[PATCH v3 08/21] lib/crc: Switch ARM and arm64 to 'ksimd' scoped guard API

[Ard Biesheuvel]

From: Ard Biesheuvel <ardb@xxxxxxxxxx>

Before modifying the prototypes of kernel_neon_begin() and
kernel_neon_end() to accommodate kernel mode FP/SIMD state buffers
allocated on the stack, move arm64 to the new 'ksimd' scoped guard API,
which encapsulates the calls to those functions.

For symmetry, do the same for 32-bit ARM too.

Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
 lib/crc/arm/crc-t10dif.h   | 16 +++++-----------
 lib/crc/arm/crc32.h        | 11 ++++-------
 lib/crc/arm64/crc-t10dif.h | 16 +++++-----------
 lib/crc/arm64/crc32.h      | 16 ++++++----------
 4 files changed, 20 insertions(+), 39 deletions(-)

diff --git a/lib/crc/arm/crc-t10dif.h b/lib/crc/arm/crc-t10dif.h
index 63441de5e3f1..7f02a767f675 100644
--- a/lib/crc/arm/crc-t10dif.h
+++ b/lib/crc/arm/crc-t10dif.h
@@ -5,7 +5,6 @@
  * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@xxxxxxxxxx>
  */
 
-#include <asm/neon.h>
 #include <asm/simd.h>
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
@@ -20,21 +19,16 @@ asmlinkage void crc_t10dif_pmull8(u16 init_crc, const u8 *buf, size_t len,
 static inline u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
 {
 	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE) {
-		if (static_branch_likely(&have_pmull)) {
-			if (likely(may_use_simd())) {
-				kernel_neon_begin();
-				crc = crc_t10dif_pmull64(crc, data, length);
-				kernel_neon_end();
-				return crc;
-			}
+		if (static_branch_likely(&have_pmull) && likely(may_use_simd()) {
+			scoped_ksimd()
+				return crc_t10dif_pmull64(crc, data, length);
 		} else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
 			   static_branch_likely(&have_neon) &&
 			   likely(may_use_simd())) {
 			u8 buf[16] __aligned(16);
 
-			kernel_neon_begin();
-			crc_t10dif_pmull8(crc, data, length, buf);
-			kernel_neon_end();
+			scoped_ksimd()
+				crc_t10dif_pmull8(crc, data, length, buf);
 
 			return crc_t10dif_generic(0, buf, sizeof(buf));
 		}
diff --git a/lib/crc/arm/crc32.h b/lib/crc/arm/crc32.h
index 7b76f52f6907..f33de6b22cd4 100644
--- a/lib/crc/arm/crc32.h
+++ b/lib/crc/arm/crc32.h
@@ -8,7 +8,6 @@
 #include <linux/cpufeature.h>
 
 #include <asm/hwcap.h>
-#include <asm/neon.h>
 #include <asm/simd.h>
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_crc32);
@@ -42,9 +41,8 @@ static inline u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
 			len -= n;
 		}
 		n = round_down(len, 16);
-		kernel_neon_begin();
-		crc = crc32_pmull_le(p, n, crc);
-		kernel_neon_end();
+		scoped_ksimd()
+			crc = crc32_pmull_le(p, n, crc);
 		p += n;
 		len -= n;
 	}
@@ -71,9 +69,8 @@ static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
 			len -= n;
 		}
 		n = round_down(len, 16);
-		kernel_neon_begin();
-		crc = crc32c_pmull_le(p, n, crc);
-		kernel_neon_end();
+		scoped_ksimd()
+			crc = crc32c_pmull_le(p, n, crc);
 		p += n;
 		len -= n;
 	}
diff --git a/lib/crc/arm64/crc-t10dif.h b/lib/crc/arm64/crc-t10dif.h
index f88db2971805..0de03ab1aeab 100644
--- a/lib/crc/arm64/crc-t10dif.h
+++ b/lib/crc/arm64/crc-t10dif.h
@@ -7,7 +7,6 @@
 
 #include <linux/cpufeature.h>
 
-#include <asm/neon.h>
 #include <asm/simd.h>
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_asimd);
@@ -22,21 +21,16 @@ asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
 static inline u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
 {
 	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE) {
-		if (static_branch_likely(&have_pmull)) {
-			if (likely(may_use_simd())) {
-				kernel_neon_begin();
-				crc = crc_t10dif_pmull_p64(crc, data, length);
-				kernel_neon_end();
-				return crc;
-			}
+		if (static_branch_likely(&have_pmull) && likely(may_use_simd())) {
+			scoped_ksimd()
+				return crc_t10dif_pmull_p64(crc, data, length);
 		} else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
 			   static_branch_likely(&have_asimd) &&
 			   likely(may_use_simd())) {
 			u8 buf[16];
 
-			kernel_neon_begin();
-			crc_t10dif_pmull_p8(crc, data, length, buf);
-			kernel_neon_end();
+			scoped_ksimd()
+				crc_t10dif_pmull_p8(crc, data, length, buf);
 
 			return crc_t10dif_generic(0, buf, sizeof(buf));
 		}
diff --git a/lib/crc/arm64/crc32.h b/lib/crc/arm64/crc32.h
index 31e649cd40a2..1939a5dee477 100644
--- a/lib/crc/arm64/crc32.h
+++ b/lib/crc/arm64/crc32.h
@@ -2,7 +2,6 @@
 
 #include <asm/alternative.h>
 #include <asm/cpufeature.h>
-#include <asm/neon.h>
 #include <asm/simd.h>
 
 // The minimum input length to consider the 4-way interleaved code path
@@ -23,9 +22,8 @@ static inline u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
 
 	if (len >= min_len && cpu_have_named_feature(PMULL) &&
 	    likely(may_use_simd())) {
-		kernel_neon_begin();
-		crc = crc32_le_arm64_4way(crc, p, len);
-		kernel_neon_end();
+		scoped_ksimd()
+			crc = crc32_le_arm64_4way(crc, p, len);
 
 		p += round_down(len, 64);
 		len %= 64;
@@ -44,9 +42,8 @@ static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
 
 	if (len >= min_len && cpu_have_named_feature(PMULL) &&
 	    likely(may_use_simd())) {
-		kernel_neon_begin();
-		crc = crc32c_le_arm64_4way(crc, p, len);
-		kernel_neon_end();
+		scoped_ksimd()
+			crc = crc32c_le_arm64_4way(crc, p, len);
 
 		p += round_down(len, 64);
 		len %= 64;
@@ -65,9 +62,8 @@ static inline u32 crc32_be_arch(u32 crc, const u8 *p, size_t len)
 
 	if (len >= min_len && cpu_have_named_feature(PMULL) &&
 	    likely(may_use_simd())) {
-		kernel_neon_begin();
-		crc = crc32_be_arm64_4way(crc, p, len);
-		kernel_neon_end();
+		scoped_ksimd()
+			crc = crc32_be_arm64_4way(crc, p, len);
 
 		p += round_down(len, 64);
 		len %= 64;
-- 
2.51.0.710.ga91ca5db03-goog