x86 mmiotrace: use lookup_address()

Use lookup_address() from pageattr.c instead of doing the same
manually. Also had to EXPORT_SYMBOL_GPL(lookup_address) to make this
work for modules. This also fixes "undefined symbol 'init_mm'"
compile error for x86_32.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 43 insertions, 22 deletions

diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c
index 8ba48f9c91b4..28411dadb8b3 100644
--- a/arch/x86/kernel/mmiotrace/kmmio.c
+++ b/arch/x86/kernel/mmiotrace/kmmio.c
@@ -20,6 +20,7 @@
 #include <asm/cacheflush.h>
 #include <asm/errno.h>
 #include <asm/tlbflush.h>
+#include <asm/pgtable.h>
 
 #include "kmmio.h"
 
@@ -117,40 +118,55 @@ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page)
         return NULL;
 }
 
-static void arm_kmmio_fault_page(unsigned long page, int *large)
+static void arm_kmmio_fault_page(unsigned long page, int *page_level)
 {
         unsigned long address = page & PAGE_MASK;
-        pgd_t *pgd = pgd_offset_k(address);
-        pud_t *pud = pud_offset(pgd, address);
-        pmd_t *pmd = pmd_offset(pud, address);
-        pte_t *pte = pte_offset_kernel(pmd, address);
+        int level;
+        pte_t *pte = lookup_address(address, &level);
 
-        if (pmd_large(*pmd)) {
+        if (!pte) {
+                printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n",
+                                                __FUNCTION__, page);
+                return;
+        }
+
+        if (level == PG_LEVEL_2M) {
+                pmd_t *pmd = (pmd_t *)pte;
                 set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_PRESENT));
-                if (large)
-                        *large = 1;
         } else {
+                /* PG_LEVEL_4K */
                 set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
         }
 
+        if (page_level)
+                *page_level = level;
+
         __flush_tlb_one(page);
 }
 
-static void disarm_kmmio_fault_page(unsigned long page, int *large)
+static void disarm_kmmio_fault_page(unsigned long page, int *page_level)
 {
         unsigned long address = page & PAGE_MASK;
-        pgd_t *pgd = pgd_offset_k(address);
-        pud_t *pud = pud_offset(pgd, address);
-        pmd_t *pmd = pmd_offset(pud, address);
-        pte_t *pte = pte_offset_kernel(pmd, address);
+        int level;
+        pte_t *pte = lookup_address(address, &level);
 
-        if (large && *large) {
+        if (!pte) {
+                printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n",
+                                                __FUNCTION__, page);
+                return;
+        }
+
+        if (level == PG_LEVEL_2M) {
+                pmd_t *pmd = (pmd_t *)pte;
                 set_pmd(pmd, __pmd(pmd_val(*pmd) | _PAGE_PRESENT));
-                *large = 0;
         } else {
+                /* PG_LEVEL_4K */
                 set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
         }
 
+        if (page_level)
+                *page_level = level;
+
         __flush_tlb_one(page);
 }
 
diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c
index 73561fe85f03..e43947d218a5 100644
--- a/arch/x86/kernel/mmiotrace/mmio-mod.c
+++ b/arch/x86/kernel/mmiotrace/mmio-mod.c
@@ -120,19 +120,24 @@ static int write_marker(struct file *file, const char __user *buffer,
 
 static void print_pte(unsigned long address)
 {
-        pgd_t *pgd = pgd_offset_k(address);
-        pud_t *pud = pud_offset(pgd, address);
-        pmd_t *pmd = pmd_offset(pud, address);
-        if (pmd_large(*pmd)) {
+        int level;
+        pte_t *pte = lookup_address(address, &level);
+
+        if (!pte) {
+                printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n",
+                                                __FUNCTION__, address);
+                return;
+        }
+
+        if (level == PG_LEVEL_2M) {
                 printk(KERN_EMERG MODULE_NAME ": 4MB pages are not "
                                                 "currently supported: %lx\n",
                                                 address);
                 BUG();
         }
         printk(KERN_DEBUG MODULE_NAME ": pte for 0x%lx: 0x%lx 0x%lx\n",
-                address,
-                pte_val(*pte_offset_kernel(pmd, address)),
-                pte_val(*pte_offset_kernel(pmd, address)) & _PAGE_PRESENT);
+                                        address, pte_val(*pte),
+                                        pte_val(*pte) & _PAGE_PRESENT);
 }
 
 /*