cpukit: RISC-V - make riscv32 code work for riscv64 - v2

* Use #ifdefs for 32/64 bit code
* Use unsigned long which is 32-bit on riscv32 and 64-bit on riscv64 (register size)
* Move the code to a new shared riscv folder to be shared between riscv32 and riscv64
* Rename RTEMS_CPU extracted from command line to shared riscv target s/riscv*/riscv

Update #3109

aclocal/canonical-target-name.m4

@@ -12,7 +12,10 @@ case "${target}" in
   no_cpu-*rtems*)
         RTEMS_CPU=no_cpu
 	;;
-  *) 
+  riscv*-*rtems*)
+        RTEMS_CPU=riscv
+	;;
+  *)
 	RTEMS_CPU=`echo $target | sed 's%^\([[^-]]*\)-\(.*\)$%\1%'`
 	;;
 esac

c/src/aclocal/rtems-cpu-subdirs.m4

@@ -23,7 +23,7 @@ _RTEMS_CPU_SUBDIR([nios2],[$1]);;
 _RTEMS_CPU_SUBDIR([no_cpu],[$1]);;
 _RTEMS_CPU_SUBDIR([or1k],[$1]);;
 _RTEMS_CPU_SUBDIR([powerpc],[$1]);;
-_RTEMS_CPU_SUBDIR([riscv32],[$1]);;
+_RTEMS_CPU_SUBDIR([riscv],[$1]);;
 _RTEMS_CPU_SUBDIR([sh],[$1]);;
 _RTEMS_CPU_SUBDIR([sparc],[$1]);;
 _RTEMS_CPU_SUBDIR([sparc64],[$1]);;

cpukit/aclocal/canonical-target-name.m4

@@ -8,6 +8,8 @@ AC_DEFUN([RTEMS_CANONICAL_TARGET_CPU],
 [AC_REQUIRE([AC_CANONICAL_HOST])
 AC_MSG_CHECKING(rtems target cpu)
 case "${host}" in
+riscv*-*-rtems*)
+	RTEMS_CPU=riscv;;
 *-*-rtems*)
 	RTEMS_CPU="$host_cpu";;
 *)

cpukit/configure.ac

@@ -459,7 +459,7 @@ score/cpu/moxie/Makefile
 score/cpu/nios2/Makefile
 score/cpu/or1k/Makefile
 score/cpu/powerpc/Makefile
-score/cpu/riscv32/Makefile
+score/cpu/riscv/Makefile
 score/cpu/sh/Makefile
 score/cpu/sparc/Makefile
 score/cpu/sparc64/Makefile

cpukit/score/cpu/Makefile.am

@@ -14,7 +14,7 @@ DIST_SUBDIRS += nios2
 DIST_SUBDIRS += no_cpu
 DIST_SUBDIRS += or1k
 DIST_SUBDIRS += powerpc
-DIST_SUBDIRS += riscv32
+DIST_SUBDIRS += riscv
 DIST_SUBDIRS += sh
 DIST_SUBDIRS += sparc
 DIST_SUBDIRS += sparc64

cpukit/score/cpu/riscv/cpu.c

@@ -1,5 +1,5 @@
 /*
- * riscv32 CPU Dependent Source
+ * RISC-V CPU Dependent Source
  *
  * Copyright (c) 2015 University of York.
  * Hesham ALmatary <hesham@alumni.york.ac.uk>
@@ -59,12 +59,12 @@ void _CPU_Initialize(void)
   /* Do nothing */
 }
 
-void _CPU_ISR_Set_level(uint32_t level)
+void _CPU_ISR_Set_level(unsigned long level)
 {
   /* Do nothing */
 }
 
-uint32_t  _CPU_ISR_Get_level( void )
+unsigned long  _CPU_ISR_Get_level( void )
 {
   /* Do nothing */
   return 0;
@@ -80,7 +80,7 @@ void _CPU_ISR_install_raw_handler(
 }
 
 void _CPU_ISR_install_vector(
-  uint32_t    vector,
+  unsigned long    vector,
   proc_ptr    new_handler,
   proc_ptr   *old_handler
 )

cpukit/score/cpu/riscv/riscv-context-initialize.c

@@ -42,7 +42,7 @@ void _CPU_Context_Initialize(
   Context_Control *context,
   void *stack_area_begin,
   size_t stack_area_size,
-  uint32_t new_level,
+  unsigned long new_level,
   void (*entry_point)( void ),
   bool is_fp,
   void *tls_area

cpukit/score/cpu/riscv/riscv-context-switch.S

@@ -36,9 +36,6 @@
 .section .text, "ax"
 .align 4
 
-# define LREG lw
-# define SREG sw
-
 PUBLIC(_CPU_Context_switch)
 PUBLIC(_CPU_Context_restore)
 PUBLIC(_CPU_Context_restore_fp)

cpukit/score/cpu/riscv/riscv-context-validate.S

@@ -32,12 +32,11 @@
 
 .section	.text
 
-#define SREG sw
-#define LREG lw
 
 PUBLIC(_CPU_Context_validate)
 SYM(_CPU_Context_validate):
-  addi sp, sp, -144
+  /* RISC-V/RTEMS context has 36 registers of CPU_SIZEOF_POINTER size */
+  addi sp, sp, -1 * 36 * CPU_SIZEOF_POINTER
 
   SREG x1, (1 * CPU_SIZEOF_POINTER)(sp)
   /* Skip x2/sp */
@@ -197,5 +196,5 @@ restore:
 
   LREG x31, (31 * CPU_SIZEOF_POINTER)(sp)
 
-  addi sp, sp, 144
+  addi sp, sp, 36 * CPU_SIZEOF_POINTER
   ret

cpukit/score/cpu/riscv/riscv-exception-frame-print.c

@@ -36,6 +36,10 @@ void _CPU_Exception_frame_print( const CPU_Exception_frame *frame )
   int i;
 
   for ( i = 0; i < 32; ++i ) {
-    printk( "x%02i = 0x%016" PRIx32 "\n", i, frame->x[i]);
+#if __riscv_xlen == 32
+    printk( "x%02i = 0x%032" PRIx32 "\n", i, frame->x[i]);
+#else /* xlen == 64 */
+    printk( "x%02i = 0x%032" PRIx64 "\n", i, frame->x[i]);
+#endif
   }
 }

cpukit/score/cpu/riscv/riscv-exception-handler.S

@@ -3,7 +3,7 @@
  *
  * @ingroup ScoreCPU
  *
- * @brief riscv32 exception support implementation.
+ * @brief RISC-V exception support implementation.
  */
 
 /*
@@ -41,9 +41,6 @@
 #include <rtems/asm.h>
 #include <rtems/score/percpu.h>
 
-# define LREG lw
-# define SREG sw
-
 EXTERN(bsp_start_vector_table_begin)
 EXTERN(_Thread_Dispatch)
 PUBLIC(ISR_Handler)
@@ -52,7 +49,7 @@ PUBLIC(ISR_Handler)
 .align 4
 TYPE_FUNC(ISR_Handler)
 SYM(ISR_Handler):
-  addi sp, sp, -144
+  addi sp, sp, -1 * 36 * CPU_SIZEOF_POINTER
 
   SREG x1, (1 * CPU_SIZEOF_POINTER)(sp)
   /* Skip x2/sp */
@@ -103,15 +100,15 @@ SYM(ISR_Handler):
   /* Disable multitasking */
   la t1, THREAD_DISPATCH_DISABLE_LEVEL
 
-  LREG t2, (t0)
-  LREG t3, (t1)
+  lw t2, (t0)
+  lw t3, (t1)
   addi t2, t2, 1
   addi t3, t3, 1
-  SREG t2, (t0)
-  SREG t3, (t1)
+  sw t2, (t0)
+  sw t3, (t1)
 
   /* Save interrupted task stack pointer */
-  addi t4, sp, 144
+  addi t4, sp, 36 * CPU_SIZEOF_POINTER
   SREG t4, (2 * CPU_SIZEOF_POINTER)(sp)
 
   /* Keep sp (Exception frame address) in s1 */
@@ -126,7 +123,11 @@ SYM(ISR_Handler):
 
   /* calculate the offset */
   la   t5, bsp_start_vector_table_begin
+#if __riscv_xlen == 32
   slli t6, a0, 2
+#else /* xlen = 64 */
+  slli t6, a0, 3
+#endif
   add  t5, t5, t6
   LREG t5, (t5)
 
@@ -152,12 +153,12 @@ jump_to_c_handler:
   /* Enable multitasking */
   la t1, THREAD_DISPATCH_DISABLE_LEVEL
 
-  LREG t2, (t0)
-  LREG t3, (t1)
+  Lw t2, (t0)
+  lw t3, (t1)
   addi t2, t2, -1
   addi t3, t3, -1
-  SREG t2, (t0)
-  SREG t3, (t1)
+  sw t2, (t0)
+  sw t3, (t1)
 
   /* Check if _ISR_Nest_level > 0 */
   bgtz t2, exception_frame_restore
@@ -167,7 +168,7 @@ jump_to_c_handler:
 
   /* Check if dispatch needed */
   la   x31, DISPATCH_NEEDED
-  LREG x31, (x31)
+  lw x31, (x31)
   beqz x31, exception_frame_restore
 
   la x31, _Thread_Dispatch
@@ -215,6 +216,6 @@ jump_to_c_handler:
   LREG x31, (31 * CPU_SIZEOF_POINTER)(sp)
 
   /* Unwind exception frame */
-  addi sp, sp, 144
+  addi sp, sp, 36 * CPU_SIZEOF_POINTER
 
   mret

cpukit/score/cpu/riscv/rtems/score/cpu.h

@@ -66,7 +66,7 @@ extern "C" {
 #define CPU_HAS_OWN_HOST_TO_NETWORK_ROUTINES     FALSE
 #define CPU_BIG_ENDIAN                           FALSE
 #define CPU_LITTLE_ENDIAN                        TRUE
-#define CPU_MODES_INTERRUPT_MASK   0x00000001
+#define CPU_MODES_INTERRUPT_MASK   0x0000000000000001
 
 /*
  *  Processor defined structures required for cpukit/score.
@@ -75,13 +75,13 @@ extern "C" {
 #ifndef ASM
 
 typedef struct {
-  /* riscv32 has 32 32-bit general purpose registers (x0-x31). */
-  uint32_t  x[32];
+  /* riscv has 32 xlen-bit (where xlen can be 32 or 64) general purpose registers (x0-x31)*/
+  unsigned long x[32];
 
   /* Special purpose registers */
-  uint32_t  mstatus;
-  uint32_t  mcause;
-  uint32_t  mepc;
+  unsigned long mstatus;
+  unsigned long mcause;
+  unsigned long mepc;
 #ifdef RTEMS_SMP
   /**
    * @brief On SMP configurations the thread context must contain a boolean
@@ -138,7 +138,11 @@ typedef Context_Control CPU_Interrupt_frame;
 Context_Control_fp  _CPU_Null_fp_context;
 
 #define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 0
+#if __riscv_xlen == 32
 #define CPU_STACK_MINIMUM_SIZE  4096
+#else
+#define CPU_STACK_MINIMUM_SIZE  4096 * 2
+#endif
 #define CPU_ALIGNMENT 8
 #define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE
 #define CPU_HEAP_ALIGNMENT         CPU_ALIGNMENT
@@ -152,14 +156,14 @@ Context_Control_fp  _CPU_Null_fp_context;
  *
  */
 
-static inline uint32_t riscv_interrupt_disable( void )
+static inline unsigned long riscv_interrupt_disable( void )
 {
-  register uint32_t status = read_csr(mstatus);
+  register unsigned long status = read_csr(mstatus);
   clear_csr(mstatus, MSTATUS_MIE);
   return status;
 }
 
-static inline void riscv_interrupt_enable(uint32_t level)
+static inline void riscv_interrupt_enable(unsigned long level)
 {
   write_csr(mstatus, level);
 }
@@ -176,14 +180,14 @@ static inline void riscv_interrupt_enable(uint32_t level)
       riscv_interrupt_disable(); \
     } while(0)
 
-RTEMS_INLINE_ROUTINE bool _CPU_ISR_Is_enabled( uint32_t level )
+RTEMS_INLINE_ROUTINE bool _CPU_ISR_Is_enabled( unsigned long level )
 {
   return ( level & MSTATUS_MIE ) != 0;
 }
 
-void _CPU_ISR_Set_level( uint32_t level );
+void _CPU_ISR_Set_level( unsigned long level );
 
-uint32_t _CPU_ISR_Get_level( void );
+unsigned long _CPU_ISR_Get_level( void );
 
 /* end of ISR handler macros */
 
@@ -194,7 +198,7 @@ void _CPU_Context_Initialize(
   Context_Control *context,
   void *stack_area_begin,
   size_t stack_area_size,
-  uint32_t new_level,
+  unsigned long new_level,
   void (*entry_point)( void ),
   bool is_fp,
   void *tls_area
@@ -262,15 +266,31 @@ typedef struct {
 } CPU_Per_CPU_control;
 #endif /* ASM */
 
+#if __riscv_xlen == 32
 #define CPU_SIZEOF_POINTER 4
+
+/* 32-bit load/store instructions */
+#define LREG lw
+#define SREG sw
+
 #define CPU_EXCEPTION_FRAME_SIZE 128
+#else /* xlen = 64 */
+#define CPU_SIZEOF_POINTER 8
+
+/* 64-bit load/store instructions */
+#define LREG ld
+#define SREG sd
+
+#define CPU_EXCEPTION_FRAME_SIZE 256
+#endif
+
 #define CPU_PER_CPU_CONTROL_SIZE 0
 
 #ifndef ASM
 typedef uint16_t Priority_bit_map_Word;
 
 typedef struct {
-  uint32_t x[32];;
+  unsigned long x[32];;
 } CPU_Exception_frame;
 
 /**
@@ -321,7 +341,7 @@ void _CPU_ISR_install_raw_handler(
  */
 
 void _CPU_ISR_install_vector(
-  uint32_t    vector,
+  unsigned long    vector,
   proc_ptr   new_handler,
   proc_ptr   *old_handler
 );
@@ -423,8 +443,8 @@ void _CPU_Context_restore_fp(
  *
  */
 
-static inline unsigned int CPU_swap_u32(
-  unsigned int value
+static inline uint32_t CPU_swap_u32(
+  uint32_t value
 )
 {
   uint32_t   byte1, byte2, byte3, byte4, swapped;

cpukit/score/cpu/riscv/rtems/score/types.h

@@ -1,7 +1,7 @@
 /**
  * @file
  *
- * @brief riscv32 Architecture Types API
+ * @brief RISC-V Architecture Types API
  */
 
 /*