* [PATCH v3 0/2] ACPI: FPDT: expose FBPT and S3PT subtables via sysfs @ 2026-03-24 23:14 Nate DeSimone 2026-03-24 23:14 ` [PATCH v3 1/2] " Nate DeSimone 2026-03-24 23:14 ` [PATCH v3 2/2] Documentation: ABI: add FBPT and S3PT entries to sysfs-firmware-acpi Nate DeSimone 0 siblings, 2 replies; 4+ messages in thread From: Nate DeSimone @ 2026-03-24 23:14 UTC (permalink / raw) To: rafael; +Cc: lenb, linux-acpi, tony.luck The ACPI Firmware Performance Data Table (FPDT) can contain two subtables: 1. Firmware Basic Boot Performance Table (FBPT) 2. S3 Performance Table (S3PT) The existing /sys/firmware/acpi/tables/FPDT sysfs entry only exposes the top-level FPDT header, not the subtables themselves. This series adds sysfs attributes at /sys/firmware/acpi/fpdt/FBPT and /sys/firmware/acpi/fpdt/S3PT that expose the raw contents of these subtables. This mirrors the model used by /sys/firmware/dmi/tables/DMI for DMI/SMBIOS data, and allows userspace tools to parse newer FPDT record types defined in recent ACPI specifications[1] (e.g. String Event Records, Microcontroller Boot Performance Data Records, etc.) without requiring kernel changes for each new record type. [1] https://uefi.org/specs/ACPI/6.6/05_ACPI_Software_Programming_Model.html#performance-event-record-types Signed-off-by: Nate DeSimone <nathaniel.l.desimone@intel.com> --- Changes in v3: - changed sysfs_create_bin_file() error handling to a non-fatal warning Changes in v2: - removed the intermediate /sys/firmware/acpi/tables/ subdirectory - tightened file permissions for FBPT and S3PT from 0444 to 0400 - added documentation to Documentation/ABI/testing/sysfs-firmware-acpi --- Nate DeSimone (2): ACPI: FPDT: expose FBPT and S3PT subtables via sysfs Documentation: ABI: add FBPT and S3PT entries to sysfs-firmware-acpi Documentation/ABI/testing/sysfs-firmware-acpi | 6 ++++ drivers/acpi/acpi_fpdt.c | 28 +++++++++++++++++++ 2 files changed, 34 insertions(+) base-commit: 24f9515de8778410e4b84c85b196c9850d2c1e18 -- 2.34.1 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v3 1/2] ACPI: FPDT: expose FBPT and S3PT subtables via sysfs 2026-03-24 23:14 [PATCH v3 0/2] ACPI: FPDT: expose FBPT and S3PT subtables via sysfs Nate DeSimone @ 2026-03-24 23:14 ` Nate DeSimone 2026-03-26 15:32 ` Rafael J. Wysocki 2026-03-24 23:14 ` [PATCH v3 2/2] Documentation: ABI: add FBPT and S3PT entries to sysfs-firmware-acpi Nate DeSimone 1 sibling, 1 reply; 4+ messages in thread From: Nate DeSimone @ 2026-03-24 23:14 UTC (permalink / raw) To: rafael; +Cc: lenb, linux-acpi, tony.luck Add sysfs files at /sys/firmware/acpi/fpdt/FBPT and /sys/firmware/acpi/fpdt/S3PT that expose the raw contents of the FPDT subtables. Note that /sys/firmware/acpi/tables/FPDT only provides the top level table, not the subtables. Adding access to the subtables enables a usage model similar to /sys/firmware/dmi/tables/DMI, allowing userspace tools to interpret newer record types (e.g. String Event Records, Microcontroller Boot Performance Data Records, etc.) defined in recent ACPI specifications[1] without requiring kernel changes. [1] https://uefi.org/specs/ACPI/6.6/05_ACPI_Software_Programming_Model.html#performance-event-record-types Signed-off-by: Nate DeSimone <nathaniel.l.desimone@intel.com> --- drivers/acpi/acpi_fpdt.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/acpi/acpi_fpdt.c b/drivers/acpi/acpi_fpdt.c index 271092f2700a..e75dd28d31a9 100644 --- a/drivers/acpi/acpi_fpdt.c +++ b/drivers/acpi/acpi_fpdt.c @@ -141,6 +141,9 @@ static const struct attribute_group boot_attr_group = { .name = "boot", }; +static BIN_ATTR(FBPT, 0400, sysfs_bin_attr_simple_read, NULL, 0); +static BIN_ATTR(S3PT, 0400, sysfs_bin_attr_simple_read, NULL, 0); + static struct kobject *fpdt_kobj; #if defined CONFIG_X86 && defined CONFIG_PHYS_ADDR_T_64BIT @@ -254,9 +257,34 @@ static int fpdt_process_subtable(u64 address, u32 subtable_type) break; } } + + if (subtable_type == SUBTABLE_FBPT) { + bin_attr_FBPT.private = subtable_header; + bin_attr_FBPT.size = length; + result = sysfs_create_bin_file(fpdt_kobj, &bin_attr_FBPT); + if (result) + pr_warn("Failed to create FBPT sysfs attribute.\n"); + } else if (subtable_type == SUBTABLE_S3PT) { + bin_attr_S3PT.private = subtable_header; + bin_attr_S3PT.size = length; + result = sysfs_create_bin_file(fpdt_kobj, &bin_attr_S3PT); + if (result) + pr_warn("Failed to create S3PT sysfs attribute.\n"); + } + return 0; err: + if (bin_attr_FBPT.private) { + sysfs_remove_bin_file(fpdt_kobj, &bin_attr_FBPT); + bin_attr_FBPT.private = NULL; + } + + if (bin_attr_S3PT.private) { + sysfs_remove_bin_file(fpdt_kobj, &bin_attr_S3PT); + bin_attr_S3PT.private = NULL; + } + if (record_boot) sysfs_remove_group(fpdt_kobj, &boot_attr_group); -- 2.34.1 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v3 1/2] ACPI: FPDT: expose FBPT and S3PT subtables via sysfs 2026-03-24 23:14 ` [PATCH v3 1/2] " Nate DeSimone @ 2026-03-26 15:32 ` Rafael J. Wysocki 0 siblings, 0 replies; 4+ messages in thread From: Rafael J. Wysocki @ 2026-03-26 15:32 UTC (permalink / raw) To: Nate DeSimone; +Cc: rafael, lenb, linux-acpi, tony.luck On Wed, Mar 25, 2026 at 12:17 AM Nate DeSimone <nathaniel.l.desimone@intel.com> wrote: > > Add sysfs files at /sys/firmware/acpi/fpdt/FBPT and > /sys/firmware/acpi/fpdt/S3PT that expose the raw contents of the > FPDT subtables. Note that /sys/firmware/acpi/tables/FPDT only provides > the top level table, not the subtables. Adding access to the subtables > enables a usage model similar to /sys/firmware/dmi/tables/DMI, allowing > userspace tools to interpret newer record types (e.g. String Event > Records, Microcontroller Boot Performance Data Records, etc.) defined > in recent ACPI specifications[1] without requiring kernel changes. > > [1] > https://uefi.org/specs/ACPI/6.6/05_ACPI_Software_Programming_Model.html#performance-event-record-types > > Signed-off-by: Nate DeSimone <nathaniel.l.desimone@intel.com> > --- > drivers/acpi/acpi_fpdt.c | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/drivers/acpi/acpi_fpdt.c b/drivers/acpi/acpi_fpdt.c > index 271092f2700a..e75dd28d31a9 100644 > --- a/drivers/acpi/acpi_fpdt.c > +++ b/drivers/acpi/acpi_fpdt.c > @@ -141,6 +141,9 @@ static const struct attribute_group boot_attr_group = { > .name = "boot", > }; > > +static BIN_ATTR(FBPT, 0400, sysfs_bin_attr_simple_read, NULL, 0); > +static BIN_ATTR(S3PT, 0400, sysfs_bin_attr_simple_read, NULL, 0); > + > static struct kobject *fpdt_kobj; > > #if defined CONFIG_X86 && defined CONFIG_PHYS_ADDR_T_64BIT > @@ -254,9 +257,34 @@ static int fpdt_process_subtable(u64 address, u32 subtable_type) > break; > } > } > + > + if (subtable_type == SUBTABLE_FBPT) { > + bin_attr_FBPT.private = subtable_header; > + bin_attr_FBPT.size = length; > + result = sysfs_create_bin_file(fpdt_kobj, &bin_attr_FBPT); > + if (result) > + pr_warn("Failed to create FBPT sysfs attribute.\n"); > + } else if (subtable_type == SUBTABLE_S3PT) { > + bin_attr_S3PT.private = subtable_header; > + bin_attr_S3PT.size = length; > + result = sysfs_create_bin_file(fpdt_kobj, &bin_attr_S3PT); > + if (result) > + pr_warn("Failed to create S3PT sysfs attribute.\n"); > + } > + > return 0; > > err: > + if (bin_attr_FBPT.private) { > + sysfs_remove_bin_file(fpdt_kobj, &bin_attr_FBPT); > + bin_attr_FBPT.private = NULL; > + } > + > + if (bin_attr_S3PT.private) { > + sysfs_remove_bin_file(fpdt_kobj, &bin_attr_S3PT); > + bin_attr_S3PT.private = NULL; > + } > + > if (record_boot) > sysfs_remove_group(fpdt_kobj, &boot_attr_group); > > -- Both patches applied as 7.1 material, thanks! ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v3 2/2] Documentation: ABI: add FBPT and S3PT entries to sysfs-firmware-acpi 2026-03-24 23:14 [PATCH v3 0/2] ACPI: FPDT: expose FBPT and S3PT subtables via sysfs Nate DeSimone 2026-03-24 23:14 ` [PATCH v3 1/2] " Nate DeSimone @ 2026-03-24 23:14 ` Nate DeSimone 1 sibling, 0 replies; 4+ messages in thread From: Nate DeSimone @ 2026-03-24 23:14 UTC (permalink / raw) To: rafael; +Cc: lenb, linux-acpi, tony.luck Document the FBPT and S3PT sysfs attributes under /sys/firmware/acpi/fpdt/ Signed-off-by: Nate DeSimone <nathaniel.l.desimone@intel.com> --- Documentation/ABI/testing/sysfs-firmware-acpi | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi index 72e7c9161ce7..fa33dda331f2 100644 --- a/Documentation/ABI/testing/sysfs-firmware-acpi +++ b/Documentation/ABI/testing/sysfs-firmware-acpi @@ -41,6 +41,12 @@ Description: platform runtime firmware S3 resume, just prior to handoff to the OS waking vector. In nanoseconds. + FBPT: The raw binary contents of the Firmware Basic Boot + Performance Table (FBPT) subtable. + + S3PT: The raw binary contents of the S3 Performance Table + (S3PT) subtable. + What: /sys/firmware/acpi/bgrt/ Date: January 2012 Contact: Matthew Garrett <mjg@redhat.com> -- 2.34.1 ^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-03-26 15:32 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-03-24 23:14 [PATCH v3 0/2] ACPI: FPDT: expose FBPT and S3PT subtables via sysfs Nate DeSimone 2026-03-24 23:14 ` [PATCH v3 1/2] " Nate DeSimone 2026-03-26 15:32 ` Rafael J. Wysocki 2026-03-24 23:14 ` [PATCH v3 2/2] Documentation: ABI: add FBPT and S3PT entries to sysfs-firmware-acpi Nate DeSimone
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