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 dev_err_once(vdev->device, "DEPRECATION: VFIO Broadcom FlexRM platform reset is deprecated and will be removed in a future kernel release\n"); 76 77 /* Map FlexRM ring registers if not mapped */ 78 if (!reg->ioaddr) { 79 reg->ioaddr = ioremap(reg->addr, reg->size); 80 if (!reg->ioaddr) 81 return -ENOMEM; 82 } 83 84 /* Discover and shutdown each FlexRM ring */ 85 for (ring = reg->ioaddr; 86 ring < (reg->ioaddr + reg->size); ring += RING_REGS_SIZE) { 87 if (readl_relaxed(ring + RING_VER) == RING_VER_MAGIC) { 88 rc = vfio_platform_bcmflexrm_shutdown(ring); 89 if (rc) { 90 dev_warn(vdev->device, 91 "FlexRM ring%d shutdown error %d\n", 92 ring_num, rc); 93 ret |= rc; 94 } 95 ring_num++; 96 } 97 } 98 99 return ret; 100 } 101 102 module_vfio_reset_handler("brcm,iproc-flexrm-mbox", 103 vfio_platform_bcmflexrm_reset); 104 105 MODULE_LICENSE("GPL v2"); 106 MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>"); 107 MODULE_DESCRIPTION("Reset support for Broadcom FlexRM VFIO platform device"); 108