BMC/Intel-BMC/linux.git/arch/x86/include/asm/fpu/api.h, branch dev

x86/fpu: Introduce cpu_has_xfeatures(xfeatures_mask, feature_name)

2015-05-19T13:47:55+00:00

A lot of FPU using driver code is querying complex CPU features to be able to figure out whether a given set of xstate features is supported by the CPU or not. Introduce a simplified API function that can be used on any CPU type to get this information. Also add an error string return pointer, so that the driver can print a meaningful error message with a standardized feature name. Also mark xfeatures_mask as __read_only. Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

x86/fpu: Uninline the irq_ts_save()/restore() functions

2015-05-19T13:47:48+00:00

Especially the irq_ts_save() function is pretty bloaty, generating over a dozen instructions, so uninline them. Even though the API is used rarely, the space savings are measurable: text data bss dec hex filename 13331995 2572920 1634304 17539219 10ba093 vmlinux.before 13331739 2572920 1634304 17538963 10b9f93 vmlinux.after ( This also allows the removal of an include file inclusion from fpu/api.h, speeding up the kernel build slightly. ) Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

x86/fpu: Move various internal function prototypes to fpu/internal.h

2015-05-19T13:47:48+00:00

There are a number of FPU internal function prototypes and an inline function in fpu/api.h, mostly placed so historically as the code grew over the years. Move them over into fpu/internal.h where they belong. (Add sched.h include to stackprotector.h which incorrectly relied on getting it from fpu/api.h.) fpu/api.h is now a pure file that only contains FPU APIs intended for driver use. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

x86/fpu: Uninline kernel_fpu_begin()/end()

2015-05-19T13:47:48+00:00

Both inline functions call an inline function unconditionally, so we already pay the function call based clobbering cost. Uninline them. This saves quite a bit of code in various performance sensitive code paths: text data bss dec hex filename 13321334 2569888 1634304 17525526 10b6b16 vmlinux.before 13320246 2569888 1634304 17524438 10b66d6 vmlinux.after Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

x86/fpu: Move fpu__save() to fpu/internals.h

2015-05-19T13:47:48+00:00

It's an internal method, not a driver API, so move it from fpu/api.h to fpu/internal.h. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

x86/fpu: Rename fpu->has_fpu to fpu->fpregs_active

2015-05-19T13:47:36+00:00

So the current code uses fpu->has_cpu to determine whether a given user FPU context is actively loaded into the FPU's registers [*] and that those registers represent the task's current FPU state. But this term is not unambiguous: especially the distinction between fpu->has_fpu, PF_USED_MATH and fpu_fpregs_owner_ctx is not clear. Increase clarity by unambigously signalling that it's about hardware registers being active right now, by renaming it to fpu->fpregs_active. ( In later patches we'll use more of the 'fpregs' naming, which will make it easier to grep for as well. ) [*] There's the kernel_fpu_begin()/end() primitive that also activates FPU hw registers as well and uses them, without touching the fpu->fpregs_active flag. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

x86/fpu: Move XCR0 manipulation to the FPU code proper

2015-05-19T13:47:33+00:00

The suspend code accesses FPU state internals, add a helper for it and isolate it. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

x86/fpu: Remove assembly guard from asm/fpu/api.h

2015-05-19T13:47:32+00:00

asm/fpu/api.h does not contain any defines useful to assembly code, and no assembly code includes asm/fpu/api.h. Remove the historic #ifndef __ASSEMBLY__ leftover guard. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

x86/fpu: Rename i387.h to fpu/api.h

2015-05-19T13:47:30+00:00

We already have fpu/types.h, move i387.h to fpu/api.h. The file name has become a misnomer anyway: it offers generic FPU APIs, but is not limited to i387 functionality. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar