Commit 8039804c authored by Ben Cheatham's avatar Ben Cheatham Committed by Dan Williams
Browse files

cxl/core: Add CXL EINJ debugfs files 



Export CXL helper functions in einj-cxl.c for getting/injecting
available CXL protocol error types to sysfs under kernel/debug/cxl.

The kernel/debug/cxl/einj_types file will print the available CXL
protocol errors in the same format as the available_error_types
file provided by the einj module. The
kernel/debug/cxl/$dport_dev/einj_inject file is functionally the same
as the error_type and error_inject files provided by the EINJ module,
i.e.: writing an error type into $dport_dev/einj_inject will inject
said error type into the CXL dport represented by $dport_dev.

Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarBen Cheatham <Benjamin.Cheatham@amd.com>
Link: https://lore.kernel.org/r/20240311142508.31717-4-Benjamin.Cheatham@amd.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 12fb28ea

Documentation/ABI/testing/debugfs-cxl

+30 −0
Original line number Diff line number Diff line
@@ -33,3 +33,33 @@ Description: 
		device cannot clear poison from the address, -ENXIO is returned.

		The clear_poison attribute is only visible for devices

		supporting the capability.



What:		/sys/kernel/debug/cxl/einj_types

Date:		January, 2024

KernelVersion:	v6.9

Contact:	linux-cxl@vger.kernel.org

Description:

		(RO) Prints the CXL protocol error types made available by

		the platform in the format "0x<error number>	<error type>".

		The possible error types are (as of ACPI v6.5):

			0x1000	CXL.cache Protocol Correctable

			0x2000	CXL.cache Protocol Uncorrectable non-fatal

			0x4000	CXL.cache Protocol Uncorrectable fatal

			0x8000	CXL.mem Protocol Correctable

			0x10000	CXL.mem Protocol Uncorrectable non-fatal

			0x20000	CXL.mem Protocol Uncorrectable fatal



		The <error number> can be written to einj_inject to inject

		<error type> into a chosen dport.



What:		/sys/kernel/debug/cxl/$dport_dev/einj_inject

Date:		January, 2024

KernelVersion:	v6.9

Contact:	linux-cxl@vger.kernel.org

Description:

		(WO) Writing an integer to this file injects the corresponding

		CXL protocol error into $dport_dev ($dport_dev will be a device

		name from /sys/bus/pci/devices). The integer to type mapping for

		injection can be found by reading from einj_types. If the dport

		was enumerated in RCH mode, a CXL 1.1 error is injected, otherwise

		a CXL 2.0 error is injected.

drivers/cxl/core/port.c

+41 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <linux/platform_device.h>

#include <linux/memregion.h>

#include <linux/workqueue.h>

#include <linux/einj-cxl.h>

#include <linux/debugfs.h>

#include <linux/device.h>

#include <linux/module.h>
@@ -793,6 +794,40 @@ static int cxl_dport_setup_regs(struct device *host, struct cxl_dport *dport, 
	return rc;

}



DEFINE_SHOW_ATTRIBUTE(einj_cxl_available_error_type);



static int cxl_einj_inject(void *data, u64 type)

{

	struct cxl_dport *dport = data;



	if (dport->rch)

		return einj_cxl_inject_rch_error(dport->rcrb.base, type);



	return einj_cxl_inject_error(to_pci_dev(dport->dport_dev), type);

}

DEFINE_DEBUGFS_ATTRIBUTE(cxl_einj_inject_fops, NULL, cxl_einj_inject,

			 "0x%llx\n");



static void cxl_debugfs_create_dport_dir(struct cxl_dport *dport)

{

	struct dentry *dir;



	if (!einj_cxl_is_initialized())

		return;



	/*

	 * dport_dev needs to be a PCIe port for CXL 2.0+ ports because

	 * EINJ expects a dport SBDF to be specified for 2.0 error injection.

	 */

	if (!dport->rch && !dev_is_pci(dport->dport_dev))

		return;



	dir = cxl_debugfs_create_dir(dev_name(dport->dport_dev));



	debugfs_create_file("einj_inject", 0200, dir, dport,

			    &cxl_einj_inject_fops);

}



static struct cxl_port *__devm_cxl_add_port(struct device *host,

					    struct device *uport_dev,

					    resource_size_t component_reg_phys,
@@ -1149,6 +1184,8 @@ __devm_cxl_add_dport(struct cxl_port *port, struct device *dport_dev, 
	if (dev_is_pci(dport_dev))

		dport->link_latency = cxl_pci_get_latency(to_pci_dev(dport_dev));



	cxl_debugfs_create_dport_dir(dport);



	return dport;

}
@@ -2221,6 +2258,10 @@ static __init int cxl_core_init(void) 


	cxl_debugfs = debugfs_create_dir("cxl", NULL);



	if (einj_cxl_is_initialized())

		debugfs_create_file("einj_types", 0400, cxl_debugfs, NULL,

				    &einj_cxl_available_error_type_fops);



	cxl_mbox_init();



	rc = cxl_memdev_init();