Message ID | 1380672911-12812-7-git-send-email-sukadev@linux.vnet.ibm.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
On Tue, Oct 01, 2013 at 05:15:07PM -0700, Sukadev Bhattiprolu wrote: > perf_mem_data_src is an union that is initialized via the ->val field > and accessed via the bitmap fields. For this to work on big endian > platforms, we also need a big-endian represenation of perf_mem_data_src. > > diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h > index ca1d90b..846f399 100644 > --- a/include/uapi/linux/perf_event.h > +++ b/include/uapi/linux/perf_event.h > @@ -19,6 +19,50 @@ > #include <asm/byteorder.h> > > /* > + * Kernel and userspace check for endianness in incompatible ways. > + * In user space, <endian.h> defines both __BIG_ENDIAN and __LITTLE_ENDIAN > + * but sets __BYTE_ORDER to one or the other. So user space uses checks are: Why can't you use __BIG_ENDIAN_BITFIELD ? cheers
Michael Ellerman [michael@ellerman.id.au] wrote: | On Tue, Oct 01, 2013 at 05:15:07PM -0700, Sukadev Bhattiprolu wrote: | > perf_mem_data_src is an union that is initialized via the ->val field | > and accessed via the bitmap fields. For this to work on big endian | > platforms, we also need a big-endian represenation of perf_mem_data_src. | > | > diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h | > index ca1d90b..846f399 100644 | > --- a/include/uapi/linux/perf_event.h | > +++ b/include/uapi/linux/perf_event.h | > @@ -19,6 +19,50 @@ | > #include <asm/byteorder.h> | > | > /* | > + * Kernel and userspace check for endianness in incompatible ways. | > + * In user space, <endian.h> defines both __BIG_ENDIAN and __LITTLE_ENDIAN | > + * but sets __BYTE_ORDER to one or the other. So user space uses checks are: | | | Why can't you use __BIG_ENDIAN_BITFIELD ? That macro is not available when building the perf tool - bc there is a util/include/asm/byterorder.h which gets included instead of the usual <asm/byteorder.h>. | | cheers
Michael Ellerman [michael@ellerman.id.au] wrote: | On Tue, Oct 01, 2013 at 05:15:07PM -0700, Sukadev Bhattiprolu wrote: | > perf_mem_data_src is an union that is initialized via the ->val field | > and accessed via the bitmap fields. For this to work on big endian | > platforms, we also need a big-endian represenation of perf_mem_data_src. | > | > diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h | > index ca1d90b..846f399 100644 | > --- a/include/uapi/linux/perf_event.h | > +++ b/include/uapi/linux/perf_event.h | > @@ -19,6 +19,50 @@ | > #include <asm/byteorder.h> | > | > /* | > + * Kernel and userspace check for endianness in incompatible ways. | > + * In user space, <endian.h> defines both __BIG_ENDIAN and __LITTLE_ENDIAN | > + * but sets __BYTE_ORDER to one or the other. So user space uses checks are: | | | Why can't you use __BIG_ENDIAN_BITFIELD ? BTW, any clues on why there are so many different ways of checking endianness ? Any standards related stuff or just evolution ? Sukadev
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index ca1d90b..846f399 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -19,6 +19,50 @@ #include <asm/byteorder.h> /* + * Kernel and userspace check for endianness in incompatible ways. + * In user space, <endian.h> defines both __BIG_ENDIAN and __LITTLE_ENDIAN + * but sets __BYTE_ORDER to one or the other. So user space uses checks are: + * + * #if __BYTE_ORDER == __LITTLE_ENDIAN + * + * In the kernel, __BYTE_ORDER is undefined, so using the above check doesn't + * work. Further, kernel code assumes that exactly one of __BIG_ENDIAN and + * __LITTLE_ENDIAN is defined. So the kernel checks are like: + * + * #if defined(__LITTLE_ENDIAN) + * + * But we can't use that check in user space since __LITTLE_ENDIAN (and + * __BIG_ENDIAN) are always defined. + * + * Since some perf data structures depend on endianness _and_ are shared + * between kernel and user, perf needs its own notion of endian macros (at + * least until user and kernel endian checks converge). + */ +#define __PERF_LE 1234 +#define __PERF_BE 4321 + +#if defined(__BYTE_ORDER) + +#if __BYTE_ORDER == __LITTLE_ENDIAN +#define __PERF_BYTE_ORDER __PERF_LE +#elif __BYTE_ORDER == __BIG_ENDIAN +#define __PERF_BYTE_ORDER __PERF_BE +#endif + +#else /* __BYTE_ORDER */ + +#if defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN) +#error "Cannot determine endianness" +#elif defined(__LITTLE_ENDIAN) +#define __PERF_BYTE_ORDER __PERF_LE +#elif defined(__BIG_ENDIAN) +#define __PERF_BYTE_ORDER __PERF_BE +#endif + + +#endif /* __BYTE_ORDER */ + +/* * User-space ABI bits: */ @@ -695,6 +739,7 @@ enum perf_callchain_context { #define PERF_FLAG_FD_OUTPUT (1U << 1) #define PERF_FLAG_PID_CGROUP (1U << 2) /* pid=cgroup id, per-cpu mode only */ +#if __PERF_BYTE_ORDER == __PERF_LE union perf_mem_data_src { __u64 val; struct { @@ -706,6 +751,19 @@ union perf_mem_data_src { mem_rsvd:31; }; }; +#elif __PERF_BYTE_ORDER == __PERF_BE +union perf_mem_data_src { + __u64 val; + struct { + __u64 mem_rsvd:31, + mem_dtlb:7, /* tlb access */ + mem_lock:2, /* lock instr */ + mem_snoop:5, /* snoop mode */ + mem_lvl:14, /* memory hierarchy level */ + mem_op:5; /* type of opcode */ + }; +}; +#endif /* type of opcode (load/store/prefetch,code) */ #define PERF_MEM_OP_NA 0x01 /* not available */ diff --git a/tools/perf/util/include/asm/byteorder.h b/tools/perf/util/include/asm/byteorder.h index 2a9bdc0..7112913 100644 --- a/tools/perf/util/include/asm/byteorder.h +++ b/tools/perf/util/include/asm/byteorder.h @@ -1,2 +1,3 @@ #include <asm/types.h> #include "../../../../include/uapi/linux/swab.h" +#include <endian.h>