[PATCH v2 2/2] xen: rename wrong named pfn related variables

[Juergen Gross]

There are some variables in Xen specific coding which names imply them
holding a PFN, while in reality they are containing numbers of PFNs.

Rename them accordingly.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V2:
- adjust comment (Jan Beulich)
---
 arch/x86/include/asm/xen/page.h |  4 ++--
 arch/x86/xen/p2m.c              | 33 ++++++++++++++++++---------------
 arch/x86/xen/setup.c            |  2 +-
 3 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 1a162e559753..3590d6bf42c7 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -51,7 +51,7 @@ extern unsigned long *machine_to_phys_mapping;
 extern unsigned long  machine_to_phys_nr;
 extern unsigned long *xen_p2m_addr;
 extern unsigned long  xen_p2m_size;
-extern unsigned long  xen_max_p2m_pfn;
+extern unsigned long  xen_p2m_max_size;
 
 extern int xen_alloc_p2m_entry(unsigned long pfn);
 
@@ -144,7 +144,7 @@ static inline unsigned long __pfn_to_mfn(unsigned long pfn)
 
 	if (pfn < xen_p2m_size)
 		mfn = xen_p2m_addr[pfn];
-	else if (unlikely(pfn < xen_max_p2m_pfn))
+	else if (unlikely(pfn < xen_p2m_max_size))
 		return get_phys_to_machine(pfn);
 	else
 		return IDENTITY_FRAME(pfn);
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 5e6e236977c7..d75d9e077d13 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -95,8 +95,8 @@ unsigned long *xen_p2m_addr __read_mostly;
 EXPORT_SYMBOL_GPL(xen_p2m_addr);
 unsigned long xen_p2m_size __read_mostly;
 EXPORT_SYMBOL_GPL(xen_p2m_size);
-unsigned long xen_max_p2m_pfn __read_mostly;
-EXPORT_SYMBOL_GPL(xen_max_p2m_pfn);
+unsigned long xen_p2m_max_size __read_mostly;
+EXPORT_SYMBOL_GPL(xen_p2m_max_size);
 
 #ifdef CONFIG_XEN_MEMORY_HOTPLUG_LIMIT
 #define P2M_LIMIT CONFIG_XEN_MEMORY_HOTPLUG_LIMIT
@@ -120,8 +120,10 @@ static pte_t *p2m_identity_pte;
  * Used to set HYPERVISOR_shared_info->arch.max_pfn so the toolstack
  * can avoid scanning the whole P2M (which may be sized to account for
  * hotplugged memory).
+ *
+ * All populated P2M entries have an index lower than xen_p2m_pfn_limit.
  */
-static unsigned long xen_p2m_last_pfn;
+static unsigned long xen_p2m_pfn_limit;
 
 static inline unsigned p2m_top_index(unsigned long pfn)
 {
@@ -239,7 +241,7 @@ void __ref xen_build_mfn_list_list(void)
 		p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
 	}
 
-	for (pfn = 0; pfn < xen_max_p2m_pfn && pfn < MAX_P2M_PFN;
+	for (pfn = 0; pfn < xen_p2m_max_size && pfn < MAX_P2M_PFN;
 	     pfn += P2M_PER_PAGE) {
 		topidx = p2m_top_index(pfn);
 		mididx = p2m_mid_index(pfn);
@@ -284,7 +286,7 @@ void xen_setup_mfn_list_list(void)
 	else
 		HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
 			virt_to_mfn(p2m_top_mfn);
-	HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn;
+	HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_pfn_limit;
 	HYPERVISOR_shared_info->arch.p2m_generation = 0;
 	HYPERVISOR_shared_info->arch.p2m_vaddr = (unsigned long)xen_p2m_addr;
 	HYPERVISOR_shared_info->arch.p2m_cr3 =
@@ -302,7 +304,7 @@ void __init xen_build_dynamic_phys_to_machine(void)
 	for (pfn = xen_start_info->nr_pages; pfn < xen_p2m_size; pfn++)
 		xen_p2m_addr[pfn] = INVALID_P2M_ENTRY;
 
-	xen_max_p2m_pfn = xen_p2m_size;
+	xen_p2m_max_size = xen_p2m_size;
 }
 
 #define P2M_TYPE_IDENTITY	0
@@ -353,7 +355,7 @@ static void __init xen_rebuild_p2m_list(unsigned long *p2m)
 			pfn_pte(PFN_DOWN(__pa(p2m_identity)), PAGE_KERNEL_RO));
 	}
 
-	for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += chunk) {
+	for (pfn = 0; pfn < xen_p2m_max_size; pfn += chunk) {
 		/*
 		 * Try to map missing/identity PMDs or p2m-pages if possible.
 		 * We have to respect the structure of the mfn_list_list
@@ -413,21 +415,22 @@ void __init xen_vmalloc_p2m_tree(void)
 	static struct vm_struct vm;
 	unsigned long p2m_limit;
 
-	xen_p2m_last_pfn = xen_max_p2m_pfn;
+	xen_p2m_pfn_limit = xen_p2m_max_size;
 
 	p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE;
 	vm.flags = VM_ALLOC;
-	vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit),
+	vm.size = ALIGN(sizeof(unsigned long) *
+			max(xen_p2m_max_size, p2m_limit),
 			PMD_SIZE * PMDS_PER_MID_PAGE);
 	vm_area_register_early(&vm, PMD_SIZE * PMDS_PER_MID_PAGE);
 	pr_notice("p2m virtual area at %p, size is %lx\n", vm.addr, vm.size);
 
-	xen_max_p2m_pfn = vm.size / sizeof(unsigned long);
+	xen_p2m_max_size = vm.size / sizeof(unsigned long);
 
 	xen_rebuild_p2m_list(vm.addr);
 
 	xen_p2m_addr = vm.addr;
-	xen_p2m_size = xen_max_p2m_pfn;
+	xen_p2m_size = xen_p2m_max_size;
 
 	xen_inv_extra_mem();
 }
@@ -438,7 +441,7 @@ unsigned long get_phys_to_machine(unsigned long pfn)
 	unsigned int level;
 
 	if (unlikely(pfn >= xen_p2m_size)) {
-		if (pfn < xen_max_p2m_pfn)
+		if (pfn < xen_p2m_max_size)
 			return xen_chk_extra_mem(pfn);
 
 		return IDENTITY_FRAME(pfn);
@@ -618,9 +621,9 @@ int xen_alloc_p2m_entry(unsigned long pfn)
 	}
 
 	/* Expanded the p2m? */
-	if (pfn >= xen_p2m_last_pfn) {
-		xen_p2m_last_pfn = ALIGN(pfn + 1, P2M_PER_PAGE);
-		HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn;
+	if (pfn >= xen_p2m_pfn_limit) {
+		xen_p2m_pfn_limit = ALIGN(pfn + 1, P2M_PER_PAGE);
+		HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_pfn_limit;
 	}
 
 	return 0;
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 8bfc10330107..1caddd3fa0e1 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -816,7 +816,7 @@ char * __init xen_memory_setup(void)
 				n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
 				extra_pages -= n_pfns;
 				xen_add_extra_mem(pfn_s, n_pfns);
-				xen_max_p2m_pfn = pfn_s + n_pfns;
+				xen_p2m_max_size = pfn_s + n_pfns;
 			} else
 				discard = true;
 		}
-- 
2.26.2