xen: clean up x86-64 warnings

There are a couple of Xen features which rely on directly accessing
per-cpu data via a segment register, which is not yet available on
x86-64.  In the meantime, just disable direct access to the vcpu info
structure; this leaves some of the code as dead, but it will come to
life in time, and the warnings are suppressed.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 27 insertions, 54 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 8ca2f88bde1e..85692c9f6496 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -112,7 +112,14 @@ struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  *
  * 0: not available, 1: available
  */
-static int have_vcpu_info_placement = 1;
+static int have_vcpu_info_placement =
+#ifdef CONFIG_X86_32
+        1
+#else
+        0
+#endif
+        ;
+
 
 static void xen_vcpu_setup(int cpu)
 {
@@ -941,6 +948,7 @@ static void *xen_kmap_atomic_pte(struct page *page, enum km_type type)
 }
 #endif
 
+#ifdef CONFIG_X86_32
 static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
 {
         /* If there's an existing pte, then don't allow _PAGE_RW to be set */
@@ -959,6 +967,7 @@ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
 
         xen_set_pte(ptep, pte);
 }
+#endif
 
 static __init void xen_pagetable_setup_start(pgd_t *base)
 {
@@ -1025,7 +1034,6 @@ void xen_setup_vcpu_info_placement(void)
 
         /* xen_vcpu_setup managed to place the vcpu_info within the
            percpu area for all cpus, so make use of it */
-#ifdef CONFIG_X86_32
         if (have_vcpu_info_placement) {
                 printk(KERN_INFO "Xen: using vcpu_info placement\n");
 
@@ -1035,7 +1043,6 @@ void xen_setup_vcpu_info_placement(void)
                 pv_irq_ops.irq_enable = xen_irq_enable_direct;
                 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
         }
-#endif
 }
 
 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
@@ -1056,12 +1063,10 @@ static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
         goto patch_site
 
         switch (type) {
-#ifdef CONFIG_X86_32
                 SITE(pv_irq_ops, irq_enable);
                 SITE(pv_irq_ops, irq_disable);
                 SITE(pv_irq_ops, save_fl);
                 SITE(pv_irq_ops, restore_fl);
-#endif /* CONFIG_X86_32 */
 #undef SITE
 
         patch_site:
@@ -1399,48 +1404,11 @@ static void *m2v(phys_addr_t maddr)
         return __ka(m2p(maddr));
 }
 
-#ifdef CONFIG_X86_64
-static void walk(pgd_t *pgd, unsigned long addr)
-{
-        unsigned l4idx = pgd_index(addr);
-        unsigned l3idx = pud_index(addr);
-        unsigned l2idx = pmd_index(addr);
-        unsigned l1idx = pte_index(addr);
-        pgd_t l4;
-        pud_t l3;
-        pmd_t l2;
-        pte_t l1;
-
-        xen_raw_printk("walk %p, %lx -> %d %d %d %d\n",
-                       pgd, addr, l4idx, l3idx, l2idx, l1idx);
-
-        l4 = pgd[l4idx];
-        xen_raw_printk("  l4: %016lx\n", l4.pgd);
-        xen_raw_printk("      %016lx\n", pgd_val(l4));
-
-        l3 = ((pud_t *)(m2v(l4.pgd)))[l3idx];
-        xen_raw_printk("  l3: %016lx\n", l3.pud);
-        xen_raw_printk("      %016lx\n", pud_val(l3));
-
-        l2 = ((pmd_t *)(m2v(l3.pud)))[l2idx];
-        xen_raw_printk("  l2: %016lx\n", l2.pmd);
-        xen_raw_printk("      %016lx\n", pmd_val(l2));
-
-        l1 = ((pte_t *)(m2v(l2.pmd)))[l1idx];
-        xen_raw_printk("  l1: %016lx\n", l1.pte);
-        xen_raw_printk("      %016lx\n", pte_val(l1));
-}
-#endif
-
 static void set_page_prot(void *addr, pgprot_t prot)
 {
         unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
         pte_t pte = pfn_pte(pfn, prot);
 
-        xen_raw_printk("addr=%p pfn=%lx mfn=%lx prot=%016llx pte=%016llx\n",
-                       addr, pfn, get_phys_to_machine(pfn),
-                       pgprot_val(prot), pte.pte);
-
         if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
                 BUG();
 }
@@ -1698,15 +1666,6 @@ asmlinkage void __init xen_start_kernel(void)
 
         xen_raw_console_write("about to get started...\n");
 
-#if 0
-        xen_raw_printk("&boot_params=%p __pa(&boot_params)=%lx __va(__pa(&boot_params))=%lx\n",
-                       &boot_params, __pa_symbol(&boot_params),
-                       __va(__pa_symbol(&boot_params)));
-
-        walk(pgd, &boot_params);
-        walk(pgd, __va(__pa(&boot_params)));
-#endif
-
         /* Start the world */
 #ifdef CONFIG_X86_32
         i386_start_kernel();
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 3b9bda46487a..05794c566e87 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -26,8 +26,15 @@
 /* Pseudo-flag used for virtual NMI, which we don't implement yet */
 #define XEN_EFLAGS_NMI  0x80000000
 
-#if 0
-#include <asm/percpu.h>
+#if 1
+/*
+        x86-64 does not yet support direct access to percpu variables
+        via a segment override, so we just need to make sure this code
+        never gets used
+ */
+#define BUG                     ud2a
+#define PER_CPU_VAR(var, off)   0xdeadbeef
+#endif
 
 /*
         Enable events.  This clears the event mask and tests the pending
@@ -35,6 +42,8 @@
         events, then enter the hypervisor to get them handled.
  */
 ENTRY(xen_irq_enable_direct)
+        BUG
+
         /* Unmask events */
         movb $0, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
 
@@ -58,6 +67,8 @@ ENDPATCH(xen_irq_enable_direct)
         non-zero.
  */
 ENTRY(xen_irq_disable_direct)
+        BUG
+
         movb $1, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
 ENDPATCH(xen_irq_disable_direct)
         ret
@@ -74,6 +85,8 @@ ENDPATCH(xen_irq_disable_direct)
         Xen and x86 use opposite senses (mask vs enable).
  */
 ENTRY(xen_save_fl_direct)
+        BUG
+
         testb $0xff, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
         setz %ah
         addb %ah,%ah
@@ -91,6 +104,8 @@ ENDPATCH(xen_save_fl_direct)
         if so.
  */
 ENTRY(xen_restore_fl_direct)
+        BUG
+
         testb $X86_EFLAGS_IF>>8, %ah
         setz PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
         /* Preempt here doesn't matter because that will deal with
@@ -133,7 +148,6 @@ check_events:
         pop %rcx
         pop %rax
         ret
-#endif
 
 ENTRY(xen_adjust_exception_frame)
         mov 8+0(%rsp),%rcx