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Diffstat (limited to 'drivers/misc/cxl/vphb.c')
-rw-r--r--drivers/misc/cxl/vphb.c309
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);