diff options
author | Stuart Menefy <stuart.menefy@st.com> | 2006-11-23 21:42:24 -0500 |
---|---|---|
committer | Paul Mundt <lethal@linux-sh.org> | 2006-12-05 20:45:38 -0500 |
commit | 9b3a53ab76771e3669e50086c131e1574fe25847 (patch) | |
tree | 07dab1cd3972c7b82ddd5b7ad1e28628d7756dbb /arch/sh/mm/fault.c | |
parent | 9daa0c257d6c200b58092e0bfc32b77c4618a8af (diff) |
sh: TLB miss fast-path optimizations.
Handle simple TLB miss faults which can be resolved completely
from the page table in assembler.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/mm/fault.c')
-rw-r--r-- | arch/sh/mm/fault.c | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c index 128907ef7fcd..123fb80c859d 100644 --- a/arch/sh/mm/fault.c +++ b/arch/sh/mm/fault.c | |||
@@ -223,89 +223,3 @@ do_sigbus: | |||
223 | if (!user_mode(regs)) | 223 | if (!user_mode(regs)) |
224 | goto no_context; | 224 | goto no_context; |
225 | } | 225 | } |
226 | |||
227 | #ifdef CONFIG_SH_STORE_QUEUES | ||
228 | /* | ||
229 | * This is a special case for the SH-4 store queues, as pages for this | ||
230 | * space still need to be faulted in before it's possible to flush the | ||
231 | * store queue cache for writeout to the remapped region. | ||
232 | */ | ||
233 | #define P3_ADDR_MAX (P4SEG_STORE_QUE + 0x04000000) | ||
234 | #else | ||
235 | #define P3_ADDR_MAX P4SEG | ||
236 | #endif | ||
237 | |||
238 | /* | ||
239 | * Called with interrupts disabled. | ||
240 | */ | ||
241 | asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs, | ||
242 | unsigned long writeaccess, | ||
243 | unsigned long address) | ||
244 | { | ||
245 | pgd_t *pgd; | ||
246 | pud_t *pud; | ||
247 | pmd_t *pmd; | ||
248 | pte_t *pte; | ||
249 | pte_t entry; | ||
250 | struct mm_struct *mm = current->mm; | ||
251 | spinlock_t *ptl; | ||
252 | int ret = 1; | ||
253 | |||
254 | #ifdef CONFIG_SH_KGDB | ||
255 | if (kgdb_nofault && kgdb_bus_err_hook) | ||
256 | kgdb_bus_err_hook(); | ||
257 | #endif | ||
258 | |||
259 | /* | ||
260 | * We don't take page faults for P1, P2, and parts of P4, these | ||
261 | * are always mapped, whether it be due to legacy behaviour in | ||
262 | * 29-bit mode, or due to PMB configuration in 32-bit mode. | ||
263 | */ | ||
264 | if (address >= P3SEG && address < P3_ADDR_MAX) { | ||
265 | pgd = pgd_offset_k(address); | ||
266 | mm = NULL; | ||
267 | } else { | ||
268 | if (unlikely(address >= TASK_SIZE || !mm)) | ||
269 | return 1; | ||
270 | |||
271 | pgd = pgd_offset(mm, address); | ||
272 | } | ||
273 | |||
274 | pud = pud_offset(pgd, address); | ||
275 | if (pud_none_or_clear_bad(pud)) | ||
276 | return 1; | ||
277 | pmd = pmd_offset(pud, address); | ||
278 | if (pmd_none_or_clear_bad(pmd)) | ||
279 | return 1; | ||
280 | |||
281 | if (mm) | ||
282 | pte = pte_offset_map_lock(mm, pmd, address, &ptl); | ||
283 | else | ||
284 | pte = pte_offset_kernel(pmd, address); | ||
285 | |||
286 | entry = *pte; | ||
287 | if (unlikely(pte_none(entry) || pte_not_present(entry))) | ||
288 | goto unlock; | ||
289 | if (unlikely(writeaccess && !pte_write(entry))) | ||
290 | goto unlock; | ||
291 | |||
292 | if (writeaccess) | ||
293 | entry = pte_mkdirty(entry); | ||
294 | entry = pte_mkyoung(entry); | ||
295 | |||
296 | #ifdef CONFIG_CPU_SH4 | ||
297 | /* | ||
298 | * ITLB is not affected by "ldtlb" instruction. | ||
299 | * So, we need to flush the entry by ourselves. | ||
300 | */ | ||
301 | __flush_tlb_page(get_asid(), address & PAGE_MASK); | ||
302 | #endif | ||
303 | |||
304 | set_pte(pte, entry); | ||
305 | update_mmu_cache(NULL, address, entry); | ||
306 | ret = 0; | ||
307 | unlock: | ||
308 | if (mm) | ||
309 | pte_unmap_unlock(pte, ptl); | ||
310 | return ret; | ||
311 | } | ||