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hw/char/riscv_htif: Explicit little-endian implementation

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Since our RISC-V system emulation is only built for little
endian, the HTIF device aims to interface with little endian
memory accesses, thus we can explicit htif_mm_ops:endianness
being DEVICE_LITTLE_ENDIAN.

In that case tswap64() is equivalent to le64_to_cpu(), as in
"convert this 64-bit little-endian value into host cpu order".
Replace to simplify.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20241129154304.34946-3-philmd@linaro.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Philippe Mathieu-Daudé 2024-11-29 16:43:03 +01:00 • committed by Alistair Francis
parent a2ce7f806d
commit be0a70b93f
1 changed files with 6 additions and 5 deletions
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11
hw/char/riscv_htif.c
View file

@ -29,7 +29,7 @@
#include "qemu/timer.h"
#include "qemu/error-report.h"
#include "exec/address-spaces.h"
#include "exec/tswap.h"
#include "qemu/bswap.h"
#include "sysemu/dma.h"
#include "sysemu/runstate.h"
@ -212,11 +212,11 @@ static void htif_handle_tohost_write(HTIFState *s, uint64_t val_written)
} else {
uint64_t syscall[8];
cpu_physical_memory_read(payload, syscall, sizeof(syscall));
if (tswap64(syscall[0]) == PK_SYS_WRITE &&
tswap64(syscall[1]) == HTIF_DEV_CONSOLE &&
tswap64(syscall[3]) == HTIF_CONSOLE_CMD_PUTC) {
if (le64_to_cpu(syscall[0]) == PK_SYS_WRITE &&
le64_to_cpu(syscall[1]) == HTIF_DEV_CONSOLE &&
le64_to_cpu(syscall[3]) == HTIF_CONSOLE_CMD_PUTC) {
uint8_t ch;
cpu_physical_memory_read(tswap64(syscall[2]), &ch, 1);
cpu_physical_memory_read(le64_to_cpu(syscall[2]), &ch, 1);
/*
* XXX this blocks entire thread. Rewrite to use
* qemu_chr_fe_write and background I/O callbacks
@ -324,6 +324,7 @@ static void htif_mm_write(void *opaque, hwaddr addr,
static const MemoryRegionOps htif_mm_ops = {
.read = htif_mm_read,
.write = htif_mm_write,
.endianness = DEVICE_LITTLE_ENDIAN,
};
HTIFState *htif_mm_init(MemoryRegion *address_space, Chardev *chr,