| Message ID | 1454679743-18133-14-git-send-email-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
>>> On 05.02.16 at 14:42, <andrew.cooper3@citrix.com> wrote: > --- a/xen/arch/x86/cpu/common.c > +++ b/xen/arch/x86/cpu/common.c > @@ -53,8 +53,24 @@ static unsigned int cleared_caps[NCAPINTS]; > > void __init setup_clear_cpu_cap(unsigned int cap) > { > + const uint32_t *dfs; > + unsigned int i; > + > + if ( test_bit(cap, cleared_caps) ) > + return; > + > __clear_bit(cap, boot_cpu_data.x86_capability); > __set_bit(cap, cleared_caps); Perhaps __test_and_set_bit() above? > + dfs = lookup_deep_deps(cap); Ah, this is a use I can see as valid outside of cpuid.c, but it's still (as I had expected) one from an __init function. Jan
>>> On 05.02.16 at 14:42, <andrew.cooper3@citrix.com> wrote: > --- a/xen/arch/x86/cpu/common.c > +++ b/xen/arch/x86/cpu/common.c > @@ -53,8 +53,24 @@ static unsigned int cleared_caps[NCAPINTS]; > > void __init setup_clear_cpu_cap(unsigned int cap) > { > + const uint32_t *dfs; > + unsigned int i; > + > + if ( test_bit(cap, cleared_caps) ) > + return; > + > __clear_bit(cap, boot_cpu_data.x86_capability); > __set_bit(cap, cleared_caps); > + > + dfs = lookup_deep_deps(cap); > + > + if ( !dfs ) > + return; > + > + for ( i = 0; i < FSCAPINTS; ++i ) { > + cleared_caps[i] |= dfs[i]; > + boot_cpu_data.x86_capability[i] &= ~dfs[i]; > + } > } Oh, also - you're mixing styles here (note the stray blanks inside for() and if()) ... Jan
On 15/02/16 14:53, Jan Beulich wrote: >>>> On 05.02.16 at 14:42, <andrew.cooper3@citrix.com> wrote: >> --- a/xen/arch/x86/cpu/common.c >> +++ b/xen/arch/x86/cpu/common.c >> @@ -53,8 +53,24 @@ static unsigned int cleared_caps[NCAPINTS]; >> >> void __init setup_clear_cpu_cap(unsigned int cap) >> { >> + const uint32_t *dfs; >> + unsigned int i; >> + >> + if ( test_bit(cap, cleared_caps) ) >> + return; >> + >> __clear_bit(cap, boot_cpu_data.x86_capability); >> __set_bit(cap, cleared_caps); > Perhaps __test_and_set_bit() above? Hmm yes - that won't make it atomic. And I will fix up the style issues. ~Andrew
diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c index 39c340b..e205565 100644 --- a/xen/arch/x86/cpu/common.c +++ b/xen/arch/x86/cpu/common.c @@ -53,8 +53,24 @@ static unsigned int cleared_caps[NCAPINTS]; void __init setup_clear_cpu_cap(unsigned int cap) { + const uint32_t *dfs; + unsigned int i; + + if ( test_bit(cap, cleared_caps) ) + return; + __clear_bit(cap, boot_cpu_data.x86_capability); __set_bit(cap, cleared_caps); + + dfs = lookup_deep_deps(cap); + + if ( !dfs ) + return; + + for ( i = 0; i < FSCAPINTS; ++i ) { + cleared_caps[i] |= dfs[i]; + boot_cpu_data.x86_capability[i] &= ~dfs[i]; + } } static void default_init(struct cpuinfo_x86 * c)
When clearing a cpu cap, clear all dependent features. This avoids having a featureset with intermediate features disabled, but leaf features enabled. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> --- xen/arch/x86/cpu/common.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)