/* * 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(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");