Changeset 1084a784 in mainline for arch/mips32/src/mm/asid.c

Timestamp:

2005-10-04T22:09:41Z (20 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

342de62

Parents:

8e3f47b3

Message:

mips32 memory management work.
TLB Refill Exception implemented (passed basic testing).
Remove bit g from struct entry_hi.
Add generic find_mapping().
Add asid to vm_t type, define asid_t to hide architecture specific differences.
Implement ASID allocation for mips32, dummy for other architectures.
Add THE→vm (a.k.a. VM).
Add vm_install_arch().
Move pte_t definition to arch/types.h on each architecture.
Fix PTL manipulating functions on mips32 to shift pfn by 12 instead of by 14.
Fix tlb_init_arch() to initialize all entries.

Other.
Remove unnecessary header files from arch.h
Add missing headers here and there.
Remove two unnecessary ld flags from mips32 makefile.

File:

• arch/mips32/src/mm/asid.c (modified) (1 diff)

arch/mips32/src/mm/asid.c

@@ -27 +27 @@
  */
 
+#include <arch/mm/asid.h>
+#include <synch/spinlock.h>
 #include <arch.h>
-#include <memstr.h>
+#include <debug.h>
 
-/**< Array of threads that have currently some ASID assigned,
-     NULL means no thread have ASID with number of that index assigned */
-struct thread * asids[256];
-int last_asid; /**< The number of last assigned ASID */
-int asid_bitmap[32]; /**< Bitmap of ASIDs currently in TLB */
+#define ASIDS   256
 
+static spinlock_t asid_usage_lock;
+static count_t asid_usage[ASIDS];       /**< Usage tracking array for ASIDs */
 
-/** Cleanup asid_bitmap
+/** Get ASID
  *
+ * Get the least used ASID.
+ *
+ * @return ASID
  */
-void asid_bitmap_reset(void)
+asid_t asid_get(void)
 {
-        memsetb(asid_bitmap, sizeof(asid_bitmap), 0);
+        pri_t pri;
+        int i, j;
+        count_t min;
+        
+        min = (unsigned) -1;
+        
+        pri = cpu_priority_high();
+        spinlock_lock(&asid_usage_lock);
+        
+        for (i=0, j = 0; (i<ASIDS); i++) {
+                if (asid_usage[i] < min) {
+                        j = i;
+                        min = asid_usage[i];
+                        if (!min)
+                                break;
+                }
+        }
+
+        asid_usage[i]++;
+
+        spinlock_unlock(&asid_usage_lock);
+        cpu_priority_restore(pri);
+
+        return i;
 }
 
+/** Release ASID
+ *
+ * Release ASID by decrementing its usage count.
+ *
+ * @param asid ASID.
+ */
+void asid_put(asid_t asid)
+{
+        pri_t pri;
 
-/** Initialize manipulating with ASIDs
- *
- */
-void init_asids(void)
-{
-        memsetb(asids, sizeof(asids), 0);
-        asid_bitmap_reset();
-        last_asid = 0;
+        pri = cpu_priority_high();
+        spinlock_lock(&asid_usage_lock);
+
+        ASSERT(asid_usage[asid] > 0);
+        asid_usage[asid]--;
+
+        spinlock_unlock(&asid_usage_lock);
+        cpu_priority_restore(pri);
 }