From: Palmer Dabbelt <palmer@rivosinc.com>

Support for probing the Zicboz block size landed in Linux 6.6, which was
released a few weeks ago.  This provides the user-configured block size
when Zicboz is enabled.

Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20231110173716.24423-1-palmer@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
(cherry picked from commit 301c65f49f9602f39b9f3ce0ad9ff70d4bda7226)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(Mjt: fixup linux-user/syscall.c to before v8.1.0-2602-ge57039ddab
 "target/riscv: rename ext_icboz to ext_zicboz")

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 9353268cc1..bd0c99859d 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -9058,6 +9058,8 @@ static int do_getdents64(abi_long dirfd, abi_long arg2, abi_long count)
 #define     RISCV_HWPROBE_MISALIGNED_UNSUPPORTED (4 << 0)
 #define     RISCV_HWPROBE_MISALIGNED_MASK        (7 << 0)
 
+#define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6
+
 struct riscv_hwprobe {
     abi_llong  key;
     abi_ullong value;
@@ -9102,6 +9104,10 @@ static void risc_hwprobe_fill_pairs(CPURISCVState *env,
         case RISCV_HWPROBE_KEY_CPUPERF_0:
             __put_user(RISCV_HWPROBE_MISALIGNED_FAST, &pair->value);
             break;
+        case RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE:
+            value = cfg->ext_icboz ? cfg->cboz_blocksize : 0;
+            __put_user(value, &pair->value);
+            break;
         default:
             __put_user(-1, &pair->key);
             break;
-- 
2.39.2