| /* |
| * address space "slices" (meta-segments) support |
| * |
| * Copyright (C) 2007 Benjamin Herrenschmidt, IBM Corporation. |
| * |
| * Based on hugetlb implementation |
| * |
| * Copyright (C) 2003 David Gibson, IBM Corporation. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #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 <asm/mman.h> |
| #include <asm/mmu.h> |
| #include <asm/copro.h> |
| #include <asm/hugetlb.h> |
| |
| /* some sanity checks */ |
| #if (PGTABLE_RANGE >> 43) > SLICE_MASK_SIZE |
| #error PGTABLE_RANGE exceeds slice_mask high_slices size |
| #endif |
| |
| static DEFINE_SPINLOCK(slice_convert_lock); |
| |
| |
| #ifdef DEBUG |
| int _slice_debug = 1; |
| |
| static void slice_print_mask(const char *label, struct slice_mask mask) |
| { |
| char *p, buf[16 + 3 + 64 + 1]; |
| int i; |
| |
| if (!_slice_debug) |
| return; |
| p = buf; |
| for (i = 0; i < SLICE_NUM_LOW; i++) |
| *(p++) = (mask.low_slices & (1 << i)) ? '1' : '0'; |
| *(p++) = ' '; |
| *(p++) = '-'; |
| *(p++) = ' '; |
| for (i = 0; i < SLICE_NUM_HIGH; i++) |
| *(p++) = (mask.high_slices & (1ul << i)) ? '1' : '0'; |
| *(p++) = 0; |
| |
| printk(KERN_DEBUG "%s:%s\n", label, buf); |
| } |
| |
| #define slice_dbg(fmt...) do { if (_slice_debug) pr_debug(fmt); } while(0) |
| |
| #else |
| |
| static void slice_print_mask(const char *label, struct slice_mask mask) {} |
| #define slice_dbg(fmt...) |
| |
| #endif |
| |
| static struct slice_mask slice_range_to_mask(unsigned long start, |
| unsigned long len) |
| { |
| unsigned long end = start + len - 1; |
| struct slice_mask ret = { 0, 0 }; |
| |
| if (start < SLICE_LOW_TOP) { |
| unsigned long mend = min(end, SLICE_LOW_TOP); |
| unsigned long mstart = min(start, SLICE_LOW_TOP); |
| |
| ret.low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1)) |
| - (1u << GET_LOW_SLICE_INDEX(mstart)); |
| } |
| |
| if ((start + len) > SLICE_LOW_TOP) |
| ret.high_slices = (1ul << (GET_HIGH_SLICE_INDEX(end) + 1)) |
| - (1ul << GET_HIGH_SLICE_INDEX(start)); |
| |
| return ret; |
| } |
| |
| static int slice_area_is_free(struct mm_struct *mm, unsigned long addr, |
| unsigned long len) |
| { |
| struct vm_area_struct *vma; |
| |
| if ((mm->task_size - len) < addr) |
| return 0; |
| vma = find_vma(mm, addr); |
| return (!vma || (addr + len) <= vma->vm_start); |
| } |
| |
| 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 = SLICE_LOW_TOP; |
| |
| return !slice_area_is_free(mm, start, end - start); |
| } |
| |
| static struct slice_mask slice_mask_for_free(struct mm_struct *mm) |
| { |
| struct slice_mask ret = { 0, 0 }; |
| unsigned long i; |
| |
| for (i = 0; i < SLICE_NUM_LOW; i++) |
| if (!slice_low_has_vma(mm, i)) |
| ret.low_slices |= 1u << i; |
| |
| if (mm->task_size <= SLICE_LOW_TOP) |
| return ret; |
| |
| for (i = 0; i < SLICE_NUM_HIGH; i++) |
| if (!slice_high_has_vma(mm, i)) |
| ret.high_slices |= 1ul << i; |
| |
| return ret; |
| } |
| |
| static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize) |
| { |
| unsigned char *hpsizes; |
| int index, mask_index; |
| struct slice_mask ret = { 0, 0 }; |
| unsigned long i; |
| u64 lpsizes; |
| |
| lpsizes = mm->context.low_slices_psize; |
| for (i = 0; i < SLICE_NUM_LOW; i++) |
| if (((lpsizes >> (i * 4)) & 0xf) == psize) |
| ret.low_slices |= 1u << i; |
| |
| hpsizes = mm->context.high_slices_psize; |
| for (i = 0; i < SLICE_NUM_HIGH; i++) { |
| mask_index = i & 0x1; |
| index = i >> 1; |
| if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == psize) |
| ret.high_slices |= 1ul << i; |
| } |
| |
| return ret; |
| } |
| |
| static int slice_check_fit(struct slice_mask mask, struct slice_mask available) |
| { |
| return (mask.low_slices & available.low_slices) == mask.low_slices && |
| (mask.high_slices & available.high_slices) == mask.high_slices; |
| } |
| |
| static void slice_flush_segments(void *parm) |
| { |
| struct mm_struct *mm = parm; |
| unsigned long flags; |
| |
| if (mm != current->active_mm) |
| return; |
| |
| /* update the paca copy of the context struct */ |
| get_paca()->context = current->active_mm->context; |
| |
| local_irq_save(flags); |
| slb_flush_and_rebolt(); |
| local_irq_restore(flags); |
| } |
| |
| static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psize) |
| { |
| int index, mask_index; |
| /* Write the new slice psize bits */ |
| unsigned char *hpsizes; |
| u64 lpsizes; |
| unsigned long i, flags; |
| |
| slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize); |
| slice_print_mask(" mask", mask); |
| |
| /* We need to use a spinlock here to protect against |
| * concurrent 64k -> 4k demotion ... |
| */ |
| spin_lock_irqsave(&slice_convert_lock, flags); |
| |
| lpsizes = mm->context.low_slices_psize; |
| for (i = 0; i < SLICE_NUM_LOW; i++) |
| if (mask.low_slices & (1u << i)) |
| lpsizes = (lpsizes & ~(0xful << (i * 4))) | |
| (((unsigned long)psize) << (i * 4)); |
| |
| /* Assign the value back */ |
| mm->context.low_slices_psize = lpsizes; |
| |
| hpsizes = mm->context.high_slices_psize; |
| for (i = 0; i < SLICE_NUM_HIGH; i++) { |
| mask_index = i & 0x1; |
| index = i >> 1; |
| if (mask.high_slices & (1ul << i)) |
| hpsizes[index] = (hpsizes[index] & |
| ~(0xf << (mask_index * 4))) | |
| (((unsigned long)psize) << (mask_index * 4)); |
| } |
| |
| slice_dbg(" lsps=%lx, hsps=%lx\n", |
| mm->context.low_slices_psize, |
| mm->context.high_slices_psize); |
| |
| 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, |
| struct slice_mask available, |
| int end, |
| unsigned long *boundary_addr) |
| { |
| unsigned long slice; |
| if (addr < SLICE_LOW_TOP) { |
| 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 !!(available.high_slices & (1ul << slice)); |
| } |
| } |
| |
| static unsigned long slice_find_area_bottomup(struct mm_struct *mm, |
| unsigned long len, |
| struct slice_mask available, |
| int psize) |
| { |
| int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); |
| unsigned long addr, 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; |
| |
| addr = TASK_UNMAPPED_BASE; |
| while (addr < TASK_SIZE) { |
| 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 >= TASK_SIZE) |
| addr = TASK_SIZE; |
| 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 len, |
| struct slice_mask available, |
| int psize) |
| { |
| int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); |
| unsigned long addr, found, prev; |
| struct vm_unmapped_area_info info; |
| |
| info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
| info.length = len; |
| info.align_mask = PAGE_MASK & ((1ul << pshift) - 1); |
| info.align_offset = 0; |
| |
| addr = mm->mmap_base; |
| while (addr > PAGE_SIZE) { |
| 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 < PAGE_SIZE) |
| addr = PAGE_SIZE; |
| 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, len, available, psize); |
| } |
| |
| |
| static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len, |
| struct slice_mask mask, int psize, |
| int topdown) |
| { |
| if (topdown) |
| return slice_find_area_topdown(mm, len, mask, psize); |
| else |
| return slice_find_area_bottomup(mm, len, mask, psize); |
| } |
| |
| #define or_mask(dst, src) do { \ |
| (dst).low_slices |= (src).low_slices; \ |
| (dst).high_slices |= (src).high_slices; \ |
| } while (0) |
| |
| #define andnot_mask(dst, src) do { \ |
| (dst).low_slices &= ~(src).low_slices; \ |
| (dst).high_slices &= ~(src).high_slices; \ |
| } while (0) |
| |
| #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 mask = {0, 0}; |
| struct slice_mask good_mask; |
| struct slice_mask potential_mask = {0,0} /* silence stupid warning */; |
| struct slice_mask compat_mask = {0, 0}; |
| int fixed = (flags & MAP_FIXED); |
| int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); |
| struct mm_struct *mm = current->mm; |
| unsigned long newaddr; |
| |
| /* Sanity checks */ |
| BUG_ON(mm->task_size == 0); |
| |
| 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 (len > mm->task_size) |
| return -ENOMEM; |
| if (len & ((1ul << pshift) - 1)) |
| return -EINVAL; |
| if (fixed && (addr & ((1ul << pshift) - 1))) |
| return -EINVAL; |
| if (fixed && addr > (mm->task_size - len)) |
| return -ENOMEM; |
| |
| /* If hint, make sure it matches our alignment restrictions */ |
| if (!fixed && addr) { |
| addr = _ALIGN_UP(addr, 1ul << pshift); |
| slice_dbg(" aligned addr=%lx\n", addr); |
| /* Ignore hint if it's too large or overlaps a VMA */ |
| if (addr > mm->task_size - len || |
| !slice_area_is_free(mm, addr, len)) |
| addr = 0; |
| } |
| |
| /* First make up a "good" mask of slices that have the right size |
| * already |
| */ |
| good_mask = slice_mask_for_size(mm, psize); |
| slice_print_mask(" good_mask", good_mask); |
| |
| /* |
| * 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. |
| */ |
| |
| #ifdef CONFIG_PPC_64K_PAGES |
| /* If we support combo pages, we can allow 64k pages in 4k slices */ |
| if (psize == MMU_PAGE_64K) { |
| compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K); |
| if (fixed) |
| or_mask(good_mask, compat_mask); |
| } |
| #endif |
| |
| /* First check hint if it's valid or if we have MAP_FIXED */ |
| if (addr != 0 || fixed) { |
| /* Build a mask for the requested range */ |
| mask = slice_range_to_mask(addr, len); |
| slice_print_mask(" mask", mask); |
| |
| /* Check if we fit in the good mask. If we do, we just return, |
| * nothing else to do |
| */ |
| if (slice_check_fit(mask, good_mask)) { |
| slice_dbg(" fits good !\n"); |
| 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); |
| 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); |
| return newaddr; |
| } |
| } |
| |
| /* We don't fit in the good mask, check what other slices are |
| * empty and thus can be converted |
| */ |
| potential_mask = slice_mask_for_free(mm); |
| or_mask(potential_mask, good_mask); |
| slice_print_mask(" potential", potential_mask); |
| |
| if ((addr != 0 || fixed) && slice_check_fit(mask, potential_mask)) { |
| slice_dbg(" fits potential !\n"); |
| 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) { |
| addr = slice_find_area(mm, len, good_mask, psize, topdown); |
| if (addr != -ENOMEM) { |
| slice_dbg(" found area at 0x%lx\n", addr); |
| return addr; |
| } |
| } |
| |
| /* Now let's see if we can find something in the existing slices |
| * for that size plus free slices |
| */ |
| addr = slice_find_area(mm, len, potential_mask, psize, topdown); |
| |
| #ifdef CONFIG_PPC_64K_PAGES |
| if (addr == -ENOMEM && psize == MMU_PAGE_64K) { |
| /* retry the search with 4k-page slices included */ |
| or_mask(potential_mask, compat_mask); |
| addr = slice_find_area(mm, len, potential_mask, psize, |
| topdown); |
| } |
| #endif |
| |
| if (addr == -ENOMEM) |
| return -ENOMEM; |
| |
| mask = slice_range_to_mask(addr, len); |
| slice_dbg(" found potential area at 0x%lx\n", addr); |
| slice_print_mask(" mask", mask); |
| |
| convert: |
| andnot_mask(mask, good_mask); |
| andnot_mask(mask, compat_mask); |
| if (mask.low_slices || mask.high_slices) { |
| slice_convert(mm, mask, psize); |
| if (psize > MMU_PAGE_BASE) |
| on_each_cpu(slice_flush_segments, mm, 1); |
| } |
| return addr; |
| |
| } |
| 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) |
| { |
| return slice_get_unmapped_area(addr, len, flags, |
| current->mm->context.user_psize, 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) |
| { |
| return slice_get_unmapped_area(addr0, len, flags, |
| current->mm->context.user_psize, 1); |
| } |
| |
| unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr) |
| { |
| unsigned char *hpsizes; |
| int index, mask_index; |
| |
| if (addr < SLICE_LOW_TOP) { |
| u64 lpsizes; |
| lpsizes = mm->context.low_slices_psize; |
| index = GET_LOW_SLICE_INDEX(addr); |
| return (lpsizes >> (index * 4)) & 0xf; |
| } |
| hpsizes = mm->context.high_slices_psize; |
| index = GET_HIGH_SLICE_INDEX(addr); |
| mask_index = index & 0x1; |
| return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xf; |
| } |
| EXPORT_SYMBOL_GPL(get_slice_psize); |
| |
| /* |
| * This is called by hash_page when it needs to do a lazy conversion of |
| * an address space from real 64K pages to combo 4K pages (typically |
| * when hitting a non cacheable mapping on a processor or hypervisor |
| * that won't allow them for 64K pages). |
| * |
| * This is also called in init_new_context() to change back the user |
| * psize from whatever the parent context had it set to |
| * N.B. This may be called before mm->context.id has been set. |
| * |
| * This function will only change the content of the {low,high)_slice_psize |
| * masks, it will not flush SLBs as this shall be handled lazily by the |
| * caller. |
| */ |
| void slice_set_user_psize(struct mm_struct *mm, unsigned int psize) |
| { |
| int index, mask_index; |
| unsigned char *hpsizes; |
| unsigned long flags, lpsizes; |
| unsigned int old_psize; |
| int i; |
| |
| slice_dbg("slice_set_user_psize(mm=%p, psize=%d)\n", mm, psize); |
| |
| spin_lock_irqsave(&slice_convert_lock, flags); |
| |
| old_psize = mm->context.user_psize; |
| slice_dbg(" old_psize=%d\n", old_psize); |
| if (old_psize == psize) |
| goto bail; |
| |
| mm->context.user_psize = psize; |
| wmb(); |
| |
| lpsizes = mm->context.low_slices_psize; |
| for (i = 0; i < SLICE_NUM_LOW; i++) |
| if (((lpsizes >> (i * 4)) & 0xf) == old_psize) |
| lpsizes = (lpsizes & ~(0xful << (i * 4))) | |
| (((unsigned long)psize) << (i * 4)); |
| /* Assign the value back */ |
| mm->context.low_slices_psize = lpsizes; |
| |
| hpsizes = mm->context.high_slices_psize; |
| for (i = 0; i < SLICE_NUM_HIGH; i++) { |
| mask_index = i & 0x1; |
| index = i >> 1; |
| if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == old_psize) |
| hpsizes[index] = (hpsizes[index] & |
| ~(0xf << (mask_index * 4))) | |
| (((unsigned long)psize) << (mask_index * 4)); |
| } |
| |
| |
| |
| |
| slice_dbg(" lsps=%lx, hsps=%lx\n", |
| mm->context.low_slices_psize, |
| mm->context.high_slices_psize); |
| |
| bail: |
| spin_unlock_irqrestore(&slice_convert_lock, flags); |
| } |
| |
| void slice_set_psize(struct mm_struct *mm, unsigned long address, |
| unsigned int psize) |
| { |
| unsigned char *hpsizes; |
| unsigned long i, flags; |
| u64 *lpsizes; |
| |
| spin_lock_irqsave(&slice_convert_lock, flags); |
| if (address < SLICE_LOW_TOP) { |
| i = GET_LOW_SLICE_INDEX(address); |
| lpsizes = &mm->context.low_slices_psize; |
| *lpsizes = (*lpsizes & ~(0xful << (i * 4))) | |
| ((unsigned long) psize << (i * 4)); |
| } else { |
| int index, mask_index; |
| i = GET_HIGH_SLICE_INDEX(address); |
| hpsizes = mm->context.high_slices_psize; |
| mask_index = i & 0x1; |
| index = i >> 1; |
| hpsizes[index] = (hpsizes[index] & |
| ~(0xf << (mask_index * 4))) | |
| (((unsigned long)psize) << (mask_index * 4)); |
| } |
| |
| spin_unlock_irqrestore(&slice_convert_lock, flags); |
| |
| copro_flush_all_slbs(mm); |
| } |
| |
| void slice_set_range_psize(struct mm_struct *mm, unsigned long start, |
| unsigned long len, unsigned int psize) |
| { |
| struct slice_mask mask = slice_range_to_mask(start, len); |
| |
| slice_convert(mm, mask, psize); |
| } |
| |
| /* |
| * 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 is_hugepage_only_range(struct mm_struct *mm, unsigned long addr, |
| unsigned long len) |
| { |
| struct slice_mask mask, available; |
| unsigned int psize = mm->context.user_psize; |
| |
| mask = slice_range_to_mask(addr, len); |
| available = slice_mask_for_size(mm, psize); |
| #ifdef CONFIG_PPC_64K_PAGES |
| /* We need to account for 4k slices too */ |
| if (psize == MMU_PAGE_64K) { |
| struct slice_mask compat_mask; |
| compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K); |
| or_mask(available, compat_mask); |
| } |
| #endif |
| |
| #if 0 /* too verbose */ |
| slice_dbg("is_hugepage_only_range(mm=%p, addr=%lx, len=%lx)\n", |
| mm, addr, len); |
| slice_print_mask(" mask", mask); |
| slice_print_mask(" available", available); |
| #endif |
| return !slice_check_fit(mask, available); |
| } |
| |