Commit 62fa19d4 authored by Ryan Grimm's avatar Ryan Grimm Committed by Michael Ellerman
Browse files

cxl: Add ability to reset the card 



Adds reset to sysfs which will PERST the card. If load_image_on_perst is set
to "user" or "factory", the PERST will cause that image to be loaded.

load_image_on_perst is set to "user" for production.

"none" could be used for debugging. The PSL trace arrays are preserved which
then can be read through debugfs.

PERST also triggers CAPP recovery. An HMI comes in, which is handled by EEH.
EEH unbinds the driver, calls into Sapphire to reinitialize the PHB, then
rebinds the driver.

Signed-off-by: default avatarRyan Grimm <grimm@linux.vnet.ibm.com>
Acked-by: default avatarIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 1212aa1c

Documentation/ABI/testing/sysfs-class-cxl

+7 −0
Original line number Diff line number Diff line
@@ -146,3 +146,10 @@ Description: read/write 
                user or factory image to be loaded.

                Default is to reload on PERST whichever image the card has

                loaded.



What:           /sys/class/cxl/<card>/reset

Date:           October 2014

Contact:        linuxppc-dev@lists.ozlabs.org

Description:    write only

                Writing 1 will issue a PERST to card which may cause the card

                to reload the FPGA depending on load_image_on_perst.

drivers/misc/cxl/cxl.h

+1 −0
Original line number Diff line number Diff line
@@ -489,6 +489,7 @@ int cxl_alloc_irq_ranges(struct cxl_irq_ranges *irqs, struct cxl *adapter, unsig 
void cxl_release_irq_ranges(struct cxl_irq_ranges *irqs, struct cxl *adapter);

int cxl_setup_irq(struct cxl *adapter, unsigned int hwirq, unsigned int virq);

int cxl_update_image_control(struct cxl *adapter);

int cxl_reset(struct cxl *adapter);



/* common == phyp + powernv */

struct cxl_process_element_common {

drivers/misc/cxl/pci.c

+37 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <asm/msi_bitmap.h>

#include <asm/pci-bridge.h> /* for struct pci_controller */

#include <asm/pnv-pci.h>

#include <asm/io.h>



#include "cxl.h"
@@ -741,6 +742,42 @@ static void cxl_remove_afu(struct cxl_afu *afu) 
	device_unregister(&afu->dev);

}



int cxl_reset(struct cxl *adapter)

{

	struct pci_dev *dev = to_pci_dev(adapter->dev.parent);

	int rc;

	int i;

	u32 val;



	dev_info(&dev->dev, "CXL reset\n");



	for (i = 0; i < adapter->slices; i++)

		cxl_remove_afu(adapter->afu[i]);



	/* pcie_warm_reset requests a fundamental pci reset which includes a

	 * PERST assert/deassert.  PERST triggers a loading of the image

	 * if "user" or "factory" is selected in sysfs */

	if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) {

		dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n");

		return rc;

	}



	/* the PERST done above fences the PHB.  So, reset depends on EEH

	 * to unbind the driver, tell Sapphire to reinit the PHB, and rebind

	 * the driver.  Do an mmio read explictly to ensure EEH notices the

	 * fenced PHB.  Retry for a few seconds before giving up. */

	i = 0;

	while (((val = mmio_read32be(adapter->p1_mmio)) != 0xffffffff) &&

		(i < 5)) {

		msleep(500);

		i++;

	}



	if (val != 0xffffffff)

		dev_err(&dev->dev, "cxl: PERST failed to trigger EEH\n");



	return rc;

}



static int cxl_map_adapter_regs(struct cxl *adapter, struct pci_dev *dev)

{

drivers/misc/cxl/sysfs.c

+18 −0
Original line number Diff line number Diff line
@@ -56,6 +56,23 @@ static ssize_t image_loaded_show(struct device *device, 
	return scnprintf(buf, PAGE_SIZE, "factory\n");

}



static ssize_t reset_adapter_store(struct device *device,

				   struct device_attribute *attr,

				   const char *buf, size_t count)

{

	struct cxl *adapter = to_cxl_adapter(device);

	int rc;

	int val;



	rc = sscanf(buf, "%i", &val);

	if ((rc != 1) || (val != 1))

		return -EINVAL;



	if ((rc = cxl_reset(adapter)))

		return rc;

	return count;

}



static ssize_t load_image_on_perst_show(struct device *device,

				 struct device_attribute *attr,

				 char *buf)
@@ -100,6 +117,7 @@ static struct device_attribute adapter_attrs[] = { 
	__ATTR_RO(base_image),

	__ATTR_RO(image_loaded),

	__ATTR_RW(load_image_on_perst),

	__ATTR(reset, S_IWUSR, NULL, reset_adapter_store),

};

CRA Git | Maintained and supported by SUSTech CRA and CCSE