Messages in this thread | | | Date | Fri, 12 Jun 2009 12:50:49 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH 07/19] x86: unify power/cpu_(32|64).c |
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On Thu 2009-06-11 22:35:11, Rafael J. Wysocki wrote: > From: Sergio Luis <sergio@larces.uece.br> > > This is the last unification step. Here we do remove one of the files > and rename the left one as cpu.c, as both are now the same. > Also update power/Makefile, telling it to build cpu.o, instead of > cpu_(32|64).o > > Signed-off-by: Sergio Luis <sergio@larces.uece.br> > Signed-off-by: Lauro Salmito <laurosalmito@gmail.com> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> +#ifdef CONFIG_X86_32 > + store_gdt(&ctxt->gdt); > + store_idt(&ctxt->idt); > +#else > +/* CONFIG_X86_64 */ > + store_gdt((struct desc_ptr *)&ctxt->gdt_limit); > + store_idt((struct desc_ptr *)&ctxt->idt_limit); > +#endif
I'd slightly prefer /* CONFIG_X86_64 */ to be moved to line above, or dropped at all. it seems unneccessarily verbose.
> + store_tr(ctxt->tr); > + > + /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */ > + /* > + * segment registers > + */ > +#ifdef CONFIG_X86_32 > + savesegment(es, ctxt->es); > + savesegment(fs, ctxt->fs); > + savesegment(gs, ctxt->gs); > + savesegment(ss, ctxt->ss); > +#else > +/* CONFIG_X86_64 */ > + asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds)); > + asm volatile ("movw %%es, %0" : "=m" (ctxt->es)); > + asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs)); > + asm volatile ("movw %%gs, %0" : "=m" (ctxt->gs)); > + asm volatile ("movw %%ss, %0" : "=m" (ctxt->ss)); > + > + rdmsrl(MSR_FS_BASE, ctxt->fs_base); > + rdmsrl(MSR_GS_BASE, ctxt->gs_base); > + rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base); > + mtrr_save_fixed_ranges(NULL); > + > + rdmsrl(MSR_EFER, ctxt->efer); > +#endif
Can i386's mtrr_save_fixed_ranges() be moved to similar place?
> + /* > + * control registers > + */ > + ctxt->cr0 = read_cr0(); > + ctxt->cr2 = read_cr2(); > + ctxt->cr3 = read_cr3(); > +#ifdef CONFIG_X86_32 > + ctxt->cr4 = read_cr4_safe(); > +#else > +/* CONFIG_X86_64 */ > + ctxt->cr4 = read_cr4(); > + ctxt->cr8 = read_cr8(); > +#endif
Could we use read_cr4_safe on x86-64, too? Why the difference?
Should we be saving cr8 on 32-bit machines that have it? (That was interrupt priority, IIRC?)
> + /* cr4 was introduced in the Pentium CPU */ > +#ifdef CONFIG_X86_32 > + if (ctxt->cr4) > + write_cr4(ctxt->cr4); > +#else
Aha, is read_cr4_safe() needed because i486 does not have cr4?
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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