On Fri, Oct 02, 2020 at 05:44:16PM +0200, Claudio Imbrenda wrote: > Add definitions and boundaries of memory areas for some architectures. > This is needed by the next patch. > > Most architectures only get one generic memory area, wherease x86 and > s390x get some more attention: > > x86 gets > * lowest area (24-bit addresses) > * low area (32-bit addresses) > * the rest > > s390x gets > * low area (31-bit addresses) > * the rest > > Notice that the number indicates the order in which the areas are > scanned when more than one area is indicated. The default order tries > to get allocations from higher address ranges before trying lower ones. > This tries to keep the precious lower addresses as free as possible. > > Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> > --- > lib/asm-generic/memory_areas.h | 11 +++++++++++ > lib/arm/asm/memory_areas.h | 11 +++++++++++ > lib/arm64/asm/memory_areas.h | 11 +++++++++++ > lib/powerpc/asm/memory_areas.h | 11 +++++++++++ > lib/ppc64/asm/memory_areas.h | 11 +++++++++++ > lib/s390x/asm/memory_areas.h | 17 +++++++++++++++++ > lib/x86/asm/memory_areas.h | 22 ++++++++++++++++++++++ > 7 files changed, 94 insertions(+) > create mode 100644 lib/asm-generic/memory_areas.h > create mode 100644 lib/arm/asm/memory_areas.h > create mode 100644 lib/arm64/asm/memory_areas.h > create mode 100644 lib/powerpc/asm/memory_areas.h > create mode 100644 lib/ppc64/asm/memory_areas.h > create mode 100644 lib/s390x/asm/memory_areas.h > create mode 100644 lib/x86/asm/memory_areas.h > > diff --git a/lib/asm-generic/memory_areas.h b/lib/asm-generic/memory_areas.h > new file mode 100644 > index 0000000..927baa7 > --- /dev/null > +++ b/lib/asm-generic/memory_areas.h > @@ -0,0 +1,11 @@ > +#ifndef MEMORY_AREAS_H _ASM_GENERIC_MEMORY_AREAS_H_ > +#define MEMORY_AREAS_H > + > +#define AREA_NORMAL_PFN 0 > +#define AREA_NORMAL_NUMBER 0 > +#define AREA_NORMAL 1 > + > +#define AREA_ANY -1 > +#define AREA_ANY_NUMBER 0xff Do we really need both a "type number", like AREA_NORMAL, and a "number number" (AREA_NORMAL_NUMBER)? Why not just search in the order of the type numbers? Or in the reverse order, if that's better? Also, would an enum be more appropriate for the type numbers? > + > +#endif > diff --git a/lib/arm/asm/memory_areas.h b/lib/arm/asm/memory_areas.h > new file mode 100644 > index 0000000..927baa7 > --- /dev/null > +++ b/lib/arm/asm/memory_areas.h > @@ -0,0 +1,11 @@ > +#ifndef MEMORY_AREAS_H _ASMARM_MEMORY_AREAS_H_ We certainly don't want the same define as the generic file, as it's possible an arch will want to simply extend the generic code, e.g. #ifndef _ASMARM_MEMORY_AREAS_H_ #define _ASMARM_MEMORY_AREAS_H_ #include #include <asm-generic/memory_areas.h> /* ARM memory area stuff here */ #endif This comment applies to the rest of memory_areas.h files. Look at other lib/$ARCH/asm/*.h files to get the define prefix. > +#define MEMORY_AREAS_H > + > +#define AREA_NORMAL_PFN 0 > +#define AREA_NORMAL_NUMBER 0 > +#define AREA_NORMAL 1 > + > +#define AREA_ANY -1 > +#define AREA_ANY_NUMBER 0xff > + > +#endif [...] > diff --git a/lib/s390x/asm/memory_areas.h b/lib/s390x/asm/memory_areas.h > new file mode 100644 > index 0000000..4856a27 > --- /dev/null > +++ b/lib/s390x/asm/memory_areas.h > @@ -0,0 +1,17 @@ > +#ifndef MEMORY_AREAS_H > +#define MEMORY_AREAS_H > + > +#define AREA_NORMAL_PFN BIT(31-12) BIT(31 - PAGE_SHIFT) > +#define AREA_NORMAL_NUMBER 0 > +#define AREA_NORMAL 1 > + > +#define AREA_LOW_PFN 0 > +#define AREA_LOW_NUMBER 1 > +#define AREA_LOW 2 > + > +#define AREA_ANY -1 > +#define AREA_ANY_NUMBER 0xff > + > +#define AREA_DMA31 AREA_LOW I don't work on s390x, but I'd rather not add too many aliases. I think a single name with the min and max address bits embedded in it is probably best. Maybe something like AREA_0_31 and AREA_31_52, or whatever. > + > +#endif > diff --git a/lib/x86/asm/memory_areas.h b/lib/x86/asm/memory_areas.h > new file mode 100644 > index 0000000..d704df3 > --- /dev/null > +++ b/lib/x86/asm/memory_areas.h > @@ -0,0 +1,22 @@ > +#ifndef MEMORY_AREAS_H > +#define MEMORY_AREAS_H > + > +#define AREA_NORMAL_PFN BIT(32-12) > +#define AREA_NORMAL_NUMBER 0 > +#define AREA_NORMAL 1 > + > +#define AREA_LOW_PFN BIT(24-12) > +#define AREA_LOW_NUMBER 1 > +#define AREA_LOW 2 > + > +#define AREA_LOWEST_PFN 0 > +#define AREA_LOWEST_NUMBER 2 > +#define AREA_LOWEST 4 > + > +#define AREA_DMA24 AREA_LOWEST > +#define AREA_DMA32 (AREA_LOWEST | AREA_LOW) Aha, now I finally see that there's a type number and a number number because the type number is a bit, presumably for some flag field that's coming in a later patch. I'll have to look at the other patches to see how that's used, but at the moment I feel like there should be another way to represent memory areas without requiring a handful of defines and aliases for each one. Thanks, drew > + > +#define AREA_ANY -1 > +#define AREA_ANY_NUMBER 0xff > + > +#endif > -- > 2.26.2 >
