| Message ID | 6f84108ac880ef48548208738cbb169fba2fa51a.1408736066.git.geoff@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Aug 22, 2014 at 08:49:16PM +0100, Geoff Levand wrote: > Change the preprocessor macro INVALID_HWID definition from ULONG_MAX to (~0) > to allow INVALID_HWID to be used within assembly source files. > > Commit 3e98fdacc59bbbdbb659be1a144ccc48ed4860fa (arm64: kernel: make the pen of > the secondary a 64-bit unsigned value) added the preprocessor macro INVALID_HWID > to asm/cputype.h with it defined to be ULONG_MAX. Use of INVALID_HWID in an > assembly source file that includes cputype.h will generate an assembler > undefined symbol ULONG_MAX build error. The kernel does define a ULONG_MAX in > kernel.h, but that file not setup to be included in assembly files. > > Signed-off-by: Geoff Levand <geoff@infradead.org> > --- > arch/arm64/include/asm/cputype.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h > index 379d0b8..6b68380 100644 > --- a/arch/arm64/include/asm/cputype.h > +++ b/arch/arm64/include/asm/cputype.h > @@ -16,7 +16,7 @@ > #ifndef __ASM_CPUTYPE_H > #define __ASM_CPUTYPE_H > > -#define INVALID_HWID ULONG_MAX > +#define INVALID_HWID UL(~0) Does it actually expand to ULONG_MAX? ~0 is an int.
On Fri, Aug 22, 2014 at 08:49:16PM +0100, Geoff Levand wrote: > Change the preprocessor macro INVALID_HWID definition from ULONG_MAX to (~0) > to allow INVALID_HWID to be used within assembly source files. > > Commit 3e98fdacc59bbbdbb659be1a144ccc48ed4860fa (arm64: kernel: make the pen of > the secondary a 64-bit unsigned value) added the preprocessor macro INVALID_HWID > to asm/cputype.h with it defined to be ULONG_MAX. Use of INVALID_HWID in an > assembly source file that includes cputype.h will generate an assembler > undefined symbol ULONG_MAX build error. The kernel does define a ULONG_MAX in > kernel.h, but that file not setup to be included in assembly files. We don't seem to be using INVALID_HWID in any assembly at the moment, and I'm not sure I follow what we'd need it for. Why do we need this in assembly? Thanks, Mark. > Signed-off-by: Geoff Levand <geoff@infradead.org> > --- > arch/arm64/include/asm/cputype.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h > index 379d0b8..6b68380 100644 > --- a/arch/arm64/include/asm/cputype.h > +++ b/arch/arm64/include/asm/cputype.h > @@ -16,7 +16,7 @@ > #ifndef __ASM_CPUTYPE_H > #define __ASM_CPUTYPE_H > > -#define INVALID_HWID ULONG_MAX > +#define INVALID_HWID UL(~0) > > #define MPIDR_UP_BITMASK (0x1 << 30) > #define MPIDR_MT_BITMASK (0x1 << 24) > -- > 1.9.1 > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
Hi Mark, On Tue, 2014-08-26 at 17:31 +0100, Mark Rutland wrote: > On Fri, Aug 22, 2014 at 08:49:16PM +0100, Geoff Levand wrote: > > Change the preprocessor macro INVALID_HWID definition from ULONG_MAX to (~0) > > to allow INVALID_HWID to be used within assembly source files. > > > > Commit 3e98fdacc59bbbdbb659be1a144ccc48ed4860fa (arm64: kernel: make the pen of > > the secondary a 64-bit unsigned value) added the preprocessor macro INVALID_HWID > > to asm/cputype.h with it defined to be ULONG_MAX. Use of INVALID_HWID in an > > assembly source file that includes cputype.h will generate an assembler > > undefined symbol ULONG_MAX build error. The kernel does define a ULONG_MAX in > > kernel.h, but that file not setup to be included in assembly files. > > We don't seem to be using INVALID_HWID in any assembly at the moment, > and I'm not sure I follow what we'd need it for. > > Why do we need this in assembly? We currently don't use INVALID_HWID in any assembly files, but I wanted to use it for some testing and found the current definition gave an error. -Geoff
Hi Catalin, On Tue, 2014-08-26 at 16:57 +0100, Catalin Marinas wrote: > On Fri, Aug 22, 2014 at 08:49:16PM +0100, Geoff Levand wrote: > > Change the preprocessor macro INVALID_HWID definition from ULONG_MAX to (~0) > > to allow INVALID_HWID to be used within assembly source files. > > > > --- a/arch/arm64/include/asm/cputype.h > > +++ b/arch/arm64/include/asm/cputype.h > > @@ -16,7 +16,7 @@ > > #ifndef __ASM_CPUTYPE_H > > #define __ASM_CPUTYPE_H > > > > -#define INVALID_HWID ULONG_MAX > > +#define INVALID_HWID UL(~0) > > Does it actually expand to ULONG_MAX? ~0 is an int. It seems to be OK, in C: volatile unsigned long secondary_holding_pen_release = INVALID_HWID; Disassembly of section .data: 0000000000000000 <secondary_holding_pen_release>: 0: ffffffff .word 0xffffffff 4: ffffffff .word 0xffffffff In .S: mov x10, INVALID_HWID // clear secondary_holding_pen_release 2b0: 9280000a mov x10, #0xffffffffffffffff // #-1 -Geoff
On Tue, Aug 26, 2014 at 07:18:00PM +0100, Geoff Levand wrote: > On Tue, 2014-08-26 at 16:57 +0100, Catalin Marinas wrote: > > On Fri, Aug 22, 2014 at 08:49:16PM +0100, Geoff Levand wrote: > > > Change the preprocessor macro INVALID_HWID definition from ULONG_MAX to (~0) > > > to allow INVALID_HWID to be used within assembly source files. > > > > > > --- a/arch/arm64/include/asm/cputype.h > > > +++ b/arch/arm64/include/asm/cputype.h > > > @@ -16,7 +16,7 @@ > > > #ifndef __ASM_CPUTYPE_H > > > #define __ASM_CPUTYPE_H > > > > > > -#define INVALID_HWID ULONG_MAX > > > +#define INVALID_HWID UL(~0) > > > > Does it actually expand to ULONG_MAX? ~0 is an int. > > It seems to be OK, in C: > > volatile unsigned long secondary_holding_pen_release = INVALID_HWID; > > Disassembly of section .data: > > 0000000000000000 <secondary_holding_pen_release>: > 0: ffffffff .word 0xffffffff > 4: ffffffff .word 0xffffffff OK, it looks like it's sign-extending from int to unsigned long (an alternative would have been to write (~UL(0)) but the above should do as well). Anyway, the patch should come with the series that makes use of such change.
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h index 379d0b8..6b68380 100644 --- a/arch/arm64/include/asm/cputype.h +++ b/arch/arm64/include/asm/cputype.h @@ -16,7 +16,7 @@ #ifndef __ASM_CPUTYPE_H #define __ASM_CPUTYPE_H -#define INVALID_HWID ULONG_MAX +#define INVALID_HWID UL(~0) #define MPIDR_UP_BITMASK (0x1 << 30) #define MPIDR_MT_BITMASK (0x1 << 24)
Change the preprocessor macro INVALID_HWID definition from ULONG_MAX to (~0) to allow INVALID_HWID to be used within assembly source files. Commit 3e98fdacc59bbbdbb659be1a144ccc48ed4860fa (arm64: kernel: make the pen of the secondary a 64-bit unsigned value) added the preprocessor macro INVALID_HWID to asm/cputype.h with it defined to be ULONG_MAX. Use of INVALID_HWID in an assembly source file that includes cputype.h will generate an assembler undefined symbol ULONG_MAX build error. The kernel does define a ULONG_MAX in kernel.h, but that file not setup to be included in assembly files. Signed-off-by: Geoff Levand <geoff@infradead.org> --- arch/arm64/include/asm/cputype.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)