Revert "cxl: Add cxl_check_and_switch_mode() API to switch bi-modal cards"

Remove abandonned capi support for the Mellanox CX4.

This reverts commit b0b5e5918ad1babfd1d43d98c7281926a7b57b9f.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/drivers/misc/cxl/Kconfig b/drivers/misc/cxl/Kconfig
index 93397cb05b15a60c6c61eeb7e6dcb8c13a729601..3ce933707828cb45487e1ddd3928fe444ef73a37 100644 (file)
--- a/drivers/misc/cxl/Kconfig
+++ b/drivers/misc/cxl/Kconfig
@@ -33,11 +33,3 @@ config CXL
          CAPI adapters are found in POWER8 based systems.
 
          If unsure, say N.
-
-config CXL_BIMODAL
-       bool "Support for bi-modal CAPI cards"
-       depends on HOTPLUG_PCI_POWERNV = y && CXL || HOTPLUG_PCI_POWERNV = m && CXL = m
-       default y
-       help
-         Select this option to enable support for bi-modal CAPI cards, such as
-         the Mellanox CX-4.

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 429d6de1dde7ab7e62c832da8dc41cc7a87db0d6..9c5a21fee83546f2a8f7a5da102bcaacab0726f3 100644 (file)
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -55,8 +55,6 @@
        pci_read_config_byte(dev, vsec + 0xa, dest)
 #define CXL_WRITE_VSEC_MODE_CONTROL(dev, vsec, val) \
        pci_write_config_byte(dev, vsec + 0xa, val)
-#define CXL_WRITE_VSEC_MODE_CONTROL_BUS(bus, devfn, vsec, val) \
-       pci_bus_write_config_byte(bus, devfn, vsec + 0xa, val)
 #define CXL_VSEC_PROTOCOL_MASK   0xe0
 #define CXL_VSEC_PROTOCOL_1024TB 0x80
 #define CXL_VSEC_PROTOCOL_512TB  0x40
@@ -800,234 +798,36 @@ static int setup_cxl_bars(struct pci_dev *dev)
        return 0;
 }
 
-#ifdef CONFIG_CXL_BIMODAL
-
-struct cxl_switch_work {
-       struct pci_dev *dev;
-       struct work_struct work;
-       int vsec;
-       int mode;
-};
-
-static void switch_card_to_cxl(struct work_struct *work)
+/* pciex node: ibm,opal-m64-window = <0x3d058 0x0 0x3d058 0x0 0x8 0x0>; */
+static int switch_card_to_cxl(struct pci_dev *dev)
 {
-       struct cxl_switch_work *switch_work =
-               container_of(work, struct cxl_switch_work, work);
-       struct pci_dev *dev = switch_work->dev;
-       struct pci_bus *bus = dev->bus;
-       struct pci_controller *hose = pci_bus_to_host(bus);
-       struct pci_dev *bridge;
-       struct pnv_php_slot *php_slot;
-       unsigned int devfn;
+       int vsec;
        u8 val;
        int rc;
 
-       dev_info(&bus->dev, "cxl: Preparing for mode switch...\n");
-       bridge = list_first_entry_or_null(&hose->bus->devices, struct pci_dev,
-                                         bus_list);
-       if (!bridge) {
-               dev_WARN(&bus->dev, "cxl: Couldn't find root port!\n");
-               goto err_dev_put;
-       }
+       dev_info(&dev->dev, "switch card to CXL\n");
 
-       php_slot = pnv_php_find_slot(pci_device_to_OF_node(bridge));
-       if (!php_slot) {
-               dev_err(&bus->dev, "cxl: Failed to find slot hotplug "
-                                  "information. You may need to upgrade "
-                                  "skiboot. Aborting.\n");
-               goto err_dev_put;
-       }
-
-       rc = CXL_READ_VSEC_MODE_CONTROL(dev, switch_work->vsec, &val);
-       if (rc) {
-               dev_err(&bus->dev, "cxl: Failed to read CAPI mode control: %i\n", rc);
-               goto err_dev_put;
-       }
-       devfn = dev->devfn;
-
-       /* Release the reference obtained in cxl_check_and_switch_mode() */
-       pci_dev_put(dev);
-
-       dev_dbg(&bus->dev, "cxl: Removing PCI devices from kernel\n");
-       pci_lock_rescan_remove();
-       pci_hp_remove_devices(bridge->subordinate);
-       pci_unlock_rescan_remove();
-
-       /* Switch the CXL protocol on the card */
-       if (switch_work->mode == CXL_BIMODE_CXL) {
-               dev_info(&bus->dev, "cxl: Switching card to CXL mode\n");
-               val &= ~CXL_VSEC_PROTOCOL_MASK;
-               val |= CXL_VSEC_PROTOCOL_256TB | CXL_VSEC_PROTOCOL_ENABLE;
-               rc = pnv_cxl_enable_phb_kernel_api(hose, true);
-               if (rc) {
-                       dev_err(&bus->dev, "cxl: Failed to enable kernel API"
-                                          " on real PHB, aborting\n");
-                       goto err_free_work;
-               }
-       } else {
-               dev_WARN(&bus->dev, "cxl: Switching card to PCI mode not supported!\n");
-               goto err_free_work;
-       }
-
-       rc = CXL_WRITE_VSEC_MODE_CONTROL_BUS(bus, devfn, switch_work->vsec, val);
-       if (rc) {
-               dev_err(&bus->dev, "cxl: Failed to configure CXL protocol: %i\n", rc);
-               goto err_free_work;
-       }
-
-       /*
-        * The CAIA spec (v1.1, Section 10.6 Bi-modal Device Support) states
-        * we must wait 100ms after this mode switch before touching PCIe config
-        * space.
-        */
-       msleep(100);
-
-       /*
-        * Hot reset to cause the card to come back in cxl mode. A
-        * OPAL_RESET_PCI_LINK would be sufficient, but currently lacks support
-        * in skiboot, so we use a hot reset instead.
-        *
-        * We call pci_set_pcie_reset_state() on the bridge, as a CAPI card is
-        * guaranteed to sit directly under the root port, and setting the reset
-        * state on a device directly under the root port is equivalent to doing
-        * it on the root port iself.
-        */
-       dev_info(&bus->dev, "cxl: Configuration write complete, resetting card\n");
-       pci_set_pcie_reset_state(bridge, pcie_hot_reset);
-       pci_set_pcie_reset_state(bridge, pcie_deassert_reset);
-
-       dev_dbg(&bus->dev, "cxl: Offlining slot\n");
-       rc = pnv_php_set_slot_power_state(&php_slot->slot, OPAL_PCI_SLOT_OFFLINE);
-       if (rc) {
-               dev_err(&bus->dev, "cxl: OPAL offlining call failed: %i\n", rc);
-               goto err_free_work;
-       }
-
-       dev_dbg(&bus->dev, "cxl: Onlining and probing slot\n");
-       rc = pnv_php_set_slot_power_state(&php_slot->slot, OPAL_PCI_SLOT_ONLINE);
-       if (rc) {
-               dev_err(&bus->dev, "cxl: OPAL onlining call failed: %i\n", rc);
-               goto err_free_work;
-       }
-
-       pci_lock_rescan_remove();
-       pci_hp_add_devices(bridge->subordinate);
-       pci_unlock_rescan_remove();
-
-       dev_info(&bus->dev, "cxl: CAPI mode switch completed\n");
-       kfree(switch_work);
-       return;
-
-err_dev_put:
-       /* Release the reference obtained in cxl_check_and_switch_mode() */
-       pci_dev_put(dev);
-err_free_work:
-       kfree(switch_work);
-}
-
-int cxl_check_and_switch_mode(struct pci_dev *dev, int mode, int vsec)
-{
-       struct cxl_switch_work *work;
-       u8 val;
-       int rc;
-
-       if (!cpu_has_feature(CPU_FTR_HVMODE))
+       if (!(vsec = find_cxl_vsec(dev))) {
+               dev_err(&dev->dev, "ABORTING: CXL VSEC not found!\n");
                return -ENODEV;
-
-       if (!vsec) {
-               vsec = find_cxl_vsec(dev);
-               if (!vsec) {
-                       dev_info(&dev->dev, "CXL VSEC not found\n");
-                       return -ENODEV;
-               }
        }
 
-       rc = CXL_READ_VSEC_MODE_CONTROL(dev, vsec, &val);
-       if (rc) {
-               dev_err(&dev->dev, "Failed to read current mode control: %i", rc);
+       if ((rc = CXL_READ_VSEC_MODE_CONTROL(dev, vsec, &val))) {
+               dev_err(&dev->dev, "failed to read current mode control: %i", rc);
                return rc;
        }
-
-       if (mode == CXL_BIMODE_PCI) {
-               if (!(val & CXL_VSEC_PROTOCOL_ENABLE)) {
-                       dev_info(&dev->dev, "Card is already in PCI mode\n");
-                       return 0;
-               }
-               /*
-                * TODO: Before it's safe to switch the card back to PCI mode
-                * we need to disable the CAPP and make sure any cachelines the
-                * card holds have been flushed out. Needs skiboot support.
-                */
-               dev_WARN(&dev->dev, "CXL mode switch to PCI unsupported!\n");
-               return -EIO;
-       }
-
-       if (val & CXL_VSEC_PROTOCOL_ENABLE) {
-               dev_info(&dev->dev, "Card is already in CXL mode\n");
-               return 0;
+       val &= ~CXL_VSEC_PROTOCOL_MASK;
+       val |= CXL_VSEC_PROTOCOL_256TB | CXL_VSEC_PROTOCOL_ENABLE;
+       if ((rc = CXL_WRITE_VSEC_MODE_CONTROL(dev, vsec, val))) {
+               dev_err(&dev->dev, "failed to enable CXL protocol: %i", rc);
+               return rc;
        }
-
-       dev_info(&dev->dev, "Card is in PCI mode, scheduling kernel thread "
-                           "to switch to CXL mode\n");
-
-       work = kmalloc(sizeof(struct cxl_switch_work), GFP_KERNEL);
-       if (!work)
-               return -ENOMEM;
-
-       pci_dev_get(dev);
-       work->dev = dev;
-       work->vsec = vsec;
-       work->mode = mode;
-       INIT_WORK(&work->work, switch_card_to_cxl);
-
-       schedule_work(&work->work);
-
        /*
-        * We return a failure now to abort the driver init. Once the
-        * link has been cycled and the card is in cxl mode we will
-        * come back (possibly using the generic cxl driver), but
-        * return success as the card should then be in cxl mode.
-        *
-        * TODO: What if the card comes back in PCI mode even after
-        *       the switch?  Don't want to spin endlessly.
+        * The CAIA spec (v0.12 11.6 Bi-modal Device Support) states
+        * we must wait 100ms after this mode switch before touching
+        * PCIe config space.
         */
-       return -EBUSY;
-}
-EXPORT_SYMBOL_GPL(cxl_check_and_switch_mode);
-
-#endif /* CONFIG_CXL_BIMODAL */
-
-static int setup_cxl_protocol_area(struct pci_dev *dev)
-{
-       u8 val;
-       int rc;
-       int vsec = find_cxl_vsec(dev);
-
-       if (!vsec) {
-               dev_info(&dev->dev, "CXL VSEC not found\n");
-               return -ENODEV;
-       }
-
-       rc = CXL_READ_VSEC_MODE_CONTROL(dev, vsec, &val);
-       if (rc) {
-               dev_err(&dev->dev, "Failed to read current mode control: %i\n", rc);
-               return rc;
-       }
-
-       if (!(val & CXL_VSEC_PROTOCOL_ENABLE)) {
-               dev_err(&dev->dev, "Card not in CAPI mode!\n");
-               return -EIO;
-       }
-
-       if ((val & CXL_VSEC_PROTOCOL_MASK) != CXL_VSEC_PROTOCOL_256TB) {
-               val &= ~CXL_VSEC_PROTOCOL_MASK;
-               val |= CXL_VSEC_PROTOCOL_256TB;
-               rc = CXL_WRITE_VSEC_MODE_CONTROL(dev, vsec, val);
-               if (rc) {
-                       dev_err(&dev->dev, "Failed to set CXL protocol area: %i\n", rc);
-                       return rc;
-               }
-       }
+       msleep(100);
 
        return 0;
 }
@@ -1724,7 +1524,7 @@ static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev)
        if ((rc = setup_cxl_bars(dev)))
                return rc;
 
-       if ((rc = setup_cxl_protocol_area(dev)))
+       if ((rc = switch_card_to_cxl(dev)))
                return rc;
 
        if ((rc = cxl_update_image_control(adapter)))

diff --git a/include/misc/cxl.h b/include/misc/cxl.h
index 6a3711a2e217813ac12317a8901cce99824c7162..74da2e4407639cf339f474f15bca0f0b7f25ceba 100644 (file)
--- a/include/misc/cxl.h
+++ b/include/misc/cxl.h
@@ -39,31 +39,6 @@
 bool cxl_slot_is_supported(struct pci_dev *dev, int flags);
 
 
-#define CXL_BIMODE_CXL 1
-#define CXL_BIMODE_PCI 2
-
-/*
- * Check the mode that the given bi-modal CXL adapter is currently in and
- * change it if necessary. This does not apply to AFU drivers.
- *
- * If the mode matches the requested mode this function will return 0 - if the
- * driver was expecting the generic CXL driver to have bound to the adapter and
- * it gets this return value it should fail the probe function to give the CXL
- * driver a chance to probe it.
- *
- * If the mode does not match it will start a background task to unplug the
- * device from Linux and switch its mode, and will return -EBUSY. At this
- * point the calling driver should make sure it has released the device and
- * fail its probe function.
- *
- * The offset of the CXL VSEC can be provided to this function. If 0 is passed,
- * this function will search for a CXL VSEC with ID 0x1280 and return -ENODEV
- * if it is not found.
- */
-#ifdef CONFIG_CXL_BIMODAL
-int cxl_check_and_switch_mode(struct pci_dev *dev, int mode, int vsec);
-#endif
-
 /* Get the AFU associated with a pci_dev */
 struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev);