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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2017 Broadcom4 */5 6/*7 * This driver provides reset support for Broadcom FlexRM ring manager8 * to VFIO platform.9 */10 11#include <linux/delay.h>12#include <linux/device.h>13#include <linux/init.h>14#include <linux/io.h>15#include <linux/kernel.h>16#include <linux/module.h>17 18#include "../vfio_platform_private.h"19 20/* FlexRM configuration */21#define RING_REGS_SIZE 0x1000022#define RING_VER_MAGIC 0x7630303123 24/* Per-Ring register offsets */25#define RING_VER 0x00026#define RING_CONTROL 0x03427#define RING_FLUSH_DONE 0x03828 29/* Register RING_CONTROL fields */30#define CONTROL_FLUSH_SHIFT 531 32/* Register RING_FLUSH_DONE fields */33#define FLUSH_DONE_MASK 0x134 35static int vfio_platform_bcmflexrm_shutdown(void __iomem *ring)36{37 unsigned int timeout;38 39 /* Disable/inactivate ring */40 writel_relaxed(0x0, ring + RING_CONTROL);41 42 /* Set ring flush state */43 timeout = 1000; /* timeout of 1s */44 writel_relaxed(BIT(CONTROL_FLUSH_SHIFT), ring + RING_CONTROL);45 do {46 if (readl_relaxed(ring + RING_FLUSH_DONE) &47 FLUSH_DONE_MASK)48 break;49 mdelay(1);50 } while (--timeout);51 if (!timeout)52 return -ETIMEDOUT;53 54 /* Clear ring flush state */55 timeout = 1000; /* timeout of 1s */56 writel_relaxed(0x0, ring + RING_CONTROL);57 do {58 if (!(readl_relaxed(ring + RING_FLUSH_DONE) &59 FLUSH_DONE_MASK))60 break;61 mdelay(1);62 } while (--timeout);63 if (!timeout)64 return -ETIMEDOUT;65 66 return 0;67}68 69static int vfio_platform_bcmflexrm_reset(struct vfio_platform_device *vdev)70{71 void __iomem *ring;72 int rc = 0, ret = 0, ring_num = 0;73 struct vfio_platform_region *reg = &vdev->regions[0];74 75 /* Map FlexRM ring registers if not mapped */76 if (!reg->ioaddr) {77 reg->ioaddr = ioremap(reg->addr, reg->size);78 if (!reg->ioaddr)79 return -ENOMEM;80 }81 82 /* Discover and shutdown each FlexRM ring */83 for (ring = reg->ioaddr;84 ring < (reg->ioaddr + reg->size); ring += RING_REGS_SIZE) {85 if (readl_relaxed(ring + RING_VER) == RING_VER_MAGIC) {86 rc = vfio_platform_bcmflexrm_shutdown(ring);87 if (rc) {88 dev_warn(vdev->device,89 "FlexRM ring%d shutdown error %d\n",90 ring_num, rc);91 ret |= rc;92 }93 ring_num++;94 }95 }96 97 return ret;98}99 100module_vfio_reset_handler("brcm,iproc-flexrm-mbox",101 vfio_platform_bcmflexrm_reset);102 103MODULE_LICENSE("GPL v2");104MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>");105MODULE_DESCRIPTION("Reset support for Broadcom FlexRM VFIO platform device");106