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[Xen-changelog] [xen-unstable] [IA64] import linux gate.S, gate.ld.S and

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Subject: [Xen-changelog] [xen-unstable] [IA64] import linux gate.S, gate.ld.S and patch.c
From: Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>
Date: Fri, 16 Jun 2006 18:40:22 +0000
Delivery-date: Fri, 16 Jun 2006 11:42:18 -0700
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# HG changeset patch
# User awilliam@xxxxxxxxxxx
# Node ID f8ab23b4f704c7175eaaa76c44d95124e6de96aa
# Parent  b8711fcb1e9563b6b5af9981bfd724e3efa99cee
[IA64] import linux gate.S, gate.ld.S and patch.c

import gate.S, gate.ld.S and patch.c which are needed to
paravirtualize vdso area.

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
---
 linux-2.6-xen-sparse/arch/ia64/kernel/gate.S     |  376 +++++++++++++++++++++++
 linux-2.6-xen-sparse/arch/ia64/kernel/gate.lds.S |   95 +++++
 linux-2.6-xen-sparse/arch/ia64/kernel/patch.c    |  197 ++++++++++++
 3 files changed, 668 insertions(+)

diff -r b8711fcb1e95 -r f8ab23b4f704 
linux-2.6-xen-sparse/arch/ia64/kernel/gate.S
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/linux-2.6-xen-sparse/arch/ia64/kernel/gate.S      Sat Jun 03 11:16:41 
2006 -0600
@@ -0,0 +1,376 @@
+/*
+ * This file contains the code that gets mapped at the upper end of each 
task's text
+ * region.  For now, it contains the signal trampoline code only.
+ *
+ * Copyright (C) 1999-2003 Hewlett-Packard Co
+ *     David Mosberger-Tang <davidm@xxxxxxxxxx>
+ */
+
+#include <linux/config.h>
+
+#include <asm/asmmacro.h>
+#include <asm/errno.h>
+#include <asm/asm-offsets.h>
+#include <asm/sigcontext.h>
+#include <asm/system.h>
+#include <asm/unistd.h>
+
+/*
+ * We can't easily refer to symbols inside the kernel.  To avoid full runtime 
relocation,
+ * complications with the linker (which likes to create PLT stubs for branches
+ * to targets outside the shared object) and to avoid multi-phase kernel 
builds, we
+ * simply create minimalistic "patch lists" in special ELF sections.
+ */
+       .section ".data.patch.fsyscall_table", "a"
+       .previous
+#define LOAD_FSYSCALL_TABLE(reg)                       \
+[1:]   movl reg=0;                                     \
+       .xdata4 ".data.patch.fsyscall_table", 1b-.
+
+       .section ".data.patch.brl_fsys_bubble_down", "a"
+       .previous
+#define BRL_COND_FSYS_BUBBLE_DOWN(pr)                  \
+[1:](pr)brl.cond.sptk 0;                               \
+       .xdata4 ".data.patch.brl_fsys_bubble_down", 1b-.
+
+GLOBAL_ENTRY(__kernel_syscall_via_break)
+       .prologue
+       .altrp b6
+       .body
+       /*
+        * Note: for (fast) syscall restart to work, the break instruction must 
be
+        *       the first one in the bundle addressed by syscall_via_break.
+        */
+{ .mib
+       break 0x100000
+       nop.i 0
+       br.ret.sptk.many b6
+}
+END(__kernel_syscall_via_break)
+
+/*
+ * On entry:
+ *     r11 = saved ar.pfs
+ *     r15 = system call #
+ *     b0  = saved return address
+ *     b6  = return address
+ * On exit:
+ *     r11 = saved ar.pfs
+ *     r15 = system call #
+ *     b0  = saved return address
+ *     all other "scratch" registers:  undefined
+ *     all "preserved" registers:      same as on entry
+ */
+
+GLOBAL_ENTRY(__kernel_syscall_via_epc)
+       .prologue
+       .altrp b6
+       .body
+{
+       /*
+        * Note: the kernel cannot assume that the first two instructions in 
this
+        * bundle get executed.  The remaining code must be safe even if
+        * they do not get executed.
+        */
+       adds r17=-1024,r15                      // A
+       mov r10=0                               // A    default to successful 
syscall execution
+       epc                                     // B    causes split-issue
+}
+       ;;
+       rsm psr.be | psr.i                      // M2 (5 cyc to srlz.d)
+       LOAD_FSYSCALL_TABLE(r14)                // X
+       ;;
+       mov r16=IA64_KR(CURRENT)                // M2 (12 cyc)
+       shladd r18=r17,3,r14                    // A
+       mov r19=NR_syscalls-1                   // A
+       ;;
+       lfetch [r18]                            // M0|1
+       mov r29=psr                             // M2 (12 cyc)
+       // If r17 is a NaT, p6 will be zero
+       cmp.geu p6,p7=r19,r17                   // A    (sysnr > 0 && sysnr < 
1024+NR_syscalls)?
+       ;;
+       mov r21=ar.fpsr                         // M2 (12 cyc)
+       tnat.nz p10,p9=r15                      // I0
+       mov.i r26=ar.pfs                        // I0 (would stall anyhow due 
to srlz.d...)
+       ;;
+       srlz.d                                  // M0 (forces split-issue) 
ensure PSR.BE==0
+(p6)   ld8 r18=[r18]                           // M0|1
+       nop.i 0
+       ;;
+       nop.m 0
+(p6)   tbit.z.unc p8,p0=r18,0                  // I0 (dual-issues with "mov 
b7=r18"!)
+       nop.i 0
+       ;;
+(p8)   ssm psr.i
+(p6)   mov b7=r18                              // I0
+(p8)   br.dptk.many b7                         // B
+
+       mov r27=ar.rsc                          // M2 (12 cyc)
+/*
+ * brl.cond doesn't work as intended because the linker would convert this 
branch
+ * into a branch to a PLT.  Perhaps there will be a way to avoid this with some
+ * future version of the linker.  In the meantime, we just use an indirect 
branch
+ * instead.
+ */
+#ifdef CONFIG_ITANIUM
+(p6)   add r14=-8,r14                          // r14 <- addr of 
fsys_bubble_down entry
+       ;;
+(p6)   ld8 r14=[r14]                           // r14 <- fsys_bubble_down
+       ;;
+(p6)   mov b7=r14
+(p6)   br.sptk.many b7
+#else
+       BRL_COND_FSYS_BUBBLE_DOWN(p6)
+#endif
+       ssm psr.i
+       mov r10=-1
+(p10)  mov r8=EINVAL
+(p9)   mov r8=ENOSYS
+       FSYS_RETURN
+END(__kernel_syscall_via_epc)
+
+#      define ARG0_OFF         (16 + IA64_SIGFRAME_ARG0_OFFSET)
+#      define ARG1_OFF         (16 + IA64_SIGFRAME_ARG1_OFFSET)
+#      define ARG2_OFF         (16 + IA64_SIGFRAME_ARG2_OFFSET)
+#      define SIGHANDLER_OFF   (16 + IA64_SIGFRAME_HANDLER_OFFSET)
+#      define SIGCONTEXT_OFF   (16 + IA64_SIGFRAME_SIGCONTEXT_OFFSET)
+
+#      define FLAGS_OFF        IA64_SIGCONTEXT_FLAGS_OFFSET
+#      define CFM_OFF          IA64_SIGCONTEXT_CFM_OFFSET
+#      define FR6_OFF          IA64_SIGCONTEXT_FR6_OFFSET
+#      define BSP_OFF          IA64_SIGCONTEXT_AR_BSP_OFFSET
+#      define RNAT_OFF         IA64_SIGCONTEXT_AR_RNAT_OFFSET
+#      define UNAT_OFF         IA64_SIGCONTEXT_AR_UNAT_OFFSET
+#      define FPSR_OFF         IA64_SIGCONTEXT_AR_FPSR_OFFSET
+#      define PR_OFF           IA64_SIGCONTEXT_PR_OFFSET
+#      define RP_OFF           IA64_SIGCONTEXT_IP_OFFSET
+#      define SP_OFF           IA64_SIGCONTEXT_R12_OFFSET
+#      define RBS_BASE_OFF     IA64_SIGCONTEXT_RBS_BASE_OFFSET
+#      define LOADRS_OFF       IA64_SIGCONTEXT_LOADRS_OFFSET
+#      define base0            r2
+#      define base1            r3
+       /*
+        * When we get here, the memory stack looks like this:
+        *
+        *   +===============================+
+                *   |                               |
+                *   //     struct sigframe          //
+                *   |                               |
+        *   +-------------------------------+ <-- sp+16
+        *   |      16 byte of scratch       |
+        *   |            space              |
+        *   +-------------------------------+ <-- sp
+        *
+        * The register stack looks _exactly_ the way it looked at the time the 
signal
+        * occurred.  In other words, we're treading on a potential mine-field: 
each
+        * incoming general register may be a NaT value (including sp, in which 
case the
+        * process ends up dying with a SIGSEGV).
+        *
+        * The first thing need to do is a cover to get the registers onto the 
backing
+        * store.  Once that is done, we invoke the signal handler which may 
modify some
+        * of the machine state.  After returning from the signal handler, we 
return
+        * control to the previous context by executing a sigreturn system 
call.  A signal
+        * handler may call the rt_sigreturn() function to directly return to a 
given
+        * sigcontext.  However, the user-level sigreturn() needs to do much 
more than
+        * calling the rt_sigreturn() system call as it needs to unwind the 
stack to
+        * restore preserved registers that may have been saved on the signal 
handler's
+        * call stack.
+        */
+
+#define SIGTRAMP_SAVES                                                         
                \
+       .unwabi 3, 's';         /* mark this as a sigtramp handler (saves 
scratch regs) */      \
+       .unwabi @svr4, 's'; /* backwards compatibility with old unwinders 
(remove in v2.7) */   \
+       .savesp ar.unat, UNAT_OFF+SIGCONTEXT_OFF;                               
                \
+       .savesp ar.fpsr, FPSR_OFF+SIGCONTEXT_OFF;                               
                \
+       .savesp pr, PR_OFF+SIGCONTEXT_OFF;                                      
                \
+       .savesp rp, RP_OFF+SIGCONTEXT_OFF;                                      
                \
+       .savesp ar.pfs, CFM_OFF+SIGCONTEXT_OFF;                                 
                \
+       .vframesp SP_OFF+SIGCONTEXT_OFF
+
+GLOBAL_ENTRY(__kernel_sigtramp)
+       // describe the state that is active when we get here:
+       .prologue
+       SIGTRAMP_SAVES
+       .body
+
+       .label_state 1
+
+       adds base0=SIGHANDLER_OFF,sp
+       adds base1=RBS_BASE_OFF+SIGCONTEXT_OFF,sp
+       br.call.sptk.many rp=1f
+1:
+       ld8 r17=[base0],(ARG0_OFF-SIGHANDLER_OFF)       // get pointer to 
signal handler's plabel
+       ld8 r15=[base1]                                 // get address of new 
RBS base (or NULL)
+       cover                           // push args in interrupted frame onto 
backing store
+       ;;
+       cmp.ne p1,p0=r15,r0             // do we need to switch rbs? (note: pr 
is saved by kernel)
+       mov.m r9=ar.bsp                 // fetch ar.bsp
+       .spillsp.p p1, ar.rnat, RNAT_OFF+SIGCONTEXT_OFF
+(p1)   br.cond.spnt setup_rbs          // yup -> (clobbers p8, r14-r16, and 
r18-r20)
+back_from_setup_rbs:
+       alloc r8=ar.pfs,0,0,3,0
+       ld8 out0=[base0],16             // load arg0 (signum)
+       adds base1=(ARG1_OFF-(RBS_BASE_OFF+SIGCONTEXT_OFF)),base1
+       ;;
+       ld8 out1=[base1]                // load arg1 (siginfop)
+       ld8 r10=[r17],8                 // get signal handler entry point
+       ;;
+       ld8 out2=[base0]                // load arg2 (sigcontextp)
+       ld8 gp=[r17]                    // get signal handler's global pointer
+       adds base0=(BSP_OFF+SIGCONTEXT_OFF),sp
+       ;;
+       .spillsp ar.bsp, BSP_OFF+SIGCONTEXT_OFF
+       st8 [base0]=r9                  // save sc_ar_bsp
+       adds base0=(FR6_OFF+SIGCONTEXT_OFF),sp
+       adds base1=(FR6_OFF+16+SIGCONTEXT_OFF),sp
+       ;;
+       stf.spill [base0]=f6,32
+       stf.spill [base1]=f7,32
+       ;;
+       stf.spill [base0]=f8,32
+       stf.spill [base1]=f9,32
+       mov b6=r10
+       ;;
+       stf.spill [base0]=f10,32
+       stf.spill [base1]=f11,32
+       ;;
+       stf.spill [base0]=f12,32
+       stf.spill [base1]=f13,32
+       ;;
+       stf.spill [base0]=f14,32
+       stf.spill [base1]=f15,32
+       br.call.sptk.many rp=b6                 // call the signal handler
+.ret0: adds base0=(BSP_OFF+SIGCONTEXT_OFF),sp
+       ;;
+       ld8 r15=[base0]                         // fetch sc_ar_bsp
+       mov r14=ar.bsp
+       ;;
+       cmp.ne p1,p0=r14,r15                    // do we need to restore the 
rbs?
+(p1)   br.cond.spnt restore_rbs                // yup -> (clobbers r14-r18, f6 
& f7)
+       ;;
+back_from_restore_rbs:
+       adds base0=(FR6_OFF+SIGCONTEXT_OFF),sp
+       adds base1=(FR6_OFF+16+SIGCONTEXT_OFF),sp
+       ;;
+       ldf.fill f6=[base0],32
+       ldf.fill f7=[base1],32
+       ;;
+       ldf.fill f8=[base0],32
+       ldf.fill f9=[base1],32
+       ;;
+       ldf.fill f10=[base0],32
+       ldf.fill f11=[base1],32
+       ;;
+       ldf.fill f12=[base0],32
+       ldf.fill f13=[base1],32
+       ;;
+       ldf.fill f14=[base0],32
+       ldf.fill f15=[base1],32
+       mov r15=__NR_rt_sigreturn
+       .restore sp                             // pop .prologue
+       break __BREAK_SYSCALL
+
+       .prologue
+       SIGTRAMP_SAVES
+setup_rbs:
+       mov ar.rsc=0                            // put RSE into enforced lazy 
mode
+       ;;
+       .save ar.rnat, r19
+       mov r19=ar.rnat                         // save RNaT before switching 
backing store area
+       adds r14=(RNAT_OFF+SIGCONTEXT_OFF),sp
+
+       mov r18=ar.bspstore
+       mov ar.bspstore=r15                     // switch over to new register 
backing store area
+       ;;
+
+       .spillsp ar.rnat, RNAT_OFF+SIGCONTEXT_OFF
+       st8 [r14]=r19                           // save sc_ar_rnat
+       .body
+       mov.m r16=ar.bsp                        // sc_loadrs <- (new bsp - new 
bspstore) << 16
+       adds r14=(LOADRS_OFF+SIGCONTEXT_OFF),sp
+       ;;
+       invala
+       sub r15=r16,r15
+       extr.u r20=r18,3,6
+       ;;
+       mov ar.rsc=0xf                          // set RSE into eager mode, pl 3
+       cmp.eq p8,p0=63,r20
+       shl r15=r15,16
+       ;;
+       st8 [r14]=r15                           // save sc_loadrs
+(p8)   st8 [r18]=r19           // if bspstore points at RNaT slot, store RNaT 
there now
+       .restore sp                             // pop .prologue
+       br.cond.sptk back_from_setup_rbs
+
+       .prologue
+       SIGTRAMP_SAVES
+       .spillsp ar.rnat, RNAT_OFF+SIGCONTEXT_OFF
+       .body
+restore_rbs:
+       // On input:
+       //      r14 = bsp1 (bsp at the time of return from signal handler)
+       //      r15 = bsp0 (bsp at the time the signal occurred)
+       //
+       // Here, we need to calculate bspstore0, the value that ar.bspstore 
needs
+       // to be set to, based on bsp0 and the size of the dirty partition on
+       // the alternate stack (sc_loadrs >> 16).  This can be done with the
+       // following algorithm:
+       //
+       //  bspstore0 = rse_skip_regs(bsp0, -rse_num_regs(bsp1 - (loadrs >> 
19), bsp1));
+       //
+       // This is what the code below does.
+       //
+       alloc r2=ar.pfs,0,0,0,0                 // alloc null frame
+       adds r16=(LOADRS_OFF+SIGCONTEXT_OFF),sp
+       adds r18=(RNAT_OFF+SIGCONTEXT_OFF),sp
+       ;;
+       ld8 r17=[r16]
+       ld8 r16=[r18]                   // get new rnat
+       extr.u r18=r15,3,6      // r18 <- rse_slot_num(bsp0)
+       ;;
+       mov ar.rsc=r17                  // put RSE into enforced lazy mode
+       shr.u r17=r17,16
+       ;;
+       sub r14=r14,r17         // r14 (bspstore1) <- bsp1 - (sc_loadrs >> 16)
+       shr.u r17=r17,3         // r17 <- (sc_loadrs >> 19)
+       ;;
+       loadrs                  // restore dirty partition
+       extr.u r14=r14,3,6      // r14 <- rse_slot_num(bspstore1)
+       ;;
+       add r14=r14,r17         // r14 <- rse_slot_num(bspstore1) + (sc_loadrs 
>> 19)
+       ;;
+       shr.u r14=r14,6         // r14 <- (rse_slot_num(bspstore1) + (sc_loadrs 
>> 19))/0x40
+       ;;
+       sub r14=r14,r17         // r14 <- -rse_num_regs(bspstore1, bsp1)
+       movl r17=0x8208208208208209
+       ;;
+       add r18=r18,r14         // r18 (delta) <- rse_slot_num(bsp0) - 
rse_num_regs(bspstore1,bsp1)
+       setf.sig f7=r17
+       cmp.lt p7,p0=r14,r0     // p7 <- (r14 < 0)?
+       ;;
+(p7)   adds r18=-62,r18        // delta -= 62
+       ;;
+       setf.sig f6=r18
+       ;;
+       xmpy.h f6=f6,f7
+       ;;
+       getf.sig r17=f6
+       ;;
+       add r17=r17,r18
+       shr r18=r18,63
+       ;;
+       shr r17=r17,5
+       ;;
+       sub r17=r17,r18         // r17 = delta/63
+       ;;
+       add r17=r14,r17         // r17 <- delta/63 - rse_num_regs(bspstore1, 
bsp1)
+       ;;
+       shladd r15=r17,3,r15    // r15 <- bsp0 + 8*(delta/63 - 
rse_num_regs(bspstore1, bsp1))
+       ;;
+       mov ar.bspstore=r15                     // switch back to old register 
backing store area
+       ;;
+       mov ar.rnat=r16                         // restore RNaT
+       mov ar.rsc=0xf                          // (will be restored later on 
from sc_ar_rsc)
+       // invala not necessary as that will happen when returning to user-mode
+       br.cond.sptk back_from_restore_rbs
+END(__kernel_sigtramp)
diff -r b8711fcb1e95 -r f8ab23b4f704 
linux-2.6-xen-sparse/arch/ia64/kernel/gate.lds.S
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/linux-2.6-xen-sparse/arch/ia64/kernel/gate.lds.S  Sat Jun 03 11:16:41 
2006 -0600
@@ -0,0 +1,95 @@
+/*
+ * Linker script for gate DSO.  The gate pages are an ELF shared object 
prelinked to its
+ * virtual address, with only one read-only segment and one execute-only 
segment (both fit
+ * in one page).  This script controls its layout.
+ */
+
+#include <linux/config.h>
+
+#include <asm/system.h>
+
+SECTIONS
+{
+  . = GATE_ADDR + SIZEOF_HEADERS;
+
+  .hash                                : { *(.hash) }                          
:readable
+  .dynsym                      : { *(.dynsym) }
+  .dynstr                      : { *(.dynstr) }
+  .gnu.version                 : { *(.gnu.version) }
+  .gnu.version_d               : { *(.gnu.version_d) }
+  .gnu.version_r               : { *(.gnu.version_r) }
+  .dynamic                     : { *(.dynamic) }                       
:readable :dynamic
+
+  /*
+   * This linker script is used both with -r and with -shared.  For the 
layouts to match,
+   * we need to skip more than enough space for the dynamic symbol table et 
al.  If this
+   * amount is insufficient, ld -shared will barf.  Just increase it here.
+   */
+  . = GATE_ADDR + 0x500;
+
+  .data.patch                  : {
+                                   __start_gate_mckinley_e9_patchlist = .;
+                                   *(.data.patch.mckinley_e9)
+                                   __end_gate_mckinley_e9_patchlist = .;
+
+                                   __start_gate_vtop_patchlist = .;
+                                   *(.data.patch.vtop)
+                                   __end_gate_vtop_patchlist = .;
+
+                                   __start_gate_fsyscall_patchlist = .;
+                                   *(.data.patch.fsyscall_table)
+                                   __end_gate_fsyscall_patchlist = .;
+
+                                   __start_gate_brl_fsys_bubble_down_patchlist 
= .;
+                                   *(.data.patch.brl_fsys_bubble_down)
+                                   __end_gate_brl_fsys_bubble_down_patchlist = 
.;
+  }                                                                    
:readable
+  .IA_64.unwind_info           : { *(.IA_64.unwind_info*) }
+  .IA_64.unwind                        : { *(.IA_64.unwind*) }                 
:readable :unwind
+#ifdef HAVE_BUGGY_SEGREL
+  .text (GATE_ADDR + PAGE_SIZE)        : { *(.text) *(.text.*) }               
:readable
+#else
+  . = ALIGN (PERCPU_PAGE_SIZE) + (. & (PERCPU_PAGE_SIZE - 1));
+  .text                                : { *(.text) *(.text.*) }               
:epc
+#endif
+
+  /DISCARD/                    : {
+       *(.got.plt) *(.got)
+       *(.data .data.* .gnu.linkonce.d.*)
+       *(.dynbss)
+       *(.bss .bss.* .gnu.linkonce.b.*)
+       *(__ex_table)
+  }
+}
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+PHDRS
+{
+  readable  PT_LOAD    FILEHDR PHDRS   FLAGS(4);       /* PF_R */
+#ifndef HAVE_BUGGY_SEGREL
+  epc      PT_LOAD     FILEHDR PHDRS   FLAGS(1);       /* PF_X */
+#endif
+  dynamic   PT_DYNAMIC                 FLAGS(4);       /* PF_R */
+  unwind    0x70000001; /* PT_IA_64_UNWIND, but ld doesn't match the name */
+}
+
+/*
+ * This controls what symbols we export from the DSO.
+ */
+VERSION
+{
+  LINUX_2.5 {
+    global:
+       __kernel_syscall_via_break;
+       __kernel_syscall_via_epc;
+       __kernel_sigtramp;
+
+    local: *;
+  };
+}
+
+/* The ELF entry point can be used to set the AT_SYSINFO value.  */
+ENTRY(__kernel_syscall_via_epc)
diff -r b8711fcb1e95 -r f8ab23b4f704 
linux-2.6-xen-sparse/arch/ia64/kernel/patch.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/linux-2.6-xen-sparse/arch/ia64/kernel/patch.c     Sat Jun 03 11:16:41 
2006 -0600
@@ -0,0 +1,197 @@
+/*
+ * Instruction-patching support.
+ *
+ * Copyright (C) 2003 Hewlett-Packard Co
+ *     David Mosberger-Tang <davidm@xxxxxxxxxx>
+ */
+#include <linux/init.h>
+#include <linux/string.h>
+
+#include <asm/patch.h>
+#include <asm/processor.h>
+#include <asm/sections.h>
+#include <asm/system.h>
+#include <asm/unistd.h>
+
+/*
+ * This was adapted from code written by Tony Luck:
+ *
+ * The 64-bit value in a "movl reg=value" is scattered between the two words 
of the bundle
+ * like this:
+ *
+ * 6  6         5         4         3         2         1
+ * 3210987654321098765432109876543210987654321098765432109876543210
+ * ABBBBBBBBBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCDEEEEEFFFFFFFFFGGGGGGG
+ *
+ * CCCCCCCCCCCCCCCCCCxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+ * xxxxAFFFFFFFFFEEEEEDxGGGGGGGxxxxxxxxxxxxxBBBBBBBBBBBBBBBBBBBBBBB
+ */
+static u64
+get_imm64 (u64 insn_addr)
+{
+       u64 *p = (u64 *) (insn_addr & -16);     /* mask out slot number */
+
+       return ( (p[1] & 0x0800000000000000UL) << 4)  | /*A*/
+               ((p[1] & 0x00000000007fffffUL) << 40) | /*B*/
+               ((p[0] & 0xffffc00000000000UL) >> 24) | /*C*/
+               ((p[1] & 0x0000100000000000UL) >> 23) | /*D*/
+               ((p[1] & 0x0003e00000000000UL) >> 29) | /*E*/
+               ((p[1] & 0x07fc000000000000UL) >> 43) | /*F*/
+               ((p[1] & 0x000007f000000000UL) >> 36);  /*G*/
+}
+
+/* Patch instruction with "val" where "mask" has 1 bits. */
+void
+ia64_patch (u64 insn_addr, u64 mask, u64 val)
+{
+       u64 m0, m1, v0, v1, b0, b1, *b = (u64 *) (insn_addr & -16);
+#      define insn_mask ((1UL << 41) - 1)
+       unsigned long shift;
+
+       b0 = b[0]; b1 = b[1];
+       shift = 5 + 41 * (insn_addr % 16); /* 5 bits of template, then 3 x 
41-bit instructions */
+       if (shift >= 64) {
+               m1 = mask << (shift - 64);
+               v1 = val << (shift - 64);
+       } else {
+               m0 = mask << shift; m1 = mask >> (64 - shift);
+               v0 = val  << shift; v1 = val >> (64 - shift);
+               b[0] = (b0 & ~m0) | (v0 & m0);
+       }
+       b[1] = (b1 & ~m1) | (v1 & m1);
+}
+
+void
+ia64_patch_imm64 (u64 insn_addr, u64 val)
+{
+       /* The assembler may generate offset pointing to either slot 1
+          or slot 2 for a long (2-slot) instruction, occupying slots 1
+          and 2.  */
+       insn_addr &= -16UL;
+       ia64_patch(insn_addr + 2,
+                  0x01fffefe000UL, (  ((val & 0x8000000000000000UL) >> 27) /* 
bit 63 -> 36 */
+                                    | ((val & 0x0000000000200000UL) <<  0) /* 
bit 21 -> 21 */
+                                    | ((val & 0x00000000001f0000UL) <<  6) /* 
bit 16 -> 22 */
+                                    | ((val & 0x000000000000ff80UL) << 20) /* 
bit  7 -> 27 */
+                                    | ((val & 0x000000000000007fUL) << 13) /* 
bit  0 -> 13 */));
+       ia64_patch(insn_addr + 1, 0x1ffffffffffUL, val >> 22);
+}
+
+void
+ia64_patch_imm60 (u64 insn_addr, u64 val)
+{
+       /* The assembler may generate offset pointing to either slot 1
+          or slot 2 for a long (2-slot) instruction, occupying slots 1
+          and 2.  */
+       insn_addr &= -16UL;
+       ia64_patch(insn_addr + 2,
+                  0x011ffffe000UL, (  ((val & 0x0800000000000000UL) >> 23) /* 
bit 59 -> 36 */
+                                    | ((val & 0x00000000000fffffUL) << 13) /* 
bit  0 -> 13 */));
+       ia64_patch(insn_addr + 1, 0x1fffffffffcUL, val >> 18);
+}
+
+/*
+ * We need sometimes to load the physical address of a kernel
+ * object.  Often we can convert the virtual address to physical
+ * at execution time, but sometimes (either for performance reasons
+ * or during error recovery) we cannot to this.  Patch the marked
+ * bundles to load the physical address.
+ */
+void __init
+ia64_patch_vtop (unsigned long start, unsigned long end)
+{
+       s32 *offp = (s32 *) start;
+       u64 ip;
+
+       while (offp < (s32 *) end) {
+               ip = (u64) offp + *offp;
+
+               /* replace virtual address with corresponding physical address: 
*/
+               ia64_patch_imm64(ip, ia64_tpa(get_imm64(ip)));
+               ia64_fc((void *) ip);
+               ++offp;
+       }
+       ia64_sync_i();
+       ia64_srlz_i();
+}
+
+void
+ia64_patch_mckinley_e9 (unsigned long start, unsigned long end)
+{
+       static int first_time = 1;
+       int need_workaround;
+       s32 *offp = (s32 *) start;
+       u64 *wp;
+
+       need_workaround = (local_cpu_data->family == 0x1f && 
local_cpu_data->model == 0);
+
+       if (first_time) {
+               first_time = 0;
+               if (need_workaround)
+                       printk(KERN_INFO "Leaving McKinley Errata 9 workaround 
enabled\n");
+               else
+                       printk(KERN_INFO "McKinley Errata 9 workaround not 
needed; "
+                              "disabling it\n");
+       }
+       if (need_workaround)
+               return;
+
+       while (offp < (s32 *) end) {
+               wp = (u64 *) ia64_imva((char *) offp + *offp);
+               wp[0] = 0x0000000100000000UL; /* nop.m 0; nop.i 0; nop.i 0 */
+               wp[1] = 0x0004000000000200UL;
+               wp[2] = 0x0000000100000011UL; /* nop.m 0; nop.i 0; 
br.ret.sptk.many b6 */
+               wp[3] = 0x0084006880000200UL;
+               ia64_fc(wp); ia64_fc(wp + 2);
+               ++offp;
+       }
+       ia64_sync_i();
+       ia64_srlz_i();
+}
+
+static void
+patch_fsyscall_table (unsigned long start, unsigned long end)
+{
+       extern unsigned long fsyscall_table[NR_syscalls];
+       s32 *offp = (s32 *) start;
+       u64 ip;
+
+       while (offp < (s32 *) end) {
+               ip = (u64) ia64_imva((char *) offp + *offp);
+               ia64_patch_imm64(ip, (u64) fsyscall_table);
+               ia64_fc((void *) ip);
+               ++offp;
+       }
+       ia64_sync_i();
+       ia64_srlz_i();
+}
+
+static void
+patch_brl_fsys_bubble_down (unsigned long start, unsigned long end)
+{
+       extern char fsys_bubble_down[];
+       s32 *offp = (s32 *) start;
+       u64 ip;
+
+       while (offp < (s32 *) end) {
+               ip = (u64) offp + *offp;
+               ia64_patch_imm60((u64) ia64_imva((void *) ip),
+                                (u64) (fsys_bubble_down - (ip & -16)) / 16);
+               ia64_fc((void *) ip);
+               ++offp;
+       }
+       ia64_sync_i();
+       ia64_srlz_i();
+}
+
+void
+ia64_patch_gate (void)
+{
+#      define START(name)      ((unsigned long) 
__start_gate_##name##_patchlist)
+#      define END(name)        ((unsigned long)__end_gate_##name##_patchlist)
+
+       patch_fsyscall_table(START(fsyscall), END(fsyscall));
+       patch_brl_fsys_bubble_down(START(brl_fsys_bubble_down), 
END(brl_fsys_bubble_down));
+       ia64_patch_vtop(START(vtop), END(vtop));
+       ia64_patch_mckinley_e9(START(mckinley_e9), END(mckinley_e9));
+}

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