score: Introduce CPU_CACHE_LINE_BYTES

Add CPU_CACHE_LINE_BYTES for the maximum cache line size in bytes.  The
actual processor may use no cache or a smaller cache line size.

c/src/lib/libcpu/shared/src/cache_manager.c

@@ -42,6 +42,14 @@
 #include <rtems.h>
 #include "cache_.h"
 
+#if CPU_DATA_CACHE_ALIGNMENT > CPU_CACHE_LINE_BYTES
+#error "CPU_DATA_CACHE_ALIGNMENT is greater than CPU_CACHE_LINE_BYTES"
+#endif
+
+#if CPU_INSTRUCTION_CACHE_ALIGNMENT > CPU_CACHE_LINE_BYTES
+#error "CPU_INSTRUCTION_CACHE_ALIGNMENT is greater than CPU_CACHE_LINE_BYTES"
+#endif
+
 #if defined(RTEMS_SMP)
 
 #include <rtems/score/smpimpl.h>

cpukit/score/cpu/arm/rtems/score/cpu.h

@@ -144,8 +144,10 @@
 
 #define CPU_STACK_GROWS_UP FALSE
 
-/* XXX Why 32? */
+/* FIXME: Is this the right value? */
-#define CPU_STRUCTURE_ALIGNMENT __attribute__ ((aligned (32)))
+#define CPU_CACHE_LINE_BYTES 32
+
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
 
 /*
  * The interrupt mask disables only normal interrupts (IRQ).

cpukit/score/cpu/bfin/rtems/score/cpu.h

@@ -295,29 +295,9 @@ extern "C" {
  */
 #define CPU_STACK_GROWS_UP               FALSE
 
-/**
+/* FIXME: Is this the right value? */
- * The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 32
- * of critical RTEMS structures.  On some processors it may make
+
- * sense to have these aligned on tighter boundaries than
- * the minimum requirements of the compiler in order to have as
- * much of the critical data area as possible in a cache line.
- *
- * The placement of this macro in the declaration of the variables
- * is based on the syntactically requirements of the GNU C
- * "__attribute__" extension.  For example with GNU C, use
- * the following to force a structures to a 32 byte boundary.
- *
- *     __attribute__ ((aligned (32)))
- *
- * @note Currently only the Priority Bit Map table uses this feature.
- *       To benefit from using this, the data must be heavily
- *       used so it will stay in the cache and used frequently enough
- *       in the executive to justify turning this on.
- *
- * Port Specific Information:
- *
- * XXX document implementation including references if appropriate
- */
 #define CPU_STRUCTURE_ALIGNMENT
 
 /**

cpukit/score/cpu/epiphany/rtems/score/cpu.h

@@ -260,28 +260,10 @@ extern "C" {
 
 #define CPU_STACK_GROWS_UP               FALSE
 
-/*
+/* FIXME: Is this the right value? */
- *  The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 64
- *  of critical RTEMS structures.  On some processors it may make
- *  sense to have these aligned on tighter boundaries than
- *  the minimum requirements of the compiler in order to have as
- *  much of the critical data area as possible in a cache line.
- *
- *  The placement of this macro in the declaration of the variables
- *  is based on the syntactically requirements of the GNU C
- *  "__attribute__" extension.  For example with GNU C, use
- *  the following to force a structures to a 32 byte boundary.
- *
- *      __attribute__ ((aligned (32)))
- *
- *  NOTE:  Currently only the Priority Bit Map table uses this feature.
- *         To benefit from using this, the data must be heavily
- *         used so it will stay in the cache and used frequently enough
- *         in the executive to justify turning this on.
- *
- */
 
-#define CPU_STRUCTURE_ALIGNMENT __attribute__ ((aligned (64)))
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
 
 /*
  *  Define what is required to specify how the network to host conversion

cpukit/score/cpu/i386/rtems/score/cpu.h

@@ -100,6 +100,10 @@ extern "C" {
 #endif /* __SSE__ */
 
 #define CPU_STACK_GROWS_UP               FALSE
+
+/* FIXME: The Pentium 4 used 128 bytes, it this processor still relevant? */
+#define CPU_CACHE_LINE_BYTES 64
+
 #define CPU_STRUCTURE_ALIGNMENT
 
 /*

cpukit/score/cpu/lm32/rtems/score/cpu.h

@@ -289,30 +289,10 @@ extern "C" {
  */
 #define CPU_STACK_GROWS_UP               FALSE
 
-/**
+/* L2 cache lines are 32 bytes in Milkymist SoC */
- * The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 32
- * of critical RTEMS structures.  On some processors it may make
+
- * sense to have these aligned on tighter boundaries than
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
- * the minimum requirements of the compiler in order to have as
- * much of the critical data area as possible in a cache line.
- *
- * The placement of this macro in the declaration of the variables
- * is based on the syntactically requirements of the GNU C
- * "__attribute__" extension.  For example with GNU C, use
- * the following to force a structures to a 32 byte boundary.
- *
- *     __attribute__ ((aligned (32)))
- *
- * NOTE: Currently only the Priority Bit Map table uses this feature.
- *       To benefit from using this, the data must be heavily
- *       used so it will stay in the cache and used frequently enough
- *       in the executive to justify turning this on.
- *
- * Port Specific Information:
- *
- * L2 cache lines are 32 bytes in Milkymist SoC
- */
-#define CPU_STRUCTURE_ALIGNMENT __attribute__ ((aligned (32)))
 
 /**
  * @defgroup CPUEndian Processor Dependent Endianness Support

cpukit/score/cpu/m32c/rtems/score/cpu.h

@@ -311,30 +311,10 @@ extern "C" {
  */
 #define CPU_STACK_GROWS_UP               TRUE
 
-/**
+/* FIXME: Is this the right value? */
- * The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 2
- * of critical RTEMS structures.  On some processors it may make
+
- * sense to have these aligned on tighter boundaries than
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
- * the minimum requirements of the compiler in order to have as
- * much of the critical data area as possible in a cache line.
- *
- * The placement of this macro in the declaration of the variables
- * is based on the syntactically requirements of the GNU C
- * "__attribute__" extension.  For example with GNU C, use
- * the following to force a structures to a 32 byte boundary.
- *
- *     __attribute__ ((aligned (32)))
- *
- * NOTE: Currently only the Priority Bit Map table uses this feature.
- *       To benefit from using this, the data must be heavily
- *       used so it will stay in the cache and used frequently enough
- *       in the executive to justify turning this on.
- *
- * Port Specific Information:
- *
- * XXX document implementation including references if appropriate
- */
-#define CPU_STRUCTURE_ALIGNMENT          __attribute__ ((aligned (2)))
 
 /**
  * @defgroup CPUEndian Processor Dependent Endianness Support

cpukit/score/cpu/m68k/rtems/score/cpu.h

@@ -99,7 +99,11 @@ extern "C" {
 
 #define CPU_PROVIDES_IDLE_THREAD_BODY    TRUE
 #define CPU_STACK_GROWS_UP               FALSE
-#define CPU_STRUCTURE_ALIGNMENT          __attribute__ ((aligned (4)))
+
+/* FIXME: Is this the right value? */
+#define CPU_CACHE_LINE_BYTES 16
+
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
 
 /*
  *  Define what is required to specify how the network to host conversion

cpukit/score/cpu/mips/rtems/score/cpu.h

@@ -280,32 +280,10 @@ extern "C" {
 /* our stack grows down */
 #define CPU_STACK_GROWS_UP               FALSE
 
-/*
+/* FIXME: Is this the right value? */
- *  The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 16
- *  of critical RTEMS structures.  On some processors it may make
- *  sense to have these aligned on tighter boundaries than
- *  the minimum requirements of the compiler in order to have as
- *  much of the critical data area as possible in a cache line.
- *
- *  The placement of this macro in the declaration of the variables
- *  is based on the syntactically requirements of the GNU C
- *  "__attribute__" extension.  For example with GNU C, use
- *  the following to force a structures to a 32 byte boundary.
- *
- *      __attribute__ ((aligned (32)))
- *
- *  NOTE:  Currently only the Priority Bit Map table uses this feature.
- *         To benefit from using this, the data must be heavily
- *         used so it will stay in the cache and used frequently enough
- *         in the executive to justify turning this on.
- */
 
-/* our cache line size is 16 bytes */
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
-#if __GNUC__
-#define CPU_STRUCTURE_ALIGNMENT __attribute__ ((aligned (16)))
-#else
-#define CPU_STRUCTURE_ALIGNMENT
-#endif
 
 /*
  *  Define what is required to specify how the network to host conversion

cpukit/score/cpu/moxie/rtems/score/cpu.h

@@ -260,29 +260,9 @@ extern "C" {
  */
 #define CPU_STACK_GROWS_UP               FALSE
 
-/*
+/* FIXME: Is this the right value? */
- *  The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 32
- *  of critical RTEMS structures.  On some processors it may make
+
- *  sense to have these aligned on tighter boundaries than
- *  the minimum requirements of the compiler in order to have as
- *  much of the critical data area as possible in a cache line.
- *
- *  The placement of this macro in the declaration of the variables
- *  is based on the syntactically requirements of the GNU C
- *  "__attribute__" extension.  For example with GNU C, use
- *  the following to force a structures to a 32 byte boundary.
- *
- *      __attribute__ ((aligned (32)))
- *
- *  NOTE:  Currently only the Priority Bit Map table uses this feature.
- *         To benefit from using this, the data must be heavily
- *         used so it will stay in the cache and used frequently enough
- *         in the executive to justify turning this on.
- *
- *  MOXIE Specific Information:
- *
- *  XXX
- */
 #define CPU_STRUCTURE_ALIGNMENT
 
 /*

cpukit/score/cpu/nios2/rtems/score/cpu.h

@@ -64,7 +64,11 @@ extern "C" {
 
 #define CPU_STACK_GROWS_UP FALSE
 
-#define CPU_STRUCTURE_ALIGNMENT __attribute__((section(".sdata"), aligned(32)))
+/* FIXME: Is this the right value? */
+#define CPU_CACHE_LINE_BYTES 32
+
+#define CPU_STRUCTURE_ALIGNMENT \
+  RTEMS_SECTION( ".sdata" ) RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
 
 #define CPU_BIG_ENDIAN FALSE
 

cpukit/score/cpu/no_cpu/rtems/score/cpu.h

@@ -310,6 +310,13 @@ extern "C" {
  */
 #define CPU_STACK_GROWS_UP               TRUE
 
+/**
+ * The maximum cache line size in bytes.
+ *
+ * The actual processor may use no cache or a smaller cache line size.
+ */
+#define CPU_CACHE_LINE_BYTES 32
+
 /**
  * The following is the variable attribute used to force alignment
  * of critical RTEMS structures.  On some processors it may make
@@ -317,23 +324,11 @@ extern "C" {
  * the minimum requirements of the compiler in order to have as
  * much of the critical data area as possible in a cache line.
  *
- * The placement of this macro in the declaration of the variables
- * is based on the syntactically requirements of the GNU C
- * "__attribute__" extension.  For example with GNU C, use
- * the following to force a structures to a 32 byte boundary.
- *
- *     __attribute__ ((aligned (32)))
- *
- * NOTE: Currently only the Priority Bit Map table uses this feature.
- *       To benefit from using this, the data must be heavily
- *       used so it will stay in the cache and used frequently enough
- *       in the executive to justify turning this on.
- *
  * Port Specific Information:
  *
  * XXX document implementation including references if appropriate
  */
-#define CPU_STRUCTURE_ALIGNMENT
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
 
 /**
  * @defgroup CPUEndian Processor Dependent Endianness Support

cpukit/score/cpu/or1k/rtems/score/cpu.h

@@ -252,28 +252,10 @@ extern "C" {
 
 #define CPU_STACK_GROWS_UP               FALSE
 
-/*
+/* FIXME: Is this the right value? */
- *  The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 32
- *  of critical RTEMS structures.  On some processors it may make
- *  sense to have these aligned on tighter boundaries than
- *  the minimum requirements of the compiler in order to have as
- *  much of the critical data area as possible in a cache line.
- *
- *  The placement of this macro in the declaration of the variables
- *  is based on the syntactically requirements of the GNU C
- *  "__attribute__" extension.  For example with GNU C, use
- *  the following to force a structures to a 32 byte boundary.
- *
- *      __attribute__ ((aligned (32)))
- *
- *  NOTE:  Currently only the Priority Bit Map table uses this feature.
- *         To benefit from using this, the data must be heavily
- *         used so it will stay in the cache and used frequently enough
- *         in the executive to justify turning this on.
- *
- */
 
-#define CPU_STRUCTURE_ALIGNMENT __attribute__ ((aligned (32)))
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
 
 /*
  *  Define what is required to specify how the network to host conversion

cpukit/score/cpu/powerpc/rtems/score/cpu.h

@@ -101,28 +101,9 @@ extern "C" {
 
 #define CPU_STACK_GROWS_UP               FALSE
 
-/*
+#define CPU_CACHE_LINE_BYTES PPC_STRUCTURE_ALIGNMENT
- *  The following is the variable attribute used to force alignment
- *  of critical RTEMS structures.  On some processors it may make
- *  sense to have these aligned on tighter boundaries than
- *  the minimum requirements of the compiler in order to have as
- *  much of the critical data area as possible in a cache line.
- *
- *  The placement of this macro in the declaration of the variables
- *  is based on the syntactically requirements of the GNU C
- *  "__attribute__" extension.  For example with GNU C, use
- *  the following to force a structures to a 32 byte boundary.
- *
- *      __attribute__ ((aligned (32)))
- *
- *  NOTE:  Currently only the Priority Bit Map table uses this feature.
- *         To benefit from using this, the data must be heavily
- *         used so it will stay in the cache and used frequently enough
- *         in the executive to justify turning this on.
- */
 
-#define CPU_STRUCTURE_ALIGNMENT \
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
-  __attribute__ ((aligned (PPC_STRUCTURE_ALIGNMENT)))
 
 /*
  *  Define what is required to specify how the network to host conversion

cpukit/score/cpu/sh/rtems/score/cpu.h

@@ -229,27 +229,10 @@ extern "C" {
 
 #define CPU_STACK_GROWS_UP               FALSE
 
-/*
+/* FIXME: Is this the right value? */
- *  The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 16
- *  of critical RTEMS structures.  On some processors it may make
- *  sense to have these aligned on tighter boundaries than
- *  the minimum requirements of the compiler in order to have as
- *  much of the critical data area as possible in a cache line.
- *
- *  The placement of this macro in the declaration of the variables
- *  is based on the syntactically requirements of the GNU C
- *  "__attribute__" extension.  For example with GNU C, use
- *  the following to force a structures to a 32 byte boundary.
- *
- *      __attribute__ ((aligned (32)))
- *
- *  NOTE:  Currently only the Priority Bit Map table uses this feature.
- *         To benefit from using this, the data must be heavily
- *         used so it will stay in the cache and used frequently enough
- *         in the executive to justify turning this on.
- */
 
-#define CPU_STRUCTURE_ALIGNMENT __attribute__ ((aligned(16)))
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
 
 /*
  *  Define what is required to specify how the network to host conversion

cpukit/score/cpu/sparc/rtems/score/cpu.h

@@ -210,17 +210,10 @@ extern "C" {
  */
 #define CPU_STACK_GROWS_UP               FALSE
 
-/**
+/* FIXME: Is this the right value? */
- * The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 32
- * of critical data structures.  On some processors it may make
+
- * sense to have these aligned on tighter boundaries than
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
- * the minimum requirements of the compiler in order to have as
- * much of the critical data area as possible in a cache line.
- *
- * The SPARC does not appear to have particularly strict alignment
- * requirements.  This value was chosen to take advantages of caches.
- */
-#define CPU_STRUCTURE_ALIGNMENT          __attribute__ ((aligned (32)))
 
 /**
  * Define what is required to specify how the network to host conversion

cpukit/score/cpu/sparc64/rtems/score/cpu.h

@@ -170,6 +170,9 @@ extern "C" {
 
 #define CPU_STACK_GROWS_UP               FALSE
 
+/* FIXME: Is this the right value? */
+#define CPU_CACHE_LINE_BYTES 32
+
 /*
  *  The following is the variable attribute used to force alignment
  *  of critical data structures.  On some processors it may make
@@ -184,7 +187,7 @@ extern "C" {
  *  and is 16 if quad-word fp instructions are available (e.g. LDQF).
  */
 
-#define CPU_STRUCTURE_ALIGNMENT          __attribute__ ((aligned (16)))
+#define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( 16 )
 
 /*
  *  Define what is required to specify how the network to host conversion

cpukit/score/cpu/v850/rtems/score/cpu.h

@@ -289,29 +289,9 @@ extern "C" {
  */
 #define CPU_STACK_GROWS_UP               FALSE
 
-/**
+/* FIXME: Is this the right value? */
- * The following is the variable attribute used to force alignment
+#define CPU_CACHE_LINE_BYTES 32
- * of critical RTEMS structures.  On some processors it may make
+
- * sense to have these aligned on tighter boundaries than
- * the minimum requirements of the compiler in order to have as
- * much of the critical data area as possible in a cache line.
- *
- * The placement of this macro in the declaration of the variables
- * is based on the syntactically requirements of the GNU C
- * "__attribute__" extension.  For example with GNU C, use
- * the following to force a structures to a 32 byte boundary.
- *
- *     __attribute__ ((aligned (32)))
- *
- * @note Currently only the Priority Bit Map table uses this feature.
- *       To benefit from using this, the data must be heavily
- *       used so it will stay in the cache and used frequently enough
- *       in the executive to justify turning this on.
- *
- * Port Specific Information:
- *
- * Until proven otherwise, use the compiler default.
- */
 #define CPU_STRUCTURE_ALIGNMENT
 
 /**