[3.11.y.z extended stable] Patch "ARM: 7864/1: Handle 64-bit memory in case of 32-bit phys_addr_t" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ARM: 7864/1: Handle 64-bit memory in case of 32-bit phys_addr_t

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 7ed46dfbcbc63658f9430e753c23a98497ed19b0 Mon Sep 17 00:00:00 2001
From: Magnus Damm <damm at opensource.se>
Date: Tue, 22 Oct 2013 17:59:54 +0100
Subject: ARM: 7864/1: Handle 64-bit memory in case of 32-bit phys_addr_t

commit 6d7d5da7d75c6df676c8b72d32b02ff024438f0c upstream.

Use CONFIG_ARCH_PHYS_ADDR_T_64BIT to determine
if ignoring or truncating of memory banks is
neccessary. This may be needed in the case of
64-bit memory bank addresses but when phys_addr_t
is kept 32-bit.

Signed-off-by: Magnus Damm <damm at opensource.se>
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
Cc: Wang Nan <wangnan0 at huawei.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/arm/kernel/setup.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index afc2489..f58f646 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -622,6 +622,7 @@ void __init dump_machine_table(void)
 int __init arm_add_memory(phys_addr_t start, phys_addr_t size)
 {
 	struct membank *bank = &meminfo.bank[meminfo.nr_banks];
+	u64 aligned_start;

 	if (meminfo.nr_banks >= NR_BANKS) {
 		printk(KERN_CRIT "NR_BANKS too low, "
@@ -634,10 +635,16 @@ int __init arm_add_memory(phys_addr_t start, phys_addr_t size)
 	 * Size is appropriately rounded down, start is rounded up.
 	 */
 	size -= start & ~PAGE_MASK;
-	bank->start = PAGE_ALIGN(start);
+	aligned_start = PAGE_ALIGN(start);

-#ifndef CONFIG_ARM_LPAE
-	if (bank->start + size < bank->start) {
+#ifndef CONFIG_ARCH_PHYS_ADDR_T_64BIT
+	if (aligned_start > ULONG_MAX) {
+		printk(KERN_CRIT "Ignoring memory at 0x%08llx outside "
+		       "32-bit physical address space\n", (long long)start);
+		return -EINVAL;
+	}
+
+	if (aligned_start + size > ULONG_MAX) {
 		printk(KERN_CRIT "Truncating memory at 0x%08llx to fit in "
 			"32-bit physical address space\n", (long long)start);
 		/*
@@ -645,10 +652,11 @@ int __init arm_add_memory(phys_addr_t start, phys_addr_t size)
 		 * 32 bits, we use ULONG_MAX as the upper limit rather than 4GB.
 		 * This means we lose a page after masking.
 		 */
-		size = ULONG_MAX - bank->start;
+		size = ULONG_MAX - aligned_start;
 	}
 #endif

+	bank->start = aligned_start;
 	bank->size = size & ~(phys_addr_t)(PAGE_SIZE - 1);

 	/*
--
1.9.1