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D27621.diff
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D27621.diff

diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -1365,16 +1365,42 @@
return (m);
}
-vm_paddr_t
-pmap_kextract(vm_offset_t va)
+/*
+ * Walks the page tables to translate a kernel virtual address to a
+ * physical address. Returns true if the kva is valid and stores the
+ * physical address in pa if it is not NULL.
+ */
+bool
+pmap_klookup(vm_offset_t va, vm_paddr_t *pa)
{
pt_entry_t *pte, tpte;
+ register_t intr;
+ uint64_t par;
+
+ /*
+ * Disable interrupts so we don't get interrupted between asking
+ * for address translation, and getting the result back.
+ */
+ intr = intr_disable();
+ par = arm64_address_translate_s1e1r(va);
+ intr_restore(intr);
+
+ if (PAR_SUCCESS(par)) {
+ if (pa != NULL)
+ *pa = (par & PAR_PA_MASK) | (va & PAR_LOW_MASK);
+ return (true);
+ }
+
+ /*
+ * Fall back to walking the page table. The address translation
+ * instruction may fail when the page is in a break-before-make
+ * sequence. As we only clear the valid bit in said sequence we
+ * can walk the page table to find the physical address.
+ */
- if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS)
- return (DMAP_TO_PHYS(va));
pte = pmap_l1(kernel_pmap, va);
if (pte == NULL)
- return (0);
+ return (false);
/*
* A concurrent pmap_update_entry() will clear the entry's valid bit
@@ -1384,20 +1410,41 @@
*/
tpte = pmap_load(pte);
if (tpte == 0)
- return (0);
- if ((tpte & ATTR_DESCR_TYPE_MASK) == ATTR_DESCR_TYPE_BLOCK)
- return ((tpte & ~ATTR_MASK) | (va & L1_OFFSET));
+ return (false);
+ if ((tpte & ATTR_DESCR_TYPE_MASK) == ATTR_DESCR_TYPE_BLOCK) {
+ if (pa != NULL)
+ *pa = (tpte & ~ATTR_MASK) | (va & L1_OFFSET);
+ return (true);
+ }
pte = pmap_l1_to_l2(&tpte, va);
tpte = pmap_load(pte);
if (tpte == 0)
- return (0);
- if ((tpte & ATTR_DESCR_TYPE_MASK) == ATTR_DESCR_TYPE_BLOCK)
- return ((tpte & ~ATTR_MASK) | (va & L2_OFFSET));
+ return (false);
+ if ((tpte & ATTR_DESCR_TYPE_MASK) == ATTR_DESCR_TYPE_BLOCK) {
+ if (pa != NULL)
+ *pa = (tpte & ~ATTR_MASK) | (va & L2_OFFSET);
+ return (true);
+ }
pte = pmap_l2_to_l3(&tpte, va);
tpte = pmap_load(pte);
if (tpte == 0)
+ return (false);
+ if (pa != NULL)
+ *pa = (tpte & ~ATTR_MASK) | (va & L3_OFFSET);
+ return (true);
+}
+
+vm_paddr_t
+pmap_kextract(vm_offset_t va)
+{
+ vm_paddr_t pa;
+
+ if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS)
+ return (DMAP_TO_PHYS(va));
+
+ if (pmap_klookup(va, &pa) == false)
return (0);
- return ((tpte & ~ATTR_MASK) | (va & L3_OFFSET));
+ return (pa);
}
/***************************************************
@@ -6833,7 +6880,7 @@
* critical section. Therefore, we must check the
* address without acquiring the kernel pmap's lock.
*/
- if (pmap_kextract(far) != 0)
+ if (pmap_klookup(far, NULL))
rv = KERN_SUCCESS;
} else {
PMAP_LOCK(pmap);
diff --git a/sys/arm64/include/armreg.h b/sys/arm64/include/armreg.h
--- a/sys/arm64/include/armreg.h
+++ b/sys/arm64/include/armreg.h
@@ -743,6 +743,7 @@
#define PAR_F (0x1 << PAR_F_SHIFT)
#define PAR_SUCCESS(x) (((x) & PAR_F) == 0)
/* When PAR_F == 0 (success) */
+#define PAR_LOW_MASK 0xfff
#define PAR_SH_SHIFT 7
#define PAR_SH_MASK (0x3 << PAR_SH_SHIFT)
#define PAR_NS_SHIFT 9
diff --git a/sys/arm64/include/pmap.h b/sys/arm64/include/pmap.h
--- a/sys/arm64/include/pmap.h
+++ b/sys/arm64/include/pmap.h
@@ -167,6 +167,7 @@
int pmap_change_attr(vm_offset_t va, vm_size_t size, int mode);
void pmap_kenter(vm_offset_t sva, vm_size_t size, vm_paddr_t pa, int mode);
void pmap_kenter_device(vm_offset_t, vm_size_t, vm_paddr_t);
+bool pmap_klookup(vm_offset_t va, vm_paddr_t *pa);
vm_paddr_t pmap_kextract(vm_offset_t va);
void pmap_kremove(vm_offset_t);
void pmap_kremove_device(vm_offset_t, vm_size_t);

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