x86: max_low_pfn_mapped fix, #2

tighten the boundary checks around max_low_pfn_mapped - dont overmap
nor undermap into holes.

also print out tseg for AMD cpus, for diagnostic purposes.
(this is an SMM area, and we split up any big mappings around that area)

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/amd_64.c

@@ -200,6 +200,7 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 		 * benefit in doing so.
 		 */
 		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
+		    printk(KERN_DEBUG "tseg: %010llx\n", tseg);
 		    if ((tseg>>PMD_SHIFT) <
 				(max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
 			((tseg>>PMD_SHIFT) <

arch/x86/mm/pageattr.c

@@ -658,11 +658,11 @@ static int cpa_process_alias(struct cpa_data *cpa)
 	struct cpa_data alias_cpa;
 	int ret = 0;
 
-	if (cpa->pfn > max_pfn_mapped)
+	if (cpa->pfn >= max_pfn_mapped)
 		return 0;
 
 #ifdef CONFIG_X86_64
-	if (cpa->pfn > max_low_pfn_mapped && cpa->pfn < (1UL<<(32-PAGE_SHIFT)))
+	if (cpa->pfn >= max_low_pfn_mapped && cpa->pfn < (1UL<<(32-PAGE_SHIFT)))
 		return 0;
 #endif
 	/*

arch/x86/mm/pat.c

@@ -449,8 +449,8 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
 	if (retval < 0)
 		return 0;
 
-	if (((pfn <= max_low_pfn_mapped) ||
-	     (pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn <= max_pfn_mapped)) &&
+	if (((pfn < max_low_pfn_mapped) ||
+	     (pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn < max_pfn_mapped)) &&
 	    ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
 		free_memtype(offset, offset + size);
 		printk(KERN_INFO

arch/x86/pci/i386.c

@@ -334,9 +334,9 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
 		flags = new_flags;
 	}
 
-	if (((vma->vm_pgoff <= max_low_pfn_mapped) ||
+	if (((vma->vm_pgoff < max_low_pfn_mapped) ||
 	     (vma->vm_pgoff >= (1UL<<(32 - PAGE_SHIFT)) &&
-	      vma->vm_pgoff <= max_pfn_mapped)) &&
+	      vma->vm_pgoff < max_pfn_mapped)) &&
 	    ioremap_change_attr((unsigned long)__va(addr), len, flags)) {
 		free_memtype(addr, addr + len);
 		return -EINVAL;