Don't use the tpa instruction to implement pmap_kextract. The tpa

instruction requires that a translation is present in the TC. This
may trigger a TLB miss and a subsequent call to vm_fault().
This implementation is deliberately non-inline for debugging and
profiling purposes. Partial or full inlining should eventually be
done.

Valuable insights by: jake

2 files changed, 26 insertions, 8 deletions

diff --git a/sys/ia64/ia64/pmap.c b/sys/ia64/ia64/pmap.c
index 738fefc..288838e 100644
--- a/sys/ia64/ia64/pmap.c
+++ b/sys/ia64/ia64/pmap.c
@@ -1334,6 +1334,31 @@ pmap_remove_pte(pmap_t pmap, struct ia64_lpte *pte, vm_offset_t va,
 }
 
 /*
+ * Extract the physical page address associated with a kernel
+ * virtual address.
+ */
+vm_paddr_t
+pmap_kextract(vm_offset_t va)
+{
+	struct ia64_lpte *pte;
+
+	KASSERT(va >= IA64_RR_BASE(5), ("Must be kernel VA"));
+
+	/* Regions 6 and 7 are direct mapped. */
+	if (va >= IA64_RR_BASE(6))
+		return (IA64_RR_MASK(va));
+
+	/* Bail out if the virtual address is beyond our limits. */
+	if (IA64_RR_MASK(va) >= nkpt * PAGE_SIZE * NKPTEPG)
+		return (0);
+
+	pte = pmap_find_kpte(va);
+	if (!pte->pte_p)
+		return (0);
+	return ((pte->pte_ppn << 12) | (va & PAGE_MASK));
+}
+
+/*
  * Add a list of wired pages to the kva
  * this routine is only used for temporary
  * kernel mappings that do not need to have
diff --git a/sys/ia64/include/pmap.h b/sys/ia64/include/pmap.h
index 2644899..4ee712d 100644
--- a/sys/ia64/include/pmap.h
+++ b/sys/ia64/include/pmap.h
@@ -59,14 +59,6 @@
 #endif
 #define MAXKPT		(PAGE_SIZE/sizeof(vm_offset_t))
 
-/*
- *	Routine:	pmap_kextract
- *	Function:
- *		Extract the physical page address associated
- *		kernel virtual address.
- */
-#define	pmap_kextract	ia64_tpa
-
 #define	vtophys(va)	pmap_kextract(((vm_offset_t) (va)))
 
 #endif /* _KERNEL */
@@ -127,6 +119,7 @@ extern vm_offset_t virtual_end;
 vm_offset_t pmap_steal_memory(vm_size_t);
 void	pmap_bootstrap(void);
 void	pmap_kenter(vm_offset_t va, vm_offset_t pa);
+vm_paddr_t pmap_kextract(vm_offset_t va);
 void	pmap_kremove(vm_offset_t);
 void	pmap_setdevram(unsigned long long basea, vm_offset_t sizea);
 int	pmap_uses_prom_console(void);