linux/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
Anup Patel e25883411e vfio: platform: reset: Add Broadcom FlexRM reset module
This patch adds Broadcom FlexRM low-level reset for
VFIO platform.

It will do the following:
1. Disable/Deactivate each FlexRM ring
2. Flush each FlexRM ring

The cleanup sequence for FlexRM rings is adapted from
Broadcom FlexRM mailbox driver.

Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Oza Oza <oza.oza@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-10-20 11:43:24 -06:00

114 lines
2.8 KiB
C

/*
* Copyright (C) 2017 Broadcom
*
* 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 version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* This driver provides reset support for Broadcom FlexRM ring manager
* to VFIO platform.
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include "vfio_platform_private.h"
/* FlexRM configuration */
#define RING_REGS_SIZE 0x10000
#define RING_VER_MAGIC 0x76303031
/* Per-Ring register offsets */
#define RING_VER 0x000
#define RING_CONTROL 0x034
#define RING_FLUSH_DONE 0x038
/* Register RING_CONTROL fields */
#define CONTROL_FLUSH_SHIFT 5
/* Register RING_FLUSH_DONE fields */
#define FLUSH_DONE_MASK 0x1
static int vfio_platform_bcmflexrm_shutdown(void __iomem *ring)
{
unsigned int timeout;
/* Disable/inactivate ring */
writel_relaxed(0x0, ring + RING_CONTROL);
/* Set ring flush state */
timeout = 1000; /* timeout of 1s */
writel_relaxed(BIT(CONTROL_FLUSH_SHIFT), ring + RING_CONTROL);
do {
if (readl_relaxed(ring + RING_FLUSH_DONE) &
FLUSH_DONE_MASK)
break;
mdelay(1);
} while (--timeout);
if (!timeout)
return -ETIMEDOUT;
/* Clear ring flush state */
timeout = 1000; /* timeout of 1s */
writel_relaxed(0x0, ring + RING_CONTROL);
do {
if (!(readl_relaxed(ring + RING_FLUSH_DONE) &
FLUSH_DONE_MASK))
break;
mdelay(1);
} while (--timeout);
if (!timeout)
return -ETIMEDOUT;
return 0;
}
static int vfio_platform_bcmflexrm_reset(struct vfio_platform_device *vdev)
{
void __iomem *ring;
int rc = 0, ret = 0, ring_num = 0;
struct vfio_platform_region *reg = &vdev->regions[0];
/* Map FlexRM ring registers if not mapped */
if (!reg->ioaddr) {
reg->ioaddr = ioremap_nocache(reg->addr, reg->size);
if (!reg->ioaddr)
return -ENOMEM;
}
/* Discover and shutdown each FlexRM ring */
for (ring = reg->ioaddr;
ring < (reg->ioaddr + reg->size); ring += RING_REGS_SIZE) {
if (readl_relaxed(ring + RING_VER) == RING_VER_MAGIC) {
rc = vfio_platform_bcmflexrm_shutdown(ring);
if (rc) {
dev_warn(vdev->device,
"FlexRM ring%d shutdown error %d\n",
ring_num, rc);
ret |= rc;
}
ring_num++;
}
}
return ret;
}
module_vfio_reset_handler("brcm,iproc-flexrm-mbox",
vfio_platform_bcmflexrm_reset);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>");
MODULE_DESCRIPTION("Reset support for Broadcom FlexRM VFIO platform device");