Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 29fea8aa authored by Alastair D'Silva's avatar Alastair D'Silva Committed by Michael Ellerman
Browse files

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 b0b5e591.

Signed-off-by: default avatarAlastair D'Silva <alastair@d-silva.org>
Acked-by: default avatarAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 82c6ae67

drivers/misc/cxl/Kconfig

+0 −8
Original line number Diff line number Diff line
@@ -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.

drivers/misc/cxl/pci.c

+18 −218
Original line number Diff line number Diff line
@@ -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;

	if (!(vsec = find_cxl_vsec(dev))) {

		dev_err(&dev->dev, "ABORTING: CXL VSEC not found!\n");

		return -ENODEV;

	}



	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;

	if ((rc = CXL_READ_VSEC_MODE_CONTROL(dev, vsec, &val))) {

		dev_err(&dev->dev, "failed to read current mode control: %i", rc);

		return rc;

	}

	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))

		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_WRITE_VSEC_MODE_CONTROL(dev, vsec, val))) {

		dev_err(&dev->dev, "failed to enable CXL protocol: %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;

	}



	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)))

include/misc/cxl.h

+0 −25
Original line number Diff line number Diff line
@@ -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);