xemu/include/qemu/bswap.h
Peter Maydell db5fd8d709 cpu_ldst.h, cpu-all.h, bswap.h: Update documentation on ld/st accessors
Add documentation of what the cpu_*_* accessors look like.
Correct some minor errors in the existing documentation of the
direct _p accessor family. Remove the near-duplicate comment
on the _p accessors from cpu-all.h and replace it with a reference
to the comment in bswap.h.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1421334118-3287-16-git-send-email-peter.maydell@linaro.org
2015-01-20 15:19:35 +00:00

444 lines
8.6 KiB
C

#ifndef BSWAP_H
#define BSWAP_H
#include "config-host.h"
#include <inttypes.h>
#include <limits.h>
#include <string.h>
#include "fpu/softfloat.h"
#ifdef CONFIG_MACHINE_BSWAP_H
# include <sys/endian.h>
# include <sys/types.h>
# include <machine/bswap.h>
#elif defined(__FreeBSD__)
# include <sys/endian.h>
#elif defined(CONFIG_BYTESWAP_H)
# include <byteswap.h>
static inline uint16_t bswap16(uint16_t x)
{
return bswap_16(x);
}
static inline uint32_t bswap32(uint32_t x)
{
return bswap_32(x);
}
static inline uint64_t bswap64(uint64_t x)
{
return bswap_64(x);
}
# else
static inline uint16_t bswap16(uint16_t x)
{
return (((x & 0x00ff) << 8) |
((x & 0xff00) >> 8));
}
static inline uint32_t bswap32(uint32_t x)
{
return (((x & 0x000000ffU) << 24) |
((x & 0x0000ff00U) << 8) |
((x & 0x00ff0000U) >> 8) |
((x & 0xff000000U) >> 24));
}
static inline uint64_t bswap64(uint64_t x)
{
return (((x & 0x00000000000000ffULL) << 56) |
((x & 0x000000000000ff00ULL) << 40) |
((x & 0x0000000000ff0000ULL) << 24) |
((x & 0x00000000ff000000ULL) << 8) |
((x & 0x000000ff00000000ULL) >> 8) |
((x & 0x0000ff0000000000ULL) >> 24) |
((x & 0x00ff000000000000ULL) >> 40) |
((x & 0xff00000000000000ULL) >> 56));
}
#endif /* ! CONFIG_MACHINE_BSWAP_H */
static inline void bswap16s(uint16_t *s)
{
*s = bswap16(*s);
}
static inline void bswap32s(uint32_t *s)
{
*s = bswap32(*s);
}
static inline void bswap64s(uint64_t *s)
{
*s = bswap64(*s);
}
#if defined(HOST_WORDS_BIGENDIAN)
#define be_bswap(v, size) (v)
#define le_bswap(v, size) glue(bswap, size)(v)
#define be_bswaps(v, size)
#define le_bswaps(p, size) do { *p = glue(bswap, size)(*p); } while(0)
#else
#define le_bswap(v, size) (v)
#define be_bswap(v, size) glue(bswap, size)(v)
#define le_bswaps(v, size)
#define be_bswaps(p, size) do { *p = glue(bswap, size)(*p); } while(0)
#endif
#define CPU_CONVERT(endian, size, type)\
static inline type endian ## size ## _to_cpu(type v)\
{\
return glue(endian, _bswap)(v, size);\
}\
\
static inline type cpu_to_ ## endian ## size(type v)\
{\
return glue(endian, _bswap)(v, size);\
}\
\
static inline void endian ## size ## _to_cpus(type *p)\
{\
glue(endian, _bswaps)(p, size);\
}\
\
static inline void cpu_to_ ## endian ## size ## s(type *p)\
{\
glue(endian, _bswaps)(p, size);\
}\
\
static inline type endian ## size ## _to_cpup(const type *p)\
{\
return glue(glue(endian, size), _to_cpu)(*p);\
}\
\
static inline void cpu_to_ ## endian ## size ## w(type *p, type v)\
{\
*p = glue(glue(cpu_to_, endian), size)(v);\
}
CPU_CONVERT(be, 16, uint16_t)
CPU_CONVERT(be, 32, uint32_t)
CPU_CONVERT(be, 64, uint64_t)
CPU_CONVERT(le, 16, uint16_t)
CPU_CONVERT(le, 32, uint32_t)
CPU_CONVERT(le, 64, uint64_t)
/* len must be one of 1, 2, 4 */
static inline uint32_t qemu_bswap_len(uint32_t value, int len)
{
return bswap32(value) >> (32 - 8 * len);
}
/* Unions for reinterpreting between floats and integers. */
typedef union {
float32 f;
uint32_t l;
} CPU_FloatU;
typedef union {
float64 d;
#if defined(HOST_WORDS_BIGENDIAN)
struct {
uint32_t upper;
uint32_t lower;
} l;
#else
struct {
uint32_t lower;
uint32_t upper;
} l;
#endif
uint64_t ll;
} CPU_DoubleU;
typedef union {
floatx80 d;
struct {
uint64_t lower;
uint16_t upper;
} l;
} CPU_LDoubleU;
typedef union {
float128 q;
#if defined(HOST_WORDS_BIGENDIAN)
struct {
uint32_t upmost;
uint32_t upper;
uint32_t lower;
uint32_t lowest;
} l;
struct {
uint64_t upper;
uint64_t lower;
} ll;
#else
struct {
uint32_t lowest;
uint32_t lower;
uint32_t upper;
uint32_t upmost;
} l;
struct {
uint64_t lower;
uint64_t upper;
} ll;
#endif
} CPU_QuadU;
/* unaligned/endian-independent pointer access */
/*
* the generic syntax is:
*
* load: ld{type}{sign}{size}{endian}_p(ptr)
*
* store: st{type}{size}{endian}_p(ptr, val)
*
* Note there are small differences with the softmmu access API!
*
* type is:
* (empty): integer access
* f : float access
*
* sign is:
* (empty): for 32 or 64 bit sizes (including floats and doubles)
* u : unsigned
* s : signed
*
* size is:
* b: 8 bits
* w: 16 bits
* l: 32 bits
* q: 64 bits
*
* endian is:
* he : host endian
* be : big endian
* le : little endian
* te : target endian
* (except for byte accesses, which have no endian infix).
*
* The target endian accessors are obviously only available to source
* files which are built per-target; they are defined in cpu-all.h.
*
* In all cases these functions take a host pointer.
* For accessors that take a guest address rather than a
* host address, see the cpu_{ld,st}_* accessors defined in
* cpu_ldst.h.
*/
static inline int ldub_p(const void *ptr)
{
return *(uint8_t *)ptr;
}
static inline int ldsb_p(const void *ptr)
{
return *(int8_t *)ptr;
}
static inline void stb_p(void *ptr, uint8_t v)
{
*(uint8_t *)ptr = v;
}
/* Any compiler worth its salt will turn these memcpy into native unaligned
operations. Thus we don't need to play games with packed attributes, or
inline byte-by-byte stores. */
static inline int lduw_he_p(const void *ptr)
{
uint16_t r;
memcpy(&r, ptr, sizeof(r));
return r;
}
static inline int ldsw_he_p(const void *ptr)
{
int16_t r;
memcpy(&r, ptr, sizeof(r));
return r;
}
static inline void stw_he_p(void *ptr, uint16_t v)
{
memcpy(ptr, &v, sizeof(v));
}
static inline int ldl_he_p(const void *ptr)
{
int32_t r;
memcpy(&r, ptr, sizeof(r));
return r;
}
static inline void stl_he_p(void *ptr, uint32_t v)
{
memcpy(ptr, &v, sizeof(v));
}
static inline uint64_t ldq_he_p(const void *ptr)
{
uint64_t r;
memcpy(&r, ptr, sizeof(r));
return r;
}
static inline void stq_he_p(void *ptr, uint64_t v)
{
memcpy(ptr, &v, sizeof(v));
}
static inline int lduw_le_p(const void *ptr)
{
return (uint16_t)le_bswap(lduw_he_p(ptr), 16);
}
static inline int ldsw_le_p(const void *ptr)
{
return (int16_t)le_bswap(lduw_he_p(ptr), 16);
}
static inline int ldl_le_p(const void *ptr)
{
return le_bswap(ldl_he_p(ptr), 32);
}
static inline uint64_t ldq_le_p(const void *ptr)
{
return le_bswap(ldq_he_p(ptr), 64);
}
static inline void stw_le_p(void *ptr, uint16_t v)
{
stw_he_p(ptr, le_bswap(v, 16));
}
static inline void stl_le_p(void *ptr, uint32_t v)
{
stl_he_p(ptr, le_bswap(v, 32));
}
static inline void stq_le_p(void *ptr, uint64_t v)
{
stq_he_p(ptr, le_bswap(v, 64));
}
/* float access */
static inline float32 ldfl_le_p(const void *ptr)
{
CPU_FloatU u;
u.l = ldl_le_p(ptr);
return u.f;
}
static inline void stfl_le_p(void *ptr, float32 v)
{
CPU_FloatU u;
u.f = v;
stl_le_p(ptr, u.l);
}
static inline float64 ldfq_le_p(const void *ptr)
{
CPU_DoubleU u;
u.ll = ldq_le_p(ptr);
return u.d;
}
static inline void stfq_le_p(void *ptr, float64 v)
{
CPU_DoubleU u;
u.d = v;
stq_le_p(ptr, u.ll);
}
static inline int lduw_be_p(const void *ptr)
{
return (uint16_t)be_bswap(lduw_he_p(ptr), 16);
}
static inline int ldsw_be_p(const void *ptr)
{
return (int16_t)be_bswap(lduw_he_p(ptr), 16);
}
static inline int ldl_be_p(const void *ptr)
{
return be_bswap(ldl_he_p(ptr), 32);
}
static inline uint64_t ldq_be_p(const void *ptr)
{
return be_bswap(ldq_he_p(ptr), 64);
}
static inline void stw_be_p(void *ptr, uint16_t v)
{
stw_he_p(ptr, be_bswap(v, 16));
}
static inline void stl_be_p(void *ptr, uint32_t v)
{
stl_he_p(ptr, be_bswap(v, 32));
}
static inline void stq_be_p(void *ptr, uint64_t v)
{
stq_he_p(ptr, be_bswap(v, 64));
}
/* float access */
static inline float32 ldfl_be_p(const void *ptr)
{
CPU_FloatU u;
u.l = ldl_be_p(ptr);
return u.f;
}
static inline void stfl_be_p(void *ptr, float32 v)
{
CPU_FloatU u;
u.f = v;
stl_be_p(ptr, u.l);
}
static inline float64 ldfq_be_p(const void *ptr)
{
CPU_DoubleU u;
u.ll = ldq_be_p(ptr);
return u.d;
}
static inline void stfq_be_p(void *ptr, float64 v)
{
CPU_DoubleU u;
u.d = v;
stq_be_p(ptr, u.ll);
}
static inline unsigned long leul_to_cpu(unsigned long v)
{
/* In order to break an include loop between here and
qemu-common.h, don't rely on HOST_LONG_BITS. */
#if ULONG_MAX == UINT32_MAX
return le_bswap(v, 32);
#elif ULONG_MAX == UINT64_MAX
return le_bswap(v, 64);
#else
# error Unknown sizeof long
#endif
}
#undef le_bswap
#undef be_bswap
#undef le_bswaps
#undef be_bswaps
#endif /* BSWAP_H */