old_psize; |
| |
| slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize); |
| slice_print_mask(" mask", mask); |
| |
| psize_mask = slice_mask_for_size(&mm->context, psize); |
| |
| /* We need to use a spinlock here to protect against |
| * concurrent 64k -> 4k demotion ... |
| */ |
| spin_lock_irqsave(&slice_convert_lock, flags); |
| |
| lpsizes = mm_ctx_low_slices(&mm->context); |
| for (i = 0; i < SLICE_NUM_LOW; i++) { |
| if (!(mask->low_slices & (1u << i))) |
| continue; |
| |
| mask_index = i & 0x1; |
| index = i >> 1; |
| |
| /* Update the slice_mask */ |
| old_psize = (lpsizes[index] >> (mask_index * 4)) & 0xf; |
| old_mask = slice_mask_for_size(&mm->context, old_psize); |
| old_mask->low_slices &= ~(1u << i); |
| psize_mask->low_slices |= 1u << i; |
| |
| /* Update the sizes array */ |
| lpsizes[index] = (lpsizes[index] & ~(0xf << (mask_index * 4))) | |
| (((unsigned long)psize) << (mask_index * 4)); |
| } |
| |
| hpsizes = mm_ctx_high_slices(&mm->context); |
| for (i = 0; i < GET_HIGH_SLICE_INDEX(mm_ctx_slb_addr_limit(&mm->context)); i++) { |
| if (!test_bit(i, mask->high_slices)) |
| continue; |
| |
| mask_index = i & 0x1; |
| index = i >> 1; |
| |
| /* Update the slice_mask */ |
| old_psize = (hpsizes[index] >> (mask_index * 4)) & 0xf; |
| old_mask = slice_mask_for_size(&mm->context, old_psize); |
| __clear_bit(i, old_mask->high_slices); |
| __set_bit(i, psize_mask->high_slices); |
| |
| /* Update the sizes array */ |
| hpsizes[index] = (hpsizes[index] & ~(0xf << (mask_index * 4))) | |
| (((unsigned long)psize) << (mask_index * 4)); |
| } |
| |
| slice_dbg(" lsps=%lx, hsps=%lx\n", |
| (unsigned long)mm_ctx_low_slices(&mm->context), |
| (unsigned long)mm_ctx_high_slices(&mm->context)); |
| |
| spin_unlock_irqrestore(&slice_convert_lock, flags); |
| |
| copro_flush_all_slbs(mm); |
| } |
| |
| /* |
| * Compute which slice addr is part of; |
| * set *boundary_addr to the start or end boundary of that slice |
| * (depending on 'end' parameter); |
| * return boolean indicating if the slice is marked as available in the |
| * 'available' slice_mark. |
| */ |
| static bool slice_scan_available(unsigned long addr, |
| const struct slice_mask *available, |
| int end, unsigned long *boundary_addr) |
| { |
| unsigned long slice; |
| if (slice_addr_is_low(addr)) { |
| slice = GET_LOW_SLICE_INDEX(addr); |
| *boundary_addr = (slice + end) << SLICE_LOW_SHIFT; |
| return !!(available->low_slices & (1u << slice)); |
| } else { |
| slice = GET_HIGH_SLICE_INDEX(addr); |
| *boundary_addr = (slice + end) ? |
| ((slice + end) << SLICE_HIGH_SHIFT) : SLICE_LOW_TOP; |
| return !!test_bit(slice, available->high_slices); |
| } |
| } |
| |
| static unsigned long slice_find_area_bottomup(struct mm_struct *mm, |
| unsigned long addr, unsigned long len, |
| const struct slice_mask *available, |
| int psize, unsigned long high_limit) |
| { |
| int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); |
| unsigned long found, next_end; |
| struct vm_unmapped_area_info info; |
| |
| info.flags = 0; |
| info.length = len; |
| info.align_mask = PAGE_MASK & ((1ul << pshift) - 1); |
| info.align_offset = 0; |
| /* |
| * Check till the allow max value for this mmap request |
| */ |
| while (addr < high_limit) { |
| info.low_limit = addr; |
| if (!slice_scan_available(addr, available, 1, &addr)) |
| continue; |
| |
| next_slice: |
| /* |
| * At this point [info.low_limit; addr) covers |
| * available slices only and ends at a slice boundary. |
| * Check if we need to reduce the range, or if we can |
| * extend it to cover the next available slice. |
| */ |
| if (addr >= high_limit) |
| addr = high_limit; |
| else if (slice_scan_available(addr, available, 1, &next_end)) { |
| addr = next_end; |
| goto next_slice; |
| } |
| info.high_limit = addr; |
| |
| found = vm_unmapped_area(&info); |
| if (!(found & ~PAGE_MASK)) |
| return found; |
| } |
| |
| return -ENOMEM; |
| } |
| |
| static unsigned long slice_find_area_topdown(struct mm_struct *mm, |
| unsigned long addr, unsigned long len, |
| const struct slice_mask *available, |
| int psize, unsigned long high_limit) |
| { |
| int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); |
| unsigned long found, prev; |
| struct vm_unmapped_area_info info; |
| unsigned long min_addr = max(PAGE_SIZE, mmap_min_addr); |
| |
| info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
| info.length = len; |
| info.align_mask = PAGE_MASK & ((1ul << pshift) - 1); |
| info.align_offset = 0; |
| /* |
| * If we are trying to allocate above DEFAULT_MAP_WINDOW |
| * Add the different to the mmap_base. |
| * Only for that request for which high_limit is above |
| * DEFAULT_MAP_WINDOW we should apply this. |
| */ |
| if (high_limit > DEFAULT_MAP_WINDOW) |
| addr += mm_ctx_slb_addr_limit(&mm->context) - DEFAULT_MAP_WINDOW; |
| |
| while (addr > min_addr) { |
| info.high_limit = addr; |
| if (!slice_scan_available(addr - 1, available, 0, &addr)) |
| continue; |
| |
| prev_slice: |
| /* |
| * At this point [addr; info.high_limit) covers |
| * available slices only and starts at a slice boundary. |
| * Check if we need to reduce the range, or if we can |
| * extend it to cover the previous available slice. |
| */ |
| if (addr < min_addr) |
| addr = min_addr; |
| else if (slice_scan_available(addr - 1, available, 0, &prev)) { |
| addr = prev; |
| goto prev_slice; |
| } |
| info.low_limit = addr; |
| |
| found = vm_unmapped_area(&info); |
| if (!(found & ~PAGE_MASK)) |
| return found; |
| } |
| |
| /* |
| * A failed mmap() very likely causes application failure, |
| * so fall back to the bottom-up function here. This scenario |
| * can happen with large stack limits and large mmap() |
| * allocations. |
| */ |
| return slice_find_area_bottomup(mm, TASK_UNMAPPED_BASE, len, available, psize, high_limit); |
| } |
| |
| |
| static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len, |
| const struct slice_mask *mask, int psize, |
| int topdown, unsigned long high_limit) |
| { |
| if (topdown) |
| return slice_find_area_topdown(mm, mm->mmap_base, len, mask, psize, high_limit); |
| else |
| return slice_find_area_bottomup(mm, mm->mmap_base, len, mask, psize, high_limit); |
| } |
| |
| static inline void slice_copy_mask(struct slice_mask *dst, |
| const struct slice_mask *src) |
| { |
| dst->low_slices = src->low_slices; |
| if (!SLICE_NUM_HIGH) |
| return; |
| bitmap_copy(dst->high_slices, src->high_slices, SLICE_NUM_HIGH); |
| } |
| |
| static inline void slice_or_mask(struct slice_mask *dst, |
| const struct slice_mask *src1, |
| const struct slice_mask *src2) |
| { |
| dst->low_slices = src1->low_slices | src2->low_slices; |
| if (!SLICE_NUM_HIGH) |
| return; |
| bitmap_or(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH); |
| } |
| |
| static inline void slice_andnot_mask(struct slice_mask *dst, |
| const struct slice_mask *src1, |
| const struct slice_mask *src2) |
| { |
| dst->low_slices = src1->low_slices & ~src2->low_slices; |
| if (!SLICE_NUM_HIGH) |
| return; |
| bitmap_andnot(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH); |
| } |
| |
| #ifdef CONFIG_PPC_64K_PAGES |
| #define MMU_PAGE_BASE MMU_PAGE_64K |
| #else |
| #define MMU_PAGE_BASE MMU_PAGE_4K |
| #endif |
| |
| unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len, |
| unsigned long flags, unsigned int psize, |
| int topdown) |
| { |
| struct slice_mask good_mask; |
| struct slice_mask potential_mask; |
| const struct slice_mask *maskp; |
| const struct slice_mask *compat_maskp = NULL; |
| int fixed = (flags & MAP_FIXED); |
| int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); |
| unsigned long page_size = 1UL << pshift; |
| struct mm_struct *mm = current->mm; |
| unsigned long newaddr; |
| unsigned long high_limit; |
| |
| high_limit = DEFAULT_MAP_WINDOW; |
| if (addr >= high_limit || (fixed && (addr + len > high_limit))) |
| high_limit = TASK_SIZE; |
| |
| if (len > high_limit) |
| return -ENOMEM; |
| if (len & (page_size - 1)) |
| return -EINVAL; |
| if (fixed) { |
| if (addr & (page_size - 1)) |
| return -EINVAL; |
| if (addr > high_limit - len) |
| return -ENOMEM; |
| } |
| |
| if (high_limit > mm_ctx_slb_addr_limit(&mm->context)) { |
| /* |
| * Increasing the slb_addr_limit does not require |
| * slice mask cache to be recalculated because it should |
| * be already initialised beyond the old address limit. |
| */ |
| mm_ctx_set_slb_addr_limit(&mm->context, high_limit); |
| |
| on_each_cpu(slice_flush_segments, mm, 1); |
| } |
| |
| /* Sanity checks */ |
| BUG_ON(mm->task_size == 0); |
| BUG_ON(mm_ctx_slb_addr_limit(&mm->context) == 0); |
| VM_BUG_ON(radix_enabled()); |
| |
| slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize); |
| slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d\n", |
| addr, len, flags, topdown); |
| |
| /* If hint, make sure it matches our alignment restrictions */ |
| if (!fixed && addr) { |
| addr = ALIGN(addr, page_size); |
| slice_dbg(" aligned addr=%lx\n", addr); |
| /* Ignore hint if it's too large or overlaps a VMA */ |
| if (addr > high_limit - len || addr < mmap_min_addr || |
| !slice_area_is_free(mm, addr, len)) |
| addr = 0; |
| } |
| |
| /* First make up a "good" mask of slices that have the right size |
| * already |
| */ |
| maskp = slice_mask_for_size(&mm->context, psize); |
| |
| /* |
| * Here "good" means slices that are already the right page size, |
| * "compat" means slices that have a compatible page size (i.e. |
| * 4k in a 64k pagesize kernel), and "free" means slices without |
| * any VMAs. |
| * |
| * If MAP_FIXED: |
| * check if fits in good | compat => OK |
| * check if fits in good | compat | free => convert free |
| * else bad |
| * If have hint: |
| * check if hint fits in good => OK |
| * check if hint fits in good | free => convert free |
| * Otherwise: |
| * search in good, found => OK |
| * search in good | free, found => convert free |
| * search in good | compat | free, found => convert free. |
| */ |
| |
| /* |
| * If we support combo pages, we can allow 64k pages in 4k slices |
| * The mask copies could be avoided in most cases here if we had |
| * a pointer to good mask for the next code to use. |
| */ |
| if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) { |
| compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_4K); |
| if (fixed) |
| slice_or_mask(&good_mask, maskp, compat_maskp); |
| else |
| slice_copy_mask(&good_mask, maskp); |
| } else { |
| slice_copy_mask(&good_mask, maskp); |
| } |
| |
| slice_print_mask(" good_mask", &good_mask); |
| if (compat_maskp) |
| slice_print_mask(" compat_mask", compat_maskp); |
| |
| /* First check hint if it's valid or if we have MAP_FIXED */ |
| if (addr != 0 || fixed) { |
| /* Check if we fit in the good mask. If we do, we just return, |
| * nothing else to do |
| */ |
| if (slice_check_range_fits(mm, &good_mask, addr, len)) { |
| slice_dbg(" fits good !\n"); |
| newaddr = addr; |
| goto return_addr; |
| } |
| } else { |
| /* Now let's see if we can find something in the existing |
| * slices for that size |
| */ |
| newaddr = slice_find_area(mm, len, &good_mask, |
| psize, topdown, high_limit); |
| if (newaddr != -ENOMEM) { |
| /* Found within the good mask, we don't have to setup, |
| * we thus return directly |
| */ |
| slice_dbg(" found area at 0x%lx\n", newaddr); |
| goto return_addr; |
| } |
| } |
| /* |
| * We don't fit in the good mask, check what other slices are |
| * empty and thus can be converted |
| */ |
| slice_mask_for_free(mm, &potential_mask, high_limit); |
| slice_or_mask(&potential_mask, &potential_mask, &good_mask); |
| slice_print_mask(" potential", &potential_mask); |
| |
| if (addr != 0 || fixed) { |
| if (slice_check_range_fits(mm, &potential_mask, addr, len)) { |
| slice_dbg(" fits potential !\n"); |
| newaddr = addr; |
| goto convert; |
| } |
| } |
| |
| /* If we have MAP_FIXED and failed the above steps, then error out */ |
| if (fixed) |
| return -EBUSY; |
| |
| slice_dbg(" search...\n"); |
| |
| /* If we had a hint that didn't work out, see if we can fit |
| * anywhere in the good area. |
| */ |
| if (addr) { |
| newaddr = slice_find_area(mm, len, &good_mask, |
| psize, topdown, high_limit); |
| if (newaddr != -ENOMEM) { |
| slice_dbg(" found area at 0x%lx\n", newaddr); |
| goto return_addr; |
| } |
| } |
| |
| /* Now let's see if we can find something in the existing slices |
| * for that size plus free slices |
| */ |
| newaddr = slice_find_area(mm, len, &potential_mask, |
| psize, topdown, high_limit); |
| |
| if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && newaddr == -ENOMEM && |
| psize == MMU_PAGE_64K) { |
| /* retry the search with 4k-page slices included */ |
| slice_or_mask(&potential_mask, &potential_mask, compat_maskp); |
| newaddr = slice_find_area(mm, len, &potential_mask, |
| psize, topdown, high_limit); |
| } |
| |
| if (newaddr == -ENOMEM) |
| return -ENOMEM; |
| |
| slice_range_to_mask(newaddr, len, &potential_mask); |
| slice_dbg(" found potential area at 0x%lx\n", newaddr); |
| slice_print_mask(" mask", &potential_mask); |
| |
| convert: |
| /* |
| * Try to allocate the context before we do slice convert |
| * so that we handle the context allocation failure gracefully. |
| */ |
| if (need_extra_context(mm, newaddr)) { |
| if (alloc_extended_context(mm, newaddr) < 0) |
| return -ENOMEM; |
| } |
| |
| slice_andnot_mask(&potential_mask, &potential_mask, &good_mask); |
| if (compat_maskp && !fixed) |
| slice_andnot_mask(&potential_mask, &potential_mask, compat_maskp); |
| if (potential_mask.low_slices || |
| (SLICE_NUM_HIGH && |
| !bitmap_empty(potential_mask.high_slices, SLICE_NUM_HIGH))) { |
| slice_convert(mm, &potential_mask, psize); |
| if (psize > MMU_PAGE_BASE) |
| on_each_cpu(slice_flush_segments, mm, 1); |
| } |
| return newaddr; |
| |
| return_addr: |
| if (need_extra_context(mm, newaddr)) { |
| if (alloc_extended_context(mm, newaddr) < 0) |
| return -ENOMEM; |
| } |
| return newaddr; |
| } |
| EXPORT_SYMBOL_GPL(slice_get_unmapped_area); |
| |
| unsigned long arch_get_unmapped_area(struct file *filp, |
| unsigned long addr, |
| unsigned long len, |
| unsigned long pgoff, |
| unsigned long flags) |
| { |
| if (radix_enabled()) |
| return generic_get_unmapped_area(filp, addr, len, pgoff, flags); |
| |
| return slice_get_unmapped_area(addr, len, flags, |
| mm_ctx_user_psize(¤t->mm->context), 0); |
| } |
| |
| unsigned long arch_get_unmapped_area_topdown(struct file *filp, |
| const unsigned long addr0, |
| const unsigned long len, |
| const unsigned long pgoff, |
| const unsigned long flags) |
| { |
| if (radix_enabled()) |
| return generic_get_unmapped_area_topdown(filp, addr0, len, pgoff, flags); |
| |
| return slice_get_unmapped_area(addr0, len, flags, |
| mm_ctx_user_psize(¤t->mm->context), 1); |
| } |
| |
| unsigned int notrace get_slice_psize(struct mm_struct *mm, unsigned long addr) |
| { |
| unsigned char *psizes; |
| int index, mask_index; |
| |
| VM_BUG_ON(radix_enabled()); |
| |
| if (slice_addr_is_low(addr)) { |
| psizes = mm_ctx_low_slices(&mm->context); |
| index = GET_LOW_SLICE_INDEX(addr); |
| } else { |
| psizes = mm_ctx_high_slices(&mm->context); |
| index = GET_HIGH_SLICE_INDEX(addr); |
| } |
| mask_index = index & 0x1; |
| return (psizes[index >> 1] >> (mask_index * 4)) & 0xf; |
| } |
| EXPORT_SYMBOL_GPL(get_slice_psize); |
| |
| void slice_init_new_context_exec(struct mm_struct *mm) |
| { |
| unsigned char *hpsizes, *lpsizes; |
| struct slice_mask *mask; |
| unsigned int psize = mmu_virtual_psize; |
| |
| slice_dbg("slice_init_new_context_exec(mm=%p)\n", mm); |
| |
| /* |
| * In the case of exec, use the default limit. In the |
| * case of fork it is just inherited from the mm being |
| * duplicated. |
| */ |
| mm_ctx_set_slb_addr_limit(&mm->context, SLB_ADDR_LIMIT_DEFAULT); |
| mm_ctx_set_user_psize(&mm->context, psize); |
| |
| /* |
| * Set all slice psizes to the default. |
| */ |
| lpsizes = mm_ctx_low_slices(&mm->context); |
| memset(lpsizes, (psize << 4) | psize, SLICE_NUM_LOW >> 1); |
| |
| hpsizes = mm_ctx_high_slices(&mm->context); |
| memset(hpsizes, (psize << 4) | psize, SLICE_NUM_HIGH >> 1); |
| |
| /* |
| * Slice mask cache starts zeroed, fill the default size cache. |
| */ |
| mask = slice_mask_for_size(&mm->context, psize); |
| mask->low_slices = ~0UL; |
| if (SLICE_NUM_HIGH) |
| bitmap_fill(mask->high_slices, SLICE_NUM_HIGH); |
| } |
| |
| void slice_setup_new_exec(void) |
| { |
| struct mm_struct *mm = current->mm; |
| |
| slice_dbg("slice_setup_new_exec(mm=%p)\n", mm); |
| |
| if (!is_32bit_task()) |
| return; |
| |
| mm_ctx_set_slb_addr_limit(&mm->context, DEFAULT_MAP_WINDOW); |
| } |
| |
| void slice_set_range_psize(struct mm_struct *mm, unsigned long start, |
| unsigned long len, unsigned int psize) |
| { |
| struct slice_mask mask; |
| |
| VM_BUG_ON(radix_enabled()); |
| |
| slice_range_to_mask(start, len, &mask); |
| slice_convert(mm, &mask, psize); |
| } |
| |
| #ifdef CONFIG_HUGETLB_PAGE |
| /* |
| * is_hugepage_only_range() is used by generic code to verify whether |
| * a normal mmap mapping (non hugetlbfs) is valid on a given area. |
| * |
| * until the generic code provides a more generic hook and/or starts |
| * calling arch get_unmapped_area for MAP_FIXED (which our implementation |
| * here knows how to deal with), we hijack it to keep standard mappings |
| * away from us. |
| * |
| * because of that generic code limitation, MAP_FIXED mapping cannot |
| * "convert" back a slice with no VMAs to the standard page size, only |
| * get_unmapped_area() can. It would be possible to fix it here but I |
| * prefer working on fixing the generic code instead. |
| * |
| * WARNING: This will not work if hugetlbfs isn't enabled since the |
| * generic code will redefine that function as 0 in that. This is ok |
| * for now as we only use slices with hugetlbfs enabled. This should |
| * be fixed as the generic code gets fixed. |
| */ |
| int slice_is_hugepage_only_range(struct mm_struct *mm, unsigned long addr, |
| unsigned long len) |
| { |
| const struct slice_mask *maskp; |
| unsigned int psize = mm_ctx_user_psize(&mm->context); |
| |
| VM_BUG_ON(radix_enabled()); |
| |
| maskp = slice_mask_for_size(&mm->context, psize); |
| |
| /* We need to account for 4k slices too */ |
| if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) { |
| const struct slice_mask *compat_maskp; |
| struct slice_mask available; |
| |
| compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_4K); |
| slice_or_mask(&available, maskp, compat_maskp); |
| return !slice_check_range_fits(mm, &available, addr, len); |
| } |
| |
| return !slice_check_range_fits(mm, maskp, addr, len); |
| } |
| |
| unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) |
| { |
| /* With radix we don't use slice, so derive it from vma*/ |
| if (radix_enabled()) |
| return vma_kernel_pagesize(vma); |
| |
| return 1UL << mmu_psize_to_shift(get_slice_psize(vma->vm_mm, vma->vm_start)); |
| } |
| |
| static int file_to_psize(struct file *file) |
| { |
| struct hstate *hstate = hstate_file(file); |
| return shift_to_mmu_psize(huge_page_shift(hstate)); |
| } |
| |
| unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, |
| unsigned long len, unsigned long pgoff, |
| unsigned long flags) |
| { |
| if (radix_enabled()) |
| return generic_hugetlb_get_unmapped_area(file, addr, len, pgoff, flags); |
| |
| return slice_get_unmapped_area(addr, len, flags, file_to_psize(file), 1); |
| } |
| #endif |