Please disregard this series. Need to resend this series. Had some issues with my git-send and while testing sent the series by mistake. On 5/22/25 14:51, Babu Moger wrote: > > This series adds the support for L3 Smart Data Cache Injection Allocation > Enforcement (SDCIAE) to resctrl infrastructure. It is refered to as "io_alloc" > in resctrl subsystem. > > Upcoming AMD hardware implements Smart Data Cache Injection (SDCI). > Smart Data Cache Injection (SDCI) is a mechanism that enables direct > insertion of data from I/O devices into the L3 cache. By directly caching > data from I/O devices rather than first storing the I/O data in DRAM, SDCI > reduces demands on DRAM bandwidth and reduces latency to the processor > consuming the I/O data. > > The SDCIAE (SDCI Allocation Enforcement) PQE feature allows system software > to control the portion of the L3 cache used for SDCI devices. > > When enabled, SDCIAE forces all SDCI lines to be placed into the L3 cache > partitions identified by the highest-supported L3_MASK_n register, where n > is the maximum supported CLOSID. > > The feature details are documented in the APM listed below [1]. > [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming > Publication # 24593 Revision 3.41 section 19.4.7 L3 Smart Data Cache > Injection Allocation Enforcement (SDCIAE) > Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 > > The feature requires linux support of TPH (TLP Processing Hints). > The support is available in linux kernel after the commit > 48d0fd2b903e3 ("PCI/TPH: Add TPH documentation") > > The patches are based on top of commit > 54d14f25664bbb (tip/x86/cache) ("MAINTAINERS: Add reviewers for fs/resctrl") > > # Linux Implementation > > Feature adds following interface files when the resctrl "io_alloc" feature is > supported on L3 resource: > > /sys/fs/resctrl/info/L3/io_alloc: Report the feature status. Enable/disable the > feature by writing to the interface. > > /sys/fs/resctrl/info/L3/io_alloc_cbm: List the Capacity Bit Masks (CBMs) available > for I/O devices when io_alloc feature is enabled. > Configure the CBM by writing to the interface. > > When CDP is enabled, these files will be created both in L3CODE and L3DATA. > > # Examples: > > a. Check if io_alloc feature is available > #mount -t resctrl resctrl /sys/fs/resctrl/ > > # cat /sys/fs/resctrl/info/L3/io_alloc > disabled > > b. Enable the io_alloc feature. > > # echo 1 > /sys/fs/resctrl/info/L3/io_alloc > # cat /sys/fs/resctrl/info/L3/io_alloc > enabled > > c. Check the CBM values for the io_alloc feature. > > # cat /sys/fs/resctrl/info/L3/io_alloc_cbm > L3:0=ffff;1=ffff > > d. Change the CBM value for the domain 1: > # echo L3:1=FF > /sys/fs/resctrl/info/L3/io_alloc_cbm > > # cat /sys/fs/resctrl/info/L3/io_alloc_cbm > L3:0=ffff;1=00ff > > d. Disable io_alloc feature and exit. > > # echo 0 > /sys/fs/resctrl/info/L3/io_alloc > # cat /sys/fs/resctrl/info/L3/io_alloc > disabled > > #umount /sys/fs/resctrl/ > > --- > v5: > Patches are created on top of recent resctrl FS/ARCH code restructure. > The files monitor.c/rdtgroup.c have been split between FS and ARCH directories. > Resolved the conflict due to the merge. > > Updated bit_usage to reflect the io_alloc CBM as discussed in the thread: > https://lore.kernel.org/lkml/3ca0a5dc-ad9c-4767-9011-b79d986e1e8d@xxxxxxxxx/ > Modified rdt_bit_usage_show() to read io_alloc_cbm in hw_shareable, ensuring > that bit_usage accurately represents the CBMs. > > Moved prototypes of resctrl_arch_io_alloc_enable() and > resctrl_arch_get_io_alloc_enabled() to include/linux/resctrl.h. > > Used rdt_kn_name to get the rdtgroup name instead of accesssing it directly > while printing group name used by the io_alloc_closid. > > Updated show_doms() to print the resource if only it is valid. Pass NULL while > printing io_alloc CBM. > > Changed the code to access io_alloc CBMs via either L3CODE or L3DATA resources. > > v4: The "io_alloc" interface will report "enabled/disabled/not supported" > instead of 0 or 1.. > > Updated resctrl_io_alloc_closid_get() to verify the max closid availability > using closids_supported(). > > Updated the documentation for "shareable_bits" and "bit_usage". > > NOTE: io_alloc is about specific CLOS. rdt_bit_usage_show() is not designed > handle bit_usage for specific CLOS. Its about overall system. So, we cannot > really tell the user which CLOS is shared across both hardware and software. > This is something we need to discuss. > > Introduced io_alloc_init() to initialize fflags. > > Printed the group name when io_alloc enablement fails to help user. > > Added rdtgroup_mutex before rdt_last_cmd_puts() in resctrl_io_alloc_cbm_show(). > Returned -ENODEV when resource type is CDP_DATA. > > Kept the resource name while printing the CBM (L3:0=ffff) that way we dont have > to change show_doms() just for this feature and it is consistant across all the > schemata display. > > Added new patch to call parse_cbm() directly to avoid code duplication. > > Checked all the series(v1-v3) again to verify if I missed any comment. > > v3: Rewrote commit log for the last 3 patches. Changed the text to bit > more generic than the AMD specific feature. Added AMD feature > specifics in the end. > > Renamed the rdt_get_sdciae_alloc_cfg() to rdt_set_io_alloc_capable(). > Renamed the _resctrl_io_alloc_enable() to _resctrl_sdciae_enable() > as it is arch specific. > > Changed the return to void in _resctrl_sdciae_enable() instead of int. > > The number of CLOSIDs is determined based on the minimum supported > across all resources (in closid_init). It needs to match the max > supported on the resource. Added the check to verify if MAX CLOSID > availability on the system. > > Added CDP check to make sure io_alloc is configured in CDP_CODE. > Highest CLOSID corresponds to CDP_CODE. > > Added resctrl_io_alloc_closid_free() to free the io_alloc CLOSID. > > Added errors in few cases when CLOSID allocation fails. > Fixes splat reported when info/L3/bit_usage is accesed when io_alloc is enabled. > https://lore.kernel.org/lkml/SJ1PR11MB60837B532254E7B23BC27E84FC052@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > > v2: Added dependancy on X86_FEATURE_CAT_L3 > Removed the "" in CPU feature definition. > > Changed sdciae_capable to io_alloc_capable to make it as generic feature. > Moved io_alloc_capable field in struct resctrl_cache. > > Changed the name of few arch functions similar to ABMC series. > resctrl_arch_get_io_alloc_enabled() > resctrl_arch_io_alloc_enable() > > Renamed the feature to "io_alloc". > Added generic texts for the feature in commit log and resctrl.rst doc. > Added resctrl_io_alloc_init_cat() to initialize io_alloc to default values > when enabled. > Fixed io_alloc interface to show only on L3 resource. > Added the locks while processing io_alloc CBMs. > > Previous versions: > v4: https://lore.kernel.org/lkml/cover.1745275431.git.babu.moger@xxxxxxx/ > v3: https://lore.kernel.org/lkml/cover.1738272037.git.babu.moger@xxxxxxx/ > v2: https://lore.kernel.org/lkml/cover.1734556832.git.babu.moger@xxxxxxx/ > v1: https://lore.kernel.org/lkml/cover.1723824984.git.babu.moger@xxxxxxx/ > > > Babu Moger (8): > x86/cpufeatures: Add support for L3 Smart Data Cache Injection > Allocation Enforcement > x86/resctrl: Add SDCIAE feature in the command line options > x86/resctrl: Detect io_alloc feature > x86/resctrl: Implement "io_alloc" enable/disable handlers > x86/resctrl: Add user interface to enable/disable io_alloc feature > x86/resctrl: Introduce interface to display io_alloc CBMs > x86/resctrl: Modify rdt_parse_data to pass mode and CLOSID > x86/resctrl: Introduce interface to modify io_alloc Capacity Bit Masks > > .../admin-guide/kernel-parameters.txt | 2 +- > Documentation/filesystems/resctrl.rst | 57 +++ > arch/x86/include/asm/cpufeatures.h | 1 + > arch/x86/include/asm/msr-index.h | 1 + > arch/x86/kernel/cpu/cpuid-deps.c | 1 + > arch/x86/kernel/cpu/resctrl/core.c | 9 + > arch/x86/kernel/cpu/resctrl/internal.h | 5 + > arch/x86/kernel/cpu/resctrl/rdtgroup.c | 37 ++ > arch/x86/kernel/cpu/scattered.c | 1 + > fs/resctrl/ctrlmondata.c | 41 +- > fs/resctrl/internal.h | 10 + > fs/resctrl/rdtgroup.c | 350 +++++++++++++++++- > include/linux/resctrl.h | 18 + > 13 files changed, 510 insertions(+), 23 deletions(-) > -- Thanks Babu Moger
