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-rw-r--r--Documentation/ABI/testing/debugfs-cxl30
-rw-r--r--Documentation/firmware-guide/acpi/apei/einj.rst34
-rw-r--r--MAINTAINERS1
-rw-r--r--drivers/acpi/apei/Kconfig13
-rw-r--r--drivers/acpi/apei/Makefile2
-rw-r--r--drivers/acpi/apei/apei-internal.h18
-rw-r--r--drivers/acpi/apei/einj-core.c (renamed from drivers/acpi/apei/einj.c)122
-rw-r--r--drivers/acpi/apei/einj-cxl.c113
-rw-r--r--drivers/cxl/core/port.c41
-rw-r--r--include/linux/einj-cxl.h44
10 files changed, 397 insertions, 21 deletions
diff --git a/Documentation/ABI/testing/debugfs-cxl b/Documentation/ABI/testing/debugfs-cxl
index fe61d372e3fa..4c0f62f881ca 100644
--- a/Documentation/ABI/testing/debugfs-cxl
+++ b/Documentation/ABI/testing/debugfs-cxl
@@ -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.
diff --git a/Documentation/firmware-guide/acpi/apei/einj.rst b/Documentation/firmware-guide/acpi/apei/einj.rst
index d6b61d22f525..c52b9da08fa9 100644
--- a/Documentation/firmware-guide/acpi/apei/einj.rst
+++ b/Documentation/firmware-guide/acpi/apei/einj.rst
@@ -32,6 +32,10 @@ configuration::
CONFIG_ACPI_APEI
CONFIG_ACPI_APEI_EINJ
+...and to (optionally) enable CXL protocol error injection set::
+
+ CONFIG_ACPI_APEI_EINJ_CXL
+
The EINJ user interface is in <debugfs mount point>/apei/einj.
The following files belong to it:
@@ -118,6 +122,24 @@ The following files belong to it:
this actually works depends on what operations the BIOS actually
includes in the trigger phase.
+CXL error types are supported from ACPI 6.5 onwards (given a CXL port
+is present). The EINJ user interface for CXL error types is at
+<debugfs mount point>/cxl. The following files belong to it:
+
+- einj_types:
+
+ Provides the same functionality as available_error_types above, but
+ for CXL error types
+
+- $dport_dev/einj_inject:
+
+ Injects a CXL error type into the CXL port represented by $dport_dev,
+ where $dport_dev is the name of the CXL port (usually a PCIe device name).
+ Error injections targeting a CXL 2.0+ port can use the legacy interface
+ under <debugfs mount point>/apei/einj, while CXL 1.1/1.0 port injections
+ must use this file.
+
+
BIOS versions based on the ACPI 4.0 specification have limited options
in controlling where the errors are injected. Your BIOS may support an
extension (enabled with the param_extension=1 module parameter, or boot
@@ -181,6 +203,18 @@ You should see something like this in dmesg::
[22715.834759] EDAC sbridge MC3: PROCESSOR 0:306e7 TIME 1422553404 SOCKET 0 APIC 0
[22716.616173] EDAC MC3: 1 CE memory read error on CPU_SrcID#0_Channel#0_DIMM#0 (channel:0 slot:0 page:0x12345 offset:0x0 grain:32 syndrome:0x0 - area:DRAM err_code:0001:0090 socket:0 channel_mask:1 rank:0)
+A CXL error injection example with $dport_dev=0000:e0:01.1::
+
+ # cd /sys/kernel/debug/cxl/
+ # ls
+ 0000:e0:01.1 0000:0c:00.0
+ # cat einj_types # See which errors can be injected
+ 0x00008000 CXL.mem Protocol Correctable
+ 0x00010000 CXL.mem Protocol Uncorrectable non-fatal
+ 0x00020000 CXL.mem Protocol Uncorrectable fatal
+ # cd 0000:e0:01.1 # Navigate to dport to inject into
+ # echo 0x8000 > einj_inject # Inject error
+
Special notes for injection into SGX enclaves:
There may be a separate BIOS setup option to enable SGX injection.
diff --git a/MAINTAINERS b/MAINTAINERS
index 2ecaaec6a6bf..90cf8403dd17 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5289,6 +5289,7 @@ M: Dan Williams <dan.j.williams@intel.com>
L: linux-cxl@vger.kernel.org
S: Maintained
F: drivers/cxl/
+F: include/linux/cxl-einj.h
F: include/linux/cxl-event.h
F: include/uapi/linux/cxl_mem.h
F: tools/testing/cxl/
diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig
index 6b18f8bc7be3..3cfe7e7475f2 100644
--- a/drivers/acpi/apei/Kconfig
+++ b/drivers/acpi/apei/Kconfig
@@ -60,6 +60,19 @@ config ACPI_APEI_EINJ
mainly used for debugging and testing the other parts of
APEI and some other RAS features.
+config ACPI_APEI_EINJ_CXL
+ bool "CXL Error INJection Support"
+ default ACPI_APEI_EINJ
+ depends on ACPI_APEI_EINJ
+ depends on CXL_BUS && CXL_BUS <= ACPI_APEI_EINJ
+ help
+ Support for CXL protocol Error INJection through debugfs/cxl.
+ Availability and which errors are supported is dependent on
+ the host platform. Look to ACPI v6.5 section 18.6.4 and kernel
+ EINJ documentation for more information.
+
+ If unsure say 'n'
+
config ACPI_APEI_ERST_DEBUG
tristate "APEI Error Record Serialization Table (ERST) Debug Support"
depends on ACPI_APEI
diff --git a/drivers/acpi/apei/Makefile b/drivers/acpi/apei/Makefile
index 4dfac2128737..2c474e6477e1 100644
--- a/drivers/acpi/apei/Makefile
+++ b/drivers/acpi/apei/Makefile
@@ -2,6 +2,8 @@
obj-$(CONFIG_ACPI_APEI) += apei.o
obj-$(CONFIG_ACPI_APEI_GHES) += ghes.o
obj-$(CONFIG_ACPI_APEI_EINJ) += einj.o
+einj-y := einj-core.o
+einj-$(CONFIG_ACPI_APEI_EINJ_CXL) += einj-cxl.o
obj-$(CONFIG_ACPI_APEI_ERST_DEBUG) += erst-dbg.o
apei-y := apei-base.o hest.o erst.o bert.o
diff --git a/drivers/acpi/apei/apei-internal.h b/drivers/acpi/apei/apei-internal.h
index 67c2c3b959e1..cd2766c69d78 100644
--- a/drivers/acpi/apei/apei-internal.h
+++ b/drivers/acpi/apei/apei-internal.h
@@ -130,4 +130,22 @@ static inline u32 cper_estatus_len(struct acpi_hest_generic_status *estatus)
}
int apei_osc_setup(void);
+
+int einj_get_available_error_type(u32 *type);
+int einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2, u64 param3,
+ u64 param4);
+int einj_cxl_rch_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
+ u64 param3, u64 param4);
+bool einj_is_cxl_error_type(u64 type);
+int einj_validate_error_type(u64 type);
+
+#ifndef ACPI_EINJ_CXL_CACHE_CORRECTABLE
+#define ACPI_EINJ_CXL_CACHE_CORRECTABLE BIT(12)
+#define ACPI_EINJ_CXL_CACHE_UNCORRECTABLE BIT(13)
+#define ACPI_EINJ_CXL_CACHE_FATAL BIT(14)
+#define ACPI_EINJ_CXL_MEM_CORRECTABLE BIT(15)
+#define ACPI_EINJ_CXL_MEM_UNCORRECTABLE BIT(16)
+#define ACPI_EINJ_CXL_MEM_FATAL BIT(17)
+#endif
+
#endif
diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj-core.c
index 89fb9331c611..66e7f529e92f 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj-core.c
@@ -21,6 +21,7 @@
#include <linux/nmi.h>
#include <linux/delay.h>
#include <linux/mm.h>
+#include <linux/platform_device.h>
#include <asm/unaligned.h>
#include "apei-internal.h"
@@ -36,6 +37,12 @@
#define MEM_ERROR_MASK (ACPI_EINJ_MEMORY_CORRECTABLE | \
ACPI_EINJ_MEMORY_UNCORRECTABLE | \
ACPI_EINJ_MEMORY_FATAL)
+#define CXL_ERROR_MASK (ACPI_EINJ_CXL_CACHE_CORRECTABLE | \
+ ACPI_EINJ_CXL_CACHE_UNCORRECTABLE | \
+ ACPI_EINJ_CXL_CACHE_FATAL | \
+ ACPI_EINJ_CXL_MEM_CORRECTABLE | \
+ ACPI_EINJ_CXL_MEM_UNCORRECTABLE | \
+ ACPI_EINJ_CXL_MEM_FATAL)
/*
* ACPI version 5 provides a SET_ERROR_TYPE_WITH_ADDRESS action.
@@ -137,6 +144,11 @@ static struct apei_exec_ins_type einj_ins_type[] = {
*/
static DEFINE_MUTEX(einj_mutex);
+/*
+ * Exported APIs use this flag to exit early if einj_probe() failed.
+ */
+bool einj_initialized __ro_after_init;
+
static void *einj_param;
static void einj_exec_ctx_init(struct apei_exec_context *ctx)
@@ -160,7 +172,7 @@ static int __einj_get_available_error_type(u32 *type)
}
/* Get error injection capabilities of the platform */
-static int einj_get_available_error_type(u32 *type)
+int einj_get_available_error_type(u32 *type)
{
int rc;
@@ -530,8 +542,8 @@ static int __einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
}
/* Inject the specified hardware error */
-static int einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
- u64 param3, u64 param4)
+int einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2, u64 param3,
+ u64 param4)
{
int rc;
u64 base_addr, size;
@@ -554,8 +566,17 @@ static int einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
if (type & ACPI5_VENDOR_BIT) {
if (vendor_flags != SETWA_FLAGS_MEM)
goto inject;
- } else if (!(type & MEM_ERROR_MASK) && !(flags & SETWA_FLAGS_MEM))
+ } else if (!(type & MEM_ERROR_MASK) && !(flags & SETWA_FLAGS_MEM)) {
goto inject;
+ }
+
+ /*
+ * Injections targeting a CXL 1.0/1.1 port have to be injected
+ * via the einj_cxl_rch_error_inject() path as that does the proper
+ * validation of the given RCRB base (MMIO) address.
+ */
+ if (einj_is_cxl_error_type(type) && (flags & SETWA_FLAGS_MEM))
+ return -EINVAL;
/*
* Disallow crazy address masks that give BIOS leeway to pick
@@ -587,6 +608,21 @@ inject:
return rc;
}
+int einj_cxl_rch_error_inject(u32 type, u32 flags, u64 param1, u64 param2,
+ u64 param3, u64 param4)
+{
+ int rc;
+
+ if (!(einj_is_cxl_error_type(type) && (flags & SETWA_FLAGS_MEM)))
+ return -EINVAL;
+
+ mutex_lock(&einj_mutex);
+ rc = __einj_error_inject(type, flags, param1, param2, param3, param4);
+ mutex_unlock(&einj_mutex);
+
+ return rc;
+}
+
static u32 error_type;
static u32 error_flags;
static u64 error_param1;
@@ -607,12 +643,6 @@ static struct { u32 mask; const char *str; } const einj_error_type_string[] = {
{ BIT(9), "Platform Correctable" },
{ BIT(10), "Platform Uncorrectable non-fatal" },
{ BIT(11), "Platform Uncorrectable fatal"},
- { BIT(12), "CXL.cache Protocol Correctable" },
- { BIT(13), "CXL.cache Protocol Uncorrectable non-fatal" },
- { BIT(14), "CXL.cache Protocol Uncorrectable fatal" },
- { BIT(15), "CXL.mem Protocol Correctable" },
- { BIT(16), "CXL.mem Protocol Uncorrectable non-fatal" },
- { BIT(17), "CXL.mem Protocol Uncorrectable fatal" },
{ BIT(31), "Vendor Defined Error Types" },
};
@@ -641,22 +671,26 @@ static int error_type_get(void *data, u64 *val)
return 0;
}
-static int error_type_set(void *data, u64 val)
+bool einj_is_cxl_error_type(u64 type)
{
+ return (type & CXL_ERROR_MASK) && (!(type & ACPI5_VENDOR_BIT));
+}
+
+int einj_validate_error_type(u64 type)
+{
+ u32 tval, vendor, available_error_type = 0;
int rc;
- u32 available_error_type = 0;
- u32 tval, vendor;
/* Only low 32 bits for error type are valid */
- if (val & GENMASK_ULL(63, 32))
+ if (type & GENMASK_ULL(63, 32))
return -EINVAL;
/*
* Vendor defined types have 0x80000000 bit set, and
* are not enumerated by ACPI_EINJ_GET_ERROR_TYPE
*/
- vendor = val & ACPI5_VENDOR_BIT;
- tval = val & 0x7fffffff;
+ vendor = type & ACPI5_VENDOR_BIT;
+ tval = type & GENMASK(30, 0);
/* Only one error type can be specified */
if (tval & (tval - 1))
@@ -665,9 +699,21 @@ static int error_type_set(void *data, u64 val)
rc = einj_get_available_error_type(&available_error_type);
if (rc)
return rc;
- if (!(val & available_error_type))
+ if (!(type & available_error_type))
return -EINVAL;
}
+
+ return 0;
+}
+
+static int error_type_set(void *data, u64 val)
+{
+ int rc;
+
+ rc = einj_validate_error_type(val);
+ if (rc)
+ return rc;
+
error_type = val;
return 0;
@@ -703,21 +749,21 @@ static int einj_check_table(struct acpi_table_einj *einj_tab)
return 0;
}
-static int __init einj_init(void)
+static int __init einj_probe(struct platform_device *pdev)
{
int rc;
acpi_status status;
struct apei_exec_context ctx;
if (acpi_disabled) {
- pr_info("ACPI disabled.\n");
+ pr_debug("ACPI disabled.\n");
return -ENODEV;
}
status = acpi_get_table(ACPI_SIG_EINJ, 0,
(struct acpi_table_header **)&einj_tab);
if (status == AE_NOT_FOUND) {
- pr_warn("EINJ table not found.\n");
+ pr_debug("EINJ table not found.\n");
return -ENODEV;
} else if (ACPI_FAILURE(status)) {
pr_err("Failed to get EINJ table: %s\n",
@@ -805,7 +851,7 @@ err_put_table:
return rc;
}
-static void __exit einj_exit(void)
+static void __exit einj_remove(struct platform_device *pdev)
{
struct apei_exec_context ctx;
@@ -826,6 +872,40 @@ static void __exit einj_exit(void)
acpi_put_table((struct acpi_table_header *)einj_tab);
}
+static struct platform_device *einj_dev;
+static struct platform_driver einj_driver = {
+ .remove_new = einj_remove,
+ .driver = {
+ .name = "acpi-einj",
+ },
+};
+
+static int __init einj_init(void)
+{
+ struct platform_device_info einj_dev_info = {
+ .name = "acpi-einj",
+ .id = -1,
+ };
+ int rc;
+
+ einj_dev = platform_device_register_full(&einj_dev_info);
+ if (IS_ERR(einj_dev))
+ return PTR_ERR(einj_dev);
+
+ rc = platform_driver_probe(&einj_driver, einj_probe);
+ einj_initialized = rc == 0;
+
+ return 0;
+}
+
+static void __exit einj_exit(void)
+{
+ if (einj_initialized)
+ platform_driver_unregister(&einj_driver);
+
+ platform_device_del(einj_dev);
+}
+
module_init(einj_init);
module_exit(einj_exit);
diff --git a/drivers/acpi/apei/einj-cxl.c b/drivers/acpi/apei/einj-cxl.c
new file mode 100644
index 000000000000..8b8be0c90709
--- /dev/null
+++ b/drivers/acpi/apei/einj-cxl.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CXL Error INJection support. Used by CXL core to inject
+ * protocol errors into CXL ports.
+ *
+ * Copyright (C) 2023 Advanced Micro Devices, Inc.
+ *
+ * Author: Ben Cheatham <benjamin.cheatham@amd.com>
+ */
+#include <linux/einj-cxl.h>
+#include <linux/seq_file.h>
+#include <linux/pci.h>
+
+#include "apei-internal.h"
+
+/* Defined in einj-core.c */
+extern bool einj_initialized;
+
+static struct { u32 mask; const char *str; } const einj_cxl_error_type_string[] = {
+ { ACPI_EINJ_CXL_CACHE_CORRECTABLE, "CXL.cache Protocol Correctable" },
+ { ACPI_EINJ_CXL_CACHE_UNCORRECTABLE, "CXL.cache Protocol Uncorrectable non-fatal" },
+ { ACPI_EINJ_CXL_CACHE_FATAL, "CXL.cache Protocol Uncorrectable fatal" },
+ { ACPI_EINJ_CXL_MEM_CORRECTABLE, "CXL.mem Protocol Correctable" },
+ { ACPI_EINJ_CXL_MEM_UNCORRECTABLE, "CXL.mem Protocol Uncorrectable non-fatal" },
+ { ACPI_EINJ_CXL_MEM_FATAL, "CXL.mem Protocol Uncorrectable fatal" },
+};
+
+int einj_cxl_available_error_type_show(struct seq_file *m, void *v)
+{
+ int cxl_err, rc;
+ u32 available_error_type = 0;
+
+ rc = einj_get_available_error_type(&available_error_type);
+ if (rc)
+ return rc;
+
+ for (int pos = 0; pos < ARRAY_SIZE(einj_cxl_error_type_string); pos++) {
+ cxl_err = ACPI_EINJ_CXL_CACHE_CORRECTABLE << pos;
+
+ if (available_error_type & cxl_err)
+ seq_printf(m, "0x%08x\t%s\n",
+ einj_cxl_error_type_string[pos].mask,
+ einj_cxl_error_type_string[pos].str);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(einj_cxl_available_error_type_show, CXL);
+
+static int cxl_dport_get_sbdf(struct pci_dev *dport_dev, u64 *sbdf)
+{
+ struct pci_bus *pbus;
+ struct pci_host_bridge *bridge;
+ u64 seg = 0, bus;
+
+ pbus = dport_dev->bus;
+ bridge = pci_find_host_bridge(pbus);
+
+ if (!bridge)
+ return -ENODEV;
+
+ if (bridge->domain_nr != PCI_DOMAIN_NR_NOT_SET)
+ seg = bridge->domain_nr;
+
+ bus = pbus->number;
+ *sbdf = (seg << 24) | (bus << 16) | dport_dev->devfn;
+
+ return 0;
+}
+
+int einj_cxl_inject_rch_error(u64 rcrb, u64 type)
+{
+ int rc;
+
+ /* Only CXL error types can be specified */
+ if (!einj_is_cxl_error_type(type))
+ return -EINVAL;
+
+ rc = einj_validate_error_type(type);
+ if (rc)
+ return rc;
+
+ return einj_cxl_rch_error_inject(type, 0x2, rcrb, GENMASK_ULL(63, 0),
+ 0, 0);
+}
+EXPORT_SYMBOL_NS_GPL(einj_cxl_inject_rch_error, CXL);
+
+int einj_cxl_inject_error(struct pci_dev *dport, u64 type)
+{
+ u64 param4 = 0;
+ int rc;
+
+ /* Only CXL error types can be specified */
+ if (!einj_is_cxl_error_type(type))
+ return -EINVAL;
+
+ rc = einj_validate_error_type(type);
+ if (rc)
+ return rc;
+
+ rc = cxl_dport_get_sbdf(dport, &param4);
+ if (rc)
+ return rc;
+
+ return einj_error_inject(type, 0x4, 0, 0, 0, param4);
+}
+EXPORT_SYMBOL_NS_GPL(einj_cxl_inject_error, CXL);
+
+bool einj_cxl_is_initialized(void)
+{
+ return einj_initialized;
+}
+EXPORT_SYMBOL_NS_GPL(einj_cxl_is_initialized, CXL);
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 9ab542e7af65..2b0cab556072 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -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,
@@ -1150,6 +1185,8 @@ __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;
}
@@ -2236,6 +2273,10 @@ 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();
diff --git a/include/linux/einj-cxl.h b/include/linux/einj-cxl.h
new file mode 100644
index 000000000000..624ff6ff41f9
--- /dev/null
+++ b/include/linux/einj-cxl.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * CXL protocol Error INJection support.
+ *
+ * Copyright (c) 2023 Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Author: Ben Cheatham <benjamin.cheatham@amd.com>
+ */
+#ifndef EINJ_CXL_H
+#define EINJ_CXL_H
+
+#include <linux/errno.h>
+#include <linux/types.h>
+
+struct pci_dev;
+struct seq_file;
+
+#if IS_ENABLED(CONFIG_ACPI_APEI_EINJ_CXL)
+int einj_cxl_available_error_type_show(struct seq_file *m, void *v);
+int einj_cxl_inject_error(struct pci_dev *dport_dev, u64 type);
+int einj_cxl_inject_rch_error(u64 rcrb, u64 type);
+bool einj_cxl_is_initialized(void);
+#else /* !IS_ENABLED(CONFIG_ACPI_APEI_EINJ_CXL) */
+static inline int einj_cxl_available_error_type_show(struct seq_file *m,
+ void *v)
+{
+ return -ENXIO;
+}
+
+static inline int einj_cxl_inject_error(struct pci_dev *dport_dev, u64 type)
+{
+ return -ENXIO;
+}
+
+static inline int einj_cxl_inject_rch_error(u64 rcrb, u64 type)
+{
+ return -ENXIO;
+}
+
+static inline bool einj_cxl_is_initialized(void) { return false; }
+#endif /* CONFIG_ACPI_APEI_EINJ_CXL */
+
+#endif /* EINJ_CXL_H */