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Diffstat (limited to 'arch/x86/mm/pat_rbtree.c')
-rw-r--r--arch/x86/mm/pat_rbtree.c268
1 files changed, 0 insertions, 268 deletions
diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c
deleted file mode 100644
index 65ebe4b88f7c..000000000000
--- a/arch/x86/mm/pat_rbtree.c
+++ /dev/null
@@ -1,268 +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 (augmented rbtree) used to store the PAT memory type
- * reservations.
- */
-
-#include <linux/seq_file.h>
-#include <linux/debugfs.h>
-#include <linux/kernel.h>
-#include <linux/rbtree_augmented.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 struct rb_root memtype_rbroot = RB_ROOT;
-
-static int is_node_overlap(struct memtype *node, u64 start, u64 end)
-{
- if (node->start >= end || node->end <= start)
- return 0;
-
- return 1;
-}
-
-static u64 get_subtree_max_end(struct rb_node *node)
-{
- u64 ret = 0;
- if (node) {
- struct memtype *data = rb_entry(node, struct memtype, rb);
- ret = data->subtree_max_end;
- }
- return ret;
-}
-
-#define NODE_END(node) ((node)->end)
-
-RB_DECLARE_CALLBACKS_MAX(static, memtype_rb_augment_cb,
- struct memtype, rb, u64, subtree_max_end, NODE_END)
-
-/* Find the first (lowest start addr) overlapping range from rb tree */
-static struct memtype *memtype_rb_lowest_match(struct rb_root *root,
- u64 start, u64 end)
-{
- struct rb_node *node = root->rb_node;
- struct memtype *last_lower = NULL;
-
- while (node) {
- struct memtype *data = rb_entry(node, struct memtype, rb);
-
- if (get_subtree_max_end(node->rb_left) > start) {
- /* Lowest overlap if any must be on left side */
- node = node->rb_left;
- } else if (is_node_overlap(data, start, end)) {
- last_lower = data;
- break;
- } else if (start >= data->start) {
- /* Lowest overlap if any must be on right side */
- node = node->rb_right;
- } else {
- break;
- }
- }
- return last_lower; /* Returns NULL if there is no overlap */
-}
-
-enum {
- MEMTYPE_EXACT_MATCH = 0,
- MEMTYPE_END_MATCH = 1
-};
-
-static struct memtype *memtype_rb_match(struct rb_root *root,
- u64 start, u64 end, int match_type)
-{
- struct memtype *match;
-
- match = memtype_rb_lowest_match(root, start, end);
- while (match != NULL && match->start < end) {
- struct rb_node *node;
-
- 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;
-
- node = rb_next(&match->rb);
- if (node)
- match = rb_entry(node, struct memtype, rb);
- else
- match = NULL;
- }
-
- return NULL; /* Returns NULL if there is no match */
-}
-
-static int memtype_rb_check_conflict(struct rb_root *root,
- u64 start, u64 end,
- enum page_cache_mode reqtype,
- enum page_cache_mode *newtype)
-{
- struct rb_node *node;
- struct memtype *match;
- enum page_cache_mode found_type = reqtype;
-
- match = memtype_rb_lowest_match(&memtype_rbroot, start, end);
- 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;
-
- node = rb_next(&match->rb);
- while (node) {
- match = rb_entry(node, struct memtype, rb);
-
- if (match->start >= end) /* Checked all possible matches */
- goto success;
-
- if (is_node_overlap(match, start, end) &&
- match->type != found_type) {
- goto failure;
- }
-
- node = rb_next(&match->rb);
- }
-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;
-}
-
-static void memtype_rb_insert(struct rb_root *root, struct memtype *newdata)
-{
- struct rb_node **node = &(root->rb_node);
- struct rb_node *parent = NULL;
-
- while (*node) {
- struct memtype *data = rb_entry(*node, struct memtype, rb);
-
- parent = *node;
- if (data->subtree_max_end < newdata->end)
- data->subtree_max_end = newdata->end;
- if (newdata->start <= data->start)
- node = &((*node)->rb_left);
- else if (newdata->start > data->start)
- node = &((*node)->rb_right);
- }
-
- newdata->subtree_max_end = newdata->end;
- rb_link_node(&newdata->rb, parent, node);
- rb_insert_augmented(&newdata->rb, root, &memtype_rb_augment_cb);
-}
-
-int rbt_memtype_check_insert(struct memtype *new,
- enum page_cache_mode *ret_type)
-{
- int err = 0;
-
- err = memtype_rb_check_conflict(&memtype_rbroot, new->start, new->end,
- new->type, ret_type);
-
- if (!err) {
- if (ret_type)
- new->type = *ret_type;
-
- new->subtree_max_end = new->end;
- memtype_rb_insert(&memtype_rbroot, new);
- }
- return err;
-}
-
-struct memtype *rbt_memtype_erase(u64 start, u64 end)
-{
- struct memtype *data;
-
- /*
- * Since the memtype_rbroot tree allows overlapping ranges,
- * rbt_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_rb_match(&memtype_rbroot, start, end,
- MEMTYPE_EXACT_MATCH);
- if (!data) {
- data = memtype_rb_match(&memtype_rbroot, start, end,
- MEMTYPE_END_MATCH);
- if (!data)
- return ERR_PTR(-EINVAL);
- }
-
- if (data->start == start) {
- /* munmap: erase this node */
- rb_erase_augmented(&data->rb, &memtype_rbroot,
- &memtype_rb_augment_cb);
- } else {
- /* mremap: update the end value of this node */
- rb_erase_augmented(&data->rb, &memtype_rbroot,
- &memtype_rb_augment_cb);
- data->end = start;
- data->subtree_max_end = data->end;
- memtype_rb_insert(&memtype_rbroot, data);
- return NULL;
- }
-
- return data;
-}
-
-struct memtype *rbt_memtype_lookup(u64 addr)
-{
- return memtype_rb_lowest_match(&memtype_rbroot, addr, addr + PAGE_SIZE);
-}
-
-#if defined(CONFIG_DEBUG_FS)
-int rbt_memtype_copy_nth_element(struct memtype *out, loff_t pos)
-{
- struct rb_node *node;
- int i = 1;
-
- node = rb_first(&memtype_rbroot);
- while (node && pos != i) {
- node = rb_next(node);
- i++;
- }
-
- if (node) { /* pos == i */
- struct memtype *this = rb_entry(node, struct memtype, rb);
- *out = *this;
- return 0;
- } else {
- return 1;
- }
-}
-#endif
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