CPA: Add reference count debugging code

Signed-off-by: Andi Kleen <ak@suse.de>

---
 arch/x86/mm/pageattr_64.c |   41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

Index: linux/arch/x86/mm/pageattr_64.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr_64.c
+++ linux/arch/x86/mm/pageattr_64.c
@@ -8,6 +8,7 @@
 #include <linux/highmem.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/kallsyms.h>
 #include <asm/uaccess.h>
 #include <asm/processor.h>
 #include <asm/tlbflush.h>
@@ -345,6 +346,34 @@ __change_page_attr(unsigned long address
 	return 0;
 } 
 
+void print_level(char *what, void *pg)
+{
+	struct page *p = virt_to_page(pg);
+	printk("%s %c%c %lu ", what,
+		PageReserved(p) ? 'R' : '.',
+		PagePrivate(p) ? 'P' : '.',
+		page_private(p));
+}
+
+void print_addr(unsigned long address)
+{
+	pmd_t *pmd;
+	pud_t *pud;
+
+	printk("TREE %lx: ", address);
+	pud = pud_offset(pgd_offset_k(address), address);
+	print_level("pud", pud);
+
+	if (!pud_large(*pud)) {
+		pmd = pmd_offset(pud, address);
+		print_level("pmd", pmd);
+
+		if (!pmd_large(*pmd))
+			print_level("pte", pte_offset_kernel(pmd, address));
+	}
+	printk("\n");
+}
+
 /**
  * change_page_attr_addr - Change page table attributes in linear mapping
  * @address: Virtual address in linear mapping.
@@ -369,6 +398,13 @@ int change_page_attr_addr(unsigned long 
 		kernel_map = 1;
 	}
 
+	printk("cpa %lx-%lx %u pages to %lx from ", address,
+			address+(numpages*PAGE_SIZE), numpages,
+			pgprot_val(prot));
+	print_symbol("%s\n", __builtin_return_address(0));
+	for (i = 0; i < (numpages * PAGE_SIZE); i += PMD_PAGE_SIZE)
+		print_addr(address + i);
+
 	down_write(&init_mm.mmap_sem);
 	for (i = 0; i < numpages; i++, address += PAGE_SIZE) {
 		unsigned long pfn = __pa(address) >> PAGE_SHIFT;
@@ -391,6 +427,11 @@ int change_page_attr_addr(unsigned long 
 		} 
 	} 	
 	up_write(&init_mm.mmap_sem); 
+
+	printk("after\n");
+	for (i = 0; i < (numpages * PAGE_SIZE); i += PMD_PAGE_SIZE)
+		print_addr(address + i);
+
 	return err;
 }