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lavu/riscv: fallback to raw hwprobe() system call

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Not all C run-times support this, and even then, it will be a while
before distributions provide recent enough versions thereof.

Since this is a trivial system call wrapper, we might just as well call
the corresponding kernel system call directly where the C run-time lacks
support but the kernel headers are new enough (as is the case on Debian
Unstable at the time of writing). In doing so, we need to add a few more
guards as the first suitable kernel (headers) release did not expose the
V, Zba and Zbb extensions.
This commit is contained in:
Rémi Denis-Courmont 2024-05-03 20:08:03 +03:00
parent 4ced36744e
commit 61ec7450ff
2 changed files with 21 additions and 1 deletions
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2
configure vendored
View File

@ -2273,6 +2273,7 @@ HAVE_LIST_PUB="
HEADERS_LIST="
arpa_inet_h
asm_hwprobe_h
asm_types_h
cdio_paranoia_h
cdio_paranoia_paranoia_h
@ -5548,6 +5549,7 @@ elif enabled ppc; then
elif enabled riscv; then
check_headers asm/hwprobe.h
check_headers sys/hwprobe.h
if test_cpp_condition stddef.h "__riscv_zbb"; then

20
libavutil/riscv/cpu.c
View File

@ -31,12 +31,24 @@
#endif
#if HAVE_SYS_HWPROBE_H
#include <sys/hwprobe.h>
#elif HAVE_ASM_HWPROBE_H
#include <asm/hwprobe.h>
#include <sys/syscall.h>
#include <unistd.h>
static int __riscv_hwprobe(struct riscv_hwprobe *pairs, size_t pair_count,
size_t cpu_count, unsigned long *cpus,
unsigned int flags)
{
return syscall(__NR_riscv_hwprobe, pairs, pair_count, cpu_count, cpus,
flags);
}
#endif
int ff_get_cpu_flags_riscv(void)
{
int ret = 0;
#if HAVE_SYS_HWPROBE_H
#if HAVE_SYS_HWPROBE_H || HAVE_ASM_HWPROBE_H
struct riscv_hwprobe pairs[] = {
{ RISCV_HWPROBE_KEY_BASE_BEHAVIOR, 0 },
{ RISCV_HWPROBE_KEY_IMA_EXT_0, 0 },
@ -47,13 +59,19 @@ int ff_get_cpu_flags_riscv(void)
ret |= AV_CPU_FLAG_RVI;
if (pairs[1].value & RISCV_HWPROBE_IMA_FD)
ret |= AV_CPU_FLAG_RVF | AV_CPU_FLAG_RVD;
#ifdef RISCV_HWPROBE_IMA_V
if (pairs[1].value & RISCV_HWPROBE_IMA_V)
ret |= AV_CPU_FLAG_RVV_I32 | AV_CPU_FLAG_RVV_I64
| AV_CPU_FLAG_RVV_F32 | AV_CPU_FLAG_RVV_F64;
#endif
#ifdef RISCV_HWPROBE_EXT_ZBA
if (pairs[1].value & RISCV_HWPROBE_EXT_ZBA)
ret |= AV_CPU_FLAG_RVB_ADDR;
#endif
#ifdef RISCV_HWPROBE_EXT_ZBB
if (pairs[1].value & RISCV_HWPROBE_EXT_ZBB)
ret |= AV_CPU_FLAG_RVB_BASIC;
#endif
#ifdef RISCV_HWPROBE_EXT_ZVBB
if (pairs[1].value & RISCV_HWPROBE_EXT_ZVBB)
ret |= AV_CPU_FLAG_RV_ZVBB;