Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingol Molnar:
 "Misc fixes:

   - EFI crash fix

   - Xen PV fixes

   - do not allow PTI on 2-level 32-bit kernels for now

   - documentation fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/APM: Fix build warning when PROC_FS is not enabled
  Revert "x86/mm/legacy: Populate the user page-table with user pgd's"
  x86/efi: Load fixmap GDT in efi_call_phys_epilog() before setting %cr3
  x86/xen: Disable CPU0 hotplug for Xen PV
  x86/EISA: Don't probe EISA bus for Xen PV guests
  x86/doc: Fix Documentation/x86/earlyprintk.txt

arch/x86/include/asm/pgtable-2level.h

@@ -19,9 +19,6 @@ static inline void native_set_pte(pte_t *ptep , pte_t pte)
 
 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
 {
-#ifdef CONFIG_PAGE_TABLE_ISOLATION
-	pmd.pud.p4d.pgd = pti_set_user_pgtbl(&pmdp->pud.p4d.pgd, pmd.pud.p4d.pgd);
-#endif
 	*pmdp = pmd;
 }
 
@@ -61,9 +58,6 @@ static inline pte_t native_ptep_get_and_clear(pte_t *xp)
 #ifdef CONFIG_SMP
 static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
 {
-#ifdef CONFIG_PAGE_TABLE_ISOLATION
-	pti_set_user_pgtbl(&xp->pud.p4d.pgd, __pgd(0));
-#endif
 	return __pmd(xchg((pmdval_t *)xp, 0));
 }
 #else
@@ -73,9 +67,6 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
 #ifdef CONFIG_SMP
 static inline pud_t native_pudp_get_and_clear(pud_t *xp)
 {
-#ifdef CONFIG_PAGE_TABLE_ISOLATION
-	pti_set_user_pgtbl(&xp->p4d.pgd, __pgd(0));
-#endif
 	return __pud(xchg((pudval_t *)xp, 0));
 }
 #else

arch/x86/kernel/apm_32.c

@@ -1640,6 +1640,7 @@ static int do_open(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+#ifdef CONFIG_PROC_FS
 static int proc_apm_show(struct seq_file *m, void *v)
 {
 	unsigned short	bx;
@@ -1719,6 +1720,7 @@ static int proc_apm_show(struct seq_file *m, void *v)
 		   units);
 	return 0;
 }
+#endif
 
 static int apm(void *unused)
 {

arch/x86/kernel/eisa.c

@@ -7,11 +7,17 @@
 #include <linux/eisa.h>
 #include <linux/io.h>
 
+#include <xen/xen.h>
+
 static __init int eisa_bus_probe(void)
 {
-	void __iomem *p = ioremap(0x0FFFD9, 4);
+	void __iomem *p;
 
-	if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
+	if (xen_pv_domain() && !xen_initial_domain())
+		return 0;
+
+	p = ioremap(0x0FFFD9, 4);
+	if (p && readl(p) == 'E' + ('I' << 8) + ('S' << 16) + ('A' << 24))
 		EISA_bus = 1;
 	iounmap(p);
 	return 0;

arch/x86/kernel/topology.c

@@ -111,8 +111,10 @@ int arch_register_cpu(int num)
 	/*
 	 * Currently CPU0 is only hotpluggable on Intel platforms. Other
 	 * vendors can add hotplug support later.
+	 * Xen PV guests don't support CPU0 hotplug at all.
 	 */
-	if (c->x86_vendor != X86_VENDOR_INTEL)
+	if (c->x86_vendor != X86_VENDOR_INTEL ||
+	    boot_cpu_has(X86_FEATURE_XENPV))
 		cpu0_hotpluggable = 0;
 
 	/*

arch/x86/platform/efi/efi_32.c

@@ -85,10 +85,9 @@ pgd_t * __init efi_call_phys_prolog(void)
 
 void __init efi_call_phys_epilog(pgd_t *save_pgd)
 {
+	load_fixmap_gdt(0);
 	load_cr3(save_pgd);
 	__flush_tlb_all();
-
-	load_fixmap_gdt(0);
 }
 
 void __init efi_runtime_update_mappings(void)