On 12/18/23 10:47 PM, Dan Williams wrote:
> Ben Cheatham wrote:
>> Implement CXL helper functions in the EINJ module for getting the
>> available CXL protocol error types and injecting CXL errors 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 $dport_dev.
>>
>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>> Signed-off-by: Ben Cheatham <Benjamin.Cheatham@xxxxxxx>
>> ---
>> Documentation/ABI/testing/debugfs-cxl | 23 ++++
>> drivers/acpi/apei/einj.c | 144 ++++++++++++++++++++++++--
>> drivers/cxl/core/port.c | 33 ++++++
>> drivers/cxl/einj.h | 58 +++++++++++
>> 4 files changed, 248 insertions(+), 10 deletions(-)
>> create mode 100644 drivers/cxl/einj.h
>>
>> diff --git a/Documentation/ABI/testing/debugfs-cxl b/Documentation/ABI/testing/debugfs-cxl
>> index fe61d372e3fa..97a8684bad84 100644
>> --- a/Documentation/ABI/testing/debugfs-cxl
>> +++ b/Documentation/ABI/testing/debugfs-cxl
>> @@ -33,3 +33,26 @@ Description:
>> device cannot clear poison from the address, -ENXIO is returned.
>> The clear_poison attribute is only visible for devices
>> supporting the capability.
>> +
>> +What: /sys/kernel/debug/cxl/einj_types
>> +Date: November, 2023
>> +KernelVersion: v6.8
>> +Contact: linux-cxl@xxxxxxxxxxxxxxx
>> +Description:
>> + (RO) Prints the CXL protocol error types made available by
>> + the platform in the format "0x<error number> <error type>".
>> + The <error number> can be written to einj_inject to inject
>> + <error type> into a chosen dport. This file is only visible if
>> + CONFIG_CXL_EINJ is enabled.
>
> I don't think the Kconfig dependency needs to be mentioned here.
>
I'll remove it.
>> +
>> +What: /sys/kernel/debug/cxl/$dport_dev/einj_inject
>> +Date: November, 2023
>> +KernelVersion: v6.8
>> +Contact: linux-cxl@xxxxxxxxxxxxxxx
>> +Description:
>> + (WO) Writing an integer to this file injects the corresponding
>> + CXL protocol error into $dport_dev (integer to type mapping is
>> + available by reading from einj_types).
>
> Maybe mention that $dport_dev is a device name from /sys/bus/pci/devices?
>
Will do!
>> + enumerated in RCH mode, a CXL 1.1 error is injected, otherwise
>> + a CXL 2.0 error is injected. This file is only visible if
>> + CONFIG_CXL_EINJ is enabled.
>
> Same "drop the Kconfig mention" here.
>
>> diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
>> index 26a887d2a5cd..1a2195779b52 100644
>> --- a/drivers/acpi/apei/einj.c
>> +++ b/drivers/acpi/apei/einj.c
>> @@ -24,6 +24,7 @@
>> #include <asm/unaligned.h>
>>
>> #include "apei-internal.h"
>> +#include "../../cxl/einj.h"
>
> I thought this was going to move to a top-level header?
>
Sorry, I either misunderstood you a couple of versions ago or misread the original request.
I'll move it under include/linux.
>>
>> #undef pr_fmt
>> #define pr_fmt(fmt) "EINJ: " fmt
>> @@ -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.
>> @@ -537,8 +544,11 @@ 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
>> @@ -590,6 +600,9 @@ 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",
>> @@ -617,29 +630,44 @@ DEFINE_SHOW_ATTRIBUTE(available_error_type);
>>
>> static bool einj_initialized;
>>
>> -static int error_type_get(void *data, u64 *val)
>> +int einj_cxl_available_error_type_show(struct seq_file *m, void *v)
>
> Oh nice an einj_cxl_ prefix in the global namespace, looks appropriate. I
> mention this here because I don't think a later cxl_einj_ wrapper makes
> sense, see below.
>
>> {
>> - *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_puts(m, einj_cxl_error_type_string[pos]);
>> + }
>>
>> 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 & 0x7fffffff;
>>
>> /* Only one error type can be specified */
>> if (tval & (tval - 1))
>> @@ -648,9 +676,105 @@ 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 << 24;
>> +
>> + bus = pbus->number << 16;
>> + *sbdf = seg | bus | dport_dev->devfn;
>> +
>> + return 0;
>> +}
>> +
>> +int einj_cxl_inject_rch_error(u64 rcrb, u64 type)
>> +{
>> + u64 param1 = 0, param2 = 0, param4 = 0;
>> + u32 flags;
>> + int rc;
>> +
>> + if (!einj_initialized)
>> + return -ENXIO;
>> +
>> + /* Only CXL error types can be specified */
>> + if (type & ~CXL_ERROR_MASK || (type & ACPI5_VENDOR_BIT))
>> + return -EINVAL;
>> +
>> + rc = validate_error_type(type);
>> + if (rc)
>> + return rc;
>> +
>> + param1 = (u64) rcrb;
>> + param2 = 0xfffffffffffff000;
>> + flags = 0x2;
>> +
>> + return einj_error_inject(type, flags, param1, param2, 0, param4);
>> +}
>> +EXPORT_SYMBOL_NS_GPL(einj_cxl_inject_rch_error, CXL);
>> +
>> +int einj_cxl_inject_error(struct pci_dev *dport, u64 type)
>> +{
>> + u64 param1 = 0, param2 = 0, param4 = 0;
>> + u32 flags;
>> + int rc;
>> +
>> + if (!einj_initialized)
>> + return -ENXIO;
>> +
>> + /* Only CXL error types can be specified */
>> + if (type & ~CXL_ERROR_MASK || (type & ACPI5_VENDOR_BIT))
>> + return -EINVAL;
>> +
>> + rc = validate_error_type(type);
>> + if (rc)
>> + return rc;
>> +
>> + rc = cxl_dport_get_sbdf(dport, ¶m4);
>> + if (rc)
>> + return rc;
>> +
>> + flags = 0x4;
>> +
>> + return einj_error_inject(type, flags, param1, param2, 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 (val & CXL_ERROR_MASK && !(val & ACPI5_VENDOR_BIT))
>> + return -EINVAL;
>> +
>> + rc = validate_error_type(val);
>> + if (rc)
>> + return rc;
>> +
>> error_type = val;
>>
>> return 0;
>> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
>> index 38441634e4c6..4ed4a24138c3 100644
>> --- a/drivers/cxl/core/port.c
>> +++ b/drivers/cxl/core/port.c
>> @@ -11,6 +11,7 @@
>> #include <linux/idr.h>
>> #include <cxlmem.h>
>> #include <cxlpci.h>
>> +#include <einj.h>
>> #include <cxl.h>
>> #include "core.h"
>>
>> @@ -783,6 +784,32 @@ static int cxl_dport_setup_regs(struct device *host, struct cxl_dport *dport,
>> return rc;
>> }
>>
>> +DEFINE_SHOW_ATTRIBUTE(cxl_einj_available_error_type);
>> +
>> +static int cxl_einj_inject(void *data, u64 type)
>> +{
>> + struct cxl_dport *dport = data;
>> +
>> + if (dport->rch)
>> + return cxl_einj_inject_rch_error(dport->rcrb.base, type);
>> +
>> + if (!dev_is_pci(dport->dport_dev))
>> + return -EINVAL;
>> +
>> + return cxl_einj_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;
>
> I think an "IS_ENABLED(CONFIG_CXL_EINJ)" is warranted here.
>
I agree. I'll add one.
>> +
>> + dir = cxl_debugfs_create_dir(dev_name(dport->dport_dev));
>> +
>> + debugfs_create_file("einj_inject", 0200, dir, dport,
>> + &cxl_einj_inject_fops);
>
> I will note that I am little bit uneasy about this ACPI'ism escaping
> into the common core, but he mitigation for me is that if some other
> platform firmware invented a platform-firmware method for error inject
> it would simply need to reuse the einj_cxl_ namespace to make it common.
>
I'll be honest; I'm not sure I understand the concern here, but that's probably
just inexperience on my part. That being said, I don't mind changing it if you
have any suggestions!
>
>> +}
>> +
>> static struct cxl_port *__devm_cxl_add_port(struct device *host,
>> struct device *uport_dev,
>> resource_size_t component_reg_phys,
>> @@ -1136,6 +1163,8 @@ struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port,
>> } else {
>> dev_dbg(dport_dev, "dport added to %s\n",
>> dev_name(&port->dev));
>> +
>> + cxl_debugfs_create_dport_dir(dport);
>> }
>>
>> return dport;
>> @@ -1170,6 +1199,8 @@ struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
>> } else {
>> dev_dbg(dport_dev, "RCH dport added to %s\n",
>> dev_name(&port->dev));
>> +
>> + cxl_debugfs_create_dport_dir(dport);
>> }
>
> Move the above 2 invocations into 1 common call from
> __devm_cxl_add_dport().
>
Will do.
>>
>> return dport;
>> @@ -2109,6 +2140,8 @@ static __init int cxl_core_init(void)
>> int rc;
>>
>> cxl_debugfs = debugfs_create_dir("cxl", NULL);
>> + debugfs_create_file("einj_types", 0400, cxl_debugfs, NULL,
>> + &cxl_einj_available_error_type_fops);
>
> This should be gated by "IS_ENABLED(CONFIG_CXL_EINJ)"
>
Will do.
>>
>> cxl_mbox_init();
>>
>> diff --git a/drivers/cxl/einj.h b/drivers/cxl/einj.h
>> new file mode 100644
>> index 000000000000..b913763c3238
>> --- /dev/null
>> +++ b/drivers/cxl/einj.h
>> @@ -0,0 +1,58 @@
>> +/* 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@xxxxxxx>
>> + */
>> +#ifndef CXL_EINJ_H
>> +#define CXL_EINJ_H
>> +#include <linux/pci.h>
>> +
>> +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);
>
> See below, these should be within the ifdef guard.
>
>> +
>> +#if IS_ENABLED(CONFIG_CXL_EINJ)
>
> This should be
>
> #ifdef CONFIG_ACPI_APEI_EINJ
>
> ...because that is the module defining the exported public interface.
>
Makes sense, I'll change it.
>> +static inline int cxl_einj_available_error_type_show(struct seq_file *m,
>> + void *v)
>> +{
>> + return einj_cxl_available_error_type_show(m, v);
>> +}
>> +
>> +static inline int cxl_einj_inject_error(struct pci_dev *dport_dev, u64 type)
>> +{
>> + return einj_cxl_inject_error(dport_dev, type);
>> +}
>> +
>> +static inline int cxl_einj_inject_rch_error(u64 rcrb, u64 type)
>> +{
>> + return einj_cxl_inject_rch_error(rcrb, type);
>> +}
>
> Above 3 static inlines can be deleted, this section of the ifdef would
> just be:
>
> 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);
>
Sounds good. I originally tried this but was getting compile-time errors in einj.c
most likely due to gating around CONFIG_CXL_EINJ instead of CONFIG_ACPI_APEI_EINJ.
>> +
>> +#else
>> +static inline int cxl_einj_available_error_type_show(struct seq_file *m,
>> + void *v)
>> +{
>> + return -ENXIO;
>> +}
>> +
>> +static inline int cxl_einj_type_show(struct seq_file *m, void *data)
>> +{
>> + return -ENXIO;
>> +}
>> +
>> +static inline int cxl_einj_inject_error(struct pci_dev *dport_dev, u64 type)
>> +{
>> + return -ENXIO;
>> +}
>> +
>> +static inline int cxl_einj_inject_rch_error(u64 rcrb, u64 type)
>> +{
>> + return -ENXIO;
>> +}
>> +#endif
>
> Rename these to their einj_cxl_ equivalent.
Gladly! I wasn't a fan of using cxl_einj_ and einj_cxl_ at the same time since the prefixes are so similiar :/.
Thanks again,
Ben
