X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/8f6c56a50524aa785f7e596d52dddfb331e18961..89b3af67bb32e691275bf6fa803d1834b2284115:/osfmk/i386/perfmon.c

diff --git a/osfmk/i386/perfmon.c b/osfmk/i386/perfmon.c
index f2cb2b850..109ab1e7a 100644
--- a/osfmk/i386/perfmon.c
+++ b/osfmk/i386/perfmon.c
@@ -36,13 +36,24 @@
 #include <i386/cpuid.h>
 #include <i386/lock.h>
 #include <vm/vm_kern.h>
+#include <kern/task.h>
 
-#ifdef DEBUG
+#if DEBUG
 #define	DBG(x...)	kprintf(x)
 #else
 #define	DBG(x...)
 #endif
 
+decl_simple_lock_data(,pmc_lock)
+static task_t	pmc_owner = TASK_NULL;
+static int	pmc_thread_count = 0;
+
+/* PMC Facility Owner:
+ * TASK_NULL - no one owns it
+ * kernel_task - owned by pmc
+ * other task - owned by another task
+ */
+
 /*
  * Table of ESCRs and addresses associated with performance counters/CCCRs.
  * See Intel SDM Vol 3, Table 15-4 (section 15.9):
@@ -280,24 +291,18 @@ pmc_p6_intr(void *state)
 			(*pmc_table->ovf_func[id])(id, state);
 }
 
-int
-pmc_init(void)
+void *
+pmc_alloc(void)
 {
 	int		ret;
-	cpu_core_t	*my_core;
 	pmc_table_t	*pmc_table;
 	pmc_machine_t	pmc_type;
 
-	my_core = cpu_core();
-	assert(my_core);
-
 	pmc_type = _pmc_machine_type();
 	if (pmc_type == pmc_none) {
-		return KERN_FAILURE;
+		return NULL;
 	}
 	
-	pmc_table = (pmc_table_t *) my_core->pmc;
-	if (pmc_table == NULL) {
 		ret = kmem_alloc(kernel_map,
 			(void *) &pmc_table, sizeof(pmc_table_t));
 		if (ret != KERN_SUCCESS)
@@ -321,18 +326,10 @@ pmc_init(void)
 		default:
 			break;
 		}
-		if (!atomic_cmpxchg((uint32_t *) &my_core->pmc,
-				    0, (uint32_t) pmc_table)) {
-			kmem_free(kernel_map,
-				  (vm_offset_t) pmc_table, sizeof(pmc_table_t));
-		}
-	}
-	DBG("pmc_init() done for cpu %d my_core->pmc=0x%x type=%d\n",
-		cpu_number(), my_core->pmc, pmc_type);
-
-	return KERN_SUCCESS;
+	return (void *) pmc_table;
 }
 
+
 static inline pmc_table_t *
 pmc_table_valid(pmc_id_t id)
 {
@@ -556,3 +553,81 @@ pmc_set_ovf_func(pmc_id_t id, pmc_ovf_func_t func)
 
 	return KERN_SUCCESS;
 }
+
+int
+pmc_acquire(task_t task)
+{
+	kern_return_t retval = KERN_SUCCESS;
+  
+	simple_lock(&pmc_lock);
+  
+	if(pmc_owner == task) {
+		DBG("pmc_acquire - "
+		    "ACQUIRED: already owner\n");
+		retval = KERN_SUCCESS;
+		/* already own it */
+	} else if(pmc_owner == TASK_NULL) { /* no one owns it */
+		pmc_owner = task;
+		pmc_thread_count = 0;
+		DBG("pmc_acquire - "
+		    "ACQUIRED: no current owner - made new owner\n");
+		retval = KERN_SUCCESS;
+	} else { /* someone already owns it */
+		if(pmc_owner == kernel_task) {
+			if(pmc_thread_count == 0) {
+				/* kernel owns it but no threads using it */
+				pmc_owner = task;
+				pmc_thread_count = 0;
+				DBG("pmc_acquire - "
+				    "ACQUIRED: owned by kernel, no threads\n");
+				retval = KERN_SUCCESS;
+			} else {
+				DBG("pmc_acquire - "
+				    "DENIED: owned by kernel, in use\n");
+				retval = KERN_RESOURCE_SHORTAGE;
+			}
+		} else { /* non-kernel owner */
+			DBG("pmc_acquire - "	
+			    "DENIED: owned by another task\n");
+			retval = KERN_RESOURCE_SHORTAGE;
+		}
+	}
+  
+	simple_unlock(&pmc_lock);
+	return retval;
+}
+
+int
+pmc_release(task_t task)
+{
+	kern_return_t retval = KERN_SUCCESS;
+	task_t old_pmc_owner = pmc_owner;
+  
+	simple_lock(&pmc_lock);
+  
+	if(task != pmc_owner) {
+		retval = KERN_NO_ACCESS;
+	} else {
+		if(old_pmc_owner == kernel_task) {
+			if(pmc_thread_count>0) {
+				DBG("pmc_release - "
+				    "NOT RELEASED: owned by kernel, in use\n");
+				retval = KERN_NO_ACCESS;
+			} else {
+				DBG("pmc_release - "
+				    "RELEASED: was owned by kernel\n");
+				pmc_owner = TASK_NULL;
+				retval = KERN_SUCCESS;
+			}
+		} else {
+			DBG("pmc_release - "
+			    "RELEASED: was owned by user\n");
+			pmc_owner = TASK_NULL;
+			retval = KERN_SUCCESS;
+		}
+	}
+
+	simple_unlock(&pmc_lock);
+	return retval;
+}
+