From de087eb1f800283b2f6c3054c3dccb2f89e017bf Mon Sep 17 00:00:00 2001
From: Bahadir Balban <bbalban@b-labs.co.uk>
Date: Fri, 21 Aug 2009 12:10:34 +0300
Subject: [PATCH] Clean up to kernel code, Added `used' field to capabilities

With the addition of used field, capability structure can be
used for resource accounting over the capability.
---
 include/l4/generic/capability.h |  3 +++
 src/api/capability.c            |  4 ++--
 src/api/space.c                 |  7 -------
 src/generic/resource.c          | 28 ++++++++++++++++++++++++++++
 src/glue/arm/memory.c           | 10 ----------
 tasks/mm0/include/capability.h  |  2 ++
 6 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/include/l4/generic/capability.h b/include/l4/generic/capability.h
index 2cac2da..ed1cf42 100644
--- a/include/l4/generic/capability.h
+++ b/include/l4/generic/capability.h
@@ -59,6 +59,9 @@ struct capability {
 	unsigned long start;	/* Resource start value */
 	unsigned long end;	/* Resource end value */
 	unsigned long size;	/* Resource size */
+
+	/* Used amount on resource */
+	unsigned long used;
 };
 
 struct cap_list {
diff --git a/src/api/capability.c b/src/api/capability.c
index 0ee2b43..4dabe4e 100644
--- a/src/api/capability.c
+++ b/src/api/capability.c
@@ -14,7 +14,7 @@
 #include INC_API(syscall.h)
 
 
-int task_read_capabilities(void *userbuf)
+int read_task_capabilities(void *userbuf)
 {
 	int copy_size, copy_offset = 0;
 	struct capability *cap;
@@ -69,7 +69,7 @@ int sys_capability_control(unsigned int req, unsigned int flags, void *userbuf)
 
 	/* Return all capabilities as an array of capabilities */
 	case CAP_CONTROL_READ_CAPS:
-		err = task_read_capabilities(userbuf);
+		err = read_task_capabilities(userbuf);
 		break;
 
 	default:
diff --git a/src/api/space.c b/src/api/space.c
index b3407cb..786f37e 100644
--- a/src/api/space.c
+++ b/src/api/space.c
@@ -9,13 +9,6 @@
 #include <l4/api/errno.h>
 #include <l4/api/space.h>
 
-/* NOTE:
- * For lazy mm switching, a list of newly created mappings that are common to
- * all tasks (e.g. any mapping done in the kernel) can be kept here so that when
- * a new task is scheduled, the same mappings are copied to its page tables as
- * well. struct link new_mappings;
- */
-
 int sys_map(unsigned long phys, unsigned long virt, unsigned long npages,
 	    unsigned long flags, unsigned int tid)
 {
diff --git a/src/generic/resource.c b/src/generic/resource.c
index d200ea2..068cef2 100644
--- a/src/generic/resource.c
+++ b/src/generic/resource.c
@@ -313,6 +313,7 @@ void init_kernel_container(struct kernel_container *kcont)
 	 */
 }
 
+
 /*
  * Copies cinfo structures to real capabilities for each pager.
  *
@@ -341,6 +342,33 @@ int copy_pager_info(struct pager *pager, struct pager_info *pinfo)
 
 		cap_list_insert(cap, &pager->cap_list);
 	}
+
+	/*
+	 * Find pager's capability capability, check its
+	 * current use count and initialize it
+	 *
+	 * FIXME: We may want to do this capability checking
+	 * in a more generic and straightforward place.
+	 */
+
+	list_foreach_struct(cap, &pager->cap_list.caps, list) {
+		/* Find capability pool capability */
+		if ((cap->type & CAP_RTYPE_MASK) == CAP_RTYPE_CAPPOOL) {
+			/* Verify that we did not excess allocated */
+			if (cap->size < pinfo->ncaps) {
+				printk("FATAL: Pager needs more capabilities "
+				       "than allocated for initialization.\n");
+				BUG();
+			}
+
+			/*
+			 * Initialize used count. The rest of the checking
+			 * of spending on this cap will be done in the
+			 * cap syscall
+			 */
+			cap->used = pinfo->ncaps;
+		}
+	}
 	return 0;
 }
 
diff --git a/src/glue/arm/memory.c b/src/glue/arm/memory.c
index 1cc52c9..2ed9932 100644
--- a/src/glue/arm/memory.c
+++ b/src/glue/arm/memory.c
@@ -44,16 +44,6 @@ void task_init_registers(struct ktcb *task, unsigned long pc)
 	task->context.spsr = ARM_MODE_USR;
 }
 
-#if 0
-/* Sets up struct page array and the physical memory descriptor. */
-void paging_init(void)
-{
-	read_bootdesc();
-	physmem_init();
-	memory_init();
-	copy_bootdesc();
-}
-#endif
 
 /*
  * Copies global kernel entries into another pgd. Even for sub-pmd ranges
diff --git a/tasks/mm0/include/capability.h b/tasks/mm0/include/capability.h
index 3294bc4..6fe1a59 100644
--- a/tasks/mm0/include/capability.h
+++ b/tasks/mm0/include/capability.h
@@ -30,6 +30,8 @@ struct capability {
 	unsigned long start;	/* Resource start value */
 	unsigned long end;	/* Resource end value */
 	unsigned long size;	/* Resource size */
+
+	unsigned long used;	/* Resource used size */
 };