linux-brain/arch/arm/mach-ep93xx/crunch.c
Gustavo A. R. Silva 1f7585f30a ARM: ep93xx: Mark expected switch fall-through
Mark switch cases where we are expecting to fall through.

Fix the following warnings (Building: arm-ep93xx_defconfig arm):

arch/arm/mach-ep93xx/crunch.c: In function 'crunch_do':
arch/arm/mach-ep93xx/crunch.c:46:3: warning: this statement may
fall through [-Wimplicit-fallthrough=]
      memset(crunch_state, 0, sizeof(*crunch_state));
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/arm/mach-ep93xx/crunch.c:53:2: note: here
     case THREAD_NOTIFY_EXIT:
     ^~~~

Notice that, in this particular case, the code comment is
modified in accordance with what GCC is expecting to find.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
2019-08-09 19:53:35 -05:00

87 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* arch/arm/kernel/crunch.c
* Cirrus MaverickCrunch context switching and handling
*
* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/io.h>
#include <asm/thread_notify.h>
#include "soc.h"
struct crunch_state *crunch_owner;
void crunch_task_release(struct thread_info *thread)
{
local_irq_disable();
if (crunch_owner == &thread->crunchstate)
crunch_owner = NULL;
local_irq_enable();
}
static int crunch_enabled(u32 devcfg)
{
return !!(devcfg & EP93XX_SYSCON_DEVCFG_CPENA);
}
static int crunch_do(struct notifier_block *self, unsigned long cmd, void *t)
{
struct thread_info *thread = (struct thread_info *)t;
struct crunch_state *crunch_state;
u32 devcfg;
crunch_state = &thread->crunchstate;
switch (cmd) {
case THREAD_NOTIFY_FLUSH:
memset(crunch_state, 0, sizeof(*crunch_state));
/*
* FALLTHROUGH: Ensure we don't try to overwrite our newly
* initialised state information on the first fault.
*/
/* Fall through */
case THREAD_NOTIFY_EXIT:
crunch_task_release(thread);
break;
case THREAD_NOTIFY_SWITCH:
devcfg = __raw_readl(EP93XX_SYSCON_DEVCFG);
if (crunch_enabled(devcfg) || crunch_owner == crunch_state) {
/*
* We don't use ep93xx_syscon_swlocked_write() here
* because we are on the context switch path and
* preemption is already disabled.
*/
devcfg ^= EP93XX_SYSCON_DEVCFG_CPENA;
__raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
__raw_writel(devcfg, EP93XX_SYSCON_DEVCFG);
}
break;
}
return NOTIFY_DONE;
}
static struct notifier_block crunch_notifier_block = {
.notifier_call = crunch_do,
};
int __init crunch_init(void)
{
thread_register_notifier(&crunch_notifier_block);
elf_hwcap |= HWCAP_CRUNCH;
return 0;
}