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path: root/drivers/misc/sgi-gru/grufault.c
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Diffstat (limited to 'drivers/misc/sgi-gru/grufault.c')
-rw-r--r--drivers/misc/sgi-gru/grufault.c11
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 3d33015bbf3..8c389d606c3 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -214,12 +214,14 @@ static int non_atomic_pte_lookup(struct vm_area_struct *vma,
}
/*
- *
* atomic_pte_lookup
*
* Convert a user virtual address to a physical address
* Only supports Intel large pages (2MB only) on x86_64.
* ZZZ - hugepage support is incomplete
+ *
+ * NOTE: mmap_sem is already held on entry to this function. This
+ * guarantees existence of the page tables.
*/
static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr,
int write, unsigned long *paddr, int *pageshift)
@@ -229,9 +231,6 @@ static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr,
pud_t *pudp;
pte_t pte;
- WARN_ON(irqs_disabled()); /* ZZZ debug */
-
- local_irq_disable();
pgdp = pgd_offset(vma->vm_mm, vaddr);
if (unlikely(pgd_none(*pgdp)))
goto err;
@@ -250,8 +249,6 @@ static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr,
#endif
pte = *pte_offset_kernel(pmdp, vaddr);
- local_irq_enable();
-
if (unlikely(!pte_present(pte) ||
(write && (!pte_write(pte) || !pte_dirty(pte)))))
return 1;
@@ -324,6 +321,7 @@ static int gru_try_dropin(struct gru_thread_state *gts,
* Atomic lookup is faster & usually works even if called in non-atomic
* context.
*/
+ rmb(); /* Must/check ms_range_active before loading PTEs */
ret = atomic_pte_lookup(vma, vaddr, write, &paddr, &pageshift);
if (ret) {
if (!cb)
@@ -543,6 +541,7 @@ int gru_get_exception_detail(unsigned long arg)
ucbnum = get_cb_number((void *)excdet.cb);
cbrnum = thread_cbr_number(gts, ucbnum);
cbe = get_cbe_by_index(gts->ts_gru, cbrnum);
+ prefetchw(cbe); /* Harmless on hardware, required for emulator */
excdet.opc = cbe->opccpy;
excdet.exopc = cbe->exopccpy;
excdet.ecause = cbe->ecause;