[UNIKRAFT PATCH] arch: Define the cache line size for each architecture

[Alexander Jung <a.jung@xxxxxxxxxxx>]

This definition statically describes the d-cache line size in
bytes for {x86_64,arm,arm64}.

The d-cache line is a L1 data cache nearest to the processor and
the line size refers to the data memory block.

The d-line cache size can also be discovered by querying the
d-cache build egister at the expense of using more memory and
instruction cycles during boot.  Defining this size statically
increases performance since it is already known for the
respective architecture.

Signed-off-by: Alexander Jung <alexander.jung@xxxxxxxxx>
---
 arch/arm/arm/include/uk/asm/lcpu.h    | 2 ++
 arch/arm/arm64/include/uk/asm/lcpu.h  | 2 ++
 arch/x86/x86_64/include/uk/asm/lcpu.h | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/arch/arm/arm/include/uk/asm/lcpu.h 
b/arch/arm/arm/include/uk/asm/lcpu.h
index cdeffc3..33f3a6b 100644
--- a/arch/arm/arm/include/uk/asm/lcpu.h
+++ b/arch/arm/arm/include/uk/asm/lcpu.h
@@ -29,6 +29,8 @@
 #error Do not include this header directly
 #endif
 
+#define CACHE_LINE_SIZE        32
+
 struct __regs {
        unsigned long r0;
        unsigned long r1;
diff --git a/arch/arm/arm64/include/uk/asm/lcpu.h 
b/arch/arm/arm64/include/uk/asm/lcpu.h
index 45d1b23..4597e40 100644
--- a/arch/arm/arm64/include/uk/asm/lcpu.h
+++ b/arch/arm/arm64/include/uk/asm/lcpu.h
@@ -30,6 +30,8 @@
 #error Do not include this header directly
 #endif
 
+#define CACHE_LINE_SIZE        64
+
 #ifdef __ASSEMBLY__
 /*
  * Stack size to save general purpose registers and essential system
diff --git a/arch/x86/x86_64/include/uk/asm/lcpu.h 
b/arch/x86/x86_64/include/uk/asm/lcpu.h
index 6a471a1..ff137f8 100644
--- a/arch/x86/x86_64/include/uk/asm/lcpu.h
+++ b/arch/x86/x86_64/include/uk/asm/lcpu.h
@@ -32,6 +32,8 @@
 #error Do not include this header directly
 #endif
 
+#define CACHE_LINE_SIZE        64
+
 #ifndef __ASSEMBLY__
 struct __regs {
        unsigned long pad; /* 8 bytes to make struct size multiple of 16 */
-- 
2.11.0