Revision cf66b8a0ba142fbd1bf10ac8f3ae92d1b0cb7b8f authored by Chris Wilson on 06 December 2018, 08:44:31 UTC, committed by Joonas Lahtinen on 12 December 2018, 07:06:14 UTC
Braswell is really picky about having our writes posted to memory before
we execute or else the GPU may see stale values. A wmb() is insufficient
as it only ensures the writes are visible to other cores, we need a full
mb() to ensure the writes are in memory and visible to the GPU.

The most frequent failure in flushing before execution is that we see
stale PTE values and execute the wrong pages.

References: 987abd5c62f9 ("drm/i915/execlists: Force write serialisation into context image vs execution")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181206084431.9805-3-chris@chris-wilson.co.uk
(cherry picked from commit 490b8c65b9db45896769e1095e78725775f47b3e)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
1 parent d76b21e
Raw File
compat.c
// SPDX-License-Identifier: GPL-2.0
/*
 * 32 bit compatibility code for System V IPC
 *
 * Copyright (C) 1997,1998	Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997		David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1999		Arun Sharma <arun.sharma@intel.com>
 * Copyright (C) 2000		VA Linux Co
 * Copyright (C) 2000		Don Dugger <n0ano@valinux.com>
 * Copyright (C) 2000           Hewlett-Packard Co.
 * Copyright (C) 2000           David Mosberger-Tang <davidm@hpl.hp.com>
 * Copyright (C) 2000           Gerhard Tonn (ton@de.ibm.com)
 * Copyright (C) 2000-2002      Andi Kleen, SuSE Labs (x86-64 port)
 * Copyright (C) 2000		Silicon Graphics, Inc.
 * Copyright (C) 2001		IBM
 * Copyright (C) 2004		IBM Deutschland Entwicklung GmbH, IBM Corporation
 * Copyright (C) 2004		Arnd Bergmann (arnd@arndb.de)
 *
 * This code is collected from the versions for sparc64, mips64, s390x, ia64,
 * ppc64 and x86_64, all of which are based on the original sparc64 version
 * by Jakub Jelinek.
 *
 */
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/highuid.h>
#include <linux/init.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/syscalls.h>
#include <linux/ptrace.h>

#include <linux/mutex.h>
#include <linux/uaccess.h>

#include "util.h"

int get_compat_ipc64_perm(struct ipc64_perm *to,
			  struct compat_ipc64_perm __user *from)
{
	struct compat_ipc64_perm v;
	if (copy_from_user(&v, from, sizeof(v)))
		return -EFAULT;
	to->uid = v.uid;
	to->gid = v.gid;
	to->mode = v.mode;
	return 0;
}

int get_compat_ipc_perm(struct ipc64_perm *to,
			struct compat_ipc_perm __user *from)
{
	struct compat_ipc_perm v;
	if (copy_from_user(&v, from, sizeof(v)))
		return -EFAULT;
	to->uid = v.uid;
	to->gid = v.gid;
	to->mode = v.mode;
	return 0;
}

void to_compat_ipc64_perm(struct compat_ipc64_perm *to, struct ipc64_perm *from)
{
	to->key = from->key;
	to->uid = from->uid;
	to->gid = from->gid;
	to->cuid = from->cuid;
	to->cgid = from->cgid;
	to->mode = from->mode;
	to->seq = from->seq;
}

void to_compat_ipc_perm(struct compat_ipc_perm *to, struct ipc64_perm *from)
{
	to->key = from->key;
	SET_UID(to->uid, from->uid);
	SET_GID(to->gid, from->gid);
	SET_UID(to->cuid, from->cuid);
	SET_GID(to->cgid, from->cgid);
	to->mode = from->mode;
	to->seq = from->seq;
}
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