1 files changed, 309 insertions, 0 deletions
diff --git a/drivers/misc/cxl/vphb.c b/drivers/misc/cxl/vphb.c
new file mode 100644
index 0000000000..6332db8044
--- /dev/null
+++ b/drivers/misc/cxl/vphb.c
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2014 IBM Corp.
+ */
+
+#include <linux/pci.h>
+#include <misc/cxl.h>
+#include "cxl.h"
+
+static int cxl_pci_probe_mode(struct pci_bus *bus)
+{
+	return PCI_PROBE_NORMAL;
+}
+
+static int cxl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+{
+	return -ENODEV;
+}
+
+static void cxl_teardown_msi_irqs(struct pci_dev *pdev)
+{
+	/*
+	 * MSI should never be set but need still need to provide this call
+	 * back.
+	 */
+}
+
+static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
+{
+	struct pci_controller *phb;
+	struct cxl_afu *afu;
+	struct cxl_context *ctx;
+
+	phb = pci_bus_to_host(dev->bus);
+	afu = (struct cxl_afu *)phb->private_data;
+
+	if (!cxl_ops->link_ok(afu->adapter, afu)) {
+		dev_warn(&dev->dev, "%s: Device link is down, refusing to enable AFU\n", __func__);
+		return false;
+	}
+
+	dev->dev.archdata.dma_offset = PAGE_OFFSET;
+
+	/*
+	 * Allocate a context to do cxl things too.  If we eventually do real
+	 * DMA ops, we'll need a default context to attach them to
+	 */
+	ctx = cxl_dev_context_init(dev);
+	if (IS_ERR(ctx))
+		return false;
+	dev->dev.archdata.cxl_ctx = ctx;
+
+	return (cxl_ops->afu_check_and_enable(afu) == 0);
+}
+
+static void cxl_pci_disable_device(struct pci_dev *dev)
+{
+	struct cxl_context *ctx = cxl_get_context(dev);
+
+	if (ctx) {
+		if (ctx->status == STARTED) {
+			dev_err(&dev->dev, "Default context started\n");
+			return;
+		}
+		dev->dev.archdata.cxl_ctx = NULL;
+		cxl_release_context(ctx);
+	}
+}
+
+static void cxl_pci_reset_secondary_bus(struct pci_dev *dev)
+{
+	/* Should we do an AFU reset here ? */
+}
+
+static int cxl_pcie_cfg_record(u8 bus, u8 devfn)
+{
+	return (bus << 8) + devfn;
+}
+
+static inline struct cxl_afu *pci_bus_to_afu(struct pci_bus *bus)
+{
+	struct pci_controller *phb = bus ? pci_bus_to_host(bus) : NULL;
+
+	return phb ? phb->private_data : NULL;
+}
+
+static void cxl_afu_configured_put(struct cxl_afu *afu)
+{
+	atomic_dec_if_positive(&afu->configured_state);
+}
+
+static bool cxl_afu_configured_get(struct cxl_afu *afu)
+{
+	return atomic_inc_unless_negative(&afu->configured_state);
+}
+
+static inline int cxl_pcie_config_info(struct pci_bus *bus, unsigned int devfn,
+				       struct cxl_afu *afu, int *_record)
+{
+	int record;
+
+	record = cxl_pcie_cfg_record(bus->number, devfn);
+	if (record > afu->crs_num)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	*_record = record;
+	return 0;
+}
+
+static int cxl_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
+				int offset, int len, u32 *val)
+{
+	int rc, record;
+	struct cxl_afu *afu;
+	u8 val8;
+	u16 val16;
+	u32 val32;
+
+	afu = pci_bus_to_afu(bus);
+	/* Grab a reader lock on afu. */
+	if (afu == NULL || !cxl_afu_configured_get(afu))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	rc = cxl_pcie_config_info(bus, devfn, afu, &record);
+	if (rc)
+		goto out;
+
+	switch (len) {
+	case 1:
+		rc = cxl_ops->afu_cr_read8(afu, record, offset,	&val8);
+		*val = val8;
+		break;
+	case 2:
+		rc = cxl_ops->afu_cr_read16(afu, record, offset, &val16);
+		*val = val16;
+		break;
+	case 4:
+		rc = cxl_ops->afu_cr_read32(afu, record, offset, &val32);
+		*val = val32;
+		break;
+	default:
+		WARN_ON(1);
+	}
+
+out:
+	cxl_afu_configured_put(afu);
+	return rc ? PCIBIOS_DEVICE_NOT_FOUND : 0;
+}
+
+static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
+				 int offset, int len, u32 val)
+{
+	int rc, record;
+	struct cxl_afu *afu;
+
+	afu = pci_bus_to_afu(bus);
+	/* Grab a reader lock on afu. */
+	if (afu == NULL || !cxl_afu_configured_get(afu))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	rc = cxl_pcie_config_info(bus, devfn, afu, &record);
+	if (rc)
+		goto out;
+
+	switch (len) {
+	case 1:
+		rc = cxl_ops->afu_cr_write8(afu, record, offset, val & 0xff);
+		break;
+	case 2:
+		rc = cxl_ops->afu_cr_write16(afu, record, offset, val & 0xffff);
+		break;
+	case 4:
+		rc = cxl_ops->afu_cr_write32(afu, record, offset, val);
+		break;
+	default:
+		WARN_ON(1);
+	}
+
+out:
+	cxl_afu_configured_put(afu);
+	return rc ? PCIBIOS_SET_FAILED : 0;
+}
+
+static struct pci_ops cxl_pcie_pci_ops =
+{
+	.read = cxl_pcie_read_config,
+	.write = cxl_pcie_write_config,
+};
+
+
+static struct pci_controller_ops cxl_pci_controller_ops =
+{
+	.probe_mode = cxl_pci_probe_mode,
+	.enable_device_hook = cxl_pci_enable_device_hook,
+	.disable_device = cxl_pci_disable_device,
+	.release_device = cxl_pci_disable_device,
+	.reset_secondary_bus = cxl_pci_reset_secondary_bus,
+	.setup_msi_irqs = cxl_setup_msi_irqs,
+	.teardown_msi_irqs = cxl_teardown_msi_irqs,
+};
+
+int cxl_pci_vphb_add(struct cxl_afu *afu)
+{
+	struct pci_controller *phb;
+	struct device_node *vphb_dn;
+	struct device *parent;
+
+	/*
+	 * If there are no AFU configuration records we won't have anything to
+	 * expose under the vPHB, so skip creating one, returning success since
+	 * this is still a valid case. This will also opt us out of EEH
+	 * handling since we won't have anything special to do if there are no
+	 * kernel drivers attached to the vPHB, and EEH handling is not yet
+	 * supported in the peer model.
+	 */
+	if (!afu->crs_num)
+		return 0;
+
+	/* The parent device is the adapter. Reuse the device node of
+	 * the adapter.
+	 * We don't seem to care what device node is used for the vPHB,
+	 * but tools such as lsvpd walk up the device parents looking
+	 * for a valid location code, so we might as well show devices
+	 * attached to the adapter as being located on that adapter.
+	 */
+	parent = afu->adapter->dev.parent;
+	vphb_dn = parent->of_node;
+
+	/* Alloc and setup PHB data structure */
+	phb = pcibios_alloc_controller(vphb_dn);
+	if (!phb)
+		return -ENODEV;
+
+	/* Setup parent in sysfs */
+	phb->parent = parent;
+
+	/* Setup the PHB using arch provided callback */
+	phb->ops = &cxl_pcie_pci_ops;
+	phb->cfg_addr = NULL;
+	phb->cfg_data = NULL;
+	phb->private_data = afu;
+	phb->controller_ops = cxl_pci_controller_ops;
+
+	/* Scan the bus */
+	pcibios_scan_phb(phb);
+	if (phb->bus == NULL)
+		return -ENXIO;
+
+	/* Set release hook on root bus */
+	pci_set_host_bridge_release(to_pci_host_bridge(phb->bus->bridge),
+				    pcibios_free_controller_deferred,
+				    (void *) phb);
+
+	/* Claim resources. This might need some rework as well depending
+	 * whether we are doing probe-only or not, like assigning unassigned
+	 * resources etc...
+	 */
+	pcibios_claim_one_bus(phb->bus);
+
+	/* Add probed PCI devices to the device model */
+	pci_bus_add_devices(phb->bus);
+
+	afu->phb = phb;
+
+	return 0;
+}
+
+void cxl_pci_vphb_remove(struct cxl_afu *afu)
+{
+	struct pci_controller *phb;
+
+	/* If there is no configuration record we won't have one of these */
+	if (!afu || !afu->phb)
+		return;
+
+	phb = afu->phb;
+	afu->phb = NULL;
+
+	pci_remove_root_bus(phb->bus);
+	/*
+	 * We don't free phb here - that's handled by
+	 * pcibios_free_controller_deferred()
+	 */
+}
+
+bool cxl_pci_is_vphb_device(struct pci_dev *dev)
+{
+	struct pci_controller *phb;
+
+	phb = pci_bus_to_host(dev->bus);
+
+	return (phb->ops == &cxl_pcie_pci_ops);
+}
+
+struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev)
+{
+	struct pci_controller *phb;
+
+	phb = pci_bus_to_host(dev->bus);
+
+	return (struct cxl_afu *)phb->private_data;
+}
+EXPORT_SYMBOL_GPL(cxl_pci_to_afu);
+
+unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev)
+{
+	return cxl_pcie_cfg_record(dev->bus->number, dev->devfn);
+}
+EXPORT_SYMBOL_GPL(cxl_pci_to_cfg_record);