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Revision b85bfa246efd24ea3fdb5ee949c28e3110c6d299 authored by Daniel Kurtz on 22 September 2018, 19:58:26 UTC, committed by Linus Walleij on 25 September 2018, 10:39:19 UTC 
pinctrl/amd: poll InterruptEnable bits in amd_gpio_irq_set_type
 
From the AMD BKDG, if WAKE_INT_MASTER_REG.MaskStsEn is set, a software
write to the debounce registers of *any* gpio will block wake/interrupt
status generation for *all* gpios for a length of time that depends on
WAKE_INT_MASTER_REG.MaskStsLength[11:0].  During this period the Interrupt
Delivery bit (INTERRUPT_ENABLE) will read as 0.

In commit 4c1de0414a1340 ("pinctrl/amd: poll InterruptEnable bits in
enable_irq") we tried to fix this same "gpio Interrupts are blocked
immediately after writing debounce registers" problem, but incorrectly
assumed it only affected the gpio whose debounce was being configured
and not ALL gpios.

To solve this for all gpios, we move the polling loop from
amd_gpio_irq_enable() to amd_gpio_irq_set_type(), while holding the gpio
spinlock.  This ensures that another gpio operation (e.g.
amd_gpio_irq_unmask()) can read a temporarily disabled IRQ and
incorrectly disable it while trying to modify some other register bits.

Fixes: 4c1de0414a1340 pinctrl/amd: poll InterruptEnable bits in enable_irq
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
1 parent 6bf4ca7
Raw File
msgpool.c 
// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>

#include <linux/err.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/vmalloc.h>

#include <linux/ceph/messenger.h>
#include <linux/ceph/msgpool.h>

static void *msgpool_alloc(gfp_t gfp_mask, void *arg)
{
	struct ceph_msgpool *pool = arg;
	struct ceph_msg *msg;

	msg = ceph_msg_new(pool->type, pool->front_len, gfp_mask, true);
	if (!msg) {
		dout("msgpool_alloc %s failed\n", pool->name);
	} else {
		dout("msgpool_alloc %s %p\n", pool->name, msg);
		msg->pool = pool;
	}
	return msg;
}

static void msgpool_free(void *element, void *arg)
{
	struct ceph_msgpool *pool = arg;
	struct ceph_msg *msg = element;

	dout("msgpool_release %s %p\n", pool->name, msg);
	msg->pool = NULL;
	ceph_msg_put(msg);
}

int ceph_msgpool_init(struct ceph_msgpool *pool, int type,
		      int front_len, int size, bool blocking, const char *name)
{
	dout("msgpool %s init\n", name);
	pool->type = type;
	pool->front_len = front_len;
	pool->pool = mempool_create(size, msgpool_alloc, msgpool_free, pool);
	if (!pool->pool)
		return -ENOMEM;
	pool->name = name;
	return 0;
}

void ceph_msgpool_destroy(struct ceph_msgpool *pool)
{
	dout("msgpool %s destroy\n", pool->name);
	mempool_destroy(pool->pool);
}

struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool,
				  int front_len)
{
	struct ceph_msg *msg;

	if (front_len > pool->front_len) {
		dout("msgpool_get %s need front %d, pool size is %d\n",
		       pool->name, front_len, pool->front_len);
		WARN_ON(1);

		/* try to alloc a fresh message */
		return ceph_msg_new(pool->type, front_len, GFP_NOFS, false);
	}

	msg = mempool_alloc(pool->pool, GFP_NOFS);
	dout("msgpool_get %s %p\n", pool->name, msg);
	return msg;
}

void ceph_msgpool_put(struct ceph_msgpool *pool, struct ceph_msg *msg)
{
	dout("msgpool_put %s %p\n", pool->name, msg);

	/* reset msg front_len; user may have changed it */
	msg->front.iov_len = pool->front_len;
	msg->hdr.front_len = cpu_to_le32(pool->front_len);

	kref_init(&msg->kref);  /* retake single ref */
	mempool_free(msg, pool->pool);
}
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