Changeset 208b5f5 in mainline for kernel/arch/sparc32/include/arch/atomic.h

Timestamp:

2013-12-29T14:32:55Z (10 years ago)

Author:

Martin Decky <martin@…>

Branches:

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

Children:

4c14b88, 6fa9a99d, 9be30cdf, aacdb8e

Parents:

2a13328

Message:

cherrypick important fixes and updates from lp:~jceel/helenos/leon3

File:

• kernel/arch/sparc32/include/arch/atomic.h (modified) (7 diffs)

kernel/arch/sparc32/include/arch/atomic.h

@@ -37 +37 @@
 
 #include <typedefs.h>
+#include <arch/asm.h>
 #include <arch/barrier.h>
 #include <preemption.h>
@@ -47 +48 @@
     REQUIRES(val->count < ATOMIC_COUNT_MAX)
 {
-        // FIXME TODO
+        // FIXME: Isn't there any intrinsic atomic operation?
+        ipl_t ipl = interrupts_disable();
         val->count++;
+        interrupts_restore(ipl);
 }
 
@@ -56 +59 @@
     REQUIRES(val->count > ATOMIC_COUNT_MIN)
 {
-        // FIXME TODO
+        // FIXME: Isn't there any intrinsic atomic operation?
+        ipl_t ipl = interrupts_disable();
         val->count--;
+        interrupts_restore(ipl);
 }
 
@@ -65 +70 @@
     REQUIRES(val->count < ATOMIC_COUNT_MAX)
 {
-        // FIXME TODO
+        // FIXME: Isn't there any intrinsic atomic operation?
         
+        ipl_t ipl = interrupts_disable();
         atomic_count_t prev = val->count;
         
         val->count++;
+        interrupts_restore(ipl);
         return prev;
 }
@@ -78 +85 @@
     REQUIRES(val->count > ATOMIC_COUNT_MIN)
 {
-        // FIXME TODO
+        // FIXME: Isn't there any intrinsic atomic operation?
         
+        ipl_t ipl = interrupts_disable();
         atomic_count_t prev = val->count;
         
         val->count--;
+        interrupts_restore(ipl);
         return prev;
 }
@@ -93 +102 @@
     REQUIRES_EXTENT_MUTABLE(val)
 {
-        // FIXME TODO
+        atomic_count_t prev;
+        volatile uintptr_t ptr = (uintptr_t) &val->count;
         
-        atomic_count_t prev = val->count;
-        val->count = 1;
+        asm volatile (
+                "ldstub [%[ptr]] %[prev]\n"
+                : [prev] "=r" (prev)
+                : [ptr] "r" (ptr)
+                : "memory"
+        );
+        
         return prev;
 }
@@ -104 +119 @@
     REQUIRES_EXTENT_MUTABLE(val)
 {
-        // FIXME TODO
+        atomic_count_t tmp1 = 0;
         
-        do {
-                while (val->count);
-        } while (test_and_set(val));
+        volatile uintptr_t ptr = (uintptr_t) &val->count;
+        
+        preemption_disable();
+        
+        asm volatile (
+                "0:\n"
+                        "ldstub %0, %1\n"
+                        "tst %1\n"
+                        "be 2f\n"
+                        "nop\n"
+                "1:\n"
+                        "ldub %0, %1\n"
+                        "tst %1\n"
+                        "bne 1b\n"
+                        "nop\n"
+                        "ba,a 0b\n"
+                "2:\n"
+                : "+m" (*((atomic_count_t *) ptr)),
+                  "+r" (tmp1)
+                : "r" (0)
+        );
+        
+        /*
+         * Prevent critical section code from bleeding out this way up.
+         */
+        CS_ENTER_BARRIER();
 }