// SPDX-License-Identifier: GPL-2.0-only /* * Mediated virtual PCI serial host device driver * * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. * Author: Neo Jia * Kirti Wankhede * * Sample driver that creates mdev device that simulates serial port over PCI * card. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * #defines */ #define VERSION_STRING "0.1" #define DRIVER_AUTHOR "NVIDIA Corporation" #define MTTY_CLASS_NAME "mtty" #define MTTY_NAME "mtty" #define MTTY_STRING_LEN 16 #define MTTY_CONFIG_SPACE_SIZE 0xff #define MTTY_IO_BAR_SIZE 0x8 #define MTTY_MMIO_BAR_SIZE 0x100000 #define STORE_LE16(addr, val) (*(u16 *)addr = val) #define STORE_LE32(addr, val) (*(u32 *)addr = val) #define MAX_FIFO_SIZE 16 #define CIRCULAR_BUF_INC_IDX(idx) (idx = (idx + 1) & (MAX_FIFO_SIZE - 1)) #define MTTY_VFIO_PCI_OFFSET_SHIFT 40 #define MTTY_VFIO_PCI_OFFSET_TO_INDEX(off) (off >> MTTY_VFIO_PCI_OFFSET_SHIFT) #define MTTY_VFIO_PCI_INDEX_TO_OFFSET(index) \ ((u64)(index) << MTTY_VFIO_PCI_OFFSET_SHIFT) #define MTTY_VFIO_PCI_OFFSET_MASK \ (((u64)(1) << MTTY_VFIO_PCI_OFFSET_SHIFT) - 1) #define MAX_MTTYS 24 /* * Global Structures */ static struct mtty_dev { dev_t vd_devt; struct class *vd_class; struct cdev vd_cdev; struct idr vd_idr; struct device dev; struct mdev_parent parent; } mtty_dev; struct mdev_region_info { u64 start; u64 phys_start; u32 size; u64 vfio_offset; }; #if defined(DEBUG_REGS) static const char *wr_reg[] = { "TX", "IER", "FCR", "LCR", "MCR", "LSR", "MSR", "SCR" }; static const char *rd_reg[] = { "RX", "IER", "IIR", "LCR", "MCR", "LSR", "MSR", "SCR" }; #endif /* loop back buffer */ struct rxtx { u8 fifo[MAX_FIFO_SIZE]; u8 head, tail; u8 count; }; struct serial_port { u8 uart_reg[8]; /* 8 registers */ struct rxtx rxtx; /* loop back buffer */ bool dlab; bool overrun; u16 divisor; u8 fcr; /* FIFO control register */ u8 max_fifo_size; u8 intr_trigger_level; /* interrupt trigger level */ }; /* State of each mdev device */ struct mdev_state { struct vfio_device vdev; int irq_fd; struct eventfd_ctx *intx_evtfd; struct eventfd_ctx *msi_evtfd; int irq_index; u8 *vconfig; struct mutex ops_lock; struct mdev_device *mdev; struct mdev_region_info region_info[VFIO_PCI_NUM_REGIONS]; u32 bar_mask[VFIO_PCI_NUM_REGIONS]; struct list_head next; struct serial_port s[2]; struct mutex rxtx_lock; struct vfio_device_info dev_info; int nr_ports; }; static struct mtty_type { struct mdev_type type; int nr_ports; } mtty_types[2] = { { .nr_ports = 1, .type.sysfs_name = "1", .type.pretty_name = "Single port serial" }, { .nr_ports = 2, .type.sysfs_name = "2", .type.pretty_name = "Dual port serial" }, }; static struct mdev_type *mtty_mdev_types[] = { &mtty_types[0].type, &mtty_types[1].type, }; static atomic_t mdev_avail_ports = ATOMIC_INIT(MAX_MTTYS); static const struct file_operations vd_fops = { .owner = THIS_MODULE, }; static const struct vfio_device_ops mtty_dev_ops; /* function prototypes */ static int mtty_trigger_interrupt(struct mdev_state *mdev_state); /* Helper functions */ static void dump_buffer(u8 *buf, uint32_t count) { #if defined(DEBUG) int i; pr_info("Buffer:\n"); for (i = 0; i < count; i++) { pr_info("%2x ", *(buf + i)); if ((i + 1) % 16 == 0) pr_info("\n"); } #endif } static void mtty_create_config_space(struct mdev_state *mdev_state) { /* PCI dev ID */ STORE_LE32((u32 *) &mdev_state->vconfig[0x0], 0x32534348); /* Control: I/O+, Mem-, BusMaster- */ STORE_LE16((u16 *) &mdev_state->vconfig[0x4], 0x0001); /* Status: capabilities list absent */ STORE_LE16((u16 *) &mdev_state->vconfig[0x6], 0x0200); /* Rev ID */ mdev_state->vconfig[0x8] = 0x10; /* programming interface class : 16550-compatible serial controller */ mdev_state->vconfig[0x9] = 0x02; /* Sub class : 00 */ mdev_state->vconfig[0xa] = 0x00; /* Base class : Simple Communication controllers */ mdev_state->vconfig[0xb] = 0x07; /* base address registers */ /* BAR0: IO space */ STORE_LE32((u32 *) &mdev_state->vconfig[0x10], 0x000001); mdev_state->bar_mask[0] = ~(MTTY_IO_BAR_SIZE) + 1; if (mdev_state->nr_ports == 2) { /* BAR1: IO space */ STORE_LE32((u32 *) &mdev_state->vconfig[0x14], 0x000001); mdev_state->bar_mask[1] = ~(MTTY_IO_BAR_SIZE) + 1; } /* Subsystem ID */ STORE_LE32((u32 *) &mdev_state->vconfig[0x2c], 0x32534348); mdev_state->vconfig[0x34] = 0x00; /* Cap Ptr */ mdev_state->vconfig[0x3d] = 0x01; /* interrupt pin (INTA#) */ /* Vendor specific data */ mdev_state->vconfig[0x40] = 0x23; mdev_state->vconfig[0x43] = 0x80; mdev_state->vconfig[0x44] = 0x23; mdev_state->vconfig[0x48] = 0x23; mdev_state->vconfig[0x4c] = 0x23; mdev_state->vconfig[0x60] = 0x50; mdev_state->vconfig[0x61] = 0x43; mdev_state->vconfig[0x62] = 0x49; mdev_state->vconfig[0x63] = 0x20; mdev_state->vconfig[0x64] = 0x53; mdev_state->vconfig[0x65] = 0x65; mdev_state->vconfig[0x66] = 0x72; mdev_state->vconfig[0x67] = 0x69; mdev_state->vconfig[0x68] = 0x61; mdev_state->vconfig[0x69] = 0x6c; mdev_state->vconfig[0x6a] = 0x2f; mdev_state->vconfig[0x6b] = 0x55; mdev_state->vconfig[0x6c] = 0x41; mdev_state->vconfig[0x6d] = 0x52; mdev_state->vconfig[0x6e] = 0x54; } static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset, u8 *buf, u32 count) { u32 cfg_addr, bar_mask, bar_index = 0; switch (offset) { case 0x04: /* device control */ case 0x06: /* device status */ /* do nothing */ break; case 0x3c: /* interrupt line */ mdev_state->vconfig[0x3c] = buf[0]; break; case 0x3d: /* * Interrupt Pin is hardwired to INTA. * This field is write protected by hardware */ break; case 0x10: /* BAR0 */ case 0x14: /* BAR1 */ if (offset == 0x10) bar_index = 0; else if (offset == 0x14) bar_index = 1; if ((mdev_state->nr_ports == 1) && (bar_index == 1)) { STORE_LE32(&mdev_state->vconfig[offset], 0); break; } cfg_addr = *(u32 *)buf; pr_info("BAR%d addr 0x%x\n", bar_index, cfg_addr); if (cfg_addr == 0xffffffff) { bar_mask = mdev_state->bar_mask[bar_index]; cfg_addr = (cfg_addr & bar_mask); } cfg_addr |= (mdev_state->vconfig[offset] & 0x3ul); STORE_LE32(&mdev_state->vconfig[offset], cfg_addr); break; case 0x18: /* BAR2 */ case 0x1c: /* BAR3 */ case 0x20: /* BAR4 */ STORE_LE32(&mdev_state->vconfig[offset], 0); break; default: pr_info("PCI config write @0x%x of %d bytes not handled\n", offset, count); break; } } static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state, u16 offset, u8 *buf, u32 count) { u8 data = *buf; /* Handle data written by guest */ switch (offset) { case UART_TX: /* if DLAB set, data is LSB of divisor */ if (mdev_state->s[index].dlab) { mdev_state->s[index].divisor |= data; break; } mutex_lock(&mdev_state->rxtx_lock); /* save in TX buffer */ if (mdev_state->s[index].rxtx.count < mdev_state->s[index].max_fifo_size) { mdev_state->s[index].rxtx.fifo[ mdev_state->s[index].rxtx.head] = data; mdev_state->s[index].rxtx.count++; CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.head); mdev_state->s[index].overrun = false; /* * Trigger interrupt if receive data interrupt is * enabled and fifo reached trigger level */ if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_RDI) && (mdev_state->s[index].rxtx.count == mdev_state->s[index].intr_trigger_level)) { /* trigger interrupt */ #if defined(DEBUG_INTR) pr_err("Serial port %d: Fifo level trigger\n", index); #endif mtty_trigger_interrupt(mdev_state); } } else { #if defined(DEBUG_INTR) pr_err("Serial port %d: Buffer Overflow\n", index); #endif mdev_state->s[index].overrun = true; /* * Trigger interrupt if receiver line status interrupt * is enabled */ if (mdev_state->s[index].uart_reg[UART_IER] & UART_IER_RLSI) mtty_trigger_interrupt(mdev_state); } mutex_unlock(&mdev_state->rxtx_lock); break; case UART_IER: /* if DLAB set, data is MSB of divisor */ if (mdev_state->s[index].dlab) mdev_state->s[index].divisor |= (u16)data << 8; else { mdev_state->s[index].uart_reg[offset] = data; mutex_lock(&mdev_state->rxtx_lock); if ((data & UART_IER_THRI) && (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail)) { #if defined(DEBUG_INTR) pr_err("Serial port %d: IER_THRI write\n", index); #endif mtty_trigger_interrupt(mdev_state); } mutex_unlock(&mdev_state->rxtx_lock); } break; case UART_FCR: mdev_state->s[index].fcr = data; mutex_lock(&mdev_state->rxtx_lock); if (data & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)) { /* clear loop back FIFO */ mdev_state->s[index].rxtx.count = 0; mdev_state->s[index].rxtx.head = 0; mdev_state->s[index].rxtx.tail = 0; } mutex_unlock(&mdev_state->rxtx_lock); switch (data & UART_FCR_TRIGGER_MASK) { case UART_FCR_TRIGGER_1: mdev_state->s[index].intr_trigger_level = 1; break; case UART_FCR_TRIGGER_4: mdev_state->s[index].intr_trigger_level = 4; break; case UART_FCR_TRIGGER_8: mdev_state->s[index].intr_trigger_level = 8; break; case UART_FCR_TRIGGER_14: mdev_state->s[index].intr_trigger_level = 14; break; } /* * Set trigger level to 1 otherwise or implement timer with * timeout of 4 characters and on expiring that timer set * Recevice data timeout in IIR register */ mdev_state->s[index].intr_trigger_level = 1; if (data & UART_FCR_ENABLE_FIFO) mdev_state->s[index].max_fifo_size = MAX_FIFO_SIZE; else { mdev_state->s[index].max_fifo_size = 1; mdev_state->s[index].intr_trigger_level = 1; } break; case UART_LCR: if (data & UART_LCR_DLAB) { mdev_state->s[index].dlab = true; mdev_state->s[index].divisor = 0; } else mdev_state->s[index].dlab = false; mdev_state->s[index].uart_reg[offset] = data; break; case UART_MCR: mdev_state->s[index].uart_reg[offset] = data; if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) && (data & UART_MCR_OUT2)) { #if defined(DEBUG_INTR) pr_err("Serial port %d: MCR_OUT2 write\n", index); #endif mtty_trigger_interrupt(mdev_state); } if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) && (data & (UART_MCR_RTS | UART_MCR_DTR))) { #if defined(DEBUG_INTR) pr_err("Serial port %d: MCR RTS/DTR write\n", index); #endif mtty_trigger_interrupt(mdev_state); } break; case UART_LSR: case UART_MSR: /* do nothing */ break; case UART_SCR: mdev_state->s[index].uart_reg[offset] = data; break; default: break; } } static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state, u16 offset, u8 *buf, u32 count) { /* Handle read requests by guest */ switch (offset) { case UART_RX: /* if DLAB set, data is LSB of divisor */ if (mdev_state->s[index].dlab) { *buf = (u8)mdev_state->s[index].divisor; break; } mutex_lock(&mdev_state->rxtx_lock); /* return data in tx buffer */ if (mdev_state->s[index].rxtx.head != mdev_state->s[index].rxtx.tail) { *buf = mdev_state->s[index].rxtx.fifo[ mdev_state->s[index].rxtx.tail]; mdev_state->s[index].rxtx.count--; CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.tail); } if (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail) { /* * Trigger interrupt if tx buffer empty interrupt is * enabled and fifo is empty */ #if defined(DEBUG_INTR) pr_err("Serial port %d: Buffer Empty\n", index); #endif if (mdev_state->s[index].uart_reg[UART_IER] & UART_IER_THRI) mtty_trigger_interrupt(mdev_state); } mutex_unlock(&mdev_state->rxtx_lock); break; case UART_IER: if (mdev_state->s[index].dlab) { *buf = (u8)(mdev_state->s[index].divisor >> 8); break; } *buf = mdev_state->s[index].uart_reg[offset] & 0x0f; break; case UART_IIR: { u8 ier = mdev_state->s[index].uart_reg[UART_IER]; *buf = 0; mutex_lock(&mdev_state->rxtx_lock); /* Interrupt priority 1: Parity, overrun, framing or break */ if ((ier & UART_IER_RLSI) && mdev_state->s[index].overrun) *buf |= UART_IIR_RLSI; /* Interrupt priority 2: Fifo trigger level reached */ if ((ier & UART_IER_RDI) && (mdev_state->s[index].rxtx.count >= mdev_state->s[index].intr_trigger_level)) *buf |= UART_IIR_RDI; /* Interrupt priotiry 3: transmitter holding register empty */ if ((ier & UART_IER_THRI) && (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail)) *buf |= UART_IIR_THRI; /* Interrupt priotiry 4: Modem status: CTS, DSR, RI or DCD */ if ((ier & UART_IER_MSI) && (mdev_state->s[index].uart_reg[UART_MCR] & (UART_MCR_RTS | UART_MCR_DTR))) *buf |= UART_IIR_MSI; /* bit0: 0=> interrupt pending, 1=> no interrupt is pending */ if (*buf == 0) *buf = UART_IIR_NO_INT; /* set bit 6 & 7 to be 16550 compatible */ *buf |= 0xC0; mutex_unlock(&mdev_state->rxtx_lock); } break; case UART_LCR: case UART_MCR: *buf = mdev_state->s[index].uart_reg[offset]; break; case UART_LSR: { u8 lsr = 0; mutex_lock(&mdev_state->rxtx_lock); /* atleast one char in FIFO */ if (mdev_state->s[index].rxtx.head != mdev_state->s[index].rxtx.tail) lsr |= UART_LSR_DR; /* if FIFO overrun */ if (mdev_state->s[index].overrun) lsr |= UART_LSR_OE; /* transmit FIFO empty and tramsitter empty */ if (mdev_state->s[index].rxtx.head == mdev_state->s[index].rxtx.tail) lsr |= UART_LSR_TEMT | UART_LSR_THRE; mutex_unlock(&mdev_state->rxtx_lock); *buf = lsr; break; } case UART_MSR: *buf = UART_MSR_DSR | UART_MSR_DDSR | UART_MSR_DCD; mutex_lock(&mdev_state->rxtx_lock); /* if AFE is 1 and FIFO have space, set CTS bit */ if (mdev_state->s[index].uart_reg[UART_MCR] & UART_MCR_AFE) { if (mdev_state->s[index].rxtx.count < mdev_state->s[index].max_fifo_size) *buf |= UART_MSR_CTS | UART_MSR_DCTS; } else *buf |= UART_MSR_CTS | UART_MSR_DCTS; mutex_unlock(&mdev_state->rxtx_lock); break; case UART_SCR: *buf = mdev_state->s[index].uart_reg[offset]; break; default: break; } } static void mdev_read_base(struct mdev_state *mdev_state) { int index, pos; u32 start_lo, start_hi; u32 mem_type; pos = PCI_BASE_ADDRESS_0; for (index = 0; index <= VFIO_PCI_BAR5_REGION_INDEX; index++) { if (!mdev_state->region_info[index].size) continue; start_lo = (*(u32 *)(mdev_state->vconfig + pos)) & PCI_BASE_ADDRESS_MEM_MASK; mem_type = (*(u32 *)(mdev_state->vconfig + pos)) & PCI_BASE_ADDRESS_MEM_TYPE_MASK; switch (mem_type) { case PCI_BASE_ADDRESS_MEM_TYPE_64: start_hi = (*(u32 *)(mdev_state->vconfig + pos + 4)); pos += 4; break; case PCI_BASE_ADDRESS_MEM_TYPE_32: case PCI_BASE_ADDRESS_MEM_TYPE_1M: /* 1M mem BAR treated as 32-bit BAR */ default: /* mem unknown type treated as 32-bit BAR */ start_hi = 0; break; } pos += 4; mdev_state->region_info[index].start = ((u64)start_hi << 32) | start_lo; } } static ssize_t mdev_access(struct mdev_state *mdev_state, u8 *buf, size_t count, loff_t pos, bool is_write) { unsigned int index; loff_t offset; int ret = 0; if (!buf) return -EINVAL; mutex_lock(&mdev_state->ops_lock); index = MTTY_VFIO_PCI_OFFSET_TO_INDEX(pos); offset = pos & MTTY_VFIO_PCI_OFFSET_MASK; switch (index) { case VFIO_PCI_CONFIG_REGION_INDEX: #if defined(DEBUG) pr_info("%s: PCI config space %s at offset 0x%llx\n", __func__, is_write ? "write" : "read", offset); #endif if (is_write) { dump_buffer(buf, count); handle_pci_cfg_write(mdev_state, offset, buf, count); } else { memcpy(buf, (mdev_state->vconfig + offset), count); dump_buffer(buf, count); } break; case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX: if (!mdev_state->region_info[index].start) mdev_read_base(mdev_state); if (is_write) { dump_buffer(buf, count); #if defined(DEBUG_REGS) pr_info("%s: BAR%d WR @0x%llx %s val:0x%02x dlab:%d\n", __func__, index, offset, wr_reg[offset], *buf, mdev_state->s[index].dlab); #endif handle_bar_write(index, mdev_state, offset, buf, count); } else { handle_bar_read(index, mdev_state, offset, buf, count); dump_buffer(buf, count); #if defined(DEBUG_REGS) pr_info("%s: BAR%d RD @0x%llx %s val:0x%02x dlab:%d\n", __func__, index, offset, rd_reg[offset], *buf, mdev_state->s[index].dlab); #endif } break; default: ret = -1; goto accessfailed; } ret = count; accessfailed: mutex_unlock(&mdev_state->ops_lock); return ret; } static int mtty_init_dev(struct vfio_device *vdev) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); struct mdev_device *mdev = to_mdev_device(vdev->dev); struct mtty_type *type = container_of(mdev->type, struct mtty_type, type); int avail_ports = atomic_read(&mdev_avail_ports); int ret; do { if (avail_ports < type->nr_ports) return -ENOSPC; } while (!atomic_try_cmpxchg(&mdev_avail_ports, &avail_ports, avail_ports - type->nr_ports)); mdev_state->nr_ports = type->nr_ports; mdev_state->irq_index = -1; mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE; mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE; mutex_init(&mdev_state->rxtx_lock); mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL); if (!mdev_state->vconfig) { ret = -ENOMEM; goto err_nr_ports; } mutex_init(&mdev_state->ops_lock); mdev_state->mdev = mdev; mtty_create_config_space(mdev_state); return 0; err_nr_ports: atomic_add(type->nr_ports, &mdev_avail_ports); return ret; } static int mtty_probe(struct mdev_device *mdev) { struct mdev_state *mdev_state; int ret; mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev, &mtty_dev_ops); if (IS_ERR(mdev_state)) return PTR_ERR(mdev_state); ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev); if (ret) goto err_put_vdev; dev_set_drvdata(&mdev->dev, mdev_state); return 0; err_put_vdev: vfio_put_device(&mdev_state->vdev); return ret; } static void mtty_release_dev(struct vfio_device *vdev) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); atomic_add(mdev_state->nr_ports, &mdev_avail_ports); kfree(mdev_state->vconfig); vfio_free_device(vdev); } static void mtty_remove(struct mdev_device *mdev) { struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev); vfio_unregister_group_dev(&mdev_state->vdev); vfio_put_device(&mdev_state->vdev); } static int mtty_reset(struct mdev_state *mdev_state) { pr_info("%s: called\n", __func__); return 0; } static ssize_t mtty_read(struct vfio_device *vdev, char __user *buf, size_t count, loff_t *ppos) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); unsigned int done = 0; int ret; while (count) { size_t filled; if (count >= 4 && !(*ppos % 4)) { u32 val; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, false); if (ret <= 0) goto read_err; if (copy_to_user(buf, &val, sizeof(val))) goto read_err; filled = 4; } else if (count >= 2 && !(*ppos % 2)) { u16 val; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, false); if (ret <= 0) goto read_err; if (copy_to_user(buf, &val, sizeof(val))) goto read_err; filled = 2; } else { u8 val; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, false); if (ret <= 0) goto read_err; if (copy_to_user(buf, &val, sizeof(val))) goto read_err; filled = 1; } count -= filled; done += filled; *ppos += filled; buf += filled; } return done; read_err: return -EFAULT; } static ssize_t mtty_write(struct vfio_device *vdev, const char __user *buf, size_t count, loff_t *ppos) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); unsigned int done = 0; int ret; while (count) { size_t filled; if (count >= 4 && !(*ppos % 4)) { u32 val; if (copy_from_user(&val, buf, sizeof(val))) goto write_err; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, true); if (ret <= 0) goto write_err; filled = 4; } else if (count >= 2 && !(*ppos % 2)) { u16 val; if (copy_from_user(&val, buf, sizeof(val))) goto write_err; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, true); if (ret <= 0) goto write_err; filled = 2; } else { u8 val; if (copy_from_user(&val, buf, sizeof(val))) goto write_err; ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val), *ppos, true); if (ret <= 0) goto write_err; filled = 1; } count -= filled; done += filled; *ppos += filled; buf += filled; } return done; write_err: return -EFAULT; } static int mtty_set_irqs(struct mdev_state *mdev_state, uint32_t flags, unsigned int index, unsigned int start, unsigned int count, void *data) { int ret = 0; mutex_lock(&mdev_state->ops_lock); switch (index) { case VFIO_PCI_INTX_IRQ_INDEX: switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) { case VFIO_IRQ_SET_ACTION_MASK: case VFIO_IRQ_SET_ACTION_UNMASK: break; case VFIO_IRQ_SET_ACTION_TRIGGER: { if (flags & VFIO_IRQ_SET_DATA_NONE) { pr_info("%s: disable INTx\n", __func__); if (mdev_state->intx_evtfd) eventfd_ctx_put(mdev_state->intx_evtfd); break; } if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { int fd = *(int *)data; if (fd > 0) { struct eventfd_ctx *evt; evt = eventfd_ctx_fdget(fd); if (IS_ERR(evt)) { ret = PTR_ERR(evt); break; } mdev_state->intx_evtfd = evt; mdev_state->irq_fd = fd; mdev_state->irq_index = index; break; } } break; } } break; case VFIO_PCI_MSI_IRQ_INDEX: switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) { case VFIO_IRQ_SET_ACTION_MASK: case VFIO_IRQ_SET_ACTION_UNMASK: break; case VFIO_IRQ_SET_ACTION_TRIGGER: if (flags & VFIO_IRQ_SET_DATA_NONE) { if (mdev_state->msi_evtfd) eventfd_ctx_put(mdev_state->msi_evtfd); pr_info("%s: disable MSI\n", __func__); mdev_state->irq_index = VFIO_PCI_INTX_IRQ_INDEX; break; } if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { int fd = *(int *)data; struct eventfd_ctx *evt; if (fd <= 0) break; if (mdev_state->msi_evtfd) break; evt = eventfd_ctx_fdget(fd); if (IS_ERR(evt)) { ret = PTR_ERR(evt); break; } mdev_state->msi_evtfd = evt; mdev_state->irq_fd = fd; mdev_state->irq_index = index; } break; } break; case VFIO_PCI_MSIX_IRQ_INDEX: pr_info("%s: MSIX_IRQ\n", __func__); break; case VFIO_PCI_ERR_IRQ_INDEX: pr_info("%s: ERR_IRQ\n", __func__); break; case VFIO_PCI_REQ_IRQ_INDEX: pr_info("%s: REQ_IRQ\n", __func__); break; } mutex_unlock(&mdev_state->ops_lock); return ret; } static int mtty_trigger_interrupt(struct mdev_state *mdev_state) { int ret = -1; if ((mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX) && (!mdev_state->msi_evtfd)) return -EINVAL; else if ((mdev_state->irq_index == VFIO_PCI_INTX_IRQ_INDEX) && (!mdev_state->intx_evtfd)) { pr_info("%s: Intr eventfd not found\n", __func__); return -EINVAL; } if (mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX) ret = eventfd_signal(mdev_state->msi_evtfd, 1); else ret = eventfd_signal(mdev_state->intx_evtfd, 1); #if defined(DEBUG_INTR) pr_info("Intx triggered\n"); #endif if (ret != 1) pr_err("%s: eventfd signal failed (%d)\n", __func__, ret); return ret; } static int mtty_get_region_info(struct mdev_state *mdev_state, struct vfio_region_info *region_info, u16 *cap_type_id, void **cap_type) { unsigned int size = 0; u32 bar_index; bar_index = region_info->index; if (bar_index >= VFIO_PCI_NUM_REGIONS) return -EINVAL; mutex_lock(&mdev_state->ops_lock); switch (bar_index) { case VFIO_PCI_CONFIG_REGION_INDEX: size = MTTY_CONFIG_SPACE_SIZE; break; case VFIO_PCI_BAR0_REGION_INDEX: size = MTTY_IO_BAR_SIZE; break; case VFIO_PCI_BAR1_REGION_INDEX: if (mdev_state->nr_ports == 2) size = MTTY_IO_BAR_SIZE; break; default: size = 0; break; } mdev_state->region_info[bar_index].size = size; mdev_state->region_info[bar_index].vfio_offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index); region_info->size = size; region_info->offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index); region_info->flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE; mutex_unlock(&mdev_state->ops_lock); return 0; } static int mtty_get_irq_info(struct vfio_irq_info *irq_info) { switch (irq_info->index) { case VFIO_PCI_INTX_IRQ_INDEX: case VFIO_PCI_MSI_IRQ_INDEX: case VFIO_PCI_REQ_IRQ_INDEX: break; default: return -EINVAL; } irq_info->flags = VFIO_IRQ_INFO_EVENTFD; irq_info->count = 1; if (irq_info->index == VFIO_PCI_INTX_IRQ_INDEX) irq_info->flags |= (VFIO_IRQ_INFO_MASKABLE | VFIO_IRQ_INFO_AUTOMASKED); else irq_info->flags |= VFIO_IRQ_INFO_NORESIZE; return 0; } static int mtty_get_device_info(struct vfio_device_info *dev_info) { dev_info->flags = VFIO_DEVICE_FLAGS_PCI; dev_info->num_regions = VFIO_PCI_NUM_REGIONS; dev_info->num_irqs = VFIO_PCI_NUM_IRQS; return 0; } static long mtty_ioctl(struct vfio_device *vdev, unsigned int cmd, unsigned long arg) { struct mdev_state *mdev_state = container_of(vdev, struct mdev_state, vdev); int ret = 0; unsigned long minsz; switch (cmd) { case VFIO_DEVICE_GET_INFO: { struct vfio_device_info info; minsz = offsetofend(struct vfio_device_info, num_irqs); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if (info.argsz < minsz) return -EINVAL; ret = mtty_get_device_info(&info); if (ret) return ret; memcpy(&mdev_state->dev_info, &info, sizeof(info)); if (copy_to_user((void __user *)arg, &info, minsz)) return -EFAULT; return 0; } case VFIO_DEVICE_GET_REGION_INFO: { struct vfio_region_info info; u16 cap_type_id = 0; void *cap_type = NULL; minsz = offsetofend(struct vfio_region_info, offset); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if (info.argsz < minsz) return -EINVAL; ret = mtty_get_region_info(mdev_state, &info, &cap_type_id, &cap_type); if (ret) return ret; if (copy_to_user((void __user *)arg, &info, minsz)) return -EFAULT; return 0; } case VFIO_DEVICE_GET_IRQ_INFO: { struct vfio_irq_info info; minsz = offsetofend(struct vfio_irq_info, count); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if ((info.argsz < minsz) || (info.index >= mdev_state->dev_info.num_irqs)) return -EINVAL; ret = mtty_get_irq_info(&info); if (ret) return ret; if (copy_to_user((void __user *)arg, &info, minsz)) return -EFAULT; return 0; } case VFIO_DEVICE_SET_IRQS: { struct vfio_irq_set hdr; u8 *data = NULL, *ptr = NULL; size_t data_size = 0; minsz = offsetofend(struct vfio_irq_set, count); if (copy_from_user(&hdr, (void __user *)arg, minsz)) return -EFAULT; ret = vfio_set_irqs_validate_and_prepare(&hdr, mdev_state->dev_info.num_irqs, VFIO_PCI_NUM_IRQS, &data_size); if (ret) return ret; if (data_size) { ptr = data = memdup_user((void __user *)(arg + minsz), data_size); if (IS_ERR(data)) return PTR_ERR(data); } ret = mtty_set_irqs(mdev_state, hdr.flags, hdr.index, hdr.start, hdr.count, data); kfree(ptr); return ret; } case VFIO_DEVICE_RESET: return mtty_reset(mdev_state); } return -ENOTTY; } static ssize_t sample_mdev_dev_show(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "This is MDEV %s\n", dev_name(dev)); } static DEVICE_ATTR_RO(sample_mdev_dev); static struct attribute *mdev_dev_attrs[] = { &dev_attr_sample_mdev_dev.attr, NULL, }; static const struct attribute_group mdev_dev_group = { .name = "vendor", .attrs = mdev_dev_attrs, }; static const struct attribute_group *mdev_dev_groups[] = { &mdev_dev_group, NULL, }; static ssize_t available_instances_show(struct mdev_type *mtype, struct mdev_type_attribute *attr, char *buf) { struct mtty_type *type = container_of(mtype, struct mtty_type, type); return sprintf(buf, "%d\n", atomic_read(&mdev_avail_ports) / type->nr_ports); } static MDEV_TYPE_ATTR_RO(available_instances); static const struct attribute *mdev_types_attrs[] = { &mdev_type_attr_available_instances.attr, NULL, }; static const struct vfio_device_ops mtty_dev_ops = { .name = "vfio-mtty", .init = mtty_init_dev, .release = mtty_release_dev, .read = mtty_read, .write = mtty_write, .ioctl = mtty_ioctl, }; static struct mdev_driver mtty_driver = { .device_api = VFIO_DEVICE_API_PCI_STRING, .driver = { .name = "mtty", .owner = THIS_MODULE, .mod_name = KBUILD_MODNAME, .dev_groups = mdev_dev_groups, }, .probe = mtty_probe, .remove = mtty_remove, .types_attrs = mdev_types_attrs, }; static void mtty_device_release(struct device *dev) { dev_dbg(dev, "mtty: released\n"); } static int __init mtty_dev_init(void) { int ret = 0; pr_info("mtty_dev: %s\n", __func__); memset(&mtty_dev, 0, sizeof(mtty_dev)); idr_init(&mtty_dev.vd_idr); ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK + 1, MTTY_NAME); if (ret < 0) { pr_err("Error: failed to register mtty_dev, err:%d\n", ret); return ret; } cdev_init(&mtty_dev.vd_cdev, &vd_fops); cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK + 1); pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt)); ret = mdev_register_driver(&mtty_driver); if (ret) goto err_cdev; mtty_dev.vd_class = class_create(THIS_MODULE, MTTY_CLASS_NAME); if (IS_ERR(mtty_dev.vd_class)) { pr_err("Error: failed to register mtty_dev class\n"); ret = PTR_ERR(mtty_dev.vd_class); goto err_driver; } mtty_dev.dev.class = mtty_dev.vd_class; mtty_dev.dev.release = mtty_device_release; dev_set_name(&mtty_dev.dev, "%s", MTTY_NAME); ret = device_register(&mtty_dev.dev); if (ret) goto err_class; ret = mdev_register_parent(&mtty_dev.parent, &mtty_dev.dev, &mtty_driver, mtty_mdev_types, ARRAY_SIZE(mtty_mdev_types)); if (ret) goto err_device; return 0; err_device: device_unregister(&mtty_dev.dev); err_class: class_destroy(mtty_dev.vd_class); err_driver: mdev_unregister_driver(&mtty_driver); err_cdev: cdev_del(&mtty_dev.vd_cdev); unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1); return ret; } static void __exit mtty_dev_exit(void) { mtty_dev.dev.bus = NULL; mdev_unregister_parent(&mtty_dev.parent); device_unregister(&mtty_dev.dev); idr_destroy(&mtty_dev.vd_idr); mdev_unregister_driver(&mtty_driver); cdev_del(&mtty_dev.vd_cdev); unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1); class_destroy(mtty_dev.vd_class); mtty_dev.vd_class = NULL; pr_info("mtty_dev: Unloaded!\n"); } module_init(mtty_dev_init) module_exit(mtty_dev_exit) MODULE_LICENSE("GPL v2"); MODULE_INFO(supported, "Test driver that simulate serial port over PCI"); MODULE_VERSION(VERSION_STRING); MODULE_AUTHOR(DRIVER_AUTHOR);