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 $dport_dev.
> >>
> >> Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> >> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@xxxxxxx>
> > Hi Ben,
> >
> > Sorry I've not looked at this sooner.
> >
> > Anyhow, some comments inline. Mostly looks good to me.
> >
> > Jonathan
> >
> >> ---
> >> Documentation/ABI/testing/debugfs-cxl | 22 ++++
> >> MAINTAINERS | 1 +
> >> drivers/acpi/apei/einj.c | 158 ++++++++++++++++++++++++--
> >> drivers/cxl/core/port.c | 39 +++++++
> >> include/linux/einj-cxl.h | 45 ++++++++
> >> 5 files changed, 255 insertions(+), 10 deletions(-)
> >> create mode 100644 include/linux/einj-cxl.h
> >>
> >> diff --git a/Documentation/ABI/testing/debugfs-cxl b/Documentation/ABI/testing/debugfs-cxl
> >> index fe61d372e3fa..bcd985cca66a 100644
> >> --- a/Documentation/ABI/testing/debugfs-cxl
> >> +++ b/Documentation/ABI/testing/debugfs-cxl
> >> @@ -33,3 +33,25 @@ Description:
> >> device cannot clear poison from the address, -ENXIO is returned.
> >> The clear_poison attribute is only visible for devices
> >> supporting the capability.
> >> +
> >> +What: /sys/kernel/debug/cxl/einj_types
> >> +Date: January, 2024
> >> +KernelVersion: v6.9
> >> +Contact: linux-cxl@xxxxxxxxxxxxxxx
> >> +Description:
> >> + (RO) Prints the CXL protocol error types made available by
> >> + the platform in the format "0x<error number> <error type>".
> >> + The <error number> can be written to einj_inject to inject
> >> + <error type> into a chosen dport.
> >
> > I think it's a limited set, so docs could include what the error_type values can
> > be? From this description it's not obvious they are human readable strings.
> >
>
> It is a limited set, but that set has 6 variants. It may make the description
> a bit long to include all of them, but I could include an example string instead?
> If length isn't an issue then I can add them all in.
Example works.
>
> >> +
> >> +What: /sys/kernel/debug/cxl/$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 ;)
