diff options
author | Stuart Bennett <stuart@freedesktop.org> | 2009-04-28 15:17:50 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-04-29 05:33:33 -0400 |
commit | 46e91d00b1165b14b484aa33800e1bba0794ae1a (patch) | |
tree | 553b7caebd9d7fcca282caa8b8b0a9acf6d71925 /arch/x86/mm | |
parent | 0492e1bb8fe7d122901c9f3af75e537d4129712e (diff) |
tracing: x86, mmiotrace: refactor clearing/restore of page presence
* change function names to clear_* from set_*: in reality we only clear
and restore page presence, and never unconditionally set present.
Using clear_*({true, false}, ...) is therefore more honest than
set_*({false, true}, ...)
* upgrade presence storage to pteval_t: doing user-space tracing will
require saving and manipulation of the _PAGE_PROTNONE bit, in addition
to the existing _PAGE_PRESENT changes, and having multiple bools stored
and passed around does not seem optimal
[ Impact: refactor, clean up mmiotrace code ]
Signed-off-by: Stuart Bennett <stuart@freedesktop.org>
Acked-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1240946271-7083-4-git-send-email-stuart@freedesktop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm')
-rw-r--r-- | arch/x86/mm/kmmio.c | 43 |
1 files changed, 22 insertions, 21 deletions
diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c index 869181a917d..a769d1a2d93 100644 --- a/arch/x86/mm/kmmio.c +++ b/arch/x86/mm/kmmio.c | |||
@@ -32,7 +32,7 @@ struct kmmio_fault_page { | |||
32 | struct list_head list; | 32 | struct list_head list; |
33 | struct kmmio_fault_page *release_next; | 33 | struct kmmio_fault_page *release_next; |
34 | unsigned long page; /* location of the fault page */ | 34 | unsigned long page; /* location of the fault page */ |
35 | bool old_presence; /* page presence prior to arming */ | 35 | pteval_t old_presence; /* page presence prior to arming */ |
36 | bool armed; | 36 | bool armed; |
37 | 37 | ||
38 | /* | 38 | /* |
@@ -108,49 +108,51 @@ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) | |||
108 | return NULL; | 108 | return NULL; |
109 | } | 109 | } |
110 | 110 | ||
111 | static void set_pmd_presence(pmd_t *pmd, bool present, bool *old) | 111 | static void clear_pmd_presence(pmd_t *pmd, bool clear, pmdval_t *old) |
112 | { | 112 | { |
113 | pmdval_t v = pmd_val(*pmd); | 113 | pmdval_t v = pmd_val(*pmd); |
114 | *old = !!(v & _PAGE_PRESENT); | 114 | if (clear) { |
115 | v &= ~_PAGE_PRESENT; | 115 | *old = v & _PAGE_PRESENT; |
116 | if (present) | 116 | v &= ~_PAGE_PRESENT; |
117 | v |= _PAGE_PRESENT; | 117 | } else /* presume this has been called with clear==true previously */ |
118 | v |= *old; | ||
118 | set_pmd(pmd, __pmd(v)); | 119 | set_pmd(pmd, __pmd(v)); |
119 | } | 120 | } |
120 | 121 | ||
121 | static void set_pte_presence(pte_t *pte, bool present, bool *old) | 122 | static void clear_pte_presence(pte_t *pte, bool clear, pteval_t *old) |
122 | { | 123 | { |
123 | pteval_t v = pte_val(*pte); | 124 | pteval_t v = pte_val(*pte); |
124 | *old = !!(v & _PAGE_PRESENT); | 125 | if (clear) { |
125 | v &= ~_PAGE_PRESENT; | 126 | *old = v & _PAGE_PRESENT; |
126 | if (present) | 127 | v &= ~_PAGE_PRESENT; |
127 | v |= _PAGE_PRESENT; | 128 | } else /* presume this has been called with clear==true previously */ |
129 | v |= *old; | ||
128 | set_pte_atomic(pte, __pte(v)); | 130 | set_pte_atomic(pte, __pte(v)); |
129 | } | 131 | } |
130 | 132 | ||
131 | static int set_page_presence(unsigned long addr, bool present, bool *old) | 133 | static int clear_page_presence(struct kmmio_fault_page *f, bool clear) |
132 | { | 134 | { |
133 | unsigned int level; | 135 | unsigned int level; |
134 | pte_t *pte = lookup_address(addr, &level); | 136 | pte_t *pte = lookup_address(f->page, &level); |
135 | 137 | ||
136 | if (!pte) { | 138 | if (!pte) { |
137 | pr_err("kmmio: no pte for page 0x%08lx\n", addr); | 139 | pr_err("kmmio: no pte for page 0x%08lx\n", f->page); |
138 | return -1; | 140 | return -1; |
139 | } | 141 | } |
140 | 142 | ||
141 | switch (level) { | 143 | switch (level) { |
142 | case PG_LEVEL_2M: | 144 | case PG_LEVEL_2M: |
143 | set_pmd_presence((pmd_t *)pte, present, old); | 145 | clear_pmd_presence((pmd_t *)pte, clear, &f->old_presence); |
144 | break; | 146 | break; |
145 | case PG_LEVEL_4K: | 147 | case PG_LEVEL_4K: |
146 | set_pte_presence(pte, present, old); | 148 | clear_pte_presence(pte, clear, &f->old_presence); |
147 | break; | 149 | break; |
148 | default: | 150 | default: |
149 | pr_err("kmmio: unexpected page level 0x%x.\n", level); | 151 | pr_err("kmmio: unexpected page level 0x%x.\n", level); |
150 | return -1; | 152 | return -1; |
151 | } | 153 | } |
152 | 154 | ||
153 | __flush_tlb_one(addr); | 155 | __flush_tlb_one(f->page); |
154 | return 0; | 156 | return 0; |
155 | } | 157 | } |
156 | 158 | ||
@@ -171,9 +173,9 @@ static int arm_kmmio_fault_page(struct kmmio_fault_page *f) | |||
171 | WARN_ONCE(f->armed, KERN_ERR "kmmio page already armed.\n"); | 173 | WARN_ONCE(f->armed, KERN_ERR "kmmio page already armed.\n"); |
172 | if (f->armed) { | 174 | if (f->armed) { |
173 | pr_warning("kmmio double-arm: page 0x%08lx, ref %d, old %d\n", | 175 | pr_warning("kmmio double-arm: page 0x%08lx, ref %d, old %d\n", |
174 | f->page, f->count, f->old_presence); | 176 | f->page, f->count, !!f->old_presence); |
175 | } | 177 | } |
176 | ret = set_page_presence(f->page, false, &f->old_presence); | 178 | ret = clear_page_presence(f, true); |
177 | WARN_ONCE(ret < 0, KERN_ERR "kmmio arming 0x%08lx failed.\n", f->page); | 179 | WARN_ONCE(ret < 0, KERN_ERR "kmmio arming 0x%08lx failed.\n", f->page); |
178 | f->armed = true; | 180 | f->armed = true; |
179 | return ret; | 181 | return ret; |
@@ -182,8 +184,7 @@ static int arm_kmmio_fault_page(struct kmmio_fault_page *f) | |||
182 | /** Restore the given page to saved presence state. */ | 184 | /** Restore the given page to saved presence state. */ |
183 | static void disarm_kmmio_fault_page(struct kmmio_fault_page *f) | 185 | static void disarm_kmmio_fault_page(struct kmmio_fault_page *f) |
184 | { | 186 | { |
185 | bool tmp; | 187 | int ret = clear_page_presence(f, false); |
186 | int ret = set_page_presence(f->page, f->old_presence, &tmp); | ||
187 | WARN_ONCE(ret < 0, | 188 | WARN_ONCE(ret < 0, |
188 | KERN_ERR "kmmio disarming 0x%08lx failed.\n", f->page); | 189 | KERN_ERR "kmmio disarming 0x%08lx failed.\n", f->page); |
189 | f->armed = false; | 190 | f->armed = false; |