linux-dev/arch/x86/kernel/cpu/resctrl/rdtgroup.c, branch linus/master

x86: Replace cpumask_weight() with cpumask_empty() where appropriate

2022-04-10T20:35:38Z

In some cases, x86 code calls cpumask_weight() to check if any bit of a given cpumask is set. This can be done more efficiently with cpumask_empty() because cpumask_empty() stops traversing the cpumask as soon as it finds first set bit, while cpumask_weight() counts all bits unconditionally. Signed-off-by: Yury Norov Signed-off-by: Thomas Gleixner Reviewed-by: Steve Wahl Link: https://lore.kernel.org/r/20220210224933.379149-17-yury.norov@gmail.com

kernfs: move struct kernfs_root out of the public view.

2022-02-23T14:46:34Z

There is no need to have struct kernfs_root be part of kernfs.h for the whole kernel to see and poke around it. Move it internal to kernfs code and provide a helper function, kernfs_root_to_node(), to handle the one field that kernfs users were directly accessing from the structure. Cc: Imran Khan Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220222070713.3517679-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

x86/resctrl: Make resctrl_arch_get_config() return its value

2021-08-11T16:42:53Z

resctrl_arch_get_config() has no return, but does pass a single value back via one of its arguments. Return the value instead. Suggested-by: Borislav Petkov Signed-off-by: James Morse Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210811163831.14917-1-james.morse@arm.com

x86/resctrl: Merge the CDP resources

2021-08-11T16:39:42Z

resctrl uses struct rdt_resource to describe the available hardware resources. The domains of the CDP aliases share a single ctrl_val[] array. The only differences between the struct rdt_hw_resource aliases is the name and conf_type. The name from struct rdt_hw_resource is visible to user-space. To support another architecture, as many user-visible details should be handled in the filesystem parts of the code that is common to all architectures. The name and conf_type go together. Remove conf_type and the CDP aliases. When CDP is supported and enabled, schemata_list_create() can create two schemata using the single resource, generating the CODE/DATA suffix to the schema name itself. This allows the alloc_ctrlval_array() and complications around free()ing the ctrl_val arrays to be removed. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lkml.kernel.org/r/20210728170637.25610-25-james.morse@arm.com

x86/resctrl: Remove rdt_cdp_peer_get()

2021-08-11T16:33:48Z

When CDP is enabled, rdt_cdp_peer_get() finds the alternative CODE/DATA resource and returns the alternative domain. This is used to determine if bitmaps overlap when there are aliased entries in the two struct rdt_hw_resources. Now that the ctrl_val[] used by the CODE/DATA resources is the same, the search for an alternate resource/domain is not needed. Replace rdt_cdp_peer_get() with resctrl_peer_type(), which returns the alternative type. This can be passed to resctrl_arch_get_config() with the same resource and domain. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lkml.kernel.org/r/20210728170637.25610-23-james.morse@arm.com

x86/resctrl: Apply offset correction when config is staged

2021-08-11T16:03:28Z

When resctrl comes to copy the CAT MSR values from the ctrl_val[] array into hardware, it applies an offset adjustment based on the type of the resource. CODE and DATA resources have their closid mapped into an odd/even range. This mapping is based on a property of the resource. This happens once the new control value has been written to the ctrl_val[] array. Once the CDP resources are merged, there will only be a single property that needs to cover both odd/even mappings to the single ctrl_val[] array. The offset adjustment must be applied before the new value is written to the array. Move the logic from cat_wrmsr() to resctrl_arch_update_domains(). The value provided to apply_config() is now an index in the array, not the closid. The parameters provided via struct msr_param are now indexes too. As resctrl's use of closid is a u32, struct msr_param's type is changed to match. With this, the CODE and DATA resources only use the odd or even indexes in the array. This allows the temporary num_closid/2 fixes in domain_setup_ctrlval() and reset_all_ctrls() to be removed. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lkml.kernel.org/r/20210728170637.25610-20-james.morse@arm.com

x86/resctrl: Make ctrlval arrays the same size

2021-08-11T15:58:33Z

The CODE and DATA resources report a num_closid that is half the actual size supported by the hardware. This behaviour is visible to user-space when CDP is enabled. The CODE and DATA resources have their own ctrlval arrays which are half the size of the underlying hardware because num_closid was already adjusted. One holds the odd configurations values, the other even. Before the CDP resources can be merged, the 'half the closids' behaviour needs to be implemented by schemata_list_create(), but this causes the ctrl_val[] array to be full sized. Remove the logic from the architecture specific rdt_get_cdp_config() setup, and add it to schemata_list_create(). Functions that walk all the configurations, such as domain_setup_ctrlval() and reset_all_ctrls(), take num_closid directly from struct rdt_hw_resource also have to halve num_closid as only the lower half of each array is in use. domain_setup_ctrlval() and reset_all_ctrls() both copy struct rdt_hw_resource's num_closid to a struct msr_param. Correct the value here. This is temporary as a subsequent patch will merge all three ctrl_val[] arrays such that when CDP is in use, the CODA/DATA layout in the array matches the hardware. reset_all_ctrls()'s loop over the whole of ctrl_val[] is not touched as this is harmless, and will be required as it is once the resources are merged. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lkml.kernel.org/r/20210728170637.25610-19-james.morse@arm.com

x86/resctrl: Pass configuration type to resctrl_arch_get_config()

2021-08-11T15:53:53Z

The ctrl_val[] array for a struct rdt_hw_resource only holds configurations of one type. The type is implicit. Once the CDP resources are merged, the ctrl_val[] array will hold all the configurations for the hardware resource. When a particular type of configuration is needed, it must be specified explicitly. Pass the expected type from the schema into resctrl_arch_get_config(). Nothing uses this yet, but once a single ctrl_val[] array is used for the three struct rdt_hw_resources that share hardware, the type will be used to return the correct configuration value from the shared array. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lkml.kernel.org/r/20210728170637.25610-18-james.morse@arm.com

x86/resctrl: Add a helper to read a closid's configuration

2021-08-11T15:46:34Z

Functions like show_doms() reach into the architecture's private structure to retrieve the configuration from the struct rdt_hw_resource. The hardware configuration may look completely different to the values resctrl gets from user-space. The staged configuration and resctrl_arch_update_domains() allow the architecture to convert or translate these values. Resctrl shouldn't read or write the ctrl_val[] values directly. Add a helper to read the current configuration. This will allow another architecture to scale the bitmaps if necessary, and possibly use controls that don't take the user-space control format at all. Of the remaining functions that access ctrl_val[] directly, apply_config() is part of the architecture-specific code, and is called via resctrl_arch_update_domains(). reset_all_ctrls() will be an architecture specific helper. update_mba_bw() manipulates both ctrl_val[], mbps_val[] and the hardware. The mbps_val[] that matches the mba_sc state of the resource is changed, but the other is left unchanged. Abstracting this is the subject of later patches that affect set_mba_sc() too. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lkml.kernel.org/r/20210728170637.25610-17-james.morse@arm.com

x86/resctrl: Rename update_domains() to resctrl_arch_update_domains()

2021-08-11T14:36:58Z

update_domains() merges the staged configuration changes into the arch codes configuration array. Rename to make it clear it is part of the arch code interface to resctrl. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lkml.kernel.org/r/20210728170637.25610-16-james.morse@arm.com