diff mbox series

[v12,2/3] cxl/core, EINJ: Add EINJ CXL debugfs files and EINJ helper functions

Message ID 20240214200709.777166-3-Benjamin.Cheatham@amd.com (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series cxl, EINJ: Update EINJ for CXL error types | expand

Commit Message

Ben Cheatham Feb. 14, 2024, 8:07 p.m. UTC 
Implement CXL helper functions in the EINJ module for getting/injecting
available CXL protocol error types and export them 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 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.

Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>
---
 Documentation/ABI/testing/debugfs-cxl |  30 +++++
 MAINTAINERS                           |   1 +
 drivers/acpi/apei/einj.c              | 158 ++++++++++++++++++++++++--
 drivers/cxl/Kconfig                   |  12 ++
 drivers/cxl/core/port.c               |  41 +++++++
 include/linux/einj-cxl.h              |  40 +++++++
 6 files changed, 271 insertions(+), 11 deletions(-)
 create mode 100644 include/linux/einj-cxl.h

Comments

Dan Williams Feb. 15, 2024, 2:25 a.m. UTC | #1 
Ben Cheatham wrote:
> Implement CXL helper functions in the EINJ module for getting/injecting
> available CXL protocol error types and export them 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 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.
> 
> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>
[..]
> diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
> index 67998dbd1d46..d1fc3ce31fbb 100644
> --- a/drivers/cxl/Kconfig
> +++ b/drivers/cxl/Kconfig
> @@ -157,4 +157,16 @@ config CXL_PMU
>  	  monitoring units and provide standard perf based interfaces.
>  
>  	  If unsure say 'm'.
> +
> +config CXL_EINJ
> +	bool "CXL Error INJection Support"
> +	default ACPI_APEI_EINJ
> +	depends on ACPI_APEI_EINJ = CXL_BUS

So I do not see CONFIG_CXL_EINJ used anywhere, not in a Makefile, not in
a header file. My expectation is that if this variable is not set then
no symbols from einj.ko are consumed by cxl_core.ko.

> +	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'
>  endif
[..]
> diff --git a/include/linux/einj-cxl.h b/include/linux/einj-cxl.h
> new file mode 100644
> index 000000000000..92c0e2e37ad9
> --- /dev/null
> +++ b/include/linux/einj-cxl.h
> @@ -0,0 +1,40 @@
> +/* 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 CXL_EINJ_H
> +#define CXL_EINJ_H
> +
> +#include <linux/pci.h>
> +
> +#if IS_ENABLED(CONFIG_ACPI_APEI_EINJ)

Per above this needs to be IS_ENABLED(CONFIG_CXL_EINJ), otherwise what's
the point of the config symbol?

> +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_is_initialized(void);
> +#else // !IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
> +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_is_initialized(void) { return false; }
> +#endif // CONFIG_ACPI_APEI_EINJ
> +
> +#endif // CXL_EINJ_H
> -- 
> 2.34.1
> 
>
Jonathan Cameron Feb. 15, 2024, 9:33 a.m. UTC | #2 
On Wed, 14 Feb 2024 14:07:08 -0600
Ben Cheatham <Benjamin.Cheatham@amd.com> wrote:

> Implement CXL helper functions in the EINJ module for getting/injecting
> available CXL protocol error types and export them 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 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.
> 
> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>

Hi Ben,

Just one trivial thing to add to Dan's comments.

> diff --git a/include/linux/einj-cxl.h b/include/linux/einj-cxl.h
> new file mode 100644
> index 000000000000..92c0e2e37ad9
> --- /dev/null
> +++ b/include/linux/einj-cxl.h
> @@ -0,0 +1,40 @@
> +/* 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 CXL_EINJ_H
> +#define CXL_EINJ_H
> +
> +#include <linux/pci.h>
> +
> +#if IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
> +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_is_initialized(void);
> +#else // !IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
Whilst C++ Style comments are allowed for a few specific case, you should stick
to local style. In the include directory a quick grep gave me loads of
#else /*  */
lines and only 2
#else //

So C style comments preferred.


> +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_is_initialized(void) { return false; }
> +#endif // CONFIG_ACPI_APEI_EINJ
> +
> +#endif // CXL_EINJ_H
Ben Cheatham Feb. 15, 2024, 3:01 p.m. UTC | #3 
On 2/14/24 8:25 PM, Dan Williams wrote:
> Ben Cheatham wrote:
>> Implement CXL helper functions in the EINJ module for getting/injecting
>> available CXL protocol error types and export them 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 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.
>>
>> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>
> [..]
>> diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
>> index 67998dbd1d46..d1fc3ce31fbb 100644
>> --- a/drivers/cxl/Kconfig
>> +++ b/drivers/cxl/Kconfig
>> @@ -157,4 +157,16 @@ config CXL_PMU
>>  	  monitoring units and provide standard perf based interfaces.
>>  
>>  	  If unsure say 'm'.
>> +
>> +config CXL_EINJ
>> +	bool "CXL Error INJection Support"
>> +	default ACPI_APEI_EINJ
>> +	depends on ACPI_APEI_EINJ = CXL_BUS
> 
> So I do not see CONFIG_CXL_EINJ used anywhere, not in a Makefile, not in
> a header file. My expectation is that if this variable is not set then
> no symbols from einj.ko are consumed by cxl_core.ko.
> 

Yeah, you're right. More on this below.

>> +	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'
>>  endif
> [..]
>> diff --git a/include/linux/einj-cxl.h b/include/linux/einj-cxl.h
>> new file mode 100644
>> index 000000000000..92c0e2e37ad9
>> --- /dev/null
>> +++ b/include/linux/einj-cxl.h
>> @@ -0,0 +1,40 @@
>> +/* 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 CXL_EINJ_H
>> +#define CXL_EINJ_H
>> +
>> +#include <linux/pci.h>
>> +
>> +#if IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
> 
> Per above this needs to be IS_ENABLED(CONFIG_CXL_EINJ), otherwise what's
> the point of the config symbol?
> 

So I've tried changing this to IS_ENABLED(CONFIG_CXL_EINJ) and always get redefinition
errors that I can't figure out how to get around cleanly. I should've elaborated more
in the last revision, but part of changing the dependency rule from ACPI_APEI_EINJ >= CXL_BUS
to ACPI_APEI_EINJ = CXL_BUS is that the above guard stays as IS_ENABLED(CONFIG_ACPI_APEI_EINJ).

I'm pretty sure the only thing this symbol is doing is enforcing the above dependency.
I would love to be able to remove it at this point, but doing so would require moving the
dependency to either the EINJ or CXL core modules, which sounds worse. I could implement
one of the other solutions I outlined last revision, but I don't particularly like any of
those (and I know you don't either :)).

I think the solution here is to move the einj_cxl functions into a new file, gate that
file by CONFIG_CXL_EINJ (or change the name to CONFIG_EINJ_CXL to match einj-cxl.h),
and add declarations of the functions in the EINJ module used by said functions to
drivers/acpi/apei/apei-internal.h. I'm not sure of another approach at this point,
but if you have suggestions I'd be very happy to hear them!

Thanks,
Ben

>> +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_is_initialized(void);
>> +#else // !IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
>> +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_is_initialized(void) { return false; }
>> +#endif // CONFIG_ACPI_APEI_EINJ
>> +
>> +#endif // CXL_EINJ_H
>> -- 
>> 2.34.1
>>
>>
> 
> 
>
Ben Cheatham Feb. 15, 2024, 3:01 p.m. UTC | #4 
On 2/15/24 3:33 AM, Jonathan Cameron wrote:
> On Wed, 14 Feb 2024 14:07:08 -0600
> Ben Cheatham <Benjamin.Cheatham@amd.com> wrote:
> 
>> Implement CXL helper functions in the EINJ module for getting/injecting
>> available CXL protocol error types and export them 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 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.
>>
>> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@amd.com>
> 
> Hi Ben,
> 
> Just one trivial thing to add to Dan's comments.
> 
>> diff --git a/include/linux/einj-cxl.h b/include/linux/einj-cxl.h
>> new file mode 100644
>> index 000000000000..92c0e2e37ad9
>> --- /dev/null
>> +++ b/include/linux/einj-cxl.h
>> @@ -0,0 +1,40 @@
>> +/* 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 CXL_EINJ_H
>> +#define CXL_EINJ_H
>> +
>> +#include <linux/pci.h>
>> +
>> +#if IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
>> +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_is_initialized(void);
>> +#else // !IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
> Whilst C++ Style comments are allowed for a few specific case, you should stick
> to local style. In the include directory a quick grep gave me loads of
> #else /*  */
> lines and only 2
> #else //
> 
> So C style comments preferred.
> 

You are 100% correct. I did a grep for examples and didn't notice that I did it
from the base linux directory, so of course I found a bunch of examples of C++
style comments :/. I'll fix it in the next revision.

Thanks,
Ben

> 
>> +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_is_initialized(void) { return false; }
>> +#endif // CONFIG_ACPI_APEI_EINJ
>> +
>> +#endif // CXL_EINJ_H
>
Dan Williams Feb. 16, 2024, 12:15 a.m. UTC | #5 
Ben Cheatham wrote:
[..]
> >> diff --git a/include/linux/einj-cxl.h b/include/linux/einj-cxl.h
> >> new file mode 100644
> >> index 000000000000..92c0e2e37ad9
> >> --- /dev/null
> >> +++ b/include/linux/einj-cxl.h
> >> @@ -0,0 +1,40 @@
> >> +/* 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 CXL_EINJ_H
> >> +#define CXL_EINJ_H
> >> +
> >> +#include <linux/pci.h>
> >> +
> >> +#if IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
> > 
> > Per above this needs to be IS_ENABLED(CONFIG_CXL_EINJ), otherwise what's
> > the point of the config symbol?
> > 
> 
[..]
> I think the solution here is to move the einj_cxl functions into a new
> file, gate that file by CONFIG_CXL_EINJ (or change the name to
> CONFIG_EINJ_CXL to match einj-cxl.h), and add declarations of the
> functions in the EINJ module used by said functions to
> drivers/acpi/apei/apei-internal.h. I'm not sure of another approach at
> this point, but if you have suggestions I'd be very happy to hear
> them!

Yes, this is the way.
diff mbox series

Patch

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/MAINTAINERS b/MAINTAINERS
index 73d898383e51..0980ed116dc2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5291,6 +5291,7 @@  S:	Maintained
 F:	drivers/cxl/
 F:	include/linux/cxl-event.h
 F:	include/uapi/linux/cxl_mem.h
+F:  include/linux/einj-cxl.h
 F:	tools/testing/cxl/
 
 COMPUTE EXPRESS LINK PMU (CPMU)
diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
index 4782ae0a0832..ab729a12dd7f 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -21,6 +21,7 @@ 
 #include <linux/nmi.h>
 #include <linux/delay.h>
 #include <linux/mm.h>
+#include <linux/einj-cxl.h>
 #include <linux/platform_device.h>
 #include <asm/unaligned.h>
 
@@ -37,6 +38,20 @@ 
 #define MEM_ERROR_MASK		(ACPI_EINJ_MEMORY_CORRECTABLE | \
 				ACPI_EINJ_MEMORY_UNCORRECTABLE | \
 				ACPI_EINJ_MEMORY_FATAL)
+#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
+#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.
@@ -560,8 +575,11 @@  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;
+	} else if ((type & CXL_ERROR_MASK) && (flags & SETWA_FLAGS_MEM)) {
+		goto inject;
+	}
 
 	/*
 	 * Disallow crazy address masks that give BIOS leeway to pick
@@ -613,13 +631,16 @@  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(31), "Vendor Defined Error Types" },
+};
+
+static struct { u32 mask; const char *str; } const einj_cxl_error_type_string[] = {
 	{ 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" },
 };
 
 static int available_error_type_show(struct seq_file *m, void *v)
@@ -640,29 +661,46 @@  static int available_error_type_show(struct seq_file *m, void *v)
 
 DEFINE_SHOW_ATTRIBUTE(available_error_type);
 
-static int error_type_get(void *data, u64 *val)
+int einj_cxl_available_error_type_show(struct seq_file *m, void *v)
 {
-	*val = error_type;
+	int cxl_err, rc;
+	u32 available_error_type = 0;
+
+	if (!einj_initialized)
+		return -ENXIO;
+
+	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 error_type_set(void *data, u64 val)
+static int 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))
@@ -671,9 +709,101 @@  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 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;
+}
+
+static bool is_cxl_error_type(u64 type)
+{
+	return (type & CXL_ERROR_MASK) && (!(type & ACPI5_VENDOR_BIT));
+}
+
+int einj_cxl_inject_rch_error(u64 rcrb, u64 type)
+{
+	int rc;
+
+	if (!einj_initialized)
+		return -ENXIO;
+
+	/* Only CXL error types can be specified */
+	if (!is_cxl_error_type(type))
+		return -EINVAL;
+
+	rc = validate_error_type(type);
+	if (rc)
+		return rc;
+
+	return einj_error_inject(type, 0x2, rcrb, GENMASK_ULL(63, 12), 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;
+
+	if (!einj_initialized)
+		return -ENXIO;
+
+	/* Only CXL error types can be specified */
+	if (!is_cxl_error_type(type))
+		return -EINVAL;
+
+	rc = 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);
+
+static int error_type_get(void *data, u64 *val)
+{
+	*val = error_type;
+
+	return 0;
+}
+
+static int error_type_set(void *data, u64 val)
+{
+	int rc;
+
+	/* CXL error types have to be injected from cxl debugfs */
+	if (is_cxl_error_type(val))
+		return -EINVAL;
+
+	rc = validate_error_type(val);
+	if (rc)
+		return rc;
+
 	error_type = val;
 
 	return 0;
@@ -709,6 +839,12 @@  static int einj_check_table(struct acpi_table_einj *einj_tab)
 	return 0;
 }
 
+bool einj_is_initialized(void)
+{
+	return einj_initialized;
+}
+EXPORT_SYMBOL_GPL(einj_is_initialized);
+
 static int __init einj_probe(struct platform_device *pdev)
 {
 	int rc;
diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
index 67998dbd1d46..d1fc3ce31fbb 100644
--- a/drivers/cxl/Kconfig
+++ b/drivers/cxl/Kconfig
@@ -157,4 +157,16 @@  config CXL_PMU
 	  monitoring units and provide standard perf based interfaces.
 
 	  If unsure say 'm'.
+
+config CXL_EINJ
+	bool "CXL Error INJection Support"
+	default ACPI_APEI_EINJ
+	depends on ACPI_APEI_EINJ = CXL_BUS
+	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'
 endif
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index e59d9d37aa65..3700700c4e0c 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 +794,39 @@  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, "%llx\n");
+
+static void cxl_debugfs_create_dport_dir(struct cxl_dport *dport)
+{
+	struct dentry *dir;
+
+	if (!einj_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 +1183,8 @@  __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 +2257,11 @@  static __init int cxl_core_init(void)
 
 	cxl_debugfs = debugfs_create_dir("cxl", NULL);
 
+	if (einj_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..92c0e2e37ad9
--- /dev/null
+++ b/include/linux/einj-cxl.h
@@ -0,0 +1,40 @@ 
+/* 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 CXL_EINJ_H
+#define CXL_EINJ_H
+
+#include <linux/pci.h>
+
+#if IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
+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_is_initialized(void);
+#else // !IS_ENABLED(CONFIG_ACPI_APEI_EINJ)
+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_is_initialized(void) { return false; }
+#endif // CONFIG_ACPI_APEI_EINJ
+
+#endif // CXL_EINJ_H