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[PATCH v3 1/7] x86/xen: remove 32-bit Xen PV guest support



Xen is requiring 64-bit machines today and since Xen 4.14 it can be
built without 32-bit PV guest support. There is no need to carry the
burden of 32-bit PV guest support in the kernel any longer, as new
guests can be either HVM or PVH, or they can use a 64 bit kernel.

Remove the 32-bit Xen PV support from the kernel.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 arch/x86/entry/entry_32.S         | 109 +--------
 arch/x86/entry/vdso/vdso32/note.S |  30 ---
 arch/x86/include/asm/proto.h      |   2 +-
 arch/x86/include/asm/segment.h    |   2 +-
 arch/x86/kernel/head_32.S         |  31 ---
 arch/x86/xen/Kconfig              |   3 +-
 arch/x86/xen/apic.c               |  17 --
 arch/x86/xen/enlighten_pv.c       |  63 +-----
 arch/x86/xen/mmu_pv.c             | 352 ++++--------------------------
 arch/x86/xen/p2m.c                |   6 +-
 arch/x86/xen/setup.c              |  36 +--
 arch/x86/xen/smp_pv.c             |  18 --
 arch/x86/xen/vdso.h               |   6 -
 arch/x86/xen/xen-asm.S            |  14 --
 arch/x86/xen/xen-asm_32.S         | 185 ----------------
 arch/x86/xen/xen-head.S           |   6 -
 drivers/xen/Kconfig               |   4 +-
 17 files changed, 51 insertions(+), 833 deletions(-)
 delete mode 100644 arch/x86/xen/vdso.h
 delete mode 100644 arch/x86/xen/xen-asm_32.S

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 29b7d52143e9..df8c017e6161 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -449,8 +449,6 @@
 
 .macro SWITCH_TO_KERNEL_STACK
 
-       ALTERNATIVE     "", "jmp .Lend_\@", X86_FEATURE_XENPV
-
        BUG_IF_WRONG_CR3
 
        SWITCH_TO_KERNEL_CR3 scratch_reg=%eax
@@ -599,8 +597,6 @@
  */
 .macro SWITCH_TO_ENTRY_STACK
 
-       ALTERNATIVE     "", "jmp .Lend_\@", X86_FEATURE_XENPV
-
        /* Bytes to copy */
        movl    $PTREGS_SIZE, %ecx
 
@@ -872,17 +868,6 @@ SYM_ENTRY(__begin_SYSENTER_singlestep_region, 
SYM_L_GLOBAL, SYM_A_NONE)
  * will ignore all of the single-step traps generated in this range.
  */
 
-#ifdef CONFIG_XEN_PV
-/*
- * Xen doesn't set %esp to be precisely what the normal SYSENTER
- * entry point expects, so fix it up before using the normal path.
- */
-SYM_CODE_START(xen_sysenter_target)
-       addl    $5*4, %esp                      /* remove xen-provided frame */
-       jmp     .Lsysenter_past_esp
-SYM_CODE_END(xen_sysenter_target)
-#endif
-
 /*
  * 32-bit SYSENTER entry.
  *
@@ -965,9 +950,8 @@ SYM_FUNC_START(entry_SYSENTER_32)
 
        movl    %esp, %eax
        call    do_SYSENTER_32
-       /* XEN PV guests always use IRET path */
-       ALTERNATIVE "testl %eax, %eax; jz .Lsyscall_32_done", \
-                   "jmp .Lsyscall_32_done", X86_FEATURE_XENPV
+       testl   %eax, %eax
+       jz      .Lsyscall_32_done
 
        STACKLEAK_ERASE
 
@@ -1165,95 +1149,6 @@ SYM_FUNC_END(entry_INT80_32)
 #endif
 .endm
 
-#ifdef CONFIG_PARAVIRT
-SYM_CODE_START(native_iret)
-       iret
-       _ASM_EXTABLE(native_iret, asm_iret_error)
-SYM_CODE_END(native_iret)
-#endif
-
-#ifdef CONFIG_XEN_PV
-/*
- * See comment in entry_64.S for further explanation
- *
- * Note: This is not an actual IDT entry point. It's a XEN specific entry
- * point and therefore named to match the 64-bit trampoline counterpart.
- */
-SYM_FUNC_START(xen_asm_exc_xen_hypervisor_callback)
-       /*
-        * Check to see if we got the event in the critical
-        * region in xen_iret_direct, after we've reenabled
-        * events and checked for pending events.  This simulates
-        * iret instruction's behaviour where it delivers a
-        * pending interrupt when enabling interrupts:
-        */
-       cmpl    $xen_iret_start_crit, (%esp)
-       jb      1f
-       cmpl    $xen_iret_end_crit, (%esp)
-       jae     1f
-       call    xen_iret_crit_fixup
-1:
-       pushl   $-1                             /* orig_ax = -1 => not a system 
call */
-       SAVE_ALL
-       ENCODE_FRAME_POINTER
-
-       mov     %esp, %eax
-       call    xen_pv_evtchn_do_upcall
-       jmp     handle_exception_return
-SYM_FUNC_END(xen_asm_exc_xen_hypervisor_callback)
-
-/*
- * Hypervisor uses this for application faults while it executes.
- * We get here for two reasons:
- *  1. Fault while reloading DS, ES, FS or GS
- *  2. Fault while executing IRET
- * Category 1 we fix up by reattempting the load, and zeroing the segment
- * register if the load fails.
- * Category 2 we fix up by jumping to do_iret_error. We cannot use the
- * normal Linux return path in this case because if we use the IRET hypercall
- * to pop the stack frame we end up in an infinite loop of failsafe callbacks.
- * We distinguish between categories by maintaining a status value in EAX.
- */
-SYM_FUNC_START(xen_failsafe_callback)
-       pushl   %eax
-       movl    $1, %eax
-1:     mov     4(%esp), %ds
-2:     mov     8(%esp), %es
-3:     mov     12(%esp), %fs
-4:     mov     16(%esp), %gs
-       /* EAX == 0 => Category 1 (Bad segment)
-          EAX != 0 => Category 2 (Bad IRET) */
-       testl   %eax, %eax
-       popl    %eax
-       lea     16(%esp), %esp
-       jz      5f
-       jmp     asm_iret_error
-5:     pushl   $-1                             /* orig_ax = -1 => not a system 
call */
-       SAVE_ALL
-       ENCODE_FRAME_POINTER
-       jmp     handle_exception_return
-
-.section .fixup, "ax"
-6:     xorl    %eax, %eax
-       movl    %eax, 4(%esp)
-       jmp     1b
-7:     xorl    %eax, %eax
-       movl    %eax, 8(%esp)
-       jmp     2b
-8:     xorl    %eax, %eax
-       movl    %eax, 12(%esp)
-       jmp     3b
-9:     xorl    %eax, %eax
-       movl    %eax, 16(%esp)
-       jmp     4b
-.previous
-       _ASM_EXTABLE(1b, 6b)
-       _ASM_EXTABLE(2b, 7b)
-       _ASM_EXTABLE(3b, 8b)
-       _ASM_EXTABLE(4b, 9b)
-SYM_FUNC_END(xen_failsafe_callback)
-#endif /* CONFIG_XEN_PV */
-
 SYM_CODE_START_LOCAL_NOALIGN(handle_exception)
        /* the function address is in %gs's slot on the stack */
        SAVE_ALL switch_stacks=1 skip_gs=1 unwind_espfix=1
diff --git a/arch/x86/entry/vdso/vdso32/note.S 
b/arch/x86/entry/vdso/vdso32/note.S
index e78047d119f6..2cbd39939dc6 100644
--- a/arch/x86/entry/vdso/vdso32/note.S
+++ b/arch/x86/entry/vdso/vdso32/note.S
@@ -16,33 +16,3 @@ ELFNOTE_START(Linux, 0, "a")
 ELFNOTE_END
 
 BUILD_SALT
-
-#ifdef CONFIG_XEN
-/*
- * Add a special note telling glibc's dynamic linker a fake hardware
- * flavor that it will use to choose the search path for libraries in the
- * same way it uses real hardware capabilities like "mmx".
- * We supply "nosegneg" as the fake capability, to indicate that we
- * do not like negative offsets in instructions using segment overrides,
- * since we implement those inefficiently.  This makes it possible to
- * install libraries optimized to avoid those access patterns in someplace
- * like /lib/i686/tls/nosegneg.  Note that an /etc/ld.so.conf.d/file
- * corresponding to the bits here is needed to make ldconfig work right.
- * It should contain:
- *     hwcap 1 nosegneg
- * to match the mapping of bit to name that we give here.
- *
- * At runtime, the fake hardware feature will be considered to be present
- * if its bit is set in the mask word.  So, we start with the mask 0, and
- * at boot time we set VDSO_NOTE_NONEGSEG_BIT if running under Xen.
- */
-
-#include "../../xen/vdso.h"    /* Defines VDSO_NOTE_NONEGSEG_BIT.  */
-
-ELFNOTE_START(GNU, 2, "a")
-       .long 1                 /* ncaps */
-VDSO32_NOTE_MASK:              /* Symbol used by arch/x86/xen/setup.c */
-       .long 0                 /* mask */
-       .byte VDSO_NOTE_NONEGSEG_BIT; .asciz "nosegneg" /* bit, name */
-ELFNOTE_END
-#endif
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
index 6e81788a30c1..28996fe19301 100644
--- a/arch/x86/include/asm/proto.h
+++ b/arch/x86/include/asm/proto.h
@@ -25,7 +25,7 @@ void entry_SYSENTER_compat(void);
 void __end_entry_SYSENTER_compat(void);
 void entry_SYSCALL_compat(void);
 void entry_INT80_compat(void);
-#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
+#ifdef CONFIG_XEN_PV
 void xen_entry_INT80_compat(void);
 #endif
 #endif
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 6669164abadc..9646c300f128 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -301,7 +301,7 @@ static inline void vdso_read_cpunode(unsigned *cpu, 
unsigned *node)
 extern const char 
early_idt_handler_array[NUM_EXCEPTION_VECTORS][EARLY_IDT_HANDLER_SIZE];
 extern void early_ignore_irq(void);
 
-#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
+#ifdef CONFIG_XEN_PV
 extern const char 
xen_early_idt_handler_array[NUM_EXCEPTION_VECTORS][XEN_EARLY_IDT_HANDLER_SIZE];
 #endif
 
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index f66a6b90f954..7ed84c282233 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -134,38 +134,7 @@ SYM_CODE_START(startup_32)
        movl %eax,pa(initial_page_table+0xffc)
 #endif
 
-#ifdef CONFIG_PARAVIRT
-       /* This is can only trip for a broken bootloader... */
-       cmpw $0x207, pa(boot_params + BP_version)
-       jb .Ldefault_entry
-
-       /* Paravirt-compatible boot parameters.  Look to see what architecture
-               we're booting under. */
-       movl pa(boot_params + BP_hardware_subarch), %eax
-       cmpl $num_subarch_entries, %eax
-       jae .Lbad_subarch
-
-       movl pa(subarch_entries)(,%eax,4), %eax
-       subl $__PAGE_OFFSET, %eax
-       jmp *%eax
-
-.Lbad_subarch:
-SYM_INNER_LABEL_ALIGN(xen_entry, SYM_L_WEAK)
-       /* Unknown implementation; there's really
-          nothing we can do at this point. */
-       ud2a
-
-       __INITDATA
-
-subarch_entries:
-       .long .Ldefault_entry           /* normal x86/PC */
-       .long xen_entry                 /* Xen hypervisor */
-       .long .Ldefault_entry           /* Moorestown MID */
-num_subarch_entries = (. - subarch_entries) / 4
-.previous
-#else
        jmp .Ldefault_entry
-#endif /* CONFIG_PARAVIRT */
 SYM_CODE_END(startup_32)
 
 #ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 1aded63a95cb..218acbd5c7a0 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -19,6 +19,7 @@ config XEN_PV
        bool "Xen PV guest support"
        default y
        depends on XEN
+       depends on X86_64
        select PARAVIRT_XXL
        select XEN_HAVE_PVMMU
        select XEN_HAVE_VPMU
@@ -50,7 +51,7 @@ config XEN_PVHVM_SMP
 
 config XEN_512GB
        bool "Limit Xen pv-domain memory to 512GB"
-       depends on XEN_PV && X86_64
+       depends on XEN_PV
        default y
        help
          Limit paravirtualized user domains to 512GB of RAM.
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index 5e53bfbe5823..ea6e9c54da9d 100644
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -58,10 +58,6 @@ static u32 xen_apic_read(u32 reg)
 
        if (reg == APIC_LVR)
                return 0x14;
-#ifdef CONFIG_X86_32
-       if (reg == APIC_LDR)
-               return SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
-#endif
        if (reg != APIC_ID)
                return 0;
 
@@ -127,14 +123,6 @@ static int xen_phys_pkg_id(int initial_apic_id, int 
index_msb)
        return initial_apic_id >> index_msb;
 }
 
-#ifdef CONFIG_X86_32
-static int xen_x86_32_early_logical_apicid(int cpu)
-{
-       /* Match with APIC_LDR read. Otherwise setup_local_APIC complains. */
-       return 1 << cpu;
-}
-#endif
-
 static void xen_noop(void)
 {
 }
@@ -197,11 +185,6 @@ static struct apic xen_pv_apic = {
        .icr_write                      = xen_apic_icr_write,
        .wait_icr_idle                  = xen_noop,
        .safe_wait_icr_idle             = xen_safe_apic_wait_icr_idle,
-
-#ifdef CONFIG_X86_32
-       /* generic_processor_info and setup_local_APIC. */
-       .x86_32_early_logical_apicid    = xen_x86_32_early_logical_apicid,
-#endif
 };
 
 static void __init xen_apic_check(void)
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 2aab43a13a8c..7d90b3da8bb4 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -119,14 +119,6 @@ static void __init xen_banner(void)
        printk(KERN_INFO "Xen version: %d.%d%s%s\n",
               version >> 16, version & 0xffff, extra.extraversion,
               xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " 
(preserve-AD)" : "");
-
-#ifdef CONFIG_X86_32
-       pr_warn("WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! 
WARNING!\n"
-               "Support for running as 32-bit PV-guest under Xen will soon be 
removed\n"
-               "from the Linux kernel!\n"
-               "Please use either a 64-bit kernel or switch to HVM or PVH 
mode!\n"
-               "WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! 
WARNING!\n");
-#endif
 }
 
 static void __init xen_pv_init_platform(void)
@@ -538,30 +530,12 @@ static void load_TLS_descriptor(struct thread_struct *t,
 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
 {
        /*
-        * XXX sleazy hack: If we're being called in a lazy-cpu zone
-        * and lazy gs handling is enabled, it means we're in a
-        * context switch, and %gs has just been saved.  This means we
-        * can zero it out to prevent faults on exit from the
-        * hypervisor if the next process has no %gs.  Either way, it
-        * has been saved, and the new value will get loaded properly.
-        * This will go away as soon as Xen has been modified to not
-        * save/restore %gs for normal hypercalls.
-        *
-        * On x86_64, this hack is not used for %gs, because gs points
-        * to KERNEL_GS_BASE (and uses it for PDA references), so we
-        * must not zero %gs on x86_64
-        *
-        * For x86_64, we need to zero %fs, otherwise we may get an
+        * In lazy mode we need to zero %fs, otherwise we may get an
         * exception between the new %fs descriptor being loaded and
         * %fs being effectively cleared at __switch_to().
         */
-       if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
-#ifdef CONFIG_X86_32
-               lazy_load_gs(0);
-#else
+       if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU)
                loadsegment(fs, 0);
-#endif
-       }
 
        xen_mc_batch();
 
@@ -572,13 +546,11 @@ static void xen_load_tls(struct thread_struct *t, 
unsigned int cpu)
        xen_mc_issue(PARAVIRT_LAZY_CPU);
 }
 
-#ifdef CONFIG_X86_64
 static void xen_load_gs_index(unsigned int idx)
 {
        if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
                BUG();
 }
-#endif
 
 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
                                const void *ptr)
@@ -597,7 +569,6 @@ static void xen_write_ldt_entry(struct desc_struct *dt, int 
entrynum,
        preempt_enable();
 }
 
-#ifdef CONFIG_X86_64
 void noist_exc_debug(struct pt_regs *regs);
 
 DEFINE_IDTENTRY_RAW(xenpv_exc_nmi)
@@ -697,7 +668,6 @@ static bool __ref get_trap_addr(void **addr, unsigned int 
ist)
 
        return true;
 }
-#endif
 
 static int cvt_gate_to_trap(int vector, const gate_desc *val,
                            struct trap_info *info)
@@ -710,10 +680,8 @@ static int cvt_gate_to_trap(int vector, const gate_desc 
*val,
        info->vector = vector;
 
        addr = gate_offset(val);
-#ifdef CONFIG_X86_64
        if (!get_trap_addr((void **)&addr, val->bits.ist))
                return 0;
-#endif /* CONFIG_X86_64 */
        info->address = addr;
 
        info->cs = gate_segment(val);
@@ -958,15 +926,12 @@ static u64 xen_read_msr_safe(unsigned int msr, int *err)
 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
 {
        int ret;
-#ifdef CONFIG_X86_64
        unsigned int which;
        u64 base;
-#endif
 
        ret = 0;
 
        switch (msr) {
-#ifdef CONFIG_X86_64
        case MSR_FS_BASE:               which = SEGBASE_FS; goto set;
        case MSR_KERNEL_GS_BASE:        which = SEGBASE_GS_USER; goto set;
        case MSR_GS_BASE:               which = SEGBASE_GS_KERNEL; goto set;
@@ -976,7 +941,6 @@ static int xen_write_msr_safe(unsigned int msr, unsigned 
low, unsigned high)
                if (HYPERVISOR_set_segment_base(which, base) != 0)
                        ret = -EIO;
                break;
-#endif
 
        case MSR_STAR:
        case MSR_CSTAR:
@@ -1058,9 +1022,7 @@ void __init xen_setup_vcpu_info_placement(void)
 static const struct pv_info xen_info __initconst = {
        .shared_kernel_pmd = 0,
 
-#ifdef CONFIG_X86_64
        .extra_user_64bit_cs = FLAT_USER_CS64,
-#endif
        .name = "Xen",
 };
 
@@ -1086,18 +1048,14 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst 
= {
        .read_pmc = xen_read_pmc,
 
        .iret = xen_iret,
-#ifdef CONFIG_X86_64
        .usergs_sysret64 = xen_sysret64,
-#endif
 
        .load_tr_desc = paravirt_nop,
        .set_ldt = xen_set_ldt,
        .load_gdt = xen_load_gdt,
        .load_idt = xen_load_idt,
        .load_tls = xen_load_tls,
-#ifdef CONFIG_X86_64
        .load_gs_index = xen_load_gs_index,
-#endif
 
        .alloc_ldt = xen_alloc_ldt,
        .free_ldt = xen_free_ldt,
@@ -1364,13 +1322,8 @@ asmlinkage __visible void __init xen_start_kernel(void)
 
        /* keep using Xen gdt for now; no urgent need to change it */
 
-#ifdef CONFIG_X86_32
-       pv_info.kernel_rpl = 1;
-       if (xen_feature(XENFEAT_supervisor_mode_kernel))
-               pv_info.kernel_rpl = 0;
-#else
        pv_info.kernel_rpl = 0;
-#endif
+
        /* set the limit of our address space */
        xen_reserve_top();
 
@@ -1384,12 +1337,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
        if (rc != 0)
                xen_raw_printk("physdev_op failed %d\n", rc);
 
-#ifdef CONFIG_X86_32
-       /* set up basic CPUID stuff */
-       cpu_detect(&new_cpu_data);
-       set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU);
-       new_cpu_data.x86_capability[CPUID_1_EDX] = cpuid_edx(1);
-#endif
 
        if (xen_start_info->mod_start) {
            if (xen_start_info->flags & SIF_MOD_START_PFN)
@@ -1458,12 +1405,8 @@ asmlinkage __visible void __init xen_start_kernel(void)
        xen_efi_init(&boot_params);
 
        /* Start the world */
-#ifdef CONFIG_X86_32
-       i386_start_kernel();
-#else
        cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
        x86_64_start_reservations((char *)__pa_symbol(&boot_params));
-#endif
 }
 
 static int xen_cpu_up_prepare_pv(unsigned int cpu)
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index a58d9c69807a..1f9500d0b839 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -86,19 +86,8 @@
 #include "mmu.h"
 #include "debugfs.h"
 
-#ifdef CONFIG_X86_32
-/*
- * Identity map, in addition to plain kernel map.  This needs to be
- * large enough to allocate page table pages to allocate the rest.
- * Each page can map 2MB.
- */
-#define LEVEL1_IDENT_ENTRIES   (PTRS_PER_PTE * 4)
-static RESERVE_BRK_ARRAY(pte_t, level1_ident_pgt, LEVEL1_IDENT_ENTRIES);
-#endif
-#ifdef CONFIG_X86_64
 /* l3 pud for userspace vsyscall mapping */
 static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss;
-#endif /* CONFIG_X86_64 */
 
 /*
  * Protects atomic reservation decrease/increase against concurrent increases.
@@ -280,10 +269,7 @@ static inline void __xen_set_pte(pte_t *ptep, pte_t pteval)
        if (!xen_batched_set_pte(ptep, pteval)) {
                /*
                 * Could call native_set_pte() here and trap and
-                * emulate the PTE write but with 32-bit guests this
-                * needs two traps (one for each of the two 32-bit
-                * words in the PTE) so do one hypercall directly
-                * instead.
+                * emulate the PTE write, but a hypercall is much cheaper.
                 */
                struct mmu_update u;
 
@@ -439,26 +425,6 @@ static void xen_set_pud(pud_t *ptr, pud_t val)
        xen_set_pud_hyper(ptr, val);
 }
 
-#ifdef CONFIG_X86_PAE
-static void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
-{
-       trace_xen_mmu_set_pte_atomic(ptep, pte);
-       __xen_set_pte(ptep, pte);
-}
-
-static void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t 
*ptep)
-{
-       trace_xen_mmu_pte_clear(mm, addr, ptep);
-       __xen_set_pte(ptep, native_make_pte(0));
-}
-
-static void xen_pmd_clear(pmd_t *pmdp)
-{
-       trace_xen_mmu_pmd_clear(pmdp);
-       set_pmd(pmdp, __pmd(0));
-}
-#endif /* CONFIG_X86_PAE */
-
 __visible pmd_t xen_make_pmd(pmdval_t pmd)
 {
        pmd = pte_pfn_to_mfn(pmd);
@@ -466,7 +432,6 @@ __visible pmd_t xen_make_pmd(pmdval_t pmd)
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd);
 
-#ifdef CONFIG_X86_64
 __visible pudval_t xen_pud_val(pud_t pud)
 {
        return pte_mfn_to_pfn(pud.pud);
@@ -571,7 +536,6 @@ __visible p4d_t xen_make_p4d(p4dval_t p4d)
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_p4d);
 #endif  /* CONFIG_PGTABLE_LEVELS >= 5 */
-#endif /* CONFIG_X86_64 */
 
 static int xen_pmd_walk(struct mm_struct *mm, pmd_t *pmd,
                int (*func)(struct mm_struct *mm, struct page *, enum pt_level),
@@ -636,11 +600,8 @@ static int xen_p4d_walk(struct mm_struct *mm, p4d_t *p4d,
  * will be STACK_TOP_MAX, but at boot we need to pin up to
  * FIXADDR_TOP.
  *
- * For 32-bit the important bit is that we don't pin beyond there,
- * because then we start getting into Xen's ptes.
- *
- * For 64-bit, we must skip the Xen hole in the middle of the address
- * space, just after the big x86-64 virtual hole.
+ * We must skip the Xen hole in the middle of the address space, just after
+ * the big x86-64 virtual hole.
  */
 static int __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd,
                          int (*func)(struct mm_struct *mm, struct page *,
@@ -654,14 +615,12 @@ static int __xen_pgd_walk(struct mm_struct *mm, pgd_t 
*pgd,
        limit--;
        BUG_ON(limit >= FIXADDR_TOP);
 
-#ifdef CONFIG_X86_64
        /*
         * 64-bit has a great big hole in the middle of the address
         * space, which contains the Xen mappings.
         */
        hole_low = pgd_index(GUARD_HOLE_BASE_ADDR);
        hole_high = pgd_index(GUARD_HOLE_END_ADDR);
-#endif
 
        nr = pgd_index(limit) + 1;
        for (i = 0; i < nr; i++) {
@@ -787,6 +746,8 @@ static int xen_pin_page(struct mm_struct *mm, struct page 
*page,
    read-only, and can be pinned. */
 static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
 {
+       pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
        trace_xen_mmu_pgd_pin(mm, pgd);
 
        xen_mc_batch();
@@ -800,26 +761,14 @@ static void __xen_pgd_pin(struct mm_struct *mm, pgd_t 
*pgd)
                xen_mc_batch();
        }
 
-#ifdef CONFIG_X86_64
-       {
-               pgd_t *user_pgd = xen_get_user_pgd(pgd);
+       xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));
 
-               xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));
-
-               if (user_pgd) {
-                       xen_pin_page(mm, virt_to_page(user_pgd), PT_PGD);
-                       xen_do_pin(MMUEXT_PIN_L4_TABLE,
-                                  PFN_DOWN(__pa(user_pgd)));
-               }
+       if (user_pgd) {
+               xen_pin_page(mm, virt_to_page(user_pgd), PT_PGD);
+               xen_do_pin(MMUEXT_PIN_L4_TABLE,
+                          PFN_DOWN(__pa(user_pgd)));
        }
-#else /* CONFIG_X86_32 */
-#ifdef CONFIG_X86_PAE
-       /* Need to make sure unshared kernel PMD is pinnable */
-       xen_pin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
-                    PT_PMD);
-#endif
-       xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
-#endif /* CONFIG_X86_64 */
+
        xen_mc_issue(0);
 }
 
@@ -870,9 +819,7 @@ static int __init xen_mark_pinned(struct mm_struct *mm, 
struct page *page,
 static void __init xen_after_bootmem(void)
 {
        static_branch_enable(&xen_struct_pages_ready);
-#ifdef CONFIG_X86_64
        SetPagePinned(virt_to_page(level3_user_vsyscall));
-#endif
        xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
 }
 
@@ -919,29 +866,19 @@ static int xen_unpin_page(struct mm_struct *mm, struct 
page *page,
 /* Release a pagetables pages back as normal RW */
 static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
 {
+       pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
        trace_xen_mmu_pgd_unpin(mm, pgd);
 
        xen_mc_batch();
 
        xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
 
-#ifdef CONFIG_X86_64
-       {
-               pgd_t *user_pgd = xen_get_user_pgd(pgd);
-
-               if (user_pgd) {
-                       xen_do_pin(MMUEXT_UNPIN_TABLE,
-                                  PFN_DOWN(__pa(user_pgd)));
-                       xen_unpin_page(mm, virt_to_page(user_pgd), PT_PGD);
-               }
+       if (user_pgd) {
+               xen_do_pin(MMUEXT_UNPIN_TABLE,
+                          PFN_DOWN(__pa(user_pgd)));
+               xen_unpin_page(mm, virt_to_page(user_pgd), PT_PGD);
        }
-#endif
-
-#ifdef CONFIG_X86_PAE
-       /* Need to make sure unshared kernel PMD is unpinned */
-       xen_unpin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
-                      PT_PMD);
-#endif
 
        __xen_pgd_walk(mm, pgd, xen_unpin_page, USER_LIMIT);
 
@@ -1089,7 +1026,6 @@ static void __init pin_pagetable_pfn(unsigned cmd, 
unsigned long pfn)
                BUG();
 }
 
-#ifdef CONFIG_X86_64
 static void __init xen_cleanhighmap(unsigned long vaddr,
                                    unsigned long vaddr_end)
 {
@@ -1273,17 +1209,15 @@ static void __init xen_pagetable_cleanhighmap(void)
        xen_cleanhighmap(addr, roundup(addr + size, PMD_SIZE * 2));
        xen_start_info->pt_base = (unsigned 
long)__va(__pa(xen_start_info->pt_base));
 }
-#endif
 
 static void __init xen_pagetable_p2m_setup(void)
 {
        xen_vmalloc_p2m_tree();
 
-#ifdef CONFIG_X86_64
        xen_pagetable_p2m_free();
 
        xen_pagetable_cleanhighmap();
-#endif
+
        /* And revector! Bye bye old array */
        xen_start_info->mfn_list = (unsigned long)xen_p2m_addr;
 }
@@ -1420,6 +1354,8 @@ static void __xen_write_cr3(bool kernel, unsigned long 
cr3)
 }
 static void xen_write_cr3(unsigned long cr3)
 {
+       pgd_t *user_pgd = xen_get_user_pgd(__va(cr3));
+
        BUG_ON(preemptible());
 
        xen_mc_batch();  /* disables interrupts */
@@ -1430,20 +1366,14 @@ static void xen_write_cr3(unsigned long cr3)
 
        __xen_write_cr3(true, cr3);
 
-#ifdef CONFIG_X86_64
-       {
-               pgd_t *user_pgd = xen_get_user_pgd(__va(cr3));
-               if (user_pgd)
-                       __xen_write_cr3(false, __pa(user_pgd));
-               else
-                       __xen_write_cr3(false, 0);
-       }
-#endif
+       if (user_pgd)
+               __xen_write_cr3(false, __pa(user_pgd));
+       else
+               __xen_write_cr3(false, 0);
 
        xen_mc_issue(PARAVIRT_LAZY_CPU);  /* interrupts restored */
 }
 
-#ifdef CONFIG_X86_64
 /*
  * At the start of the day - when Xen launches a guest, it has already
  * built pagetables for the guest. We diligently look over them
@@ -1478,49 +1408,39 @@ static void __init xen_write_cr3_init(unsigned long cr3)
 
        xen_mc_issue(PARAVIRT_LAZY_CPU);  /* interrupts restored */
 }
-#endif
 
 static int xen_pgd_alloc(struct mm_struct *mm)
 {
        pgd_t *pgd = mm->pgd;
-       int ret = 0;
+       struct page *page = virt_to_page(pgd);
+       pgd_t *user_pgd;
+       int ret = -ENOMEM;
 
        BUG_ON(PagePinned(virt_to_page(pgd)));
+       BUG_ON(page->private != 0);
 
-#ifdef CONFIG_X86_64
-       {
-               struct page *page = virt_to_page(pgd);
-               pgd_t *user_pgd;
-
-               BUG_ON(page->private != 0);
-
-               ret = -ENOMEM;
-
-               user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
-               page->private = (unsigned long)user_pgd;
+       user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+       page->private = (unsigned long)user_pgd;
 
-               if (user_pgd != NULL) {
+       if (user_pgd != NULL) {
 #ifdef CONFIG_X86_VSYSCALL_EMULATION
-                       user_pgd[pgd_index(VSYSCALL_ADDR)] =
-                               __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
+               user_pgd[pgd_index(VSYSCALL_ADDR)] =
+                       __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
 #endif
-                       ret = 0;
-               }
-
-               BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
+               ret = 0;
        }
-#endif
+
+       BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
+
        return ret;
 }
 
 static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
 {
-#ifdef CONFIG_X86_64
        pgd_t *user_pgd = xen_get_user_pgd(pgd);
 
        if (user_pgd)
                free_page((unsigned long)user_pgd);
-#endif
 }
 
 /*
@@ -1539,7 +1459,6 @@ static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
  */
 __visible pte_t xen_make_pte_init(pteval_t pte)
 {
-#ifdef CONFIG_X86_64
        unsigned long pfn;
 
        /*
@@ -1553,7 +1472,7 @@ __visible pte_t xen_make_pte_init(pteval_t pte)
            pfn >= xen_start_info->first_p2m_pfn &&
            pfn < xen_start_info->first_p2m_pfn + xen_start_info->nr_p2m_frames)
                pte &= ~_PAGE_RW;
-#endif
+
        pte = pte_pfn_to_mfn(pte);
        return native_make_pte(pte);
 }
@@ -1561,13 +1480,6 @@ PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_init);
 
 static void __init xen_set_pte_init(pte_t *ptep, pte_t pte)
 {
-#ifdef CONFIG_X86_32
-       /* If there's an existing pte, then don't allow _PAGE_RW to be set */
-       if (pte_mfn(pte) != INVALID_P2M_ENTRY
-           && pte_val_ma(*ptep) & _PAGE_PRESENT)
-               pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
-                              pte_val_ma(pte));
-#endif
        __xen_set_pte(ptep, pte);
 }
 
@@ -1702,7 +1614,6 @@ static void xen_release_pmd(unsigned long pfn)
        xen_release_ptpage(pfn, PT_PMD);
 }
 
-#ifdef CONFIG_X86_64
 static void xen_alloc_pud(struct mm_struct *mm, unsigned long pfn)
 {
        xen_alloc_ptpage(mm, pfn, PT_PUD);
@@ -1712,19 +1623,9 @@ static void xen_release_pud(unsigned long pfn)
 {
        xen_release_ptpage(pfn, PT_PUD);
 }
-#endif
 
 void __init xen_reserve_top(void)
 {
-#ifdef CONFIG_X86_32
-       unsigned long top = HYPERVISOR_VIRT_START;
-       struct xen_platform_parameters pp;
-
-       if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
-               top = pp.virt_start;
-
-       reserve_top_address(-top);
-#endif /* CONFIG_X86_32 */
 }
 
 /*
@@ -1733,11 +1634,7 @@ void __init xen_reserve_top(void)
  */
 static void * __init __ka(phys_addr_t paddr)
 {
-#ifdef CONFIG_X86_64
        return (void *)(paddr + __START_KERNEL_map);
-#else
-       return __va(paddr);
-#endif
 }
 
 /* Convert a machine address to physical address */
@@ -1771,56 +1668,7 @@ static void __init set_page_prot(void *addr, pgprot_t 
prot)
 {
        return set_page_prot_flags(addr, prot, UVMF_NONE);
 }
-#ifdef CONFIG_X86_32
-static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
-{
-       unsigned pmdidx, pteidx;
-       unsigned ident_pte;
-       unsigned long pfn;
-
-       level1_ident_pgt = extend_brk(sizeof(pte_t) * LEVEL1_IDENT_ENTRIES,
-                                     PAGE_SIZE);
 
-       ident_pte = 0;
-       pfn = 0;
-       for (pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) {
-               pte_t *pte_page;
-
-               /* Reuse or allocate a page of ptes */
-               if (pmd_present(pmd[pmdidx]))
-                       pte_page = m2v(pmd[pmdidx].pmd);
-               else {
-                       /* Check for free pte pages */
-                       if (ident_pte == LEVEL1_IDENT_ENTRIES)
-                               break;
-
-                       pte_page = &level1_ident_pgt[ident_pte];
-                       ident_pte += PTRS_PER_PTE;
-
-                       pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);
-               }
-
-               /* Install mappings */
-               for (pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
-                       pte_t pte;
-
-                       if (pfn > max_pfn_mapped)
-                               max_pfn_mapped = pfn;
-
-                       if (!pte_none(pte_page[pteidx]))
-                               continue;
-
-                       pte = pfn_pte(pfn, PAGE_KERNEL_EXEC);
-                       pte_page[pteidx] = pte;
-               }
-       }
-
-       for (pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE)
-               set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO);
-
-       set_page_prot(pmd, PAGE_KERNEL_RO);
-}
-#endif
 void __init xen_setup_machphys_mapping(void)
 {
        struct xen_machphys_mapping mapping;
@@ -1831,13 +1679,8 @@ void __init xen_setup_machphys_mapping(void)
        } else {
                machine_to_phys_nr = MACH2PHYS_NR_ENTRIES;
        }
-#ifdef CONFIG_X86_32
-       WARN_ON((machine_to_phys_mapping + (machine_to_phys_nr - 1))
-               < machine_to_phys_mapping);
-#endif
 }
 
-#ifdef CONFIG_X86_64
 static void __init convert_pfn_mfn(void *v)
 {
        pte_t *pte = v;
@@ -2168,105 +2011,6 @@ void __init xen_relocate_p2m(void)
        xen_start_info->nr_p2m_frames = n_frames;
 }
 
-#else  /* !CONFIG_X86_64 */
-static RESERVE_BRK_ARRAY(pmd_t, initial_kernel_pmd, PTRS_PER_PMD);
-static RESERVE_BRK_ARRAY(pmd_t, swapper_kernel_pmd, PTRS_PER_PMD);
-RESERVE_BRK(fixup_kernel_pmd, PAGE_SIZE);
-RESERVE_BRK(fixup_kernel_pte, PAGE_SIZE);
-
-static void __init xen_write_cr3_init(unsigned long cr3)
-{
-       unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));
-
-       BUG_ON(read_cr3_pa() != __pa(initial_page_table));
-       BUG_ON(cr3 != __pa(swapper_pg_dir));
-
-       /*
-        * We are switching to swapper_pg_dir for the first time (from
-        * initial_page_table) and therefore need to mark that page
-        * read-only and then pin it.
-        *
-        * Xen disallows sharing of kernel PMDs for PAE
-        * guests. Therefore we must copy the kernel PMD from
-        * initial_page_table into a new kernel PMD to be used in
-        * swapper_pg_dir.
-        */
-       swapper_kernel_pmd =
-               extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
-       copy_page(swapper_kernel_pmd, initial_kernel_pmd);
-       swapper_pg_dir[KERNEL_PGD_BOUNDARY] =
-               __pgd(__pa(swapper_kernel_pmd) | _PAGE_PRESENT);
-       set_page_prot(swapper_kernel_pmd, PAGE_KERNEL_RO);
-
-       set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
-       xen_write_cr3(cr3);
-       pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, pfn);
-
-       pin_pagetable_pfn(MMUEXT_UNPIN_TABLE,
-                         PFN_DOWN(__pa(initial_page_table)));
-       set_page_prot(initial_page_table, PAGE_KERNEL);
-       set_page_prot(initial_kernel_pmd, PAGE_KERNEL);
-
-       pv_ops.mmu.write_cr3 = &xen_write_cr3;
-}
-
-/*
- * For 32 bit domains xen_start_info->pt_base is the pgd address which might be
- * not the first page table in the page table pool.
- * Iterate through the initial page tables to find the real page table base.
- */
-static phys_addr_t __init xen_find_pt_base(pmd_t *pmd)
-{
-       phys_addr_t pt_base, paddr;
-       unsigned pmdidx;
-
-       pt_base = min(__pa(xen_start_info->pt_base), __pa(pmd));
-
-       for (pmdidx = 0; pmdidx < PTRS_PER_PMD; pmdidx++)
-               if (pmd_present(pmd[pmdidx]) && !pmd_large(pmd[pmdidx])) {
-                       paddr = m2p(pmd[pmdidx].pmd);
-                       pt_base = min(pt_base, paddr);
-               }
-
-       return pt_base;
-}
-
-void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
-{
-       pmd_t *kernel_pmd;
-
-       kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);
-
-       xen_pt_base = xen_find_pt_base(kernel_pmd);
-       xen_pt_size = xen_start_info->nr_pt_frames * PAGE_SIZE;
-
-       initial_kernel_pmd =
-               extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
-
-       max_pfn_mapped = PFN_DOWN(xen_pt_base + xen_pt_size + 512 * 1024);
-
-       copy_page(initial_kernel_pmd, kernel_pmd);
-
-       xen_map_identity_early(initial_kernel_pmd, max_pfn);
-
-       copy_page(initial_page_table, pgd);
-       initial_page_table[KERNEL_PGD_BOUNDARY] =
-               __pgd(__pa(initial_kernel_pmd) | _PAGE_PRESENT);
-
-       set_page_prot(initial_kernel_pmd, PAGE_KERNEL_RO);
-       set_page_prot(initial_page_table, PAGE_KERNEL_RO);
-       set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
-
-       pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
-
-       pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE,
-                         PFN_DOWN(__pa(initial_page_table)));
-       xen_write_cr3(__pa(initial_page_table));
-
-       memblock_reserve(xen_pt_base, xen_pt_size);
-}
-#endif /* CONFIG_X86_64 */
-
 void __init xen_reserve_special_pages(void)
 {
        phys_addr_t paddr;
@@ -2300,12 +2044,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t 
phys, pgprot_t prot)
 
        switch (idx) {
        case FIX_BTMAP_END ... FIX_BTMAP_BEGIN:
-#ifdef CONFIG_X86_32
-       case FIX_WP_TEST:
-# ifdef CONFIG_HIGHMEM
-       case FIX_KMAP_BEGIN ... FIX_KMAP_END:
-# endif
-#elif defined(CONFIG_X86_VSYSCALL_EMULATION)
+#ifdef CONFIG_X86_VSYSCALL_EMULATION
        case VSYSCALL_PAGE:
 #endif
                /* All local page mappings */
@@ -2357,9 +2096,7 @@ static void __init xen_post_allocator_init(void)
        pv_ops.mmu.set_pte = xen_set_pte;
        pv_ops.mmu.set_pmd = xen_set_pmd;
        pv_ops.mmu.set_pud = xen_set_pud;
-#ifdef CONFIG_X86_64
        pv_ops.mmu.set_p4d = xen_set_p4d;
-#endif
 
        /* This will work as long as patching hasn't happened yet
           (which it hasn't) */
@@ -2367,15 +2104,11 @@ static void __init xen_post_allocator_init(void)
        pv_ops.mmu.alloc_pmd = xen_alloc_pmd;
        pv_ops.mmu.release_pte = xen_release_pte;
        pv_ops.mmu.release_pmd = xen_release_pmd;
-#ifdef CONFIG_X86_64
        pv_ops.mmu.alloc_pud = xen_alloc_pud;
        pv_ops.mmu.release_pud = xen_release_pud;
-#endif
        pv_ops.mmu.make_pte = PV_CALLEE_SAVE(xen_make_pte);
 
-#ifdef CONFIG_X86_64
        pv_ops.mmu.write_cr3 = &xen_write_cr3;
-#endif
 }
 
 static void xen_leave_lazy_mmu(void)
@@ -2420,17 +2153,11 @@ static const struct pv_mmu_ops xen_mmu_ops __initconst 
= {
        .make_pte = PV_CALLEE_SAVE(xen_make_pte_init),
        .make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
 
-#ifdef CONFIG_X86_PAE
-       .set_pte_atomic = xen_set_pte_atomic,
-       .pte_clear = xen_pte_clear,
-       .pmd_clear = xen_pmd_clear,
-#endif /* CONFIG_X86_PAE */
        .set_pud = xen_set_pud_hyper,
 
        .make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
        .pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
 
-#ifdef CONFIG_X86_64
        .pud_val = PV_CALLEE_SAVE(xen_pud_val),
        .make_pud = PV_CALLEE_SAVE(xen_make_pud),
        .set_p4d = xen_set_p4d_hyper,
@@ -2442,7 +2169,6 @@ static const struct pv_mmu_ops xen_mmu_ops __initconst = {
        .p4d_val = PV_CALLEE_SAVE(xen_p4d_val),
        .make_p4d = PV_CALLEE_SAVE(xen_make_p4d),
 #endif
-#endif /* CONFIG_X86_64 */
 
        .activate_mm = xen_activate_mm,
        .dup_mmap = xen_dup_mmap,
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 0acba2c712ab..be4151f42611 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -379,12 +379,8 @@ static void __init xen_rebuild_p2m_list(unsigned long *p2m)
 
                if (type == P2M_TYPE_PFN || i < chunk) {
                        /* Use initial p2m page contents. */
-#ifdef CONFIG_X86_64
                        mfns = alloc_p2m_page();
                        copy_page(mfns, xen_p2m_addr + pfn);
-#else
-                       mfns = xen_p2m_addr + pfn;
-#endif
                        ptep = populate_extra_pte((unsigned long)(p2m + pfn));
                        set_pte(ptep,
                                pfn_pte(PFN_DOWN(__pa(mfns)), PAGE_KERNEL));
@@ -467,7 +463,7 @@ EXPORT_SYMBOL_GPL(get_phys_to_machine);
  * Allocate new pmd(s). It is checked whether the old pmd is still in place.
  * If not, nothing is changed. This is okay as the only reason for allocating
  * a new pmd is to replace p2m_missing_pte or p2m_identity_pte by a individual
- * pmd. In case of PAE/x86-32 there are multiple pmds to allocate!
+ * pmd.
  */
 static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg)
 {
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 3566e37241d7..7eab14d56369 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -32,7 +32,6 @@
 #include <xen/features.h>
 #include <xen/hvc-console.h>
 #include "xen-ops.h"
-#include "vdso.h"
 #include "mmu.h"
 
 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
@@ -545,13 +544,10 @@ static unsigned long __init xen_get_pages_limit(void)
 {
        unsigned long limit;
 
-#ifdef CONFIG_X86_32
-       limit = GB(64) / PAGE_SIZE;
-#else
        limit = MAXMEM / PAGE_SIZE;
        if (!xen_initial_domain() && xen_512gb_limit)
                limit = GB(512) / PAGE_SIZE;
-#endif
+
        return limit;
 }
 
@@ -722,17 +718,8 @@ static void __init xen_reserve_xen_mfnlist(void)
        if (!xen_is_e820_reserved(start, size))
                return;
 
-#ifdef CONFIG_X86_32
-       /*
-        * Relocating the p2m on 32 bit system to an arbitrary virtual address
-        * is not supported, so just give up.
-        */
-       xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with 
E820 map\n");
-       BUG();
-#else
        xen_relocate_p2m();
        memblock_free(start, size);
-#endif
 }
 
 /**
@@ -921,20 +908,6 @@ char * __init xen_memory_setup(void)
        return "Xen";
 }
 
-/*
- * Set the bit indicating "nosegneg" library variants should be used.
- * We only need to bother in pure 32-bit mode; compat 32-bit processes
- * can have un-truncated segments, so wrapping around is allowed.
- */
-static void __init fiddle_vdso(void)
-{
-#ifdef CONFIG_X86_32
-       u32 *mask = vdso_image_32.data +
-               vdso_image_32.sym_VDSO32_NOTE_MASK;
-       *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
-#endif
-}
-
 static int register_callback(unsigned type, const void *func)
 {
        struct callback_register callback = {
@@ -951,11 +924,7 @@ void xen_enable_sysenter(void)
        int ret;
        unsigned sysenter_feature;
 
-#ifdef CONFIG_X86_32
-       sysenter_feature = X86_FEATURE_SEP;
-#else
        sysenter_feature = X86_FEATURE_SYSENTER32;
-#endif
 
        if (!boot_cpu_has(sysenter_feature))
                return;
@@ -967,7 +936,6 @@ void xen_enable_sysenter(void)
 
 void xen_enable_syscall(void)
 {
-#ifdef CONFIG_X86_64
        int ret;
 
        ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
@@ -983,7 +951,6 @@ void xen_enable_syscall(void)
                if (ret != 0)
                        setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
        }
-#endif /* CONFIG_X86_64 */
 }
 
 static void __init xen_pvmmu_arch_setup(void)
@@ -1024,7 +991,6 @@ void __init xen_arch_setup(void)
        disable_cpuidle();
        disable_cpufreq();
        WARN_ON(xen_set_default_idle());
-       fiddle_vdso();
 #ifdef CONFIG_NUMA
        numa_off = 1;
 #endif
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index 9ea598dcc132..3a70cb1e9550 100644
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -210,15 +210,6 @@ static void __init xen_pv_smp_prepare_boot_cpu(void)
                 * sure the old memory can be recycled. */
                make_lowmem_page_readwrite(xen_initial_gdt);
 
-#ifdef CONFIG_X86_32
-       /*
-        * Xen starts us with XEN_FLAT_RING1_DS, but linux code
-        * expects __USER_DS
-        */
-       loadsegment(ds, __USER_DS);
-       loadsegment(es, __USER_DS);
-#endif
-
        xen_filter_cpu_maps();
        xen_setup_vcpu_info_placement();
 
@@ -299,10 +290,6 @@ cpu_initialize_context(unsigned int cpu, struct 
task_struct *idle)
 
        gdt = get_cpu_gdt_rw(cpu);
 
-#ifdef CONFIG_X86_32
-       ctxt->user_regs.fs = __KERNEL_PERCPU;
-       ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
-#endif
        memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
 
        /*
@@ -340,12 +327,7 @@ cpu_initialize_context(unsigned int cpu, struct 
task_struct *idle)
        ctxt->kernel_ss = __KERNEL_DS;
        ctxt->kernel_sp = task_top_of_stack(idle);
 
-#ifdef CONFIG_X86_32
-       ctxt->event_callback_cs     = __KERNEL_CS;
-       ctxt->failsafe_callback_cs  = __KERNEL_CS;
-#else
        ctxt->gs_base_kernel = per_cpu_offset(cpu);
-#endif
        ctxt->event_callback_eip    =
                (unsigned long)xen_asm_exc_xen_hypervisor_callback;
        ctxt->failsafe_callback_eip =
diff --git a/arch/x86/xen/vdso.h b/arch/x86/xen/vdso.h
deleted file mode 100644
index 873c54c488fe..000000000000
--- a/arch/x86/xen/vdso.h
+++ /dev/null
@@ -1,6 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-/* Bit used for the pseudo-hwcap for non-negative segments.  We use
-   bit 1 to avoid bugs in some versions of glibc when bit 0 is
-   used; the choice is otherwise arbitrary. */
-#define VDSO_NOTE_NONEGSEG_BIT 1
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 508fe204520b..c59d077510bf 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -76,11 +76,7 @@ SYM_FUNC_END(xen_save_fl_direct)
  */
 SYM_FUNC_START(xen_restore_fl_direct)
        FRAME_BEGIN
-#ifdef CONFIG_X86_64
        testw $X86_EFLAGS_IF, %di
-#else
-       testb $X86_EFLAGS_IF>>8, %ah
-#endif
        setz PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
        /*
         * Preempt here doesn't matter because that will deal with any
@@ -104,15 +100,6 @@ SYM_FUNC_END(xen_restore_fl_direct)
  */
 SYM_FUNC_START(check_events)
        FRAME_BEGIN
-#ifdef CONFIG_X86_32
-       push %eax
-       push %ecx
-       push %edx
-       call xen_force_evtchn_callback
-       pop %edx
-       pop %ecx
-       pop %eax
-#else
        push %rax
        push %rcx
        push %rdx
@@ -132,7 +119,6 @@ SYM_FUNC_START(check_events)
        pop %rdx
        pop %rcx
        pop %rax
-#endif
        FRAME_END
        ret
 SYM_FUNC_END(check_events)
diff --git a/arch/x86/xen/xen-asm_32.S b/arch/x86/xen/xen-asm_32.S
deleted file mode 100644
index 4757cec33abe..000000000000
--- a/arch/x86/xen/xen-asm_32.S
+++ /dev/null
@@ -1,185 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Asm versions of Xen pv-ops, suitable for direct use.
- *
- * We only bother with direct forms (ie, vcpu in pda) of the
- * operations here; the indirect forms are better handled in C.
- */
-
-#include <asm/thread_info.h>
-#include <asm/processor-flags.h>
-#include <asm/segment.h>
-#include <asm/asm.h>
-
-#include <xen/interface/xen.h>
-
-#include <linux/linkage.h>
-
-/* Pseudo-flag used for virtual NMI, which we don't implement yet */
-#define XEN_EFLAGS_NMI  0x80000000
-
-/*
- * This is run where a normal iret would be run, with the same stack setup:
- *     8: eflags
- *     4: cs
- *     esp-> 0: eip
- *
- * This attempts to make sure that any pending events are dealt with
- * on return to usermode, but there is a small window in which an
- * event can happen just before entering usermode.  If the nested
- * interrupt ends up setting one of the TIF_WORK_MASK pending work
- * flags, they will not be tested again before returning to
- * usermode. This means that a process can end up with pending work,
- * which will be unprocessed until the process enters and leaves the
- * kernel again, which could be an unbounded amount of time.  This
- * means that a pending signal or reschedule event could be
- * indefinitely delayed.
- *
- * The fix is to notice a nested interrupt in the critical window, and
- * if one occurs, then fold the nested interrupt into the current
- * interrupt stack frame, and re-process it iteratively rather than
- * recursively.  This means that it will exit via the normal path, and
- * all pending work will be dealt with appropriately.
- *
- * Because the nested interrupt handler needs to deal with the current
- * stack state in whatever form its in, we keep things simple by only
- * using a single register which is pushed/popped on the stack.
- */
-
-.macro POP_FS
-1:
-       popw %fs
-.pushsection .fixup, "ax"
-2:     movw $0, (%esp)
-       jmp 1b
-.popsection
-       _ASM_EXTABLE(1b,2b)
-.endm
-
-SYM_CODE_START(xen_iret)
-       /* test eflags for special cases */
-       testl $(X86_EFLAGS_VM | XEN_EFLAGS_NMI), 8(%esp)
-       jnz hyper_iret
-
-       push %eax
-       ESP_OFFSET=4    # bytes pushed onto stack
-
-       /* Store vcpu_info pointer for easy access */
-#ifdef CONFIG_SMP
-       pushw %fs
-       movl $(__KERNEL_PERCPU), %eax
-       movl %eax, %fs
-       movl %fs:xen_vcpu, %eax
-       POP_FS
-#else
-       movl %ss:xen_vcpu, %eax
-#endif
-
-       /* check IF state we're restoring */
-       testb $X86_EFLAGS_IF>>8, 8+1+ESP_OFFSET(%esp)
-
-       /*
-        * Maybe enable events.  Once this happens we could get a
-        * recursive event, so the critical region starts immediately
-        * afterwards.  However, if that happens we don't end up
-        * resuming the code, so we don't have to be worried about
-        * being preempted to another CPU.
-        */
-       setz %ss:XEN_vcpu_info_mask(%eax)
-xen_iret_start_crit:
-
-       /* check for unmasked and pending */
-       cmpw $0x0001, %ss:XEN_vcpu_info_pending(%eax)
-
-       /*
-        * If there's something pending, mask events again so we can
-        * jump back into exc_xen_hypervisor_callback. Otherwise do not
-        * touch XEN_vcpu_info_mask.
-        */
-       jne 1f
-       movb $1, %ss:XEN_vcpu_info_mask(%eax)
-
-1:     popl %eax
-
-       /*
-        * From this point on the registers are restored and the stack
-        * updated, so we don't need to worry about it if we're
-        * preempted
-        */
-iret_restore_end:
-
-       /*
-        * Jump to hypervisor_callback after fixing up the stack.
-        * Events are masked, so jumping out of the critical region is
-        * OK.
-        */
-       je xen_asm_exc_xen_hypervisor_callback
-
-1:     iret
-xen_iret_end_crit:
-       _ASM_EXTABLE(1b, asm_iret_error)
-
-hyper_iret:
-       /* put this out of line since its very rarely used */
-       jmp hypercall_page + __HYPERVISOR_iret * 32
-SYM_CODE_END(xen_iret)
-
-       .globl xen_iret_start_crit, xen_iret_end_crit
-
-/*
- * This is called by xen_asm_exc_xen_hypervisor_callback in entry_32.S when it 
sees
- * that the EIP at the time of interrupt was between
- * xen_iret_start_crit and xen_iret_end_crit.
- *
- * The stack format at this point is:
- *     ----------------
- *      ss             : (ss/esp may be present if we came from usermode)
- *      esp            :
- *      eflags         }  outer exception info
- *      cs             }
- *      eip            }
- *     ----------------
- *      eax            :  outer eax if it hasn't been restored
- *     ----------------
- *      eflags         }
- *      cs             }  nested exception info
- *      eip            }
- *      return address : (into xen_asm_exc_xen_hypervisor_callback)
- *
- * In order to deliver the nested exception properly, we need to discard the
- * nested exception frame such that when we handle the exception, we do it
- * in the context of the outer exception rather than starting a new one.
- *
- * The only caveat is that if the outer eax hasn't been restored yet (i.e.
- * it's still on stack), we need to restore its value here.
-*/
-.pushsection .noinstr.text, "ax"
-SYM_CODE_START(xen_iret_crit_fixup)
-       /*
-        * Paranoia: Make sure we're really coming from kernel space.
-        * One could imagine a case where userspace jumps into the
-        * critical range address, but just before the CPU delivers a
-        * PF, it decides to deliver an interrupt instead.  Unlikely?
-        * Definitely.  Easy to avoid?  Yes.
-        */
-       testb $2, 2*4(%esp)             /* nested CS */
-       jnz 2f
-
-       /*
-        * If eip is before iret_restore_end then stack
-        * hasn't been restored yet.
-        */
-       cmpl $iret_restore_end, 1*4(%esp)
-       jae 1f
-
-       movl 4*4(%esp), %eax            /* load outer EAX */
-       ret $4*4                        /* discard nested EIP, CS, and EFLAGS as
-                                        * well as the just restored EAX */
-
-1:
-       ret $3*4                        /* discard nested EIP, CS, and EFLAGS */
-
-2:
-       ret
-SYM_CODE_END(xen_iret_crit_fixup)
-.popsection
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 1ba601df3a37..2d7c8f34f56c 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -35,13 +35,8 @@ SYM_CODE_START(startup_xen)
        rep __ASM_SIZE(stos)
 
        mov %_ASM_SI, xen_start_info
-#ifdef CONFIG_X86_64
        mov initial_stack(%rip), %rsp
-#else
-       mov initial_stack, %esp
-#endif
 
-#ifdef CONFIG_X86_64
        /* Set up %gs.
         *
         * The base of %gs always points to fixed_percpu_data.  If the
@@ -53,7 +48,6 @@ SYM_CODE_START(startup_xen)
        movq    $INIT_PER_CPU_VAR(fixed_percpu_data),%rax
        cdq
        wrmsr
-#endif
 
        call xen_start_kernel
 SYM_CODE_END(startup_xen)
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 1d339ef92422..ea6c1e7e3e42 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -52,9 +52,7 @@ config XEN_BALLOON_MEMORY_HOTPLUG
 
 config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT
        int "Hotplugged memory limit (in GiB) for a PV guest"
-       default 512 if X86_64
-       default 4 if X86_32
-       range 0 64 if X86_32
+       default 512
        depends on XEN_HAVE_PVMMU
        depends on XEN_BALLOON_MEMORY_HOTPLUG
        help
-- 
2.26.2




 


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