arch/riscv: Remove CONFIG_ARCH_RV_HARTID_BASE offset from riscv_mhartid

The function is supposed to return the physical hart ID. It is needed
for e.g. external interrupt acknowledgment (see mpfs_plic.c).

This offset is moved initially to up_cpu_index (which is also wrong, but
less wrong than the current implementation). Finally, a translation
between physical <-> logical shall be provided.

Author: pussuw

arch/risc-v/src/common/riscv_cpuindex.c

@@ -45,5 +45,5 @@
 
 int up_cpu_index(void)
 {
-  return (int)riscv_mhartid();
+  return (int)riscv_mhartid() - CONFIG_ARCH_RV_HARTID_BASE;
 }

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

@@ -418,7 +418,7 @@ int riscv_smp_call_handler(int irq, void *c, void *arg);
  * Name: riscv_mhartid
  *
  * Description:
- *   Context aware way to query hart id
+ *   Context aware way to query hart id (physical core ID)
  *
  * Returned Value:
  *   Hart id

arch/risc-v/src/common/riscv_macros.S

@@ -349,7 +349,7 @@
  * Name: riscv_mhartid
  *
  * Description:
- *   Context aware way to query hart id
+ *   Context aware way to query hart id (physical core ID)
  *
  * Returned Value:
  *   Hart id
@@ -362,9 +362,6 @@
   REGLOAD \out, RISCV_PERCPU_HARTID(\out)
 #else
   csrr    \out, CSR_MHARTID
-#  if CONFIG_ARCH_RV_HARTID_BASE > 0
-  add    \out, \out, - CONFIG_ARCH_RV_HARTID_BASE
-#  endif
 #endif
 .endm
 

arch/risc-v/src/common/riscv_mhartid.S

@@ -38,7 +38,7 @@
  * Name: riscv_mhartid
  *
  * Description:
- *   Context aware way to query hart id
+ *   Context aware way to query hart id (physical core ID)
  *
  * Returned Value:
  *   Hart id