arch/risc-v: implement standard ecall interface for nuttsbi

NuttSBI have a simple ecall interface for the kernel, which make
it hard to add new SBI call for NuttSBI. So implement standard
ecall interface for NuttSBI and make life easier.

Signed-off-by: Inochi Amaoto <inochiama@outlook.com>

arch/risc-v/src/common/riscv_internal.h

@@ -168,6 +168,19 @@
 
 #endif
 
+/* SBI Extension IDs */
+
+#define SBI_EXT_HSM             0x48534D
+#define SBI_EXT_TIME            0x54494D45
+
+/* SBI function IDs for TIME extension */
+
+#define SBI_EXT_TIME_SET_TIMER  0x0
+
+/* SBI function IDs for HSM extension */
+
+#define SBI_EXT_HSM_HART_START  0x0
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/

arch/risc-v/src/common/supervisor/riscv_sbi.c

@@ -22,19 +22,6 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-/* SBI Extension IDs */
-
-#define SBI_EXT_HSM             0x48534D
-#define SBI_EXT_TIME            0x54494D45
-
-/* SBI function IDs for TIME extension */
-
-#define SBI_EXT_TIME_SET_TIMER  0x0
-
-/* SBI function IDs for HSM extension */
-
-#define SBI_EXT_HSM_HART_START  0x0
-
 /****************************************************************************
  * Included Files
  ****************************************************************************/
@@ -54,7 +41,6 @@
  * Private Functions
  ****************************************************************************/
 
-#ifndef CONFIG_NUTTSBI
 static inline uintptr_t sbi_ecall(unsigned int extid, unsigned int fid,
                                   uintptr_t parm0, uintptr_t parm1,
                                   uintptr_t parm2, uintptr_t parm3,
@@ -79,7 +65,6 @@ static inline uintptr_t sbi_ecall(unsigned int extid, unsigned int fid,
 
   return r1;
 }
-#endif /* CONFIG_NUTTSBI */
 
 /****************************************************************************
  * Public Functions
@@ -98,9 +83,6 @@ static inline uintptr_t sbi_ecall(unsigned int extid, unsigned int fid,
 
 void riscv_sbi_set_timer(uint64_t stime_value)
 {
-#ifdef CONFIG_NUTTSBI
-  sbi_mcall_set_timer(stime_value);
-#else
 #ifdef CONFIG_ARCH_RV64
   sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0, 0, 0, 0,
             0);
@@ -108,7 +90,6 @@ void riscv_sbi_set_timer(uint64_t stime_value)
   sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value,
             stime_value >> 32, 0, 0, 0, 0);
 #endif
-#endif
 }
 
 /****************************************************************************
@@ -125,9 +106,9 @@ void riscv_sbi_set_timer(uint64_t stime_value)
 uint64_t riscv_sbi_get_time(void)
 {
 #ifdef CONFIG_NUTTSBI
-  return sbi_mcall_get_time();
+  return sbi_ecall(SBI_EXT_FIRMWARE, SBI_EXT_FIRMWARE_GET_MTIME, 0, 0,
-#else
+                   0, 0, 0, 0);
-#ifdef CONFIG_ARCH_RV64
+#elif defined(CONFIG_ARCH_RV64)
   return READ_CSR(CSR_TIME);
 #else
   uint32_t hi;
@@ -142,7 +123,6 @@ uint64_t riscv_sbi_get_time(void)
 
   return (((uint64_t) hi) << 32) | lo;
 #endif
-#endif
 }
 
 #ifndef CONFIG_NUTTSBI

arch/risc-v/src/nuttsbi/sbi_mcall.c

@@ -51,9 +51,25 @@ void sbi_mcall_handle(uintptr_t *regs)
 {
   /* Check the environment call number */
 
-  switch (regs[REG_A0])
+  switch (regs[REG_A7])
   {
-    case MCALL_GET_TIMER:
+    case SBI_EXT_TIME:
+      switch (regs[REG_A6])
+      {
+        case SBI_EXT_TIME_SET_TIMER:
+#ifdef CONFIG_ARCH_RV64
+          sbi_set_mtimecmp(regs[REG_A0]);
+#else
+          sbi_set_mtimecmp(regs[REG_A0] + ((uint64_t)regs[REG_A1] << 32));
+#endif
+          CLEAR_CSR(CSR_MIP, MIP_STIP);
+          SET_CSR(CSR_MIE, MIE_MTIE);
+          break;
+        default:
+          break;
+      }
+      break;
+    case SBI_EXT_FIRMWARE:
 #ifdef CONFIG_ARCH_RV64
       regs[REG_A0]    = sbi_get_mtime();
 #else
@@ -65,16 +81,6 @@ void sbi_mcall_handle(uintptr_t *regs)
 #endif
       break;
 
-    case MCALL_SET_TIMER:
-#ifdef CONFIG_ARCH_RV64
-      sbi_set_mtimecmp(regs[REG_A1]);
-#else
-      sbi_set_mtimecmp(regs[REG_A1] + ((uint64_t)regs[REG_A2] << 32));
-#endif
-      CLEAR_CSR(CSR_MIP, MIP_STIP);
-      SET_CSR(CSR_MIE, MIE_MTIE);
-      break;
-
     default:
       break;
   }

arch/risc-v/src/nuttsbi/sbi_mcall.h

@@ -30,105 +30,10 @@
 #include <stdint.h>
 
 /****************************************************************************
- * Public Types
+ * Pre-processor Definitions
  ****************************************************************************/
 
-enum mcall_num_e
+#define SBI_EXT_FIRMWARE              0x0A000000
-{
+#define SBI_EXT_FIRMWARE_GET_MTIME    0x0
-  MCALL_INVALID,
-  MCALL_GET_TIMER,
-  MCALL_SET_TIMER,
-  MCALL_LAST
-};
-
-/****************************************************************************
- * Public Function Prototypes
- ****************************************************************************/
-
-/****************************************************************************
- * Name: mcall0
- *
- * Description:
- *   Generate an environment call to machine mode
- *
- * Input Parameters:
- *   nbr - Environment call number
- *
- ****************************************************************************/
-
-static inline uintptr_t mcall0(unsigned int nbr)
-{
-  register long r0 asm("a0") = (long)(nbr);
-
-  asm volatile
-    (
-     "ecall"
-     :: "r"(r0)
-     : "memory"
-     );
-
-  asm volatile("nop" : "=r"(r0));
-
-  return r0;
-}
-
-/****************************************************************************
- * Name: mcall1
- *
- * Description:
- *   Generate an environment call to machine mode
- *
- * Input Parameters:
- *   nbr - Environment call number
- *   parm1 - Argument for ecall
- *
- ****************************************************************************/
-
-static inline uintptr_t mcall1(unsigned int nbr, uintptr_t parm1)
-{
-  register long r0 asm("a0") = (long)(nbr);
-  register long r1 asm("a1") = (long)(parm1);
-
-  asm volatile
-    (
-     "ecall"
-     :: "r"(r0), "r"(r1)
-     : "memory"
-     );
-
-  asm volatile("nop" : "=r"(r0));
-
-  return r0;
-}
-
-/****************************************************************************
- * Name: sbi_mcall_get_time
- *
- * Description:
- *   Read the current system time (mtime)
- *
- * Returned Value:
- *   time - Value of mtime
- *
- ****************************************************************************/
-
-#define sbi_mcall_get_time() \
-  mcall0(MCALL_GET_TIMER)
-
-/****************************************************************************
- * Name: sbi_mcall_set_timer
- *
- * Description:
- *   Set new compare match value for timer. Time is in absolute time, so
- *   user must either obtain system time and calculate the offset, or keep
- *   the old compare match value in memory
- *
- * Input Parameters:
- *   stime_value - Absolute time for next compare match event
- *
- ****************************************************************************/
-
-#define sbi_mcall_set_timer(stime_value) \
-  (void)mcall1(MCALL_SET_TIMER, stime_value)
 
 #endif /* __ARCH_RISC_V_SRC_NUTTSBI_SBI_MCALL_H */