Merge commit 'v2.6.31-rc7' into x86/cleanups

Merge reason: we were on -rc1 before - go up to -rc7

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 80 insertions, 39 deletions

diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index a6974e9b8eb..1e2cb846b3c 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -1,6 +1,8 @@
-/*P:400 This contains run_guest() which actually calls into the Host<->Guest
+/*P:400
+ * This contains run_guest() which actually calls into the Host<->Guest
  * Switcher and analyzes the return, such as determining if the Guest wants the
- * Host to do something.  This file also contains useful helper routines. :*/
+ * Host to do something.  This file also contains useful helper routines.
+:*/
 #include <linux/module.h>
 #include <linux/stringify.h>
 #include <linux/stddef.h>
@@ -24,7 +26,8 @@ static struct page **switcher_page;
 /* This One Big lock protects all inter-guest data structures. */
 DEFINE_MUTEX(lguest_lock);
 
-/*H:010 We need to set up the Switcher at a high virtual address.  Remember the
+/*H:010
+ * We need to set up the Switcher at a high virtual address.  Remember the
  * Switcher is a few hundred bytes of assembler code which actually changes the
  * CPU to run the Guest, and then changes back to the Host when a trap or
  * interrupt happens.
@@ -33,7 +36,8 @@ DEFINE_MUTEX(lguest_lock);
  * Host since it will be running as the switchover occurs.
  *
  * Trying to map memory at a particular address is an unusual thing to do, so
- * it's not a simple one-liner. */
+ * it's not a simple one-liner.
+ */
 static __init int map_switcher(void)
 {
 	int i, err;
@@ -47,8 +51,10 @@ static __init int map_switcher(void)
 	 * easy.
 	 */
 
-	/* We allocate an array of struct page pointers.  map_vm_area() wants
-	 * this, rather than just an array of pages. */
+	/*
+	 * We allocate an array of struct page pointers.  map_vm_area() wants
+	 * this, rather than just an array of pages.
+	 */
 	switcher_page = kmalloc(sizeof(switcher_page[0])*TOTAL_SWITCHER_PAGES,
 				GFP_KERNEL);
 	if (!switcher_page) {
@@ -56,8 +62,10 @@ static __init int map_switcher(void)
 		goto out;
 	}
 
-	/* Now we actually allocate the pages.  The Guest will see these pages,
-	 * so we make sure they're zeroed. */
+	/*
+	 * Now we actually allocate the pages.  The Guest will see these pages,
+	 * so we make sure they're zeroed.
+	 */
 	for (i = 0; i < TOTAL_SWITCHER_PAGES; i++) {
 		unsigned long addr = get_zeroed_page(GFP_KERNEL);
 		if (!addr) {
@@ -67,19 +75,23 @@ static __init int map_switcher(void)
 		switcher_page[i] = virt_to_page(addr);
 	}
 
-	/* First we check that the Switcher won't overlap the fixmap area at
+	/*
+	 * First we check that the Switcher won't overlap the fixmap area at
 	 * the top of memory.  It's currently nowhere near, but it could have
-	 * very strange effects if it ever happened. */
+	 * very strange effects if it ever happened.
+	 */
 	if (SWITCHER_ADDR + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){
 		err = -ENOMEM;
 		printk("lguest: mapping switcher would thwack fixmap\n");
 		goto free_pages;
 	}
 
-	/* Now we reserve the "virtual memory area" we want: 0xFFC00000
+	/*
+	 * Now we reserve the "virtual memory area" we want: 0xFFC00000
 	 * (SWITCHER_ADDR).  We might not get it in theory, but in practice
 	 * it's worked so far.  The end address needs +1 because __get_vm_area
-	 * allocates an extra guard page, so we need space for that. */
+	 * allocates an extra guard page, so we need space for that.
+	 */
 	switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE,
 				     VM_ALLOC, SWITCHER_ADDR, SWITCHER_ADDR
 				     + (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE);
@@ -89,11 +101,13 @@ static __init int map_switcher(void)
 		goto free_pages;
 	}
 
-	/* This code actually sets up the pages we've allocated to appear at
+	/*
+	 * This code actually sets up the pages we've allocated to appear at
 	 * SWITCHER_ADDR.  map_vm_area() takes the vma we allocated above, the
 	 * kind of pages we're mapping (kernel pages), and a pointer to our
 	 * array of struct pages.  It increments that pointer, but we don't
-	 * care. */
+	 * care.
+	 */
 	pagep = switcher_page;
 	err = map_vm_area(switcher_vma, PAGE_KERNEL_EXEC, &pagep);
 	if (err) {
@@ -101,8 +115,10 @@ static __init int map_switcher(void)
 		goto free_vma;
 	}
 
-	/* Now the Switcher is mapped at the right address, we can't fail!
-	 * Copy in the compiled-in Switcher code (from <arch>_switcher.S). */
+	/*
+	 * Now the Switcher is mapped at the right address, we can't fail!
+	 * Copy in the compiled-in Switcher code (from <arch>_switcher.S).
+	 */
 	memcpy(switcher_vma->addr, start_switcher_text,
 	       end_switcher_text - start_switcher_text);
 
@@ -124,8 +140,7 @@ out:
 }
 /*:*/
 
-/* Cleaning up the mapping when the module is unloaded is almost...
- * too easy. */
+/* Cleaning up the mapping when the module is unloaded is almost... too easy. */
 static void unmap_switcher(void)
 {
 	unsigned int i;
@@ -151,16 +166,19 @@ static void unmap_switcher(void)
  * But we can't trust the Guest: it might be trying to access the Launcher
  * code.  We have to check that the range is below the pfn_limit the Launcher
  * gave us.  We have to make sure that addr + len doesn't give us a false
- * positive by overflowing, too. */
+ * positive by overflowing, too.
+ */
 bool lguest_address_ok(const struct lguest *lg,
 		       unsigned long addr, unsigned long len)
 {
 	return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
 }
 
-/* This routine copies memory from the Guest.  Here we can see how useful the
+/*
+ * This routine copies memory from the Guest.  Here we can see how useful the
  * kill_lguest() routine we met in the Launcher can be: we return a random
- * value (all zeroes) instead of needing to return an error. */
+ * value (all zeroes) instead of needing to return an error.
+ */
 void __lgread(struct lg_cpu *cpu, void *b, unsigned long addr, unsigned bytes)
 {
 	if (!lguest_address_ok(cpu->lg, addr, bytes)
@@ -181,9 +199,11 @@ void __lgwrite(struct lg_cpu *cpu, unsigned long addr, const void *b,
 }
 /*:*/
 
-/*H:030 Let's jump straight to the the main loop which runs the Guest.
+/*H:030
+ * Let's jump straight to the the main loop which runs the Guest.
  * Remember, this is called by the Launcher reading /dev/lguest, and we keep
- * going around and around until something interesting happens. */
+ * going around and around until something interesting happens.
+ */
 int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 {
 	/* We stop running once the Guest is dead. */
@@ -195,10 +215,17 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 		if (cpu->hcall)
 			do_hypercalls(cpu);
 
-		/* It's possible the Guest did a NOTIFY hypercall to the
-		 * Launcher, in which case we return from the read() now. */
+		/*
+		 * It's possible the Guest did a NOTIFY hypercall to the
+		 * Launcher.
+		 */
 		if (cpu->pending_notify) {
+			/*
+			 * Does it just needs to write to a registered
+			 * eventfd (ie. the appropriate virtqueue thread)?
+			 */
 			if (!send_notify_to_eventfd(cpu)) {
+				/* OK, we tell the main Laucher. */
 				if (put_user(cpu->pending_notify, user))
 					return -EFAULT;
 				return sizeof(cpu->pending_notify);
@@ -209,29 +236,39 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 		if (signal_pending(current))
 			return -ERESTARTSYS;
 
-		/* Check if there are any interrupts which can be delivered now:
+		/*
+		 * Check if there are any interrupts which can be delivered now:
 		 * if so, this sets up the hander to be executed when we next
-		 * run the Guest. */
+		 * run the Guest.
+		 */
 		irq = interrupt_pending(cpu, &more);
 		if (irq < LGUEST_IRQS)
 			try_deliver_interrupt(cpu, irq, more);
 
-		/* All long-lived kernel loops need to check with this horrible
+		/*
+		 * All long-lived kernel loops need to check with this horrible
 		 * thing called the freezer.  If the Host is trying to suspend,
-		 * it stops us. */
+		 * it stops us.
+		 */
 		try_to_freeze();
 
-		/* Just make absolutely sure the Guest is still alive.  One of
-		 * those hypercalls could have been fatal, for example. */
+		/*
+		 * Just make absolutely sure the Guest is still alive.  One of
+		 * those hypercalls could have been fatal, for example.
+		 */
 		if (cpu->lg->dead)
 			break;
 
-		/* If the Guest asked to be stopped, we sleep.  The Guest's
-		 * clock timer will wake us. */
+		/*
+		 * If the Guest asked to be stopped, we sleep.  The Guest's
+		 * clock timer will wake us.
+		 */
 		if (cpu->halted) {
 			set_current_state(TASK_INTERRUPTIBLE);
-			/* Just before we sleep, make sure no interrupt snuck in
-			 * which we should be doing. */
+			/*
+			 * Just before we sleep, make sure no interrupt snuck in
+			 * which we should be doing.
+			 */
 			if (interrupt_pending(cpu, &more) < LGUEST_IRQS)
 				set_current_state(TASK_RUNNING);
 			else
@@ -239,8 +276,10 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 			continue;
 		}
 
-		/* OK, now we're ready to jump into the Guest.  First we put up
-		 * the "Do Not Disturb" sign: */
+		/*
+		 * OK, now we're ready to jump into the Guest.  First we put up
+		 * the "Do Not Disturb" sign:
+		 */
 		local_irq_disable();
 
 		/* Actually run the Guest until something happens. */
@@ -327,8 +366,10 @@ static void __exit fini(void)
 }
 /*:*/
 
-/* The Host side of lguest can be a module.  This is a nice way for people to
- * play with it.  */
+/*
+ * The Host side of lguest can be a module.  This is a nice way for people to
+ * play with it.
+ */
 module_init(init);
 module_exit(fini);
 MODULE_LICENSE("GPL");