diff options
Diffstat (limited to 'drivers/vfio/platform/vfio_platform_common.c')
-rw-r--r-- | drivers/vfio/platform/vfio_platform_common.c | 749 |
1 files changed, 749 insertions, 0 deletions
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c new file mode 100644 index 000000000..e15ef1a94 --- /dev/null +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -0,0 +1,749 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013 - Virtual Open Systems + * Author: Antonios Motakis <a.motakis@virtualopensystems.com> + */ + +#define dev_fmt(fmt) "VFIO: " fmt + +#include <linux/device.h> +#include <linux/acpi.h> +#include <linux/iommu.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <linux/vfio.h> + +#include "vfio_platform_private.h" + +#define DRIVER_VERSION "0.10" +#define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>" +#define DRIVER_DESC "VFIO platform base module" + +#define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL) + +static LIST_HEAD(reset_list); +static DEFINE_MUTEX(driver_lock); + +static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat, + struct module **module) +{ + struct vfio_platform_reset_node *iter; + vfio_platform_reset_fn_t reset_fn = NULL; + + mutex_lock(&driver_lock); + list_for_each_entry(iter, &reset_list, link) { + if (!strcmp(iter->compat, compat) && + try_module_get(iter->owner)) { + *module = iter->owner; + reset_fn = iter->of_reset; + break; + } + } + mutex_unlock(&driver_lock); + return reset_fn; +} + +static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, + struct device *dev) +{ + struct acpi_device *adev; + + if (acpi_disabled) + return -ENOENT; + + adev = ACPI_COMPANION(dev); + if (!adev) { + dev_err(dev, "ACPI companion device not found for %s\n", + vdev->name); + return -ENODEV; + } + +#ifdef CONFIG_ACPI + vdev->acpihid = acpi_device_hid(adev); +#endif + return WARN_ON(!vdev->acpihid) ? -EINVAL : 0; +} + +static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, + const char **extra_dbg) +{ +#ifdef CONFIG_ACPI + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + acpi_status acpi_ret; + + acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, NULL); + if (ACPI_FAILURE(acpi_ret)) { + if (extra_dbg) + *extra_dbg = acpi_format_exception(acpi_ret); + return -EINVAL; + } + + return 0; +#else + return -ENOENT; +#endif +} + +static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) +{ +#ifdef CONFIG_ACPI + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + + return acpi_has_method(handle, "_RST"); +#else + return false; +#endif +} + +static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) +{ + if (VFIO_PLATFORM_IS_ACPI(vdev)) + return vfio_platform_acpi_has_reset(vdev); + + return vdev->of_reset ? true : false; +} + +static int vfio_platform_get_reset(struct vfio_platform_device *vdev) +{ + if (VFIO_PLATFORM_IS_ACPI(vdev)) + return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT; + + vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, + &vdev->reset_module); + if (!vdev->of_reset) { + request_module("vfio-reset:%s", vdev->compat); + vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, + &vdev->reset_module); + } + + return vdev->of_reset ? 0 : -ENOENT; +} + +static void vfio_platform_put_reset(struct vfio_platform_device *vdev) +{ + if (VFIO_PLATFORM_IS_ACPI(vdev)) + return; + + if (vdev->of_reset) + module_put(vdev->reset_module); +} + +static int vfio_platform_regions_init(struct vfio_platform_device *vdev) +{ + int cnt = 0, i; + + while (vdev->get_resource(vdev, cnt)) + cnt++; + + vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region), + GFP_KERNEL); + if (!vdev->regions) + return -ENOMEM; + + for (i = 0; i < cnt; i++) { + struct resource *res = + vdev->get_resource(vdev, i); + + if (!res) + goto err; + + vdev->regions[i].addr = res->start; + vdev->regions[i].size = resource_size(res); + vdev->regions[i].flags = 0; + + switch (resource_type(res)) { + case IORESOURCE_MEM: + vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO; + vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ; + if (!(res->flags & IORESOURCE_READONLY)) + vdev->regions[i].flags |= + VFIO_REGION_INFO_FLAG_WRITE; + + /* + * Only regions addressed with PAGE granularity may be + * MMAPed securely. + */ + if (!(vdev->regions[i].addr & ~PAGE_MASK) && + !(vdev->regions[i].size & ~PAGE_MASK)) + vdev->regions[i].flags |= + VFIO_REGION_INFO_FLAG_MMAP; + + break; + case IORESOURCE_IO: + vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO; + break; + default: + goto err; + } + } + + vdev->num_regions = cnt; + + return 0; +err: + kfree(vdev->regions); + return -EINVAL; +} + +static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) +{ + int i; + + for (i = 0; i < vdev->num_regions; i++) + iounmap(vdev->regions[i].ioaddr); + + vdev->num_regions = 0; + kfree(vdev->regions); +} + +static int vfio_platform_call_reset(struct vfio_platform_device *vdev, + const char **extra_dbg) +{ + if (VFIO_PLATFORM_IS_ACPI(vdev)) { + dev_info(vdev->device, "reset\n"); + return vfio_platform_acpi_call_reset(vdev, extra_dbg); + } else if (vdev->of_reset) { + dev_info(vdev->device, "reset\n"); + return vdev->of_reset(vdev); + } + + dev_warn(vdev->device, "no reset function found!\n"); + return -EINVAL; +} + +static void vfio_platform_release(void *device_data) +{ + struct vfio_platform_device *vdev = device_data; + + mutex_lock(&driver_lock); + + if (!(--vdev->refcnt)) { + const char *extra_dbg = NULL; + int ret; + + ret = vfio_platform_call_reset(vdev, &extra_dbg); + if (ret && vdev->reset_required) { + dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n", + ret, extra_dbg ? extra_dbg : ""); + WARN_ON(1); + } + pm_runtime_put(vdev->device); + vfio_platform_regions_cleanup(vdev); + vfio_platform_irq_cleanup(vdev); + } + + mutex_unlock(&driver_lock); + + module_put(vdev->parent_module); +} + +static int vfio_platform_open(void *device_data) +{ + struct vfio_platform_device *vdev = device_data; + int ret; + + if (!try_module_get(vdev->parent_module)) + return -ENODEV; + + mutex_lock(&driver_lock); + + if (!vdev->refcnt) { + const char *extra_dbg = NULL; + + ret = vfio_platform_regions_init(vdev); + if (ret) + goto err_reg; + + ret = vfio_platform_irq_init(vdev); + if (ret) + goto err_irq; + + ret = pm_runtime_get_sync(vdev->device); + if (ret < 0) + goto err_rst; + + ret = vfio_platform_call_reset(vdev, &extra_dbg); + if (ret && vdev->reset_required) { + dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n", + ret, extra_dbg ? extra_dbg : ""); + goto err_rst; + } + } + + vdev->refcnt++; + + mutex_unlock(&driver_lock); + return 0; + +err_rst: + pm_runtime_put(vdev->device); + vfio_platform_irq_cleanup(vdev); +err_irq: + vfio_platform_regions_cleanup(vdev); +err_reg: + mutex_unlock(&driver_lock); + module_put(vdev->parent_module); + return ret; +} + +static long vfio_platform_ioctl(void *device_data, + unsigned int cmd, unsigned long arg) +{ + struct vfio_platform_device *vdev = device_data; + unsigned long minsz; + + if (cmd == 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; + + if (vfio_platform_has_reset(vdev)) + vdev->flags |= VFIO_DEVICE_FLAGS_RESET; + info.flags = vdev->flags; + info.num_regions = vdev->num_regions; + info.num_irqs = vdev->num_irqs; + + return copy_to_user((void __user *)arg, &info, minsz) ? + -EFAULT : 0; + + } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) { + struct vfio_region_info info; + + minsz = offsetofend(struct vfio_region_info, offset); + + if (copy_from_user(&info, (void __user *)arg, minsz)) + return -EFAULT; + + if (info.argsz < minsz) + return -EINVAL; + + if (info.index >= vdev->num_regions) + return -EINVAL; + + /* map offset to the physical address */ + info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index); + info.size = vdev->regions[info.index].size; + info.flags = vdev->regions[info.index].flags; + + return copy_to_user((void __user *)arg, &info, minsz) ? + -EFAULT : 0; + + } else if (cmd == 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) + return -EINVAL; + + if (info.index >= vdev->num_irqs) + return -EINVAL; + + info.flags = vdev->irqs[info.index].flags; + info.count = vdev->irqs[info.index].count; + + return copy_to_user((void __user *)arg, &info, minsz) ? + -EFAULT : 0; + + } else if (cmd == VFIO_DEVICE_SET_IRQS) { + struct vfio_irq_set hdr; + u8 *data = NULL; + int ret = 0; + 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, vdev->num_irqs, + vdev->num_irqs, &data_size); + if (ret) + return ret; + + if (data_size) { + data = memdup_user((void __user *)(arg + minsz), + data_size); + if (IS_ERR(data)) + return PTR_ERR(data); + } + + mutex_lock(&vdev->igate); + + ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index, + hdr.start, hdr.count, data); + mutex_unlock(&vdev->igate); + kfree(data); + + return ret; + + } else if (cmd == VFIO_DEVICE_RESET) { + return vfio_platform_call_reset(vdev, NULL); + } + + return -ENOTTY; +} + +static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg, + char __user *buf, size_t count, + loff_t off) +{ + unsigned int done = 0; + + if (!reg->ioaddr) { + reg->ioaddr = + ioremap(reg->addr, reg->size); + + if (!reg->ioaddr) + return -ENOMEM; + } + + while (count) { + size_t filled; + + if (count >= 4 && !(off % 4)) { + u32 val; + + val = ioread32(reg->ioaddr + off); + if (copy_to_user(buf, &val, 4)) + goto err; + + filled = 4; + } else if (count >= 2 && !(off % 2)) { + u16 val; + + val = ioread16(reg->ioaddr + off); + if (copy_to_user(buf, &val, 2)) + goto err; + + filled = 2; + } else { + u8 val; + + val = ioread8(reg->ioaddr + off); + if (copy_to_user(buf, &val, 1)) + goto err; + + filled = 1; + } + + + count -= filled; + done += filled; + off += filled; + buf += filled; + } + + return done; +err: + return -EFAULT; +} + +static ssize_t vfio_platform_read(void *device_data, char __user *buf, + size_t count, loff_t *ppos) +{ + struct vfio_platform_device *vdev = device_data; + unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); + loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; + + if (index >= vdev->num_regions) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)) + return -EINVAL; + + if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) + return vfio_platform_read_mmio(&vdev->regions[index], + buf, count, off); + else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) + return -EINVAL; /* not implemented */ + + return -EINVAL; +} + +static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg, + const char __user *buf, size_t count, + loff_t off) +{ + unsigned int done = 0; + + if (!reg->ioaddr) { + reg->ioaddr = + ioremap(reg->addr, reg->size); + + if (!reg->ioaddr) + return -ENOMEM; + } + + while (count) { + size_t filled; + + if (count >= 4 && !(off % 4)) { + u32 val; + + if (copy_from_user(&val, buf, 4)) + goto err; + iowrite32(val, reg->ioaddr + off); + + filled = 4; + } else if (count >= 2 && !(off % 2)) { + u16 val; + + if (copy_from_user(&val, buf, 2)) + goto err; + iowrite16(val, reg->ioaddr + off); + + filled = 2; + } else { + u8 val; + + if (copy_from_user(&val, buf, 1)) + goto err; + iowrite8(val, reg->ioaddr + off); + + filled = 1; + } + + count -= filled; + done += filled; + off += filled; + buf += filled; + } + + return done; +err: + return -EFAULT; +} + +static ssize_t vfio_platform_write(void *device_data, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct vfio_platform_device *vdev = device_data; + unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); + loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; + + if (index >= vdev->num_regions) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)) + return -EINVAL; + + if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) + return vfio_platform_write_mmio(&vdev->regions[index], + buf, count, off); + else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) + return -EINVAL; /* not implemented */ + + return -EINVAL; +} + +static int vfio_platform_mmap_mmio(struct vfio_platform_region region, + struct vm_area_struct *vma) +{ + u64 req_len, pgoff, req_start; + + req_len = vma->vm_end - vma->vm_start; + pgoff = vma->vm_pgoff & + ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1); + req_start = pgoff << PAGE_SHIFT; + + if (region.size < PAGE_SIZE || req_start + req_len > region.size) + return -EINVAL; + + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; + + return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, + req_len, vma->vm_page_prot); +} + +static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma) +{ + struct vfio_platform_device *vdev = device_data; + unsigned int index; + + index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT); + + if (vma->vm_end < vma->vm_start) + return -EINVAL; + if (!(vma->vm_flags & VM_SHARED)) + return -EINVAL; + if (index >= vdev->num_regions) + return -EINVAL; + if (vma->vm_start & ~PAGE_MASK) + return -EINVAL; + if (vma->vm_end & ~PAGE_MASK) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) + && (vma->vm_flags & VM_READ)) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) + && (vma->vm_flags & VM_WRITE)) + return -EINVAL; + + vma->vm_private_data = vdev; + + if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) + return vfio_platform_mmap_mmio(vdev->regions[index], vma); + + else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) + return -EINVAL; /* not implemented */ + + return -EINVAL; +} + +static const struct vfio_device_ops vfio_platform_ops = { + .name = "vfio-platform", + .open = vfio_platform_open, + .release = vfio_platform_release, + .ioctl = vfio_platform_ioctl, + .read = vfio_platform_read, + .write = vfio_platform_write, + .mmap = vfio_platform_mmap, +}; + +static int vfio_platform_of_probe(struct vfio_platform_device *vdev, + struct device *dev) +{ + int ret; + + ret = device_property_read_string(dev, "compatible", + &vdev->compat); + if (ret) + dev_err(dev, "Cannot retrieve compat for %s\n", vdev->name); + + return ret; +} + +/* + * There can be two kernel build combinations. One build where + * ACPI is not selected in Kconfig and another one with the ACPI Kconfig. + * + * In the first case, vfio_platform_acpi_probe will return since + * acpi_disabled is 1. DT user will not see any kind of messages from + * ACPI. + * + * In the second case, both DT and ACPI is compiled in but the system is + * booting with any of these combinations. + * + * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine + * terminates immediately without any messages. + * + * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are + * valid checks. We cannot claim that this system is DT. + */ +int vfio_platform_probe_common(struct vfio_platform_device *vdev, + struct device *dev) +{ + struct iommu_group *group; + int ret; + + if (!vdev) + return -EINVAL; + + ret = vfio_platform_acpi_probe(vdev, dev); + if (ret) + ret = vfio_platform_of_probe(vdev, dev); + + if (ret) + return ret; + + vdev->device = dev; + + ret = vfio_platform_get_reset(vdev); + if (ret && vdev->reset_required) { + dev_err(dev, "No reset function found for device %s\n", + vdev->name); + return ret; + } + + group = vfio_iommu_group_get(dev); + if (!group) { + dev_err(dev, "No IOMMU group for device %s\n", vdev->name); + ret = -EINVAL; + goto put_reset; + } + + ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev); + if (ret) + goto put_iommu; + + mutex_init(&vdev->igate); + + pm_runtime_enable(vdev->device); + return 0; + +put_iommu: + vfio_iommu_group_put(group, dev); +put_reset: + vfio_platform_put_reset(vdev); + return ret; +} +EXPORT_SYMBOL_GPL(vfio_platform_probe_common); + +struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) +{ + struct vfio_platform_device *vdev; + + vdev = vfio_del_group_dev(dev); + + if (vdev) { + pm_runtime_disable(vdev->device); + vfio_platform_put_reset(vdev); + vfio_iommu_group_put(dev->iommu_group, dev); + } + + return vdev; +} +EXPORT_SYMBOL_GPL(vfio_platform_remove_common); + +void __vfio_platform_register_reset(struct vfio_platform_reset_node *node) +{ + mutex_lock(&driver_lock); + list_add(&node->link, &reset_list); + mutex_unlock(&driver_lock); +} +EXPORT_SYMBOL_GPL(__vfio_platform_register_reset); + +void vfio_platform_unregister_reset(const char *compat, + vfio_platform_reset_fn_t fn) +{ + struct vfio_platform_reset_node *iter, *temp; + + mutex_lock(&driver_lock); + list_for_each_entry_safe(iter, temp, &reset_list, link) { + if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) { + list_del(&iter->link); + break; + } + } + + mutex_unlock(&driver_lock); + +} +EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset); + +MODULE_VERSION(DRIVER_VERSION); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); |