git: 064adb4ba083 - stable/14 - armv8rng: Don't require toolchain to support FEAT_RNG

[Andrew Turner]

The branch stable/14 has been updated by andrew:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=064adb4ba083d00747e3fae6b111545e557ebb1e

commit 064adb4ba083d00747e3fae6b111545e557ebb1e
Author:     Jessica Clarke <jrt...@freebsd.org>
AuthorDate: 2023-12-01 23:59:07 +0000
Commit:     Andrew Turner <and...@freebsd.org>
CommitDate: 2024-10-21 15:03:26 +0000

    armv8rng: Don't require toolchain to support FEAT_RNG
    
    We have the mechanism in place to support encoding system registers
    explicitly, so use that rather than requiring LLVM 13+, which breaks our
    current set of GitHub CI builds.
    
    Fixes:  9eecef052155 ("Add an Armv8 rndr random number provider")
    (cherry picked from commit 9560ac4b638edf688566f576adc65d3654f2240c)
---
 sys/arm64/include/armreg.h | 9 +++++++++
 sys/dev/random/armv8rng.c  | 8 ++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/sys/arm64/include/armreg.h b/sys/arm64/include/armreg.h
index b96d2223eb0b..e6b5d313a3cf 100644
--- a/sys/arm64/include/armreg.h
+++ b/sys/arm64/include/armreg.h
@@ -2105,6 +2105,15 @@
 #define        PMXEVTYPER_EL0_CRm              13
 #define        PMXEVTYPER_EL0_op2              1
 
+/* RNDRRS */
+#define        RNDRRS                          MRS_REG(RNDRRS)
+#define        RNDRRS_REG                      MRS_REG_ALT_NAME(RNDRRS)
+#define        RNDRRS_op0                      3
+#define        RNDRRS_op1                      3
+#define        RNDRRS_CRn                      2
+#define        RNDRRS_CRm                      4
+#define        RNDRRS_op2                      1
+
 /* SCTLR_EL1 - System Control Register */
 #define        SCTLR_RES1      0x30d00800      /* Reserved ARMv8.0, write 1 */
 #define        SCTLR_M                         (UL(0x1) << 0)
diff --git a/sys/dev/random/armv8rng.c b/sys/dev/random/armv8rng.c
index 3cca42a5bbf3..61698bfff820 100644
--- a/sys/dev/random/armv8rng.c
+++ b/sys/dev/random/armv8rng.c
@@ -59,10 +59,10 @@ random_rndr_read_one(u_long *buf)
        loop = 10;
        do {
                __asm __volatile(
-                   ".arch_extension rng   \n"
-                   "mrs        %0, rndrrs \n" /* Read the random number */
-                   "cset       %w1, ne    \n" /* 1 on success, 0 on failure */
-                   ".arch_extension norng \n"
+                   /* Read the random number */
+                   "mrs        %0, " __XSTRING(RNDRRS_REG) "\n"
+                   /* 1 on success, 0 on failure */
+                   "cset       %w1, ne\n"
                    : "=&r" (val), "=&r"(ret) :: "cc");
        } while (ret != 0 && --loop > 0);