1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2017 Broadcom 4 */ 5 6 /* 7 * This driver provides reset support for Broadcom FlexRM ring manager 8 * 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 0x10000 22 #define RING_VER_MAGIC 0x76303031 23 24 /* Per-Ring register offsets */ 25 #define RING_VER 0x000 26 #define RING_CONTROL 0x034 27 #define RING_FLUSH_DONE 0x038 28 29 /* Register RING_CONTROL fields */ 30 #define CONTROL_FLUSH_SHIFT 5 31 32 /* Register RING_FLUSH_DONE fields */ 33 #define FLUSH_DONE_MASK 0x1 34 35 static 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 69 static 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 } 99 100 module_vfio_reset_handler("brcm,iproc-flexrm-mbox", 101 vfio_platform_bcmflexrm_reset); 102 103 MODULE_LICENSE("GPL v2"); 104 MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>"); 105 MODULE_DESCRIPTION("Reset support for Broadcom FlexRM VFIO platform device"); 106