On 2/14/24 11:46 AM, Jonathan Cameron wrote:
> On Wed, 14 Feb 2024 10:41:00 -0600
> Ben Cheatham <benjamin.cheatham@xxxxxxx> wrote:
>
>> On 2/14/24 9:27 AM, Jonathan Cameron wrote:
>>> On Thu, 8 Feb 2024 14:00:41 -0600
>>> Ben Cheatham <Benjamin.Cheatham@xxxxxxx> 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.
>>>>
>>>> Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
>>>> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@xxxxxxx>
>>> Hi Ben,
>>>
>>> Sorry I've not looked at this sooner.
>>>
>>> Anyhow, some comments inline. Mostly looks good to me.
>>>
>>> Jonathan
>>>
>>>> ---
>>>> Documentation/ABI/testing/debugfs-cxl | 22 ++++
>>>> MAINTAINERS | 1 +
>>>> drivers/acpi/apei/einj.c | 158 ++++++++++++++++++++++++--
>>>> drivers/cxl/core/port.c | 39 +++++++
>>>> include/linux/einj-cxl.h | 45 ++++++++
>>>> 5 files changed, 255 insertions(+), 10 deletions(-)
>>>> create mode 100644 include/linux/einj-cxl.h
>>>>
>>>> diff --git a/Documentation/ABI/testing/debugfs-cxl b/Documentation/ABI/testing/debugfs-cxl
>>>> index fe61d372e3fa..bcd985cca66a 100644
>>>> --- a/Documentation/ABI/testing/debugfs-cxl
>>>> +++ b/Documentation/ABI/testing/debugfs-cxl
>>>> @@ -33,3 +33,25 @@ 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@xxxxxxxxxxxxxxx
>>>> +Description:
>>>> + (RO) Prints the CXL protocol error types made available by
>>>> + the platform in the format "0x<error number> <error type>".
>>>> + The <error number> can be written to einj_inject to inject
>>>> + <error type> into a chosen dport.
>>>
>>> I think it's a limited set, so docs could include what the error_type values can
>>> be? From this description it's not obvious they are human readable strings.
>>>
>>
>> It is a limited set, but that set has 6 variants. It may make the description
>> a bit long to include all of them, but I could include an example string instead?
>> If length isn't an issue then I can add them all in.
>
> Example works.
>
I tried adding them all in and it didn't make the description too long, so I went
ahead and did that instead of an example.
>>
>>>> +
>>>> +What: /sys/kernel/debug/cxl/$dport_dev/einj_inject
>>>> +Date: January, 2024
>>>> +KernelVersion: v6.9
>>>> +Contact: linux-cxl@xxxxxxxxxxxxxxx
>>>> +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 9104430e148e..02d7feb2ed1f 100644
>>>> --- a/MAINTAINERS
>>>> +++ b/MAINTAINERS
>>>> @@ -5246,6 +5246,7 @@ L: linux-cxl@xxxxxxxxxxxxxxx
>>>> S: Maintained
>>>> F: drivers/cxl/
>>>> 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 73dde21d3e89..9137cc01f791 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.
>>>> @@ -543,8 +558,11 @@ 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
>>>> @@ -596,6 +614,9 @@ static const char * const einj_error_type_string[] = {
>>>> "0x00000200\tPlatform Correctable\n",
>>>> "0x00000400\tPlatform Uncorrectable non-fatal\n",
>>>> "0x00000800\tPlatform Uncorrectable fatal\n",
>>>> +};
>>>> +
>>>> +static const char * const einj_cxl_error_type_string[] = {
>>>> "0x00001000\tCXL.cache Protocol Correctable\n",
>>>> "0x00002000\tCXL.cache Protocol Uncorrectable non-fatal\n",
>>>> "0x00004000\tCXL.cache Protocol Uncorrectable fatal\n",
>>>> @@ -621,29 +642,44 @@ 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++) {
>>>
>>> Trivial so feel free to ignore but, I'd stick to local styles and have pos
>>> declared in more traditional c style.
>>>
>>
>> Will do.
>>
>>>> + cxl_err = ACPI_EINJ_CXL_CACHE_CORRECTABLE << pos;
>>>
>>> Maybe clearer as
>>> cxl_err = FIELD_PREP(CXL_ERROR_MASK, BIT(pos));
>>>
>>
>> I'll think about it. I think I agree with you, but I've seen a good amount of
>> people who aren't familiar with the FIELD_* macros in which case it isn't much clearer.
>
> Lets teach them ;)
>
Sounds good!
Thanks,
Ben
