[coreboot-gerrit] New patch to review for coreboot: 80bf2c5 ARM: Fix up page table/cachability management.

[Gabe Black]

Gabe Black ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3653

-gerrit

commit 80bf2c53a23020cf05757a185cb6d8fa1e652e3c
Author: Gabe Black 
Date:   Sat May 18 22:45:54 2013 -0700

ARM: Fix up page table/cachability management.

When modifying the page tables, use writel to ensure the writes happen, flush
    the page tables themselves to ensure they're visible to the MMU if it doesn't
    look at the caches, and invalidate the right TLB entries.

The first two changes are probably safer but may not be strictly necessary.
    The third change is necessary because we were invalidating the TLB using i
    which was in megabytes but using an instruction that expects an address in
    bytes.

One symptom of this problem was that the framebuffer, which was supposed to be
    marked uncacheable, was only being partially updated since some of the updates
    were still in the cache. With this change the graphics show up correctly.

Change-Id: I5475df29690371459b0d37a304eebc62f81dd76b
    Signed-off-by: Gabe Black 
---
 src/arch/armv7/lib/mmu.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/arch/armv7/lib/mmu.c b/src/arch/armv7/lib/mmu.c
index 594bba5..7d6d46a 100644
--- a/src/arch/armv7/lib/mmu.c
+++ b/src/arch/armv7/lib/mmu.c
@@ -34,6 +34,7 @@
 #include <console/console.h>

#include <arch/cache.h>
+#include <arch/io.h>

#define L1_TLB_ENTRIES	4096	/* 1 entry for each 1MB address space */

@@ -44,11 +45,14 @@ void mmu_disable_range(unsigned long start_mb, unsigned long size_mb)
    unsigned int i;
    uint32_t *ttb_entry = (uint32_t *)ttb_addr;
    printk(BIOS_DEBUG, "Disabling: 0x%08lx:0x%08lx\n",
-			start_mb << 20, ((start_mb + size_mb) << 20) - 1);
+			start_mb*MiB, start_mb*MiB + size_mb*MiB - 1);
+
+	for (i = start_mb; i < start_mb + size_mb; i++)
+		writel(0, &ttb_entry[i]);

for (i = start_mb; i < start_mb + size_mb; i++) {
-		ttb_entry[i] = 0;
-		tlbimvaa(i);
+		dccmvac((uintptr_t)&ttb_entry[i]);
+		tlbimvaa(i*MiB);
    }
 }

@@ -99,9 +103,14 @@ void mmu_config_range(unsigned long start_mb, unsigned long size_mb,
    printk(BIOS_DEBUG, "Setting dcache policy: 0x%08lx:0x%08lx [%s]\n",
    		start_mb << 20, ((start_mb + size_mb) << 20) - 1, str);

+	/* Write out page table entries. */
+	for (i = start_mb; i < start_mb + size_mb; i++)
+		writel((i << 20) | attr, &ttb_entry[i]);
+
+	/* Flush the page table entries, and old translations from the TLB. */
    for (i = start_mb; i < start_mb + size_mb; i++) {
-		ttb_entry[i] = (i << 20) | attr;
-		tlbimvaa(start_mb);
+		dccmvac((uintptr_t)&ttb_entry[i]);
+		tlbimvaa(i*MiB);
    }
 }