linux-stable.git/arch/x86/kernel/cpu/resctrl/pseudo_lock.c, branch linux-rolling-stable

Merge tag 'x86_cache_for_v6.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-05-27T16:53:02+00:00

Pull x86 resource control updates from Borislav Petkov:
 "Carve out the resctrl filesystem-related code into fs/resctrl/ so that
  multiple architectures can share the fs API for manipulating their
  respective hw resource control implementation.

  This is the second step in the work towards sharing the resctrl
  filesystem interface, the next one being plugging ARM's MPAM into the
  aforementioned fs API"

* tag 'x86_cache_for_v6.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
  MAINTAINERS: Add reviewers for fs/resctrl
  x86,fs/resctrl: Move the resctrl filesystem code to live in /fs/resctrl
  x86/resctrl: Always initialise rid field in rdt_resources_all[]
  x86/resctrl: Relax some asm #includes
  x86/resctrl: Prefer alloc(sizeof(*foo)) idiom in rdt_init_fs_context()
  x86/resctrl: Squelch whitespace anomalies in resctrl core code
  x86/resctrl: Move pseudo lock prototypes to include/linux/resctrl.h
  x86/resctrl: Fix types in resctrl_arch_mon_ctx_{alloc,free}() stubs
  x86/resctrl: Move enum resctrl_event_id to resctrl.h
  x86/resctrl: Move the filesystem bits to headers visible to fs/resctrl
  fs/resctrl: Add boiler plate for external resctrl code
  x86/resctrl: Add 'resctrl' to the title of the resctrl documentation
  x86/resctrl: Split trace.h
  x86/resctrl: Expand the width of domid by replacing mon_data_bits
  x86/resctrl: Add end-marker to the resctrl_event_id enum
  x86/resctrl: Move is_mba_sc() out of core.c
  x86/resctrl: Drop __init/__exit on assorted symbols
  x86/resctrl: Resctrl_exit() teardown resctrl but leave the mount point
  x86/resctrl: Check all domains are offline in resctrl_exit()
  x86/resctrl: Rename resctrl_sched_in() to begin with "resctrl_arch_"
  ...

x86,fs/resctrl: Move the resctrl filesystem code to live in /fs/resctrl

2025-05-16T12:36:09+00:00

Resctrl is a filesystem interface to hardware that provides cache
allocation policy and bandwidth control for groups of tasks or CPUs.

To support more than one architecture, resctrl needs to live in /fs/.

Move the code that is concerned with the filesystem interface to
/fs/resctrl.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Reviewed-by: Fenghua Yu 
Tested-by: Fenghua Yu 
Tested-by: Tony Luck 
Link: https://lore.kernel.org/20250515165855.31452-25-james.morse@arm.com

x86/resctrl: Relax some asm #includes

2025-05-16T12:34:31+00:00

checkpatch.pl identifies some direct #includes of asm headers that
can be satisfied by including the corresponding  header
instead.

Fix them.

No intentional functional change.

Signed-off-by: Dave Martin 
Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Reinette Chatre 
Reviewed-by: Fenghua Yu 
Tested-by: Fenghua Yu 
Tested-by: Peter Newman 
Tested-by: Shaopeng Tan 
Tested-by: Amit Singh Tomar  # arm64
Tested-by: Shanker Donthineni  # arm64
Tested-by: Babu Moger 
Tested-by: Tony Luck 
Link: https://lore.kernel.org/20250515165855.31452-23-james.morse@arm.com

fs/resctrl: Add boiler plate for external resctrl code

2025-05-16T09:05:40+00:00

Add Makefile and Kconfig for fs/resctrl. Add ARCH_HAS_CPU_RESCTRL
for the common parts of the resctrl interface and make X86_CPU_RESCTRL
select this.

Adding an include of asm/resctrl.h to linux/resctrl.h allows the
/fs/resctrl files to switch over to using this header instead.

Co-developed-by: Dave Martin 
Signed-off-by: Dave Martin 
Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Shaopeng Tan 
Reviewed-by: Tony Luck 
Reviewed-by: Fenghua Yu 
Reviewed-by: Reinette Chatre 
Tested-by: Fenghua Yu 
Tested-by: Carl Worth  # arm64
Tested-by: Shaopeng Tan 
Tested-by: Peter Newman 
Tested-by: Amit Singh Tomar  # arm64
Tested-by: Shanker Donthineni  # arm64
Tested-by: Babu Moger 
Tested-by: Tony Luck 
Link: https://lore.kernel.org/20250515165855.31452-16-james.morse@arm.com

x86/resctrl: Split trace.h

2025-05-16T08:47:49+00:00

trace.h contains all the tracepoints. After the move to /fs/resctrl, some
of these will be left behind. All the pseudo_lock tracepoints remain part
of the architecture. The lone tracepoint in monitor.c moves to /fs/resctrl.

Split trace.h so that each C file includes a different trace header file.
This means the trace header files are not modified when they are moved.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov (AMD) 
Reviewed-by: Shaopeng Tan 
Reviewed-by: Tony Luck 
Reviewed-by: Fenghua Yu 
Reviewed-by: Reinette Chatre 
Tested-by: Fenghua Yu 
Tested-by: Shaopeng Tan 
Tested-by: Peter Newman 
Tested-by: Amit Singh Tomar  # arm64
Tested-by: Shanker Donthineni  # arm64
Tested-by: Babu Moger 
Tested-by: Tony Luck 
Link: https://lore.kernel.org/20250515165855.31452-14-james.morse@arm.com

x86/msr: Replace wrmsr(msr, low, 0) with wrmsrq(msr, low)

2025-05-02T08:36:36+00:00

The third argument in wrmsr(msr, low, 0) is unnecessary.  Instead, use
wrmsrq(msr, low), which automatically sets the higher 32 bits of the
MSR value to 0.

Signed-off-by: Xin Li (Intel) 
Signed-off-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Cc: Andy Lutomirski 
Cc: Brian Gerst 
Cc: David Woodhouse 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Paolo Bonzini 
Cc: Sean Christopherson 
Cc: Stefano Stabellini 
Cc: Uros Bizjak 
Cc: Vitaly Kuznetsov 
Link: https://lore.kernel.org/r/20250427092027.1598740-15-xin@zytor.com

x86/msr: Convert __rdmsr() uses to native_rdmsrq() uses

2025-05-02T08:36:35+00:00

__rdmsr() is the lowest level MSR write API, with native_rdmsr()
and native_rdmsrq() serving as higher-level wrappers around it.

  #define native_rdmsr(msr, val1, val2)                   \
  do {                                                    \
          u64 __val = __rdmsr((msr));                     \
          (void)((val1) = (u32)__val);                    \
          (void)((val2) = (u32)(__val >> 32));            \
  } while (0)

  static __always_inline u64 native_rdmsrq(u32 msr)
  {
          return __rdmsr(msr);
  }

However, __rdmsr() continues to be utilized in various locations.

MSR APIs are designed for different scenarios, such as native or
pvops, with or without trace, and safe or non-safe.  Unfortunately,
the current MSR API names do not adequately reflect these factors,
making it challenging to select the most appropriate API for
various situations.

To pave the way for improving MSR API names, convert __rdmsr()
uses to native_rdmsrq() to ensure consistent usage.  Later, these
APIs can be renamed to better reflect their implications, such as
native or pvops, with or without trace, and safe or non-safe.

No functional change intended.

Signed-off-by: Xin Li (Intel) 
Signed-off-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Cc: Andy Lutomirski 
Cc: Brian Gerst 
Cc: David Woodhouse 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Paolo Bonzini 
Cc: Sean Christopherson 
Cc: Stefano Stabellini 
Cc: Uros Bizjak 
Cc: Vitaly Kuznetsov 
Link: https://lore.kernel.org/r/20250427092027.1598740-10-xin@zytor.com

x86/msr: Convert __wrmsr() uses to native_wrmsr{,q}() uses

2025-05-02T08:27:49+00:00

__wrmsr() is the lowest level MSR write API, with native_wrmsr()
and native_wrmsrq() serving as higher-level wrappers around it:

  #define native_wrmsr(msr, low, high)                    \
          __wrmsr(msr, low, high)

  #define native_wrmsrl(msr, val)                         \
          __wrmsr((msr), (u32)((u64)(val)),               \
                         (u32)((u64)(val) >> 32))

However, __wrmsr() continues to be utilized in various locations.

MSR APIs are designed for different scenarios, such as native or
pvops, with or without trace, and safe or non-safe.  Unfortunately,
the current MSR API names do not adequately reflect these factors,
making it challenging to select the most appropriate API for
various situations.

To pave the way for improving MSR API names, convert __wrmsr()
uses to native_wrmsr{,q}() to ensure consistent usage.  Later,
these APIs can be renamed to better reflect their implications,
such as native or pvops, with or without trace, and safe or
non-safe.

No functional change intended.

Signed-off-by: Xin Li (Intel) 
Signed-off-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Cc: Andy Lutomirski 
Cc: Brian Gerst 
Cc: David Woodhouse 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Paolo Bonzini 
Cc: Sean Christopherson 
Cc: Stefano Stabellini 
Cc: Uros Bizjak 
Cc: Vitaly Kuznetsov 
Link: https://lore.kernel.org/r/20250427092027.1598740-8-xin@zytor.com

x86/msr: Convert the rdpmc() macro to an __always_inline function

2025-05-02T08:26:56+00:00

Functions offer type safety and better readability compared to macros.
Additionally, always inline functions can match the performance of
macros.  Converting the rdpmc() macro into an always inline function
is simple and straightforward, so just make the change.

Moreover, the read result is now the returned value, further enhancing
readability.

Signed-off-by: Xin Li (Intel) 
Signed-off-by: Ingo Molnar 
Acked-by: Dave Hansen 
Acked-by: Peter Zijlstra (Intel) 
Cc: Andy Lutomirski 
Cc: Brian Gerst 
Cc: Juergen Gross 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Kees Cook 
Cc: Josh Poimboeuf 
Cc: Uros Bizjak 
Link: https://lore.kernel.org/r/20250427092027.1598740-6-xin@zytor.com

x86/msr: Rename rdpmcl() to rdpmc()

2025-05-02T08:25:24+00:00

Now that rdpmc() is gone, rdpmcl() is the sole PMC read helper,
simply rename rdpmcl() to rdpmc().

Signed-off-by: Xin Li (Intel) 
Signed-off-by: Ingo Molnar 
Acked-by: Dave Hansen 
Acked-by: Peter Zijlstra (Intel) 
Cc: Andy Lutomirski 
Cc: Brian Gerst 
Cc: Juergen Gross 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Kees Cook 
Cc: Borislav Petkov 
Cc: Thomas Gleixner 
Cc: Josh Poimboeuf 
Cc: Uros Bizjak 
Link: https://lore.kernel.org/r/20250427092027.1598740-5-xin@zytor.com