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Revision 80ef4464d5e27408685e609d389663aad46644b9 authored by Robert Richter on 20 March 2019, 18:57:23 UTC, committed by Joerg Roedel on 22 March 2019, 11:01:58 UTC 
iommu/iova: Fix tracking of recently failed iova address
 
If a 32 bit allocation request is too big to possibly succeed, it
early exits with a failure and then should never update max32_alloc_
size. This patch fixes current code, now the size is only updated if
the slow path failed while walking the tree. Without the fix the
allocation may enter the slow path again even if there was a failure
before of a request with the same or a smaller size.

Cc: <stable@vger.kernel.org> # 4.20+
Fixes: bee60e94a1e2 ("iommu/iova: Optimise attempts to allocate iova from 32bit address range")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
1 parent 4e50ce0
Raw File
cm_sbs.c 
/*
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

#define PREFIX "ACPI: "

ACPI_MODULE_NAME("cm_sbs");
#define ACPI_AC_CLASS		"ac_adapter"
#define ACPI_BATTERY_CLASS	"battery"
#define _COMPONENT		ACPI_SBS_COMPONENT
static struct proc_dir_entry *acpi_ac_dir;
static struct proc_dir_entry *acpi_battery_dir;

static DEFINE_MUTEX(cm_sbs_mutex);

static int lock_ac_dir_cnt;
static int lock_battery_dir_cnt;

struct proc_dir_entry *acpi_lock_ac_dir(void)
{
	mutex_lock(&cm_sbs_mutex);
	if (!acpi_ac_dir)
		acpi_ac_dir = proc_mkdir(ACPI_AC_CLASS, acpi_root_dir);
	if (acpi_ac_dir) {
		lock_ac_dir_cnt++;
	} else {
		printk(KERN_ERR PREFIX
				  "Cannot create %s\n", ACPI_AC_CLASS);
	}
	mutex_unlock(&cm_sbs_mutex);
	return acpi_ac_dir;
}
EXPORT_SYMBOL(acpi_lock_ac_dir);

void acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir_param)
{
	mutex_lock(&cm_sbs_mutex);
	if (acpi_ac_dir_param)
		lock_ac_dir_cnt--;
	if (lock_ac_dir_cnt == 0 && acpi_ac_dir_param && acpi_ac_dir) {
		remove_proc_entry(ACPI_AC_CLASS, acpi_root_dir);
		acpi_ac_dir = NULL;
	}
	mutex_unlock(&cm_sbs_mutex);
}
EXPORT_SYMBOL(acpi_unlock_ac_dir);

struct proc_dir_entry *acpi_lock_battery_dir(void)
{
	mutex_lock(&cm_sbs_mutex);
	if (!acpi_battery_dir) {
		acpi_battery_dir =
		    proc_mkdir(ACPI_BATTERY_CLASS, acpi_root_dir);
	}
	if (acpi_battery_dir) {
		lock_battery_dir_cnt++;
	} else {
		printk(KERN_ERR PREFIX
				  "Cannot create %s\n", ACPI_BATTERY_CLASS);
	}
	mutex_unlock(&cm_sbs_mutex);
	return acpi_battery_dir;
}
EXPORT_SYMBOL(acpi_lock_battery_dir);

void acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir_param)
{
	mutex_lock(&cm_sbs_mutex);
	if (acpi_battery_dir_param)
		lock_battery_dir_cnt--;
	if (lock_battery_dir_cnt == 0 && acpi_battery_dir_param
	    && acpi_battery_dir) {
		remove_proc_entry(ACPI_BATTERY_CLASS, acpi_root_dir);
		acpi_battery_dir = NULL;
	}
	mutex_unlock(&cm_sbs_mutex);
	return;
}
EXPORT_SYMBOL(acpi_unlock_battery_dir);
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