Patch set updated for coreboot: 385bd6f ARMV7: add a function to disable MMU entries

[Paul Menzel]

Paul Menzel ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3160

-gerrit

commit 385bd6f069309d07c50a103651305ae8d7212e05
Author: Ronald G. Minnich 
Date:   Tue Apr 30 10:11:30 2013 -0700

ARMV7: add a function to disable MMU entries

It is useful to be able to lock out certain address ranges,
    NULL being the most important example.

void mmu_disable_range(unsigned long start_mb, unsigned long size_mb)

will allow us to lock out selected virtual addresses on MiB boundaries.
    As in other ARM mmu functions, the addresses and quantities are in units
    of MiB.

Change-Id: If516ce955ee2d12c5a409f25acbb5a4b424f699b
    Signed-off-by: Ronald G. Minnich 
---
 src/arch/armv7/include/arch/cache.h |  2 ++
 src/arch/armv7/lib/mmu.c            | 13 +++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/src/arch/armv7/include/arch/cache.h b/src/arch/armv7/include/arch/cache.h
index 028cf18..d5c3a5b 100644
--- a/src/arch/armv7/include/arch/cache.h
+++ b/src/arch/armv7/include/arch/cache.h
@@ -303,6 +303,8 @@ enum dcache_policy {
    DCACHE_WRITETHROUGH,
 };

+/* disable the mmu for a range. Primarily useful to lock out address 0. */
+void mmu_disable_range(unsigned long start_mb, unsigned long size_mb);
 /* mmu range configuration (set dcache policy) */
 void mmu_config_range(unsigned long start_mb, unsigned long size_mb,
    					enum dcache_policy policy);
diff --git a/src/arch/armv7/lib/mmu.c b/src/arch/armv7/lib/mmu.c
index 224b566..82c7358 100644
--- a/src/arch/armv7/lib/mmu.c
+++ b/src/arch/armv7/lib/mmu.c
@@ -39,6 +39,19 @@

static uintptr_t ttb_addr;

+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);
+
+	for (i = start_mb; i < start_mb + size_mb; i++) {
+		ttb_entry[i] = 0;
+		tlbimvaa(i);
+	}
+}
+
 void mmu_config_range(unsigned long start_mb, unsigned long size_mb,
    	enum dcache_policy policy)
 {