linux-kernel - [PATCH v7u1 10/31] x86, 64bit: Don't set max_pfn

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Date:	Thu,  3 Jan 2013 16:48:30 -0800
From:	Yinghai Lu <yinghai@...nel.org>
To:	Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>,
	"H. Peter Anvin" <hpa@...or.com>
Cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Borislav Petkov <bp@...en8.de>, Jan Kiszka <jan.kiszka@....de>,
	Jason Wessel <jason.wessel@...driver.com>,
	linux-kernel@...r.kernel.org, Yinghai Lu <yinghai@...nel.org>
Subject: [PATCH v7u1 10/31] x86, 64bit: Don't set max_pfn_mapped wrong value early on native path

We are not having max_pfn_mapped set correctly until init_memory_mapping.

so don't print it initial value for 64bit

Also need to use KERNEL_IMAGE_SIZE directly for highmap cleanup.

Signed-off-by: Yinghai Lu <yinghai@...nel.org>
---
 arch/x86/kernel/head64.c |    3 ---
 arch/x86/kernel/setup.c  |    2 ++
 arch/x86/mm/init_64.c    |    6 +++++-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index a3fc233..7061d8b 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -146,9 +146,6 @@ void __init x86_64_start_kernel(char * real_mode_data)
 	/* clear bss before set_intr_gate with early_idt_handler */
 	clear_bss();
 
-	/* XXX - this is wrong... we need to build page tables from scratch */
-	max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT;
-
 	for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
 #ifdef CONFIG_EARLY_PRINTK
 		set_intr_gate(i, &early_idt_handlers[i]);
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 63160c6..04797e78 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -910,8 +910,10 @@ void __init setup_arch(char **cmdline_p)
 	setup_bios_corruption_check();
 #endif
 
+#ifdef CONFIG_X86_32
 	printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
 			(max_pfn_mapped<<PAGE_SHIFT) - 1);
+#endif
 
 	reserve_real_mode();
 
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 9c5f2b1..98385a2 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -394,10 +394,14 @@ void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 void __init cleanup_highmap(void)
 {
 	unsigned long vaddr = __START_KERNEL_map;
-	unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
+	unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 	unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 	pmd_t *pmd = level2_kernel_pgt;
 
+	/* Xen has its own end somehow with abused max_pfn_mapped */
+	if (max_pfn_mapped)
+		vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
+
 	for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 		if (pmd_none(*pmd))
 			continue;
-- 
1.7.10.4

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