[rtems commit] bsp/sparc: Ensure that data cache snooping is enabled

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    77a2226a166400d7e641eb38d126a4a014923ab4
Changeset: http://git.rtems.org/rtems/commit/?id=77a2226a166400d7e641eb38d126a4a014923ab4

Author:    Daniel Cederman <cederman at gaisler.com>
Date:      Wed Sep 10 13:39:53 2014 +0200

bsp/sparc: Ensure that data cache snooping is enabled

Check that data cache snooping exists and is enabled on all cores.

---

 c/src/lib/libbsp/shared/include/fatal.h       |    2 ++
 c/src/lib/libbsp/sparc/leon3/include/leon.h   |    6 ++++++
 c/src/lib/libbsp/sparc/leon3/startup/bspsmp.c |   14 ++++++++++++--
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/c/src/lib/libbsp/shared/include/fatal.h b/c/src/lib/libbsp/shared/include/fatal.h
index 5098c6d..11dd20d 100644
--- a/c/src/lib/libbsp/shared/include/fatal.h
+++ b/c/src/lib/libbsp/shared/include/fatal.h
@@ -52,6 +52,8 @@ typedef enum {
   LEON3_FATAL_NO_IRQMP_CONTROLLER = BSP_FATAL_CODE_BLOCK(2),
   LEON3_FATAL_CONSOLE_REGISTER_DEV,
   LEON3_FATAL_CLOCK_INITIALIZATION,
+  LEON3_FATAL_INVALID_CACHE_CONFIG_MAIN_PROCESSOR,
+  LEON3_FATAL_INVALID_CACHE_CONFIG_SECONDARY_PROCESSOR,
 
   /* LPC24XX fatal codes */
   LPC24XX_FATAL_PL111_SET_UP = BSP_FATAL_CODE_BLOCK(3),
diff --git a/c/src/lib/libbsp/sparc/leon3/include/leon.h b/c/src/lib/libbsp/sparc/leon3/include/leon.h
index a2fb302..92c36b7 100644
--- a/c/src/lib/libbsp/sparc/leon3/include/leon.h
+++ b/c/src/lib/libbsp/sparc/leon3/include/leon.h
@@ -90,6 +90,7 @@ extern "C" {
  *  The following defines the bits in the LEON Cache Control Register.
  */
 #define LEON3_REG_CACHE_CTRL_FI      0x00200000 /* Flush instruction cache */
+#define LEON3_REG_CACHE_CTRL_DS      0x00800000 /* Data cache snooping */
 
 /* LEON3 Interrupt Controller */
 extern volatile struct irqmp_regs *LEON3_IrqCtrl_Regs;
@@ -359,6 +360,11 @@ static inline uint32_t leon3_get_cache_control_register(void)
   return leon3_get_system_register(0x0);
 }
 
+static inline bool leon3_data_cache_snooping_enabled(void)
+{
+  return leon3_get_cache_control_register() & LEON3_REG_CACHE_CTRL_DS;
+}
+
 static inline uint32_t leon3_get_inst_cache_config_register(void)
 {
   return leon3_get_system_register(0x8);
diff --git a/c/src/lib/libbsp/sparc/leon3/startup/bspsmp.c b/c/src/lib/libbsp/sparc/leon3/startup/bspsmp.c
index 45ac92b..42bc15d 100644
--- a/c/src/lib/libbsp/sparc/leon3/startup/bspsmp.c
+++ b/c/src/lib/libbsp/sparc/leon3/startup/bspsmp.c
@@ -15,6 +15,7 @@
 
 #include <bsp.h>
 #include <bsp/bootcard.h>
+#include <bsp/fatal.h>
 #include <cache_.h>
 #include <leon.h>
 #include <rtems/bspIo.h>
@@ -44,7 +45,15 @@ void bsp_start_on_secondary_processor()
 {
   uint32_t cpu_index_self = _CPU_SMP_Get_current_processor();
 
-  leon3_set_cache_control_register(0x80000F);
+  /*
+   * If data cache snooping is not enabled we terminate using BSP_fatal_exit()
+   * instead of bsp_fatal().  This is done since the latter function tries to
+   * acquire a ticket lock, an operation which requires data cache snooping to
+   * be enabled.
+   */
+  if ( !leon3_data_cache_snooping_enabled() )
+    BSP_fatal_exit( LEON3_FATAL_INVALID_CACHE_CONFIG_SECONDARY_PROCESSOR );
+
   /* Unmask IPI interrupts at Interrupt controller for this CPU */
   LEON3_IrqCtrl_Regs->mask[cpu_index_self] |= 1U << LEON3_mp_irq;
 
@@ -53,7 +62,8 @@ void bsp_start_on_secondary_processor()
 
 uint32_t _CPU_SMP_Initialize( void )
 {
-  leon3_set_cache_control_register(0x80000F);
+  if ( !leon3_data_cache_snooping_enabled() )
+    bsp_fatal( LEON3_FATAL_INVALID_CACHE_CONFIG_MAIN_PROCESSOR );
 
   if ( rtems_configuration_get_maximum_processors() > 1 ) {
     LEON_Unmask_interrupt(LEON3_mp_irq);