linux-kernel - [PATCH] xe: avoid using writeq() on 32-bit

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-next>] [day] [month] [year] [list]

Date: Wed, 28 Feb 2024 13:27:33 +0100
From: Arnd Bergmann <arnd@...nel.org>
To: Lucas De Marchi <lucas.demarchi@...el.com>,
	Oded Gabbay <ogabbay@...nel.org>,
	Thomas Hellström <thomas.hellstrom@...ux.intel.com>
Cc: Arnd Bergmann <arnd@...db.de>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Daniel Vetter <daniel@...ll.ch>,
	Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Matt Roper <matthew.d.roper@...el.com>,
	Matthew Auld <matthew.auld@...el.com>,
	Matthew Brost <matthew.brost@...el.com>,
	Michal Wajdeczko <michal.wajdeczko@...el.com>,
	intel-xe@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] xe: avoid using writeq() on 32-bit

From: Arnd Bergmann <arnd@...db.de>

32-bit kernels do not provide a writeq(), failing the build:

drivers/gpu/drm/xe/xe_ggtt.c:78:2: error: use of undeclared identifier 'writeq'
   78 |         writeq(pte, &ggtt->gsm[addr >> XE_PTE_SHIFT]);

Using lo_hi_writeq() instead will write the lower 32 bits to the address
before writing the upper 32 bits to the following word, which is likely
the correct replacement to do on 32-bit targets.

Include the linux/io-64-nonatomic-lo-hi.h header to automatically pick
the regular writeq() on 64-bit machines but fall back to lo_hi_writeq()
on 32-bit ones.

Fixes: 237412e45390 ("drm/xe: Enable 32bits build")
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/gpu/drm/xe/xe_ggtt.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c
index 5d46958e3144..1ffcc63ca86d 100644
--- a/drivers/gpu/drm/xe/xe_ggtt.c
+++ b/drivers/gpu/drm/xe/xe_ggtt.c
@@ -6,6 +6,7 @@
 #include "xe_ggtt.h"
 
 #include <linux/sizes.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
 
 #include <drm/drm_managed.h>
 #include <drm/i915_drm.h>
-- 
2.39.2