[glibc] riscv: Add hwprobe vdso call support

[glibc] riscv: Add hwprobe vdso call support

[Palmer Dabbelt]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=e7919e0db28837ae5e4315933a061a7c2eda442e

commit e7919e0db28837ae5e4315933a061a7c2eda442e
Author: Evan Green <evan@rivosinc.com>
Date:   Tue Feb 27 14:56:39 2024 -0800

    riscv: Add hwprobe vdso call support
    
    The new riscv_hwprobe syscall also comes with a vDSO for faster answers
    to your most common questions. Call in today to speak with a kernel
    representative near you!
    
    Signed-off-by: Evan Green <evan@rivosinc.com>
    Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Diff:
---
 sysdeps/unix/sysv/linux/dl-vdso-setup.c | 10 ++++++++++
 sysdeps/unix/sysv/linux/dl-vdso-setup.h |  3 +++
 sysdeps/unix/sysv/linux/riscv/hwprobe.c |  4 ++--
 sysdeps/unix/sysv/linux/riscv/sysdep.h  |  1 +
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/dl-vdso-setup.c b/sysdeps/unix/sysv/linux/dl-vdso-setup.c
index 5dd7ed9d12..3a44944dbb 100644
--- a/sysdeps/unix/sysv/linux/dl-vdso-setup.c
+++ b/sysdeps/unix/sysv/linux/dl-vdso-setup.c
@@ -71,6 +71,16 @@ PROCINFO_CLASS int (*_dl_vdso_clock_getres_time64) (clockid_t,
 # ifdef HAVE_GET_TBFREQ
 PROCINFO_CLASS uint64_t (*_dl_vdso_get_tbfreq)(void) RELRO;
 # endif
+
+/* RISC-V specific ones.  */
+# ifdef HAVE_RISCV_HWPROBE
+PROCINFO_CLASS int (*_dl_vdso_riscv_hwprobe)(void *,
+                                             size_t,
+                                             size_t,
+                                             unsigned long *,
+                                             unsigned int) RELRO;
+# endif
+
 #endif
 
 #undef RELRO
diff --git a/sysdeps/unix/sysv/linux/dl-vdso-setup.h b/sysdeps/unix/sysv/linux/dl-vdso-setup.h
index e87d886940..8aee5a8212 100644
--- a/sysdeps/unix/sysv/linux/dl-vdso-setup.h
+++ b/sysdeps/unix/sysv/linux/dl-vdso-setup.h
@@ -47,6 +47,9 @@ setup_vdso_pointers (void)
 #ifdef HAVE_GET_TBFREQ
   GLRO(dl_vdso_get_tbfreq) = dl_vdso_vsym (HAVE_GET_TBFREQ);
 #endif
+#ifdef HAVE_RISCV_HWPROBE
+  GLRO(dl_vdso_riscv_hwprobe) = dl_vdso_vsym (HAVE_RISCV_HWPROBE);
+#endif
 }
 
 #endif
diff --git a/sysdeps/unix/sysv/linux/riscv/hwprobe.c b/sysdeps/unix/sysv/linux/riscv/hwprobe.c
index 28a448175b..e64c159eb3 100644
--- a/sysdeps/unix/sysv/linux/riscv/hwprobe.c
+++ b/sysdeps/unix/sysv/linux/riscv/hwprobe.c
@@ -28,8 +28,8 @@ int __riscv_hwprobe (struct riscv_hwprobe *pairs, size_t pair_count,
 {
   int r;
 
-  r = INTERNAL_SYSCALL_CALL (riscv_hwprobe, pairs, pair_count,
-                             cpu_count, cpus, flags);
+  r = INTERNAL_VSYSCALL (riscv_hwprobe, 5, pairs, pair_count,
+                         cpu_count, cpus, flags);
 
   /* Negate negative errno values to match pthreads API. */
   return -r;
diff --git a/sysdeps/unix/sysv/linux/riscv/sysdep.h b/sysdeps/unix/sysv/linux/riscv/sysdep.h
index 5583b96d23..ee015dfeb6 100644
--- a/sysdeps/unix/sysv/linux/riscv/sysdep.h
+++ b/sysdeps/unix/sysv/linux/riscv/sysdep.h
@@ -156,6 +156,7 @@
 /* List of system calls which are supported as vsyscalls (for RV32 and
    RV64).  */
 # define HAVE_GETCPU_VSYSCALL		"__vdso_getcpu"
+# define HAVE_RISCV_HWPROBE		"__vdso_riscv_hwprobe"
 
 # undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
 # define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1