[xen staging] RISCV/bitops: Use Zbb to provide arch-optimised bitops

[patchbot@xxxxxxx]

commit 7388912f275653a58769d8e77ac4d4cd452b7d37
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Thu Mar 6 14:03:15 2025 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Mar 6 14:03:15 2025 +0100

    RISCV/bitops: Use Zbb to provide arch-optimised bitops
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
 xen/arch/riscv/include/asm/bitops.h | 7 +++++++
 xen/arch/riscv/include/asm/config.h | 4 ++++
 2 files changed, 11 insertions(+)

diff --git a/xen/arch/riscv/include/asm/bitops.h 
b/xen/arch/riscv/include/asm/bitops.h
index d22eec1e87..72a4a8c155 100644
--- a/xen/arch/riscv/include/asm/bitops.h
+++ b/xen/arch/riscv/include/asm/bitops.h
@@ -125,6 +125,13 @@ static inline void clear_bit(int nr, volatile void *p)
 #undef NOT
 #undef __AMO
 
+#define arch_ffs(x)     ((x) ? 1 + __builtin_ctz(x) : 0)
+#define arch_ffsl(x)    ((x) ? 1 + __builtin_ctzl(x) : 0)
+#define arch_fls(x)     ((x) ? BITS_PER_INT - __builtin_clz(x) : 0)
+#define arch_flsl(x)    ((x) ? BITS_PER_LONG - __builtin_clzl(x) : 0)
+
+#define arch_hweightl(x) __builtin_popcountl(x)
+
 #endif /* ASM__RISCV__BITOPS_H */
 
 /*
diff --git a/xen/arch/riscv/include/asm/config.h 
b/xen/arch/riscv/include/asm/config.h
index 826e5c7172..7141bd9e46 100644
--- a/xen/arch/riscv/include/asm/config.h
+++ b/xen/arch/riscv/include/asm/config.h
@@ -119,6 +119,7 @@
 #define HYPERVISOR_VIRT_START XEN_VIRT_START
 
 #if defined(CONFIG_RISCV_64)
+# define INT_BYTEORDER 2
 # define LONG_BYTEORDER 3
 # define ELFSIZE 64
 # define MAX_VIRT_CPUS 128u
@@ -126,6 +127,9 @@
 # error "Unsupported RISCV variant"
 #endif
 
+#define BYTES_PER_INT  (1 << INT_BYTEORDER)
+#define BITS_PER_INT  (BYTES_PER_INT << 3)
+
 #define BYTES_PER_LONG (1 << LONG_BYTEORDER)
 #define BITS_PER_LONG  (BYTES_PER_LONG << 3)
 #define POINTER_ALIGN  BYTES_PER_LONG
--
generated by git-patchbot for /home/xen/git/xen.git#staging