From: Johannes Berg Date: Fri, 5 Mar 2021 12:19:58 +0000 (+0100) Subject: um: add PCI over virtio emulation driver X-Git-Tag: accepted/tizen/unified/20230118.172025~6857^2~11 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=68f5d3f3b6543266b29e047cfaf9842333019b4c;p=platform%2Fkernel%2Flinux-rpi.git um: add PCI over virtio emulation driver To support testing of PCI/PCIe drivers in UML, add a PCI bus support driver. This driver uses virtio, which in UML is really just vhost-user, to talk to devices, and adds the devices to the virtual PCI bus in the system. Since virtio already allows DMA/bus mastering this really isn't all that hard, of course we need the logic_iomem infrastructure that was added by a previous patch. The protocol to talk to the device is has a few fairly simple messages for reading to/writing from config and IO spaces, and messages for the device to send the various interrupts (INT#, MSI/MSI-X and while suspended PME#). Note that currently no offical virtio device ID is assigned for this protocol, as a consequence this patch requires defining it in the Kconfig, with a default that makes the driver refuse to work at all. Finally, in order to add support for MSI/MSI-X interrupts, some small changes are needed in the UML IRQ code, it needs to have more interrupts, changing NR_IRQS from 64 to 128 if this driver is enabled, but not actually use them for anything so that the generic IRQ domain/MSI infrastructure can allocate IRQ numbers. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger --- diff --git a/arch/um/Kconfig b/arch/um/Kconfig index e72b4b3..328ba97 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -15,7 +15,7 @@ config UML select HAVE_FUTEX_CMPXCHG if FUTEX select HAVE_DEBUG_KMEMLEAK select HAVE_DEBUG_BUGVERBOSE - select NO_DMA + select NO_DMA if !UML_DMA_EMULATION select GENERIC_IRQ_SHOW select GENERIC_CPU_DEVICES select HAVE_GCC_PLUGINS @@ -26,10 +26,21 @@ config MMU bool default y +config UML_DMA_EMULATION + bool + config NO_IOMEM bool "disable IOMEM" if EXPERT + depends on !INDIRECT_IOMEM default y +config UML_IOMEM_EMULATION + bool + select INDIRECT_IOMEM + select GENERIC_PCI_IOMAP + select GENERIC_IOMAP + select NO_GENERIC_PCI_IOPORT_MAP + config NO_IOPORT_MAP def_bool y diff --git a/arch/um/drivers/Kconfig b/arch/um/drivers/Kconfig index 03ba34b..f145842 100644 --- a/arch/um/drivers/Kconfig +++ b/arch/um/drivers/Kconfig @@ -357,3 +357,23 @@ config UML_RTC rtcwake, especially in time-travel mode. This driver enables that by providing a fake RTC clock that causes a wakeup at the right time. + +config UML_PCI_OVER_VIRTIO + bool "Enable PCI over VIRTIO device simulation" + # in theory, just VIRTIO is enough, but that causes recursion + depends on VIRTIO_UML + select FORCE_PCI + select UML_IOMEM_EMULATION + select UML_DMA_EMULATION + select PCI_MSI + select PCI_MSI_IRQ_DOMAIN + select PCI_LOCKLESS_CONFIG + +config UML_PCI_OVER_VIRTIO_DEVICE_ID + int "set the virtio device ID for PCI emulation" + default -1 + depends on UML_PCI_OVER_VIRTIO + help + There's no official device ID assigned (yet), set the one you + wish to use for experimentation here. The default of -1 is + not valid and will cause the driver to fail at probe. diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile index dcc64a0..803666e 100644 --- a/arch/um/drivers/Makefile +++ b/arch/um/drivers/Makefile @@ -64,6 +64,7 @@ obj-$(CONFIG_BLK_DEV_COW_COMMON) += cow_user.o obj-$(CONFIG_UML_RANDOM) += random.o obj-$(CONFIG_VIRTIO_UML) += virtio_uml.o obj-$(CONFIG_UML_RTC) += rtc.o +obj-$(CONFIG_UML_PCI_OVER_VIRTIO) += virt-pci.o # pcap_user.o must be added explicitly. USER_OBJS := fd.o null.o pty.o tty.o xterm.o slip_common.o pcap_user.o vde_user.o vector_user.o diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c new file mode 100644 index 0000000..dd85f36 --- /dev/null +++ b/arch/um/drivers/virt-pci.c @@ -0,0 +1,885 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Intel Corporation + * Author: Johannes Berg + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define MAX_DEVICES 8 +#define MAX_MSI_VECTORS 32 +#define CFG_SPACE_SIZE 4096 + +/* for MSI-X we have a 32-bit payload */ +#define MAX_IRQ_MSG_SIZE (sizeof(struct virtio_pcidev_msg) + sizeof(u32)) +#define NUM_IRQ_MSGS 10 + +#define HANDLE_NO_FREE(ptr) ((void *)((unsigned long)(ptr) | 1)) +#define HANDLE_IS_NO_FREE(ptr) ((unsigned long)(ptr) & 1) + +struct um_pci_device { + struct virtio_device *vdev; + + /* for now just standard BARs */ + u8 resptr[PCI_STD_NUM_BARS]; + + struct virtqueue *cmd_vq, *irq_vq; + +#define UM_PCI_STAT_WAITING 0 + unsigned long status; + + int irq; +}; + +struct um_pci_device_reg { + struct um_pci_device *dev; + void __iomem *iomem; +}; + +static struct pci_host_bridge *bridge; +static DEFINE_MUTEX(um_pci_mtx); +static struct um_pci_device_reg um_pci_devices[MAX_DEVICES]; +static struct fwnode_handle *um_pci_fwnode; +static struct irq_domain *um_pci_inner_domain; +static struct irq_domain *um_pci_msi_domain; +static unsigned long um_pci_msi_used[BITS_TO_LONGS(MAX_MSI_VECTORS)]; + +#define UM_VIRT_PCI_MAXDELAY 40000 + +static int um_pci_send_cmd(struct um_pci_device *dev, + struct virtio_pcidev_msg *cmd, + unsigned int cmd_size, + const void *extra, unsigned int extra_size, + void *out, unsigned int out_size) +{ + struct scatterlist out_sg, extra_sg, in_sg; + struct scatterlist *sgs_list[] = { + [0] = &out_sg, + [1] = extra ? &extra_sg : &in_sg, + [2] = extra ? &in_sg : NULL, + }; + int delay_count = 0; + int ret, len; + bool posted; + + if (WARN_ON(cmd_size < sizeof(*cmd))) + return -EINVAL; + + switch (cmd->op) { + case VIRTIO_PCIDEV_OP_CFG_WRITE: + case VIRTIO_PCIDEV_OP_MMIO_WRITE: + case VIRTIO_PCIDEV_OP_MMIO_MEMSET: + /* in PCI, writes are posted, so don't wait */ + posted = !out; + WARN_ON(!posted); + break; + default: + posted = false; + break; + } + + if (posted) { + u8 *ncmd = kmalloc(cmd_size + extra_size, GFP_ATOMIC); + + if (ncmd) { + memcpy(ncmd, cmd, cmd_size); + if (extra) + memcpy(ncmd + cmd_size, extra, extra_size); + cmd = (void *)ncmd; + cmd_size += extra_size; + extra = NULL; + extra_size = 0; + } else { + /* try without allocating memory */ + posted = false; + } + } + + sg_init_one(&out_sg, cmd, cmd_size); + if (extra) + sg_init_one(&extra_sg, extra, extra_size); + if (out) + sg_init_one(&in_sg, out, out_size); + + /* add to internal virtio queue */ + ret = virtqueue_add_sgs(dev->cmd_vq, sgs_list, + extra ? 2 : 1, + out ? 1 : 0, + posted ? cmd : HANDLE_NO_FREE(cmd), + GFP_ATOMIC); + if (ret) + return ret; + + if (posted) { + virtqueue_kick(dev->cmd_vq); + return 0; + } + + /* kick and poll for getting a response on the queue */ + set_bit(UM_PCI_STAT_WAITING, &dev->status); + virtqueue_kick(dev->cmd_vq); + + while (1) { + void *completed = virtqueue_get_buf(dev->cmd_vq, &len); + + if (completed == HANDLE_NO_FREE(cmd)) + break; + + if (WARN_ONCE(virtqueue_is_broken(dev->cmd_vq) || + ++delay_count > UM_VIRT_PCI_MAXDELAY, + "um virt-pci delay: %d", delay_count)) { + ret = -EIO; + break; + } + udelay(1); + } + clear_bit(UM_PCI_STAT_WAITING, &dev->status); + + return ret; +} + +static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset, + int size) +{ + struct um_pci_device_reg *reg = priv; + struct um_pci_device *dev = reg->dev; + struct virtio_pcidev_msg hdr = { + .op = VIRTIO_PCIDEV_OP_CFG_READ, + .size = size, + .addr = offset, + }; + /* maximum size - we may only use parts of it */ + u8 data[8]; + + if (!dev) + return ~0ULL; + + memset(data, 0xff, sizeof(data)); + + switch (size) { + case 1: + case 2: + case 4: +#ifdef CONFIG_64BIT + case 8: +#endif + break; + default: + WARN(1, "invalid config space read size %d\n", size); + return ~0ULL; + } + + if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, + data, sizeof(data))) + return ~0ULL; + + switch (size) { + case 1: + return data[0]; + case 2: + return le16_to_cpup((void *)data); + case 4: + return le32_to_cpup((void *)data); +#ifdef CONFIG_64BIT + case 8: + return le64_to_cpup((void *)data); +#endif + default: + return ~0ULL; + } +} + +static void um_pci_cfgspace_write(void *priv, unsigned int offset, int size, + unsigned long val) +{ + struct um_pci_device_reg *reg = priv; + struct um_pci_device *dev = reg->dev; + struct { + struct virtio_pcidev_msg hdr; + /* maximum size - we may only use parts of it */ + u8 data[8]; + } msg = { + .hdr = { + .op = VIRTIO_PCIDEV_OP_CFG_WRITE, + .size = size, + .addr = offset, + }, + }; + + if (!dev) + return; + + switch (size) { + case 1: + msg.data[0] = (u8)val; + break; + case 2: + put_unaligned_le16(val, (void *)msg.data); + break; + case 4: + put_unaligned_le32(val, (void *)msg.data); + break; +#ifdef CONFIG_64BIT + case 8: + put_unaligned_le64(val, (void *)msg.data); + break; +#endif + default: + WARN(1, "invalid config space write size %d\n", size); + return; + } + + WARN_ON(um_pci_send_cmd(dev, &msg.hdr, sizeof(msg), NULL, 0, NULL, 0)); +} + +static const struct logic_iomem_ops um_pci_device_cfgspace_ops = { + .read = um_pci_cfgspace_read, + .write = um_pci_cfgspace_write, +}; + +static void um_pci_bar_copy_from(void *priv, void *buffer, + unsigned int offset, int size) +{ + u8 *resptr = priv; + struct um_pci_device *dev = container_of(resptr - *resptr, + struct um_pci_device, + resptr[0]); + struct virtio_pcidev_msg hdr = { + .op = VIRTIO_PCIDEV_OP_MMIO_READ, + .bar = *resptr, + .size = size, + .addr = offset, + }; + + memset(buffer, 0xff, size); + + um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, buffer, size); +} + +static unsigned long um_pci_bar_read(void *priv, unsigned int offset, + int size) +{ + /* maximum size - we may only use parts of it */ + u8 data[8]; + + switch (size) { + case 1: + case 2: + case 4: +#ifdef CONFIG_64BIT + case 8: +#endif + break; + default: + WARN(1, "invalid config space read size %d\n", size); + return ~0ULL; + } + + um_pci_bar_copy_from(priv, data, offset, size); + + switch (size) { + case 1: + return data[0]; + case 2: + return le16_to_cpup((void *)data); + case 4: + return le32_to_cpup((void *)data); +#ifdef CONFIG_64BIT + case 8: + return le64_to_cpup((void *)data); +#endif + default: + return ~0ULL; + } +} + +static void um_pci_bar_copy_to(void *priv, unsigned int offset, + const void *buffer, int size) +{ + u8 *resptr = priv; + struct um_pci_device *dev = container_of(resptr - *resptr, + struct um_pci_device, + resptr[0]); + struct virtio_pcidev_msg hdr = { + .op = VIRTIO_PCIDEV_OP_MMIO_WRITE, + .bar = *resptr, + .size = size, + .addr = offset, + }; + + um_pci_send_cmd(dev, &hdr, sizeof(hdr), buffer, size, NULL, 0); +} + +static void um_pci_bar_write(void *priv, unsigned int offset, int size, + unsigned long val) +{ + /* maximum size - we may only use parts of it */ + u8 data[8]; + + switch (size) { + case 1: + data[0] = (u8)val; + break; + case 2: + put_unaligned_le16(val, (void *)data); + break; + case 4: + put_unaligned_le32(val, (void *)data); + break; +#ifdef CONFIG_64BIT + case 8: + put_unaligned_le64(val, (void *)data); + break; +#endif + default: + WARN(1, "invalid config space write size %d\n", size); + return; + } + + um_pci_bar_copy_to(priv, offset, data, size); +} + +static void um_pci_bar_set(void *priv, unsigned int offset, u8 value, int size) +{ + u8 *resptr = priv; + struct um_pci_device *dev = container_of(resptr - *resptr, + struct um_pci_device, + resptr[0]); + struct { + struct virtio_pcidev_msg hdr; + u8 data; + } msg = { + .hdr = { + .op = VIRTIO_PCIDEV_OP_CFG_WRITE, + .bar = *resptr, + .size = size, + .addr = offset, + }, + .data = value, + }; + + um_pci_send_cmd(dev, &msg.hdr, sizeof(msg), NULL, 0, NULL, 0); +} + +static const struct logic_iomem_ops um_pci_device_bar_ops = { + .read = um_pci_bar_read, + .write = um_pci_bar_write, + .set = um_pci_bar_set, + .copy_from = um_pci_bar_copy_from, + .copy_to = um_pci_bar_copy_to, +}; + +static void __iomem *um_pci_map_bus(struct pci_bus *bus, unsigned int devfn, + int where) +{ + struct um_pci_device_reg *dev; + unsigned int busn = bus->number; + + if (busn > 0) + return NULL; + + /* not allowing functions for now ... */ + if (devfn % 8) + return NULL; + + if (devfn / 8 >= ARRAY_SIZE(um_pci_devices)) + return NULL; + + dev = &um_pci_devices[devfn / 8]; + if (!dev) + return NULL; + + return (void __iomem *)((unsigned long)dev->iomem + where); +} + +static struct pci_ops um_pci_ops = { + .map_bus = um_pci_map_bus, + .read = pci_generic_config_read, + .write = pci_generic_config_write, +}; + +static void um_pci_rescan(void) +{ + pci_lock_rescan_remove(); + pci_rescan_bus(bridge->bus); + pci_unlock_rescan_remove(); +} + +static void um_pci_irq_vq_addbuf(struct virtqueue *vq, void *buf, bool kick) +{ + struct scatterlist sg[1]; + + sg_init_one(sg, buf, MAX_IRQ_MSG_SIZE); + if (virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC)) + kfree(buf); + else if (kick) + virtqueue_kick(vq); +} + +static void um_pci_handle_irq_message(struct virtqueue *vq, + struct virtio_pcidev_msg *msg) +{ + struct virtio_device *vdev = vq->vdev; + struct um_pci_device *dev = vdev->priv; + + /* we should properly chain interrupts, but on ARCH=um we don't care */ + + switch (msg->op) { + case VIRTIO_PCIDEV_OP_INT: + generic_handle_irq(dev->irq); + break; + case VIRTIO_PCIDEV_OP_MSI: + /* our MSI message is just the interrupt number */ + if (msg->size == sizeof(u32)) + generic_handle_irq(le32_to_cpup((void *)msg->data)); + else + generic_handle_irq(le16_to_cpup((void *)msg->data)); + break; + case VIRTIO_PCIDEV_OP_PME: + /* nothing to do - we already woke up due to the message */ + break; + default: + dev_err(&vdev->dev, "unexpected virt-pci message %d\n", msg->op); + break; + } +} + +static void um_pci_cmd_vq_cb(struct virtqueue *vq) +{ + struct virtio_device *vdev = vq->vdev; + struct um_pci_device *dev = vdev->priv; + void *cmd; + int len; + + if (test_bit(UM_PCI_STAT_WAITING, &dev->status)) + return; + + while ((cmd = virtqueue_get_buf(vq, &len))) { + if (WARN_ON(HANDLE_IS_NO_FREE(cmd))) + continue; + kfree(cmd); + } +} + +static void um_pci_irq_vq_cb(struct virtqueue *vq) +{ + struct virtio_pcidev_msg *msg; + int len; + + while ((msg = virtqueue_get_buf(vq, &len))) { + if (len >= sizeof(*msg)) + um_pci_handle_irq_message(vq, msg); + + /* recycle the message buffer */ + um_pci_irq_vq_addbuf(vq, msg, true); + } +} + +static int um_pci_init_vqs(struct um_pci_device *dev) +{ + struct virtqueue *vqs[2]; + static const char *const names[2] = { "cmd", "irq" }; + vq_callback_t *cbs[2] = { um_pci_cmd_vq_cb, um_pci_irq_vq_cb }; + int err, i; + + err = virtio_find_vqs(dev->vdev, 2, vqs, cbs, names, NULL); + if (err) + return err; + + dev->cmd_vq = vqs[0]; + dev->irq_vq = vqs[1]; + + for (i = 0; i < NUM_IRQ_MSGS; i++) { + void *msg = kzalloc(MAX_IRQ_MSG_SIZE, GFP_KERNEL); + + if (msg) + um_pci_irq_vq_addbuf(dev->irq_vq, msg, false); + } + + virtqueue_kick(dev->irq_vq); + + return 0; +} + +static int um_pci_virtio_probe(struct virtio_device *vdev) +{ + struct um_pci_device *dev; + int i, free = -1; + int err = -ENOSPC; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + + dev->vdev = vdev; + vdev->priv = dev; + + mutex_lock(&um_pci_mtx); + for (i = 0; i < MAX_DEVICES; i++) { + if (um_pci_devices[i].dev) + continue; + free = i; + break; + } + + if (free < 0) + goto error; + + err = um_pci_init_vqs(dev); + if (err) + goto error; + + dev->irq = irq_alloc_desc(numa_node_id()); + if (dev->irq < 0) { + err = dev->irq; + goto error; + } + um_pci_devices[free].dev = dev; + vdev->priv = dev; + + mutex_unlock(&um_pci_mtx); + + device_set_wakeup_enable(&vdev->dev, true); + + um_pci_rescan(); + return 0; +error: + mutex_unlock(&um_pci_mtx); + kfree(dev); + return err; +} + +static void um_pci_virtio_remove(struct virtio_device *vdev) +{ + struct um_pci_device *dev = vdev->priv; + int i; + + /* Stop all virtqueues */ + vdev->config->reset(vdev); + vdev->config->del_vqs(vdev); + + device_set_wakeup_enable(&vdev->dev, false); + + mutex_lock(&um_pci_mtx); + for (i = 0; i < MAX_DEVICES; i++) { + if (um_pci_devices[i].dev != dev) + continue; + um_pci_devices[i].dev = NULL; + irq_free_desc(dev->irq); + } + mutex_unlock(&um_pci_mtx); + + um_pci_rescan(); + + kfree(dev); +} + +static struct virtio_device_id id_table[] = { + { CONFIG_UML_PCI_OVER_VIRTIO_DEVICE_ID, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; +MODULE_DEVICE_TABLE(virtio, id_table); + +static struct virtio_driver um_pci_virtio_driver = { + .driver.name = "virtio-pci", + .driver.owner = THIS_MODULE, + .id_table = id_table, + .probe = um_pci_virtio_probe, + .remove = um_pci_virtio_remove, +}; + +static struct resource virt_cfgspace_resource = { + .name = "PCI config space", + .start = 0xf0000000 - MAX_DEVICES * CFG_SPACE_SIZE, + .end = 0xf0000000 - 1, + .flags = IORESOURCE_MEM, +}; + +static long um_pci_map_cfgspace(unsigned long offset, size_t size, + const struct logic_iomem_ops **ops, + void **priv) +{ + if (WARN_ON(size > CFG_SPACE_SIZE || offset % CFG_SPACE_SIZE)) + return -EINVAL; + + if (offset / CFG_SPACE_SIZE < MAX_DEVICES) { + *ops = &um_pci_device_cfgspace_ops; + *priv = &um_pci_devices[offset / CFG_SPACE_SIZE]; + return 0; + } + + WARN(1, "cannot map offset 0x%lx/0x%zx\n", offset, size); + return -ENOENT; +} + +static const struct logic_iomem_region_ops um_pci_cfgspace_ops = { + .map = um_pci_map_cfgspace, +}; + +static struct resource virt_iomem_resource = { + .name = "PCI iomem", + .start = 0xf0000000, + .end = 0xffffffff, + .flags = IORESOURCE_MEM, +}; + +struct um_pci_map_iomem_data { + unsigned long offset; + size_t size; + const struct logic_iomem_ops **ops; + void **priv; + long ret; +}; + +static int um_pci_map_iomem_walk(struct pci_dev *pdev, void *_data) +{ + struct um_pci_map_iomem_data *data = _data; + struct um_pci_device_reg *reg = &um_pci_devices[pdev->devfn / 8]; + struct um_pci_device *dev; + int i; + + if (!reg->dev) + return 0; + + for (i = 0; i < ARRAY_SIZE(dev->resptr); i++) { + struct resource *r = &pdev->resource[i]; + + if ((r->flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) + continue; + + /* + * must be the whole or part of the resource, + * not allowed to only overlap + */ + if (data->offset < r->start || data->offset > r->end) + continue; + if (data->offset + data->size - 1 > r->end) + continue; + + dev = reg->dev; + *data->ops = &um_pci_device_bar_ops; + dev->resptr[i] = i; + *data->priv = &dev->resptr[i]; + data->ret = data->offset - r->start; + + /* no need to continue */ + return 1; + } + + return 0; +} + +static long um_pci_map_iomem(unsigned long offset, size_t size, + const struct logic_iomem_ops **ops, + void **priv) +{ + struct um_pci_map_iomem_data data = { + /* we want the full address here */ + .offset = offset + virt_iomem_resource.start, + .size = size, + .ops = ops, + .priv = priv, + .ret = -ENOENT, + }; + + pci_walk_bus(bridge->bus, um_pci_map_iomem_walk, &data); + return data.ret; +} + +static const struct logic_iomem_region_ops um_pci_iomem_ops = { + .map = um_pci_map_iomem, +}; + +static void um_pci_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) +{ + /* + * This is a very low address and not actually valid 'physical' memory + * in UML, so we can simply map MSI(-X) vectors to there, it cannot be + * legitimately written to by the device in any other way. + * We use the (virtual) IRQ number here as the message to simplify the + * code that receives the message, where for now we simply trust the + * device to send the correct message. + */ + msg->address_hi = 0; + msg->address_lo = 0xa0000; + msg->data = data->irq; +} + +static struct irq_chip um_pci_msi_bottom_irq_chip = { + .name = "UM virtio MSI", + .irq_compose_msi_msg = um_pci_compose_msi_msg, +}; + +static int um_pci_inner_domain_alloc(struct irq_domain *domain, + unsigned int virq, unsigned int nr_irqs, + void *args) +{ + unsigned long bit; + + WARN_ON(nr_irqs != 1); + + mutex_lock(&um_pci_mtx); + bit = find_first_zero_bit(um_pci_msi_used, MAX_MSI_VECTORS); + if (bit >= MAX_MSI_VECTORS) { + mutex_unlock(&um_pci_mtx); + return -ENOSPC; + } + + set_bit(bit, um_pci_msi_used); + mutex_unlock(&um_pci_mtx); + + irq_domain_set_info(domain, virq, bit, &um_pci_msi_bottom_irq_chip, + domain->host_data, handle_simple_irq, + NULL, NULL); + + return 0; +} + +static void um_pci_inner_domain_free(struct irq_domain *domain, + unsigned int virq, unsigned int nr_irqs) +{ + struct irq_data *d = irq_domain_get_irq_data(domain, virq); + + mutex_lock(&um_pci_mtx); + + if (!test_bit(d->hwirq, um_pci_msi_used)) + pr_err("trying to free unused MSI#%lu\n", d->hwirq); + else + __clear_bit(d->hwirq, um_pci_msi_used); + + mutex_unlock(&um_pci_mtx); +} + +static const struct irq_domain_ops um_pci_inner_domain_ops = { + .alloc = um_pci_inner_domain_alloc, + .free = um_pci_inner_domain_free, +}; + +static struct irq_chip um_pci_msi_irq_chip = { + .name = "UM virtio PCIe MSI", + .irq_mask = pci_msi_mask_irq, + .irq_unmask = pci_msi_unmask_irq, +}; + +static struct msi_domain_info um_pci_msi_domain_info = { + .flags = MSI_FLAG_USE_DEF_DOM_OPS | + MSI_FLAG_USE_DEF_CHIP_OPS | + MSI_FLAG_PCI_MSIX, + .chip = &um_pci_msi_irq_chip, +}; + +static struct resource busn_resource = { + .name = "PCI busn", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUS, +}; + +static int um_pci_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin) +{ + struct um_pci_device_reg *reg = &um_pci_devices[pdev->devfn / 8]; + + if (WARN_ON(!reg->dev)) + return -EINVAL; + + /* Yes, we map all pins to the same IRQ ... doesn't matter for now. */ + return reg->dev->irq; +} + +void *pci_root_bus_fwnode(struct pci_bus *bus) +{ + return um_pci_fwnode; +} + +int um_pci_init(void) +{ + int err, i; + + WARN_ON(logic_iomem_add_region(&virt_cfgspace_resource, + &um_pci_cfgspace_ops)); + WARN_ON(logic_iomem_add_region(&virt_iomem_resource, + &um_pci_iomem_ops)); + + if (WARN(CONFIG_UML_PCI_OVER_VIRTIO_DEVICE_ID < 0, + "No virtio device ID configured for PCI - no PCI support\n")) + return 0; + + bridge = pci_alloc_host_bridge(0); + if (!bridge) + return -ENOMEM; + + um_pci_fwnode = irq_domain_alloc_named_fwnode("um-pci"); + if (!um_pci_fwnode) { + err = -ENOMEM; + goto free; + } + + um_pci_inner_domain = __irq_domain_add(um_pci_fwnode, MAX_MSI_VECTORS, + MAX_MSI_VECTORS, 0, + &um_pci_inner_domain_ops, NULL); + if (!um_pci_inner_domain) { + err = -ENOMEM; + goto free; + } + + um_pci_msi_domain = pci_msi_create_irq_domain(um_pci_fwnode, + &um_pci_msi_domain_info, + um_pci_inner_domain); + if (!um_pci_msi_domain) { + err = -ENOMEM; + goto free; + } + + pci_add_resource(&bridge->windows, &virt_iomem_resource); + pci_add_resource(&bridge->windows, &busn_resource); + bridge->ops = &um_pci_ops; + bridge->map_irq = um_pci_map_irq; + + for (i = 0; i < MAX_DEVICES; i++) { + resource_size_t start; + + start = virt_cfgspace_resource.start + i * CFG_SPACE_SIZE; + um_pci_devices[i].iomem = ioremap(start, CFG_SPACE_SIZE); + if (WARN(!um_pci_devices[i].iomem, "failed to map %d\n", i)) { + err = -ENOMEM; + goto free; + } + } + + err = pci_host_probe(bridge); + if (err) + goto free; + + err = register_virtio_driver(&um_pci_virtio_driver); + if (err) + goto free; + return 0; +free: + if (um_pci_inner_domain) + irq_domain_remove(um_pci_inner_domain); + if (um_pci_fwnode) + irq_domain_free_fwnode(um_pci_fwnode); + pci_free_resource_list(&bridge->windows); + pci_free_host_bridge(bridge); + return err; +} +module_init(um_pci_init); + +void um_pci_exit(void) +{ + unregister_virtio_driver(&um_pci_virtio_driver); + irq_domain_remove(um_pci_msi_domain); + irq_domain_remove(um_pci_inner_domain); + pci_free_resource_list(&bridge->windows); + pci_free_host_bridge(bridge); +} +module_exit(um_pci_exit); diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index 10b7228..0c31d19 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -18,7 +18,6 @@ generic-y += mcs_spinlock.h generic-y += mmiowb.h generic-y += module.lds.h generic-y += param.h -generic-y += pci.h generic-y += percpu.h generic-y += preempt.h generic-y += softirq_stack.h diff --git a/arch/um/include/asm/io.h b/arch/um/include/asm/io.h index 6ce18d3..9ea42cc 100644 --- a/arch/um/include/asm/io.h +++ b/arch/um/include/asm/io.h @@ -3,16 +3,23 @@ #define _ASM_UM_IO_H #include +/* get emulated iomem (if desired) */ +#include + +#ifndef ioremap #define ioremap ioremap static inline void __iomem *ioremap(phys_addr_t offset, size_t size) { return NULL; } +#endif /* ioremap */ +#ifndef iounmap #define iounmap iounmap static inline void iounmap(void __iomem *addr) { } +#endif /* iounmap */ #include diff --git a/arch/um/include/asm/irq.h b/arch/um/include/asm/irq.h index 3f5d3e8..e187c78 100644 --- a/arch/um/include/asm/irq.h +++ b/arch/um/include/asm/irq.h @@ -31,7 +31,13 @@ #endif -#define NR_IRQS 64 +#define UM_LAST_SIGNAL_IRQ 64 +/* If we have (simulated) PCI MSI, allow 64 more interrupt numbers for it */ +#ifdef CONFIG_PCI_MSI +#define NR_IRQS (UM_LAST_SIGNAL_IRQ + 64) +#else +#define NR_IRQS UM_LAST_SIGNAL_IRQ +#endif /* CONFIG_PCI_MSI */ #include #endif diff --git a/arch/um/include/asm/msi.h b/arch/um/include/asm/msi.h new file mode 100644 index 0000000..c8c6c38 --- /dev/null +++ b/arch/um/include/asm/msi.h @@ -0,0 +1 @@ +#include diff --git a/arch/um/include/asm/pci.h b/arch/um/include/asm/pci.h new file mode 100644 index 0000000..da13fd5 --- /dev/null +++ b/arch/um/include/asm/pci.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __ASM_UM_PCI_H +#define __ASM_UM_PCI_H +#include +#include + +#define PCIBIOS_MIN_IO 0 +#define PCIBIOS_MIN_MEM 0 + +#define pcibios_assign_all_busses() 1 + +extern int isa_dma_bridge_buggy; + +#ifdef CONFIG_PCI +static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel) +{ + /* no legacy IRQs */ + return -ENODEV; +} +#endif + +#ifdef CONFIG_PCI_DOMAINS +static inline int pci_proc_domain(struct pci_bus *bus) +{ + /* always show the domain in /proc */ + return 1; +} +#endif /* CONFIG_PCI */ + +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN +/* + * This is a bit of an annoying hack, and it assumes we only have + * the virt-pci (if anything). Which is true, but still. + */ +void *pci_root_bus_fwnode(struct pci_bus *bus); +#define pci_root_bus_fwnode pci_root_bus_fwnode +#endif + +#endif /* __ASM_UM_PCI_H */ diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile index e698e0c..2fdd00d 100644 --- a/arch/um/kernel/Makefile +++ b/arch/um/kernel/Makefile @@ -23,6 +23,7 @@ obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o obj-$(CONFIG_GPROF) += gprof_syms.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_STACKTRACE) += stacktrace.o +obj-$(CONFIG_GENERIC_PCI_IOMAP) += ioport.o USER_OBJS := config.o diff --git a/arch/um/kernel/ioport.c b/arch/um/kernel/ioport.c new file mode 100644 index 0000000..7220615 --- /dev/null +++ b/arch/um/kernel/ioport.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2021 Intel Corporation + * Author: Johannes Berg + */ +#include +#include + +void __iomem *__pci_ioport_map(struct pci_dev *dev, unsigned long port, + unsigned int nr) +{ + return NULL; +} diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c index f3f19da..a8873d9 100644 --- a/arch/um/kernel/irq.c +++ b/arch/um/kernel/irq.c @@ -56,7 +56,7 @@ struct irq_entry { static DEFINE_SPINLOCK(irq_lock); static LIST_HEAD(active_fds); -static DECLARE_BITMAP(irqs_allocated, NR_IRQS); +static DECLARE_BITMAP(irqs_allocated, UM_LAST_SIGNAL_IRQ); static bool irqs_suspended; static void irq_io_loop(struct irq_reg *irq, struct uml_pt_regs *regs) @@ -419,7 +419,8 @@ unsigned int do_IRQ(int irq, struct uml_pt_regs *regs) void um_free_irq(int irq, void *dev) { - if (WARN(irq < 0 || irq > NR_IRQS, "freeing invalid irq %d", irq)) + if (WARN(irq < 0 || irq > UM_LAST_SIGNAL_IRQ, + "freeing invalid irq %d", irq)) return; free_irq_by_irq_and_dev(irq, dev); @@ -648,7 +649,7 @@ void __init init_IRQ(void) irq_set_chip_and_handler(TIMER_IRQ, &alarm_irq_type, handle_edge_irq); - for (i = 1; i < NR_IRQS; i++) + for (i = 1; i < UM_LAST_SIGNAL_IRQ; i++) irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq); /* Initialize EPOLL Loop */ os_setup_epoll(); diff --git a/include/uapi/linux/virtio_pcidev.h b/include/uapi/linux/virtio_pcidev.h new file mode 100644 index 0000000..89daa88 --- /dev/null +++ b/include/uapi/linux/virtio_pcidev.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */ +/* + * Copyright (C) 2021 Intel Corporation + * Author: Johannes Berg + */ +#ifndef _UAPI_LINUX_VIRTIO_PCIDEV_H +#define _UAPI_LINUX_VIRTIO_PCIDEV_H +#include + +/** + * enum virtio_pcidev_ops - virtual PCI device operations + * @VIRTIO_PCIDEV_OP_CFG_READ: read config space, size is 1, 2, 4 or 8; + * the @data field should be filled in by the device (in little endian). + * @VIRTIO_PCIDEV_OP_CFG_WRITE: write config space, size is 1, 2, 4 or 8; + * the @data field contains the data to write (in little endian). + * @VIRTIO_PCIDEV_OP_BAR_READ: read BAR mem/pio, size can be variable; + * the @data field should be filled in by the device (in little endian). + * @VIRTIO_PCIDEV_OP_BAR_WRITE: write BAR mem/pio, size can be variable; + * the @data field contains the data to write (in little endian). + * @VIRTIO_PCIDEV_OP_MMIO_MEMSET: memset MMIO, size is variable but + * the @data field only has one byte (unlike @VIRTIO_PCIDEV_OP_MMIO_WRITE) + * @VIRTIO_PCIDEV_OP_INT: legacy INTx# pin interrupt, the addr field is 1-4 for + * the number + * @VIRTIO_PCIDEV_OP_MSI: MSI(-X) interrupt, this message basically transports + * the 16- or 32-bit write that would otherwise be done into memory, + * analogous to the write messages (@VIRTIO_PCIDEV_OP_MMIO_WRITE) above + * @VIRTIO_PCIDEV_OP_PME: Dummy message whose content is ignored (and should be + * all zeroes) to signal the PME# pin. + */ +enum virtio_pcidev_ops { + VIRTIO_PCIDEV_OP_RESERVED = 0, + VIRTIO_PCIDEV_OP_CFG_READ, + VIRTIO_PCIDEV_OP_CFG_WRITE, + VIRTIO_PCIDEV_OP_MMIO_READ, + VIRTIO_PCIDEV_OP_MMIO_WRITE, + VIRTIO_PCIDEV_OP_MMIO_MEMSET, + VIRTIO_PCIDEV_OP_INT, + VIRTIO_PCIDEV_OP_MSI, + VIRTIO_PCIDEV_OP_PME, +}; + +/** + * struct virtio_pcidev_msg - virtio PCI device operation + * @op: the operation to do + * @bar: the bar (only with BAR read/write messages) + * @reserved: reserved + * @size: the size of the read/write (in bytes) + * @addr: the address to read/write + * @data: the data, normally @size long, but just one byte for + * %VIRTIO_PCIDEV_OP_MMIO_MEMSET + * + * Note: the fields are all in native (CPU) endian, however, the + * @data values will often be in little endian (see the ops above.) + */ +struct virtio_pcidev_msg { + __u8 op; + __u8 bar; + __u16 reserved; + __u32 size; + __u64 addr; + __u8 data[]; +}; + +#endif /* _UAPI_LINUX_VIRTIO_PCIDEV_H */