[RFC,V3,05/43] rv64ilp32_abi: riscv: crc32: Utilize 64-bit width to improve the performance

Commit Message

Guo Ren March 25, 2025, 12:15 p.m. UTC

From: "Guo Ren (Alibaba DAMO Academy)" <[e-mail]>

The RV64ILP32 ABI, derived from a 64-bit ISA, uses 32-bit
BITS_PER_LONG. Therefore, crc32 algorithm could utilize 64-bit width
to improve the performance.

Signed-off-by: Guo Ren (Alibaba DAMO Academy) <[e-mail]>
---
 arch/riscv/lib/crc32-riscv.c | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

Patch

diff --git a/arch/riscv/lib/crc32-riscv.c b/arch/riscv/lib/crc32-riscv.c
index 53d56ab422c7..68dfb0565696 100644
--- a/arch/riscv/lib/crc32-riscv.c
+++ b/arch/riscv/lib/crc32-riscv.c
@@ -8,6 +8,7 @@ 
 #include <asm/hwcap.h>
 #include <asm/alternative-macros.h>
 #include <asm/byteorder.h>
+#include <asm/csr.h>
 
 #include <linux/types.h>
 #include <linux/minmax.h>
@@ -59,12 +60,12 @@ 
  */
 # define CRC32_POLY_QT_BE	0x04d101df481b4e5a
 
-static inline u64 crc32_le_prep(u32 crc, unsigned long const *ptr)
+static inline u64 crc32_le_prep(u32 crc, u64 const *ptr)
 {
 	return (u64)crc ^ (__force u64)__cpu_to_le64(*ptr);
 }
 
-static inline u32 crc32_le_zbc(unsigned long s, u32 poly, unsigned long poly_qt)
+static inline u32 crc32_le_zbc(u64 s, u32 poly, u64 poly_qt)
 {
 	u32 crc;
 
@@ -85,7 +86,7 @@  static inline u32 crc32_le_zbc(unsigned long s, u32 poly, unsigned long poly_qt)
 	return crc;
 }
 
-static inline u64 crc32_be_prep(u32 crc, unsigned long const *ptr)
+static inline u64 crc32_be_prep(u32 crc, u64 const *ptr)
 {
 	return ((u64)crc << 32) ^ (__force u64)__cpu_to_be64(*ptr);
 }
@@ -131,7 +132,7 @@  static inline u32 crc32_be_prep(u32 crc, unsigned long const *ptr)
 # error "Unexpected __riscv_xlen"
 #endif
 
-static inline u32 crc32_be_zbc(unsigned long s)
+static inline u32 crc32_be_zbc(xlen_t s)
 {
 	u32 crc;
 
@@ -156,16 +157,16 @@  typedef u32 (*fallback)(u32 crc, unsigned char const *p, size_t len);
 
 static inline u32 crc32_le_unaligned(u32 crc, unsigned char const *p,
 				     size_t len, u32 poly,
-				     unsigned long poly_qt)
+				     xlen_t poly_qt)
 {
 	size_t bits = len * 8;
-	unsigned long s = 0;
+	xlen_t s = 0;
 	u32 crc_low = 0;
 
 	for (int i = 0; i < len; i++)
-		s = ((unsigned long)*p++ << (__riscv_xlen - 8)) | (s >> 8);
+		s = ((xlen_t)*p++ << (__riscv_xlen - 8)) | (s >> 8);
 
-	s ^= (unsigned long)crc << (__riscv_xlen - bits);
+	s ^= (xlen_t)crc << (__riscv_xlen - bits);
 	if (__riscv_xlen == 32 || len < sizeof(u32))
 		crc_low = crc >> bits;
 
@@ -177,12 +178,12 @@  static inline u32 crc32_le_unaligned(u32 crc, unsigned char const *p,
 
 static inline u32 __pure crc32_le_generic(u32 crc, unsigned char const *p,
 					  size_t len, u32 poly,
-					  unsigned long poly_qt,
+					  xlen_t poly_qt,
 					  fallback crc_fb)
 {
 	size_t offset, head_len, tail_len;
-	unsigned long const *p_ul;
-	unsigned long s;
+	xlen_t const *p_ul;
+	xlen_t s;
 
 	asm goto(ALTERNATIVE("j %l[legacy]", "nop", 0,
 			     RISCV_ISA_EXT_ZBC, 1)
@@ -199,7 +200,7 @@  static inline u32 __pure crc32_le_generic(u32 crc, unsigned char const *p,
 
 	tail_len = len & OFFSET_MASK;
 	len = len >> STEP_ORDER;
-	p_ul = (unsigned long const *)p;
+	p_ul = (xlen_t const *)p;
 
 	for (int i = 0; i < len; i++) {
 		s = crc32_le_prep(crc, p_ul);
@@ -236,7 +237,7 @@  static inline u32 crc32_be_unaligned(u32 crc, unsigned char const *p,
 				     size_t len)
 {
 	size_t bits = len * 8;
-	unsigned long s = 0;
+	xlen_t s = 0;
 	u32 crc_low = 0;
 
 	s = 0;
@@ -247,7 +248,7 @@  static inline u32 crc32_be_unaligned(u32 crc, unsigned char const *p,
 		s ^= crc >> (32 - bits);
 		crc_low = crc << bits;
 	} else {
-		s ^= (unsigned long)crc << (bits - 32);
+		s ^= (xlen_t)crc << (bits - 32);
 	}
 
 	crc = crc32_be_zbc(s);
@@ -259,8 +260,8 @@  static inline u32 crc32_be_unaligned(u32 crc, unsigned char const *p,
 u32 __pure crc32_be_arch(u32 crc, const u8 *p, size_t len)
 {
 	size_t offset, head_len, tail_len;
-	unsigned long const *p_ul;
-	unsigned long s;
+	xlen_t const *p_ul;
+	xlen_t s;
 
 	asm goto(ALTERNATIVE("j %l[legacy]", "nop", 0,
 			     RISCV_ISA_EXT_ZBC, 1)
@@ -277,7 +278,7 @@  u32 __pure crc32_be_arch(u32 crc, const u8 *p, size_t len)
 
 	tail_len = len & OFFSET_MASK;
 	len = len >> STEP_ORDER;
-	p_ul = (unsigned long const *)p;
+	p_ul = (xlen_t const *)p;
 
 	for (int i = 0; i < len; i++) {
 		s = crc32_be_prep(crc, p_ul);