linux-kernel - [tip:x86/gart] x86, gart: Don't enforce GART aperture lower-bound by alignment

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 18 Apr 2011 18:39:53 GMT
From:	tip-bot for Joerg Roedel <joerg.roedel@....com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...hat.com,
	yinghai@...nel.org, joerg.roedel@....com, tglx@...utronix.de
Subject: [tip:x86/gart] x86, gart: Don't enforce GART aperture lower-bound by alignment

Commit-ID:  c387aa3a1a910ce00b86f3a85082d24f144db256
Gitweb:     http://git.kernel.org/tip/c387aa3a1a910ce00b86f3a85082d24f144db256
Author:     Joerg Roedel <joerg.roedel@....com>
AuthorDate: Mon, 18 Apr 2011 15:45:43 +0200
Committer:  H. Peter Anvin <hpa@...ux.intel.com>
CommitDate: Mon, 18 Apr 2011 10:31:38 -0700

x86, gart: Don't enforce GART aperture lower-bound by alignment

This patch changes the allocation of the GART aperture to
enforce only natural alignment instead of aligning it on
512MB. This big alignment was used to force the GART
aperture to be over 512MB. This is enforced by using 512MB
as the lower-bound address in the allocation range.

[ hpa: The actual number 512 MiB needs to be revisited, too. ]

Cc: Yinghai Lu <yinghai@...nel.org>
Signed-off-by: Joerg Roedel <joerg.roedel@....com>
Link: http://lkml.kernel.org/r/1303134346-5805-2-git-send-email-joerg.roedel@amd.com
Signed-off-by: H. Peter Anvin <hpa@...or.com>
---
 arch/x86/kernel/aperture_64.c |   34 +++++++++++++++++++---------------
 1 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 73fb469..3d2661c 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -30,6 +30,22 @@
 #include <asm/amd_nb.h>
 #include <asm/x86_init.h>
 
+/*
+ * Using 512M as goal, in case kexec will load kernel_big
+ * that will do the on-position decompress, and could overlap with
+ * with the gart aperture that is used.
+ * Sequence:
+ * kernel_small
+ * ==> kexec (with kdump trigger path or gart still enabled)
+ * ==> kernel_small (gart area become e820_reserved)
+ * ==> kexec (with kdump trigger path or gart still enabled)
+ * ==> kerne_big (uncompressed size will be big than 64M or 128M)
+ * So don't use 512M below as gart iommu, leave the space for kernel
+ * code for safe.
+ */
+#define GART_MIN_ADDR	(512ULL << 20)
+#define GART_MAX_ADDR	(1ULL   << 32)
+
 int gart_iommu_aperture;
 int gart_iommu_aperture_disabled __initdata;
 int gart_iommu_aperture_allowed __initdata;
@@ -70,21 +86,9 @@ static u32 __init allocate_aperture(void)
 	 * memory. Unfortunately we cannot move it up because that would
 	 * make the IOMMU useless.
 	 */
-	/*
-	 * using 512M as goal, in case kexec will load kernel_big
-	 * that will do the on position decompress, and  could overlap with
-	 * that position with gart that is used.
-	 * sequende:
-	 * kernel_small
-	 * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
-	 * ==> kernel_small(gart area become e820_reserved)
-	 * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
-	 * ==> kerne_big (uncompressed size will be big than 64M or 128M)
-	 * so don't use 512M below as gart iommu, leave the space for kernel
-	 * code for safe
-	 */
-	addr = memblock_find_in_range(0, 1ULL<<32, aper_size, 512ULL<<20);
-	if (addr == MEMBLOCK_ERROR || addr + aper_size > 0xffffffff) {
+	addr = memblock_find_in_range(GART_MIN_ADDR, GART_MAX_ADDR,
+				      aper_size, aper_size);
+	if (addr == MEMBLOCK_ERROR || addr + aper_size > GART_MAX_ADDR) {
 		printk(KERN_ERR
 			"Cannot allocate aperture memory hole (%lx,%uK)\n",
 				addr, aper_size>>10);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/