--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * vfio-ISM driver for s390
+ *
+ * Copyright IBM Corp.
+ */
+
+#include <linux/slab.h>
+#include "../vfio_pci_priv.h"
+
+#define ISM_VFIO_PCI_OFFSET_SHIFT 48
+#define ISM_VFIO_PCI_OFFSET_TO_INDEX(off) ((off) >> ISM_VFIO_PCI_OFFSET_SHIFT)
+#define ISM_VFIO_PCI_INDEX_TO_OFFSET(index) ((u64)(index) << ISM_VFIO_PCI_OFFSET_SHIFT)
+#define ISM_VFIO_PCI_OFFSET_MASK (((u64)(1) << ISM_VFIO_PCI_OFFSET_SHIFT) - 1)
+
+/*
+ * Use __zpci_load() to bypass automatic use of
+ * PCI MIO instructions which are not supported on ISM devices
+ */
+#define ISM_READ(size) \
+ static int ism_read##size(struct zpci_dev *zdev, int bar, \
+ size_t *filled, char __user *buf, \
+ loff_t off) \
+ { \
+ u64 req, tmp; \
+ u##size val; \
+ int ret; \
+ \
+ req = ZPCI_CREATE_REQ(READ_ONCE(zdev->fh), bar, sizeof(val)); \
+ ret = __zpci_load(&tmp, req, off); \
+ if (ret) \
+ return ret; \
+ val = (u##size)tmp; \
+ if (copy_to_user(buf, &val, sizeof(val))) \
+ return -EFAULT; \
+ *filled = sizeof(val); \
+ return 0; \
+ }
+
+ISM_READ(64);
+ISM_READ(32);
+ISM_READ(16);
+ISM_READ(8);
+
+struct ism_vfio_pci_core_device {
+ struct vfio_pci_core_device core_device;
+ struct kmem_cache *store_block_cache;
+};
+
+static int ism_vfio_pci_open_device(struct vfio_device *core_vdev)
+{
+ struct ism_vfio_pci_core_device *ivpcd;
+ struct vfio_pci_core_device *vdev;
+ int ret;
+
+ ivpcd = container_of(core_vdev, struct ism_vfio_pci_core_device,
+ core_device.vdev);
+ vdev = &ivpcd->core_device;
+
+ ret = vfio_pci_core_enable(vdev);
+ if (ret)
+ return ret;
+
+ vfio_pci_core_finish_enable(vdev);
+ return 0;
+}
+
+/*
+ * ism_vfio_pci_do_io_r()
+ *
+ * On s390, kernel primitives such as ioread() and iowrite() are switched over
+ * from function-handle-based PCI load/stores instructions to PCI memory-I/O (MIO)
+ * loads/stores when these are available and not explicitly disabled. Since these
+ * instructions cannot be used with ISM devices, ensure that classic
+ * function-handle-based PCI instructions are used instead.
+ */
+static ssize_t ism_vfio_pci_do_io_r(struct vfio_pci_core_device *vdev,
+ char __user *buf, loff_t off, size_t count,
+ int bar)
+{
+ struct zpci_dev *zdev = to_zpci(vdev->pdev);
+ ssize_t done = 0;
+ int ret;
+
+ while (count) {
+ size_t filled;
+
+ if (count >= 8 && IS_ALIGNED(off, 8)) {
+ ret = ism_read64(zdev, bar, &filled, buf, off);
+ if (ret)
+ return ret;
+ } else if (count >= 4 && IS_ALIGNED(off, 4)) {
+ ret = ism_read32(zdev, bar, &filled, buf, off);
+ if (ret)
+ return ret;
+ } else if (count >= 2 && IS_ALIGNED(off, 2)) {
+ ret = ism_read16(zdev, bar, &filled, buf, off);
+ if (ret)
+ return ret;
+ } else {
+ ret = ism_read8(zdev, bar, &filled, buf, off);
+ if (ret)
+ return ret;
+ }
+
+ count -= filled;
+ done += filled;
+ off += filled;
+ buf += filled;
+ }
+
+ return done;
+}
+
+/*
+ * ism_vfio_pci_do_io_w()
+ *
+ * Ensure that the PCI store block (PCISTB) instruction is used as required by the
+ * ISM device. The ISM device also uses a 256 TiB BAR 0 for write operations,
+ * which requires a 48bit region address space (ISM_VFIO_PCI_OFFSET_SHIFT).
+ */
+static ssize_t ism_vfio_pci_do_io_w(struct vfio_pci_core_device *vdev,
+ char __user *buf, loff_t off, size_t count,
+ int bar)
+{
+ struct zpci_dev *zdev = to_zpci(vdev->pdev);
+ struct ism_vfio_pci_core_device *ivpcd;
+ ssize_t ret;
+ void *data;
+ u64 req;
+
+ if (count > zdev->maxstbl)
+ return -EINVAL;
+ if (((off % PAGE_SIZE) + count) > PAGE_SIZE)
+ return -EINVAL;
+
+ ivpcd = container_of(vdev, struct ism_vfio_pci_core_device,
+ core_device);
+ data = kmem_cache_alloc(ivpcd->store_block_cache, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ if (copy_from_user(data, buf, count)) {
+ ret = -EFAULT;
+ goto out_free;
+ }
+
+ req = ZPCI_CREATE_REQ(READ_ONCE(zdev->fh), bar, count);
+ ret = __zpci_store_block(data, req, off);
+ if (ret)
+ goto out_free;
+
+ ret = count;
+
+out_free:
+ kmem_cache_free(ivpcd->store_block_cache, data);
+ return ret;
+}
+
+static ssize_t ism_vfio_pci_bar_rw(struct vfio_pci_core_device *vdev,
+ char __user *buf, size_t count, loff_t *ppos,
+ bool iswrite)
+{
+ int bar = ISM_VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+ loff_t pos = *ppos & ISM_VFIO_PCI_OFFSET_MASK;
+ resource_size_t end;
+ ssize_t done = 0;
+
+ if (pci_resource_start(vdev->pdev, bar))
+ end = pci_resource_len(vdev->pdev, bar);
+ else
+ return -EINVAL;
+
+ if (pos >= end)
+ return -EINVAL;
+
+ count = min(count, (size_t)(end - pos));
+
+ if (iswrite)
+ done = ism_vfio_pci_do_io_w(vdev, buf, pos, count, bar);
+ else
+ done = ism_vfio_pci_do_io_r(vdev, buf, pos, count, bar);
+
+ if (done >= 0)
+ *ppos += done;
+
+ return done;
+}
+
+static ssize_t ism_vfio_pci_config_rw(struct vfio_pci_core_device *vdev,
+ char __user *buf, size_t count,
+ loff_t *ppos, bool iswrite)
+{
+ loff_t pos = *ppos;
+ size_t done = 0;
+ int ret = 0;
+
+ pos &= ISM_VFIO_PCI_OFFSET_MASK;
+
+ while (count) {
+ /*
+ * zPCI must not use MIO instructions for config space access,
+ * so we can use common code path here.
+ */
+ ret = vfio_pci_config_rw_single(vdev, buf, count, &pos, iswrite);
+ if (ret < 0)
+ return ret;
+
+ count -= ret;
+ done += ret;
+ buf += ret;
+ pos += ret;
+ }
+
+ *ppos += done;
+
+ return done;
+}
+
+static ssize_t ism_vfio_pci_rw(struct vfio_device *core_vdev, char __user *buf,
+ size_t count, loff_t *ppos, bool iswrite)
+{
+ unsigned int index = ISM_VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+ struct vfio_pci_core_device *vdev;
+ int ret;
+
+ vdev = container_of(core_vdev, struct vfio_pci_core_device, vdev);
+
+ if (!count)
+ return 0;
+
+ switch (index) {
+ case VFIO_PCI_CONFIG_REGION_INDEX:
+ ret = ism_vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
+ break;
+
+ case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
+ ret = ism_vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static ssize_t ism_vfio_pci_read(struct vfio_device *core_vdev,
+ char __user *buf, size_t count, loff_t *ppos)
+{
+ return ism_vfio_pci_rw(core_vdev, buf, count, ppos, false);
+}
+
+static ssize_t ism_vfio_pci_write(struct vfio_device *core_vdev,
+ const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ return ism_vfio_pci_rw(core_vdev, (char __user *)buf, count, ppos,
+ true);
+}
+
+static int ism_vfio_pci_ioctl_get_region_info(struct vfio_device *core_vdev,
+ struct vfio_region_info *info,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_pci_core_device *vdev =
+ container_of(core_vdev, struct vfio_pci_core_device, vdev);
+ struct pci_dev *pdev = vdev->pdev;
+
+ switch (info->index) {
+ case VFIO_PCI_CONFIG_REGION_INDEX:
+ info->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);
+ info->size = pdev->cfg_size;
+ info->flags = VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE;
+ break;
+ case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
+ info->offset = ISM_VFIO_PCI_INDEX_TO_OFFSET(info->index);
+ info->size = pci_resource_len(pdev, info->index);
+ if (!info->size) {
+ info->flags = 0;
+ break;
+ }
+ info->flags = VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE;
+ break;
+ default:
+ info->offset = 0;
+ info->size = 0;
+ info->flags = 0;
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int ism_vfio_pci_init_dev(struct vfio_device *core_vdev)
+{
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(core_vdev->dev));
+ struct ism_vfio_pci_core_device *ivpcd;
+ char cache_name[20];
+ int ret;
+
+ ivpcd = container_of(core_vdev, struct ism_vfio_pci_core_device,
+ core_device.vdev);
+
+ snprintf(cache_name, sizeof(cache_name), "ism_sb_fid_%08x", zdev->fid);
+
+ ivpcd->store_block_cache =
+ kmem_cache_create(cache_name, zdev->maxstbl,
+ (&(struct kmem_cache_args){
+ .align = PAGE_SIZE,
+ .useroffset = 0,
+ .usersize = zdev->maxstbl,
+ }),
+ (SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT));
+ if (!ivpcd->store_block_cache)
+ return -ENOMEM;
+
+ ret = vfio_pci_core_init_dev(core_vdev);
+ if (ret)
+ kmem_cache_destroy(ivpcd->store_block_cache);
+
+ return ret;
+}
+
+static void ism_vfio_pci_release_dev(struct vfio_device *core_vdev)
+{
+ struct ism_vfio_pci_core_device *ivpcd = container_of(
+ core_vdev, struct ism_vfio_pci_core_device, core_device.vdev);
+
+ kmem_cache_destroy(ivpcd->store_block_cache);
+ vfio_pci_core_release_dev(core_vdev);
+}
+
+static const struct vfio_device_ops ism_pci_ops = {
+ .name = "ism-vfio-pci",
+ .init = ism_vfio_pci_init_dev,
+ .release = ism_vfio_pci_release_dev,
+ .open_device = ism_vfio_pci_open_device,
+ .close_device = vfio_pci_core_close_device,
+ .ioctl = vfio_pci_core_ioctl,
+ .get_region_info_caps = ism_vfio_pci_ioctl_get_region_info,
+ .device_feature = vfio_pci_core_ioctl_feature,
+ .read = ism_vfio_pci_read,
+ .write = ism_vfio_pci_write,
+ .request = vfio_pci_core_request,
+ .match = vfio_pci_core_match,
+ .match_token_uuid = vfio_pci_core_match_token_uuid,
+ .bind_iommufd = vfio_iommufd_physical_bind,
+ .unbind_iommufd = vfio_iommufd_physical_unbind,
+ .attach_ioas = vfio_iommufd_physical_attach_ioas,
+ .detach_ioas = vfio_iommufd_physical_detach_ioas,
+};
+
+static int ism_vfio_pci_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ struct ism_vfio_pci_core_device *ivpcd;
+ int ret;
+
+ ivpcd = vfio_alloc_device(ism_vfio_pci_core_device, core_device.vdev,
+ &pdev->dev, &ism_pci_ops);
+ if (IS_ERR(ivpcd))
+ return PTR_ERR(ivpcd);
+
+ dev_set_drvdata(&pdev->dev, &ivpcd->core_device);
+
+ ret = vfio_pci_core_register_device(&ivpcd->core_device);
+ if (ret)
+ vfio_put_device(&ivpcd->core_device.vdev);
+
+ return ret;
+}
+
+static void ism_vfio_pci_remove(struct pci_dev *pdev)
+{
+ struct vfio_pci_core_device *core_device;
+ struct ism_vfio_pci_core_device *ivpcd;
+
+ core_device = dev_get_drvdata(&pdev->dev);
+ ivpcd = container_of(core_device, struct ism_vfio_pci_core_device,
+ core_device);
+
+ vfio_pci_core_unregister_device(&ivpcd->core_device);
+ vfio_put_device(&ivpcd->core_device.vdev);
+}
+
+static const struct pci_device_id ism_device_table[] = {
+ { PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_IBM,
+ PCI_DEVICE_ID_IBM_ISM) },
+ {}
+};
+MODULE_DEVICE_TABLE(pci, ism_device_table);
+
+static struct pci_driver ism_vfio_pci_driver = {
+ .name = KBUILD_MODNAME,
+ .id_table = ism_device_table,
+ .probe = ism_vfio_pci_probe,
+ .remove = ism_vfio_pci_remove,
+ .err_handler = &vfio_pci_core_err_handlers,
+ .driver_managed_dma = true,
+};
+
+module_pci_driver(ism_vfio_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("vfio-pci variant driver for the IBM Internal Shared Memory (ISM) device");
+MODULE_AUTHOR("IBM Corporation");
projects / thirdparty / kernel / linux.git / commitdiff
