| Message ID | 20241211230357.97036-2-philmd@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | misc: Reduce 'exec/tswap.h' inclusions | expand |
On 12/12/24 00:03, Philippe Mathieu-Daudé wrote: > In preparation of heterogeneous emulation where cores with > different endianness can run concurrently, we need to remove > the tswap() calls -- which use a fixed per-binary endianness. > > Get the endianness of the CPU accessed using the libisa > xtensa_isa_is_big_endian() call and replace the tswap() calls > by bswap() ones when necessary. Instead read here: In preparation of heterogeneous emulation where cores with different endianness can run concurrently, replace the pair of cpu_memory_rw_debug() + tswap() calls by put/get_user_u32() ones, which still do the same under the hood, but simplify the code maintenance (having less sites to do endianness code conversion). > Suggested-by: Peter Maydell <peter.maydell@linaro.org> > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> > --- > target/xtensa/xtensa-semi.c | 15 +++++---------- > 1 file changed, 5 insertions(+), 10 deletions(-) > > diff --git a/target/xtensa/xtensa-semi.c b/target/xtensa/xtensa-semi.c > index fa21b7e11fc..2ded8e5634e 100644 > --- a/target/xtensa/xtensa-semi.c > +++ b/target/xtensa/xtensa-semi.c > @@ -30,6 +30,7 @@ > #include "chardev/char-fe.h" > #include "exec/helper-proto.h" > #include "semihosting/semihost.h" > +#include "semihosting/uaccess.h" > #include "qapi/error.h" > #include "qemu/log.h" > > @@ -323,15 +324,12 @@ void HELPER(simcall)(CPUXtensaState *env) > uint32_t fd = regs[3]; > uint32_t rq = regs[4]; > uint32_t target_tv = regs[5]; > - uint32_t target_tvv[2]; > > struct timeval tv = {0}; > > if (target_tv) { > - cpu_memory_rw_debug(cs, target_tv, > - (uint8_t *)target_tvv, sizeof(target_tvv), 0); > - tv.tv_sec = (int32_t)tswap32(target_tvv[0]); > - tv.tv_usec = (int32_t)tswap32(target_tvv[1]); > + get_user_u32(tv.tv_sec, target_tv); > + get_user_u32(tv.tv_sec, target_tv + 4); > } > if (fd < 3 && sim_console) { > if ((fd == 1 || fd == 2) && rq == SELECT_ONE_WRITE) { > @@ -387,11 +385,8 @@ void HELPER(simcall)(CPUXtensaState *env) > const char *str = semihosting_get_arg(i); > int str_size = strlen(str) + 1; > > - argptr = tswap32(regs[3] + str_offset); > - > - cpu_memory_rw_debug(cs, > - regs[3] + i * sizeof(uint32_t), > - (uint8_t *)&argptr, sizeof(argptr), 1); > + put_user_u32(regs[3] + str_offset, > + regs[3] + i * sizeof(uint32_t)); > cpu_memory_rw_debug(cs, > regs[3] + str_offset, > (uint8_t *)str, str_size, 1);
On 12/11/24 17:08, Philippe Mathieu-Daudé wrote: > On 12/12/24 00:03, Philippe Mathieu-Daudé wrote: >> In preparation of heterogeneous emulation where cores with >> different endianness can run concurrently, we need to remove >> the tswap() calls -- which use a fixed per-binary endianness. >> >> Get the endianness of the CPU accessed using the libisa >> xtensa_isa_is_big_endian() call and replace the tswap() calls >> by bswap() ones when necessary. > > Instead read here: > > In preparation of heterogeneous emulation where cores with > different endianness can run concurrently, replace the pair > of cpu_memory_rw_debug() + tswap() calls by put/get_user_u32() > ones, which still do the same under the hood, but simplify the > code maintenance (having less sites to do endianness code > conversion). > >> Suggested-by: Peter Maydell <peter.maydell@linaro.org> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/target/xtensa/xtensa-semi.c b/target/xtensa/xtensa-semi.c index fa21b7e11fc..2ded8e5634e 100644 --- a/target/xtensa/xtensa-semi.c +++ b/target/xtensa/xtensa-semi.c @@ -30,6 +30,7 @@ #include "chardev/char-fe.h" #include "exec/helper-proto.h" #include "semihosting/semihost.h" +#include "semihosting/uaccess.h" #include "qapi/error.h" #include "qemu/log.h" @@ -323,15 +324,12 @@ void HELPER(simcall)(CPUXtensaState *env) uint32_t fd = regs[3]; uint32_t rq = regs[4]; uint32_t target_tv = regs[5]; - uint32_t target_tvv[2]; struct timeval tv = {0}; if (target_tv) { - cpu_memory_rw_debug(cs, target_tv, - (uint8_t *)target_tvv, sizeof(target_tvv), 0); - tv.tv_sec = (int32_t)tswap32(target_tvv[0]); - tv.tv_usec = (int32_t)tswap32(target_tvv[1]); + get_user_u32(tv.tv_sec, target_tv); + get_user_u32(tv.tv_sec, target_tv + 4); } if (fd < 3 && sim_console) { if ((fd == 1 || fd == 2) && rq == SELECT_ONE_WRITE) { @@ -387,11 +385,8 @@ void HELPER(simcall)(CPUXtensaState *env) const char *str = semihosting_get_arg(i); int str_size = strlen(str) + 1; - argptr = tswap32(regs[3] + str_offset); - - cpu_memory_rw_debug(cs, - regs[3] + i * sizeof(uint32_t), - (uint8_t *)&argptr, sizeof(argptr), 1); + put_user_u32(regs[3] + str_offset, + regs[3] + i * sizeof(uint32_t)); cpu_memory_rw_debug(cs, regs[3] + str_offset, (uint8_t *)str, str_size, 1);
In preparation of heterogeneous emulation where cores with different endianness can run concurrently, we need to remove the tswap() calls -- which use a fixed per-binary endianness. Get the endianness of the CPU accessed using the libisa xtensa_isa_is_big_endian() call and replace the tswap() calls by bswap() ones when necessary. Suggested-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> --- target/xtensa/xtensa-semi.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-)