diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2018-06-15 14:57:14 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2018-06-15 15:23:34 +0100 |
| commit | afa4f6653dca095f63f3fe7f2001e9334f5676c1 (patch) | |
| tree | 5d3b9c27711a2b3ef5eaa2635593921092e32ae9 | |
| parent | 2948f0cde3974185ad22d6721438cf85df852877 (diff) | |
bswap: Add new stn_*_p() and ldn_*_p() memory access functions
There's a common pattern in QEMU where a function needs to perform
a data load or store of an N byte integer in a particular endianness.
At the moment this is handled by doing a switch() on the size and
calling the appropriate ld*_p or st*_p function for each size.
Provide a new family of functions ldn_*_p() and stn_*_p() which
take the size as an argument and do the switch() themselves.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180611171007.4165-2-peter.maydell@linaro.org
| -rw-r--r-- | docs/devel/loads-stores.rst | 15 | ||||
| -rw-r--r-- | include/exec/cpu-all.h | 4 | ||||
| -rw-r--r-- | include/qemu/bswap.h | 52 |
3 files changed, 71 insertions, 0 deletions
diff --git a/docs/devel/loads-stores.rst b/docs/devel/loads-stores.rst index 6a990cc243..57d8c524bf 100644 --- a/docs/devel/loads-stores.rst +++ b/docs/devel/loads-stores.rst @@ -53,9 +53,24 @@ The ``_{endian}`` infix is omitted for target-endian accesses. The target endian accessors are only available to source files which are built per-target. +There are also functions which take the size as an argument: + +load: ``ldn{endian}_p(ptr, sz)`` + +which performs an unsigned load of ``sz`` bytes from ``ptr`` +as an ``{endian}`` order value and returns it in a uint64_t. + +store: ``stn{endian}_p(ptr, sz, val)`` + +which stores ``val`` to ``ptr`` as an ``{endian}`` order value +of size ``sz`` bytes. + + Regexes for git grep - ``\<ldf\?[us]\?[bwlq]\(_[hbl]e\)\?_p\>`` - ``\<stf\?[bwlq]\(_[hbl]e\)\?_p\>`` + - ``\<ldn_\([hbl]e\)?_p\>`` + - ``\<stn_\([hbl]e\)?_p\>`` ``cpu_{ld,st}_*`` ~~~~~~~~~~~~~~~~~ diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index a635f532f9..7fa726b8e3 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -133,6 +133,8 @@ static inline void tswap64s(uint64_t *s) #define stq_p(p, v) stq_be_p(p, v) #define stfl_p(p, v) stfl_be_p(p, v) #define stfq_p(p, v) stfq_be_p(p, v) +#define ldn_p(p, sz) ldn_be_p(p, sz) +#define stn_p(p, sz, v) stn_be_p(p, sz, v) #else #define lduw_p(p) lduw_le_p(p) #define ldsw_p(p) ldsw_le_p(p) @@ -145,6 +147,8 @@ static inline void tswap64s(uint64_t *s) #define stq_p(p, v) stq_le_p(p, v) #define stfl_p(p, v) stfl_le_p(p, v) #define stfq_p(p, v) stfq_le_p(p, v) +#define ldn_p(p, sz) ldn_le_p(p, sz) +#define stn_p(p, sz, v) stn_le_p(p, sz, v) #endif /* MMU memory access macros */ diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h index 3f28f661b1..a684c1a7a2 100644 --- a/include/qemu/bswap.h +++ b/include/qemu/bswap.h @@ -290,6 +290,15 @@ typedef union { * For accessors that take a guest address rather than a * host address, see the cpu_{ld,st}_* accessors defined in * cpu_ldst.h. + * + * For cases where the size to be used is not fixed at compile time, + * there are + * stn{endian}_p(ptr, sz, val) + * which stores @val to @ptr as an @endian-order number @sz bytes in size + * and + * ldn{endian}_p(ptr, sz) + * which loads @sz bytes from @ptr as an unsigned @endian-order number + * and returns it in a uint64_t. */ static inline int ldub_p(const void *ptr) @@ -495,6 +504,49 @@ static inline unsigned long leul_to_cpu(unsigned long v) #endif } +/* Store v to p as a sz byte value in host order */ +#define DO_STN_LDN_P(END) \ + static inline void stn_## END ## _p(void *ptr, int sz, uint64_t v) \ + { \ + switch (sz) { \ + case 1: \ + stb_p(ptr, v); \ + break; \ + case 2: \ + stw_ ## END ## _p(ptr, v); \ + break; \ + case 4: \ + stl_ ## END ## _p(ptr, v); \ + break; \ + case 8: \ + stq_ ## END ## _p(ptr, v); \ + break; \ + default: \ + g_assert_not_reached(); \ + } \ + } \ + static inline uint64_t ldn_## END ## _p(const void *ptr, int sz) \ + { \ + switch (sz) { \ + case 1: \ + return ldub_p(ptr); \ + case 2: \ + return lduw_ ## END ## _p(ptr); \ + case 4: \ + return (uint32_t)ldl_ ## END ## _p(ptr); \ + case 8: \ + return ldq_ ## END ## _p(ptr); \ + default: \ + g_assert_not_reached(); \ + } \ + } + +DO_STN_LDN_P(he) +DO_STN_LDN_P(le) +DO_STN_LDN_P(be) + +#undef DO_STN_LDN_P + #undef le_bswap #undef be_bswap #undef le_bswaps |