From b503d5c50ea1594863626b8fb6f29522573db49d Mon Sep 17 00:00:00 2001
From: Neel Natu <neel@FreeBSD.org>
Date: Tue, 14 Sep 2010 01:27:53 +0000
Subject: [PATCH] Enforce that pmap_mapdev() always returns uncacheable
 mappings.

Reviewed by:	imp, jchandra, jmallett
---
 sys/mips/mips/pmap.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/sys/mips/mips/pmap.c b/sys/mips/mips/pmap.c
index 89332d3168c..6d212f7513d 100644
--- a/sys/mips/mips/pmap.c
+++ b/sys/mips/mips/pmap.c
@@ -828,8 +828,8 @@ retry:
 /*
  * add a wired page to the kva
  */
- /* PMAP_INLINE */ void
-pmap_kenter(vm_offset_t va, vm_paddr_t pa)
+static void
+pmap_kenter_attr(vm_offset_t va, vm_paddr_t pa, int attr)
 {
 	pt_entry_t *pte;
 	pt_entry_t opte, npte;
@@ -837,12 +837,7 @@ pmap_kenter(vm_offset_t va, vm_paddr_t pa)
 #ifdef PMAP_DEBUG
 	printf("pmap_kenter:  va: %p -> pa: %p\n", (void *)va, (void *)pa);
 #endif
-	npte = TLBLO_PA_TO_PFN(pa) | PTE_D | PTE_V | PTE_G | PTE_W;
-
-	if (is_cacheable_mem(pa))
-		npte |= PTE_C_CACHE;
-	else
-		npte |= PTE_C_UNCACHED;
+	npte = TLBLO_PA_TO_PFN(pa) | PTE_D | PTE_V | PTE_G | PTE_W | attr;
 
 	pte = pmap_pte(kernel_pmap, va);
 	opte = *pte;
@@ -851,6 +846,19 @@ pmap_kenter(vm_offset_t va, vm_paddr_t pa)
 		pmap_update_page(kernel_pmap, va, npte);
 }
 
+void
+pmap_kenter(vm_offset_t va, vm_paddr_t pa)
+{
+	int attr;
+
+	if (is_cacheable_mem(pa))
+		attr = PTE_C_CACHE;
+	else
+		attr = PTE_C_UNCACHED;
+
+	pmap_kenter_attr(va, pa, attr);
+}
+
 /*
  * remove a page from the kernel pagetables
  */
@@ -2863,7 +2871,7 @@ pmap_mapdev(vm_offset_t pa, vm_size_t size)
 			panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
 		pa = trunc_page(pa);
 		for (tmpva = va; size > 0;) {
-			pmap_kenter(tmpva, pa);
+			pmap_kenter_attr(tmpva, pa, PTE_C_UNCACHED);
 			size -= PAGE_SIZE;
 			tmpva += PAGE_SIZE;
 			pa += PAGE_SIZE;