diff options
Diffstat (limited to 'arch/x86/mm/pat_interval.c')
| -rw-r--r-- | arch/x86/mm/pat_interval.c | 185 |
1 files changed, 0 insertions, 185 deletions
diff --git a/arch/x86/mm/pat_interval.c b/arch/x86/mm/pat_interval.c deleted file mode 100644 index 6855362eaf21..000000000000 --- a/arch/x86/mm/pat_interval.c +++ /dev/null @@ -1,185 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Handle caching attributes in page tables (PAT) - * - * Authors: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> - * Suresh B Siddha <suresh.b.siddha@intel.com> - * - * Interval tree used to store the PAT memory type reservations. - */ - -#include <linux/seq_file.h> -#include <linux/debugfs.h> -#include <linux/kernel.h> -#include <linux/interval_tree_generic.h> -#include <linux/sched.h> -#include <linux/gfp.h> - -#include <asm/pgtable.h> -#include <asm/pat.h> - -#include "pat_internal.h" - -/* - * The memtype tree keeps track of memory type for specific - * physical memory areas. Without proper tracking, conflicting memory - * types in different mappings can cause CPU cache corruption. - * - * The tree is an interval tree (augmented rbtree) with tree ordered - * on starting address. Tree can contain multiple entries for - * different regions which overlap. All the aliases have the same - * cache attributes of course. - * - * memtype_lock protects the rbtree. - */ -static inline u64 memtype_interval_start(struct memtype *memtype) -{ - return memtype->start; -} - -static inline u64 memtype_interval_end(struct memtype *memtype) -{ - return memtype->end - 1; -} -INTERVAL_TREE_DEFINE(struct memtype, rb, u64, subtree_max_end, - memtype_interval_start, memtype_interval_end, - static, memtype_interval) - -static struct rb_root_cached memtype_rbroot = RB_ROOT_CACHED; - -enum { - MEMTYPE_EXACT_MATCH = 0, - MEMTYPE_END_MATCH = 1 -}; - -static struct memtype *memtype_match(u64 start, u64 end, int match_type) -{ - struct memtype *match; - - match = memtype_interval_iter_first(&memtype_rbroot, start, end-1); - while (match != NULL && match->start < end) { - if ((match_type == MEMTYPE_EXACT_MATCH) && - (match->start == start) && (match->end == end)) - return match; - - if ((match_type == MEMTYPE_END_MATCH) && - (match->start < start) && (match->end == end)) - return match; - - match = memtype_interval_iter_next(match, start, end-1); - } - - return NULL; /* Returns NULL if there is no match */ -} - -static int memtype_check_conflict(u64 start, u64 end, - enum page_cache_mode reqtype, - enum page_cache_mode *newtype) -{ - struct memtype *match; - enum page_cache_mode found_type = reqtype; - - match = memtype_interval_iter_first(&memtype_rbroot, start, end-1); - if (match == NULL) - goto success; - - if (match->type != found_type && newtype == NULL) - goto failure; - - dprintk("Overlap at 0x%Lx-0x%Lx\n", match->start, match->end); - found_type = match->type; - - match = memtype_interval_iter_next(match, start, end-1); - while (match) { - if (match->type != found_type) - goto failure; - - match = memtype_interval_iter_next(match, start, end-1); - } -success: - if (newtype) - *newtype = found_type; - - return 0; - -failure: - pr_info("x86/PAT: %s:%d conflicting memory types %Lx-%Lx %s<->%s\n", - current->comm, current->pid, start, end, - cattr_name(found_type), cattr_name(match->type)); - return -EBUSY; -} - -int memtype_check_insert(struct memtype *new, - enum page_cache_mode *ret_type) -{ - int err = 0; - - err = memtype_check_conflict(new->start, new->end, new->type, ret_type); - if (err) - return err; - - if (ret_type) - new->type = *ret_type; - - memtype_interval_insert(new, &memtype_rbroot); - return 0; -} - -struct memtype *memtype_erase(u64 start, u64 end) -{ - struct memtype *data; - - /* - * Since the memtype_rbroot tree allows overlapping ranges, - * memtype_erase() checks with EXACT_MATCH first, i.e. free - * a whole node for the munmap case. If no such entry is found, - * it then checks with END_MATCH, i.e. shrink the size of a node - * from the end for the mremap case. - */ - data = memtype_match(start, end, MEMTYPE_EXACT_MATCH); - if (!data) { - data = memtype_match(start, end, MEMTYPE_END_MATCH); - if (!data) - return ERR_PTR(-EINVAL); - } - - if (data->start == start) { - /* munmap: erase this node */ - memtype_interval_remove(data, &memtype_rbroot); - } else { - /* mremap: update the end value of this node */ - memtype_interval_remove(data, &memtype_rbroot); - data->end = start; - memtype_interval_insert(data, &memtype_rbroot); - return NULL; - } - - return data; -} - -struct memtype *memtype_lookup(u64 addr) -{ - return memtype_interval_iter_first(&memtype_rbroot, addr, - addr + PAGE_SIZE-1); -} - -#if defined(CONFIG_DEBUG_FS) -int memtype_copy_nth_element(struct memtype *out, loff_t pos) -{ - struct memtype *match; - int i = 1; - - match = memtype_interval_iter_first(&memtype_rbroot, 0, ULONG_MAX); - while (match && pos != i) { - match = memtype_interval_iter_next(match, 0, ULONG_MAX); - i++; - } - - if (match) { /* pos == i */ - *out = *match; - return 0; - } else { - return 1; - } -} -#endif |