Changeset 3fa509b in mainline

Timestamp:

2013-01-19T23:59:25Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

9eec7bc

Parents:

4b28c70

Message:

arm32, armv7: Add reading of performance cycles counter.

Fix comment about WFE.

Location:

kernel/arch/arm32

Files:

• include/asm.h (modified) (1 diff)
• include/cp15.h (modified) (1 diff)
• include/cycle.h (modified) (2 diffs)
• src/cpu/cpu.c (modified) (1 diff)

kernel/arch/arm32/include/asm.h

@@ -43 +43 @@
 #include <trace.h>
 
-/** No such instruction on old ARM to sleep CPU.
+/** CPU specific way to sleep cpu.
  *
  * ARMv7 introduced wait for event and wait for interrupt (wfe/wfi).

kernel/arch/arm32/include/cp15.h

@@ -416 +416 @@
 CONTROL_REG_GEN_WRITE(TLBIALLNSNHS, c8, 4, c7, 4);
 
-/* c9 are reserved */
+/* c9 are performance monitoring resgisters */
+enum {
+        PMCR_IMP_MASK = 0xff,
+        PMCR_IMP_SHIFT = 24,
+        PMCR_IDCODE_MASK = 0xff,
+        PMCR_IDCODE_SHIFT = 16,
+        PMCR_EVENT_NUM_MASK = 0x1f,
+        PMCR_EVENT_NUM_SHIFT = 11,
+        PMCR_DP_FLAG = 1 << 5,
+        PMCR_X_FLAG = 1 << 4,
+        PMCR_D_FLAG = 1 << 3,
+        PMCR_C_FLAG = 1 << 2,
+        PMCR_P_FLAG = 1 << 1,
+        PMCR_E_FLAG = 1 << 0,
+};
+CONTROL_REG_GEN_READ(PMCR, c9, 0, c12, 0);
+CONTROL_REG_GEN_WRITE(PMCR, c9, 0, c12, 0);
+enum {
+        PMCNTENSET_CYCLE_COUNTER_EN_FLAG = 1 << 31,
+#define PMCNTENSET_COUNTER_EN_FLAG(c)   (1 << c)
+};
+CONTROL_REG_GEN_READ(PMCNTENSET, c9, 0, c12, 1);
+CONTROL_REG_GEN_WRITE(PMCNTENSET, c9, 0, c12, 1);
+CONTROL_REG_GEN_READ(PMCCNTR, c9, 0, c13, 0);
+CONTROL_REG_GEN_WRITE(PMCCNTR, c9, 0, c13, 0);
+
 
 /*c10 has tons of reserved too */

kernel/arch/arm32/include/cycle.h

@@ -38 +38 @@
 
 #include <trace.h>
+#include <arch/cp15.h>
 
 /** Return count of CPU cycles.
@@ -48 +49 @@
 NO_TRACE static inline uint64_t get_cycle(void)
 {
+#ifdef PROCESSOR_ARCH_armv7_a
+        if ((ID_PFR1_read() & ID_PFR1_GEN_TIMER_EXT_MASK) ==
+            ID_PFR1_GEN_TIMER_EXT) {
+            uint32_t low = 0, high = 0;
+            asm volatile( "MRRC p15, 0, %[low], %[high], c14": [low]"=r"(low), [high]"=r"(high));
+           return ((uint64_t)high << 32) | low;
+        } else {
+                return PMCCNTR_read();
+        }
+#endif
         return 0;
 }

kernel/arch/arm32/src/cpu/cpu.c

@@ -168 +168 @@
         fpu_setup();
 #endif
+
+#ifdef PROCESSOR_ARCH_armv7_a
+        PMCR_write(PMCR_read() | PMCR_E_FLAG);
+        PMCNTENSET_write(PMCNTENSET_CYCLE_COUNTER_EN_FLAG);
+#endif
 }