Changeset 345 for soft/giet_vm/giet_kernel

Timestamp:

Jun 25, 2014, 2:19:37 PM (10 years ago)

Author:

cfuguet

Message:

giet_vm optimizations:

• Several modifications in GIET_VM in order to support compilation with GCC optimizations (-O2) activated.

• Adding missing volatile in some global variables.

• Using ioread and iowrite utility functions in peripheral drivers which prevent GCC to remove writes or reads in hardware memory mapped registers.

• Code refactoring of stdio printf functions. Now, shr_printf and tty_printf function reuse the same function body. The only difference is that shr_printf wraps printf function call with TTY get lock and release lock.

File:

• soft/giet_vm/giet_kernel/kernel_init.c (modified) (6 diffs)

soft/giet_vm/giet_kernel/kernel_init.c

@@ -116 +116 @@
 
 __attribute__((section (".kdata"))) 
-unsigned int _ptabs_vaddr[GIET_NB_VSPACE_MAX];    // virtual addresses
+volatile unsigned int _ptabs_vaddr[GIET_NB_VSPACE_MAX];    // virtual addresses
 
 __attribute__((section (".kdata")))        
-unsigned int _ptabs_ptprs[GIET_NB_VSPACE_MAX];    // physical addresses >> 13
+volatile unsigned int _ptabs_ptprs[GIET_NB_VSPACE_MAX];    // physical addresses >> 13
 
 ///////////////////////////////////////////////////////////////////////////////////
@@ -126 +126 @@
 
 __attribute__((section (".kdata"))) 
-static_scheduler_t* _schedulers[NB_PROCS_MAX<<(X_WIDTH+Y_WIDTH)]; // virtual addresses
+volatile static_scheduler_t* _schedulers[NB_PROCS_MAX<<(X_WIDTH+Y_WIDTH)]; // virtual addresses
 
 ////////////////////////////////////////////////////////////////////////////////////
@@ -133 +133 @@
 
 __attribute__((section (".kdata"))) 
-unsigned int _idle_stack[X_SIZE * Y_SIZE * NB_PROCS_MAX * 128 ]; 
+volatile unsigned int _idle_stack[X_SIZE * Y_SIZE * NB_PROCS_MAX * 128 ]; 
 
 ////////////////////////////////////////////////////////////////////////////////////
@@ -140 +140 @@
 
 __attribute__((section (".kdata"))) 
-unsigned int _init_barrier = 0;
+volatile unsigned int _init_barrier = 0;
 
 ///////////////////////////////////////////////////////////////////////////////////
@@ -340 +340 @@
 
     // busy waiting until all processors synchronized
-    while ( _init_barrier != NB_TOTAL_PROCS ) asm volatile ("nop");
+    while ( _init_barrier != NB_TOTAL_PROCS );
 
     // set registers and jump to user code
@@ -351 +351 @@
                    : 
                    : "r"(sp_value), "r"(sr_value), "r"(ptpr_value), "r"(epc_value)
-                   : "$29" );
+                   : "$29", "memory" );
 
 } // end kernel_init()