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[Xen-changelog] [xen-unstable] x86: Remove (most) Centaur CPU support. Only VIA C7 can work, as it



# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Date 1188394800 -3600
# Node ID 79053138b35c8e77ef828f920ce0c68543c6a932
# Parent  86a02b7148fabe25f374b5dbe69579a9d249c821
x86: Remove (most) Centaur CPU support. Only VIA C7 can work, as it
has CMOV support. Leave a small amount of centaur.c around to support
that. MTRR code goes entirely, as 686-class Centaur CPUs have generic
MTRR support.

Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
 xen/arch/x86/cpu/mtrr/centaur.c |  223 -----------------------
 xen/arch/x86/cpu/centaur.c      |  380 ----------------------------------------
 xen/arch/x86/cpu/mtrr/Makefile  |    1 
 xen/arch/x86/cpu/mtrr/main.c    |    9 
 xen/include/asm-x86/spinlock.h  |    8 
 xen/include/asm-x86/system.h    |   28 --
 6 files changed, 3 insertions(+), 646 deletions(-)

diff -r 86a02b7148fa -r 79053138b35c xen/arch/x86/cpu/centaur.c
--- a/xen/arch/x86/cpu/centaur.c        Wed Aug 29 11:34:01 2007 +0100
+++ b/xen/arch/x86/cpu/centaur.c        Wed Aug 29 14:40:00 2007 +0100
@@ -6,248 +6,6 @@
 #include <asm/msr.h>
 #include <asm/e820.h>
 #include "cpu.h"
-
-#ifdef CONFIG_X86_OOSTORE
-
-static u32 __init power2(u32 x)
-{
-       u32 s=1;
-       while(s<=x)
-               s<<=1;
-       return s>>=1;
-}
-
-
-/*
- *     Set up an actual MCR
- */
- 
-static void __init centaur_mcr_insert(int reg, u32 base, u32 size, int key)
-{
-       u32 lo, hi;
-       
-       hi = base & ~0xFFF;
-       lo = ~(size-1);         /* Size is a power of 2 so this makes a mask */
-       lo &= ~0xFFF;           /* Remove the ctrl value bits */
-       lo |= key;              /* Attribute we wish to set */
-       wrmsr(reg+MSR_IDT_MCR0, lo, hi);
-       mtrr_centaur_report_mcr(reg, lo, hi);   /* Tell the mtrr driver */
-}
-
-/*
- *     Figure what we can cover with MCR's
- *
- *     Shortcut: We know you can't put 4Gig of RAM on a winchip
- */
-
-static u32 __init ramtop(void)         /* 16388 */
-{
-       int i;
-       u32 top = 0;
-       u32 clip = 0xFFFFFFFFUL;
-       
-       for (i = 0; i < e820.nr_map; i++) {
-               unsigned long start, end;
-
-               if (e820.map[i].addr > 0xFFFFFFFFUL)
-                       continue;
-               /*
-                *      Don't MCR over reserved space. Ignore the ISA hole
-                *      we frob around that catastrophy already
-                */
-                                       
-               if (e820.map[i].type == E820_RESERVED)
-               {
-                       if(e820.map[i].addr >= 0x100000UL && e820.map[i].addr < 
clip)
-                               clip = e820.map[i].addr;
-                       continue;
-               }
-               start = e820.map[i].addr;
-               end = e820.map[i].addr + e820.map[i].size;
-               if (start >= end)
-                       continue;
-               if (end > top)
-                       top = end;
-       }
-       /* Everything below 'top' should be RAM except for the ISA hole.
-          Because of the limited MCR's we want to map NV/ACPI into our
-          MCR range for gunk in RAM 
-          
-          Clip might cause us to MCR insufficient RAM but that is an
-          acceptable failure mode and should only bite obscure boxes with
-          a VESA hole at 15Mb
-          
-          The second case Clip sometimes kicks in is when the EBDA is marked
-          as reserved. Again we fail safe with reasonable results
-       */
-       
-       if(top>clip)
-               top=clip;
-               
-       return top;
-}
-
-/*
- *     Compute a set of MCR's to give maximum coverage
- */
-
-static int __init centaur_mcr_compute(int nr, int key)
-{
-       u32 mem = ramtop();
-       u32 root = power2(mem);
-       u32 base = root;
-       u32 top = root;
-       u32 floor = 0;
-       int ct = 0;
-       
-       while(ct<nr)
-       {
-               u32 fspace = 0;
-
-               /*
-                *      Find the largest block we will fill going upwards
-                */
-
-               u32 high = power2(mem-top);     
-
-               /*
-                *      Find the largest block we will fill going downwards
-                */
-
-               u32 low = base/2;
-
-               /*
-                *      Don't fill below 1Mb going downwards as there
-                *      is an ISA hole in the way.
-                */             
-                
-               if(base <= 1024*1024)
-                       low = 0;
-                       
-               /*
-                *      See how much space we could cover by filling below
-                *      the ISA hole
-                */
-                
-               if(floor == 0)
-                       fspace = 512*1024;
-               else if(floor ==512*1024)
-                       fspace = 128*1024;
-
-               /* And forget ROM space */
-               
-               /*
-                *      Now install the largest coverage we get
-                */
-                
-               if(fspace > high && fspace > low)
-               {
-                       centaur_mcr_insert(ct, floor, fspace, key);
-                       floor += fspace;
-               }
-               else if(high > low)
-               {
-                       centaur_mcr_insert(ct, top, high, key);
-                       top += high;
-               }
-               else if(low > 0)
-               {
-                       base -= low;
-                       centaur_mcr_insert(ct, base, low, key);
-               }
-               else break;
-               ct++;
-       }
-       /*
-        *      We loaded ct values. We now need to set the mask. The caller
-        *      must do this bit.
-        */
-        
-       return ct;
-}
-
-static void __init centaur_create_optimal_mcr(void)
-{
-       int i;
-       /*
-        *      Allocate up to 6 mcrs to mark as much of ram as possible
-        *      as write combining and weak write ordered.
-        *
-        *      To experiment with: Linux never uses stack operations for 
-        *      mmio spaces so we could globally enable stack operation wc
-        *
-        *      Load the registers with type 31 - full write combining, all
-        *      writes weakly ordered.
-        */
-       int used = centaur_mcr_compute(6, 31);
-
-       /*
-        *      Wipe unused MCRs
-        */
-        
-       for(i=used;i<8;i++)
-               wrmsr(MSR_IDT_MCR0+i, 0, 0);
-}
-
-static void __init winchip2_create_optimal_mcr(void)
-{
-       u32 lo, hi;
-       int i;
-
-       /*
-        *      Allocate up to 6 mcrs to mark as much of ram as possible
-        *      as write combining, weak store ordered.
-        *
-        *      Load the registers with type 25
-        *              8       -       weak write ordering
-        *              16      -       weak read ordering
-        *              1       -       write combining
-        */
-
-       int used = centaur_mcr_compute(6, 25);
-       
-       /*
-        *      Mark the registers we are using.
-        */
-        
-       rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
-       for(i=0;i<used;i++)
-               lo|=1<<(9+i);
-       wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
-       
-       /*
-        *      Wipe unused MCRs
-        */
-        
-       for(i=used;i<8;i++)
-               wrmsr(MSR_IDT_MCR0+i, 0, 0);
-}
-
-/*
- *     Handle the MCR key on the Winchip 2.
- */
-
-static void __init winchip2_unprotect_mcr(void)
-{
-       u32 lo, hi;
-       u32 key;
-       
-       rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
-       lo&=~0x1C0;     /* blank bits 8-6 */
-       key = (lo>>17) & 7;
-       lo |= key<<6;   /* replace with unlock key */
-       wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
-}
-
-static void __init winchip2_protect_mcr(void)
-{
-       u32 lo, hi;
-       
-       rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
-       lo&=~0x1C0;     /* blank bits 8-6 */
-       wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
-}
-#endif /* CONFIG_X86_OOSTORE */
 
 #define ACE_PRESENT    (1 << 6)
 #define ACE_ENABLED    (1 << 7)
@@ -305,146 +63,12 @@ static void __init init_c3(struct cpuinf
 
 static void __init init_centaur(struct cpuinfo_x86 *c)
 {
-       enum {
-               ECX8=1<<1,
-               EIERRINT=1<<2,
-               DPM=1<<3,
-               DMCE=1<<4,
-               DSTPCLK=1<<5,
-               ELINEAR=1<<6,
-               DSMC=1<<7,
-               DTLOCK=1<<8,
-               EDCTLB=1<<8,
-               EMMX=1<<9,
-               DPDC=1<<11,
-               EBRPRED=1<<12,
-               DIC=1<<13,
-               DDC=1<<14,
-               DNA=1<<15,
-               ERETSTK=1<<16,
-               E2MMX=1<<19,
-               EAMD3D=1<<20,
-       };
-
-       char *name;
-       u32  fcr_set=0;
-       u32  fcr_clr=0;
-       u32  lo,hi,newlo;
-       u32  aa,bb,cc,dd;
-
        /* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
           3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
        clear_bit(0*32+31, c->x86_capability);
 
-       switch (c->x86) {
-
-               case 5:
-                       switch(c->x86_model) {
-                       case 4:
-                               name="C6";
-                               fcr_set=ECX8|DSMC|EDCTLB|EMMX|ERETSTK;
-                               fcr_clr=DPDC;
-                               printk(KERN_NOTICE "Disabling bugged TSC.\n");
-                               clear_bit(X86_FEATURE_TSC, c->x86_capability);
-#ifdef CONFIG_X86_OOSTORE
-                               centaur_create_optimal_mcr();
-                               /* Enable
-                                       write combining on non-stack, non-string
-                                       write combining on string, all types
-                                       weak write ordering 
-                                       
-                                  The C6 original lacks weak read order 
-                                  
-                                  Note 0x120 is write only on Winchip 1 */
-                                  
-                               wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);
-#endif                         
-                               break;
-                       case 8:
-                               switch(c->x86_mask) {
-                               default:
-                                       name="2";
-                                       break;
-                               case 7 ... 9:
-                                       name="2A";
-                                       break;
-                               case 10 ... 15:
-                                       name="2B";
-                                       break;
-                               }
-                               
fcr_set=ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|E2MMX|EAMD3D;
-                               fcr_clr=DPDC;
-#ifdef CONFIG_X86_OOSTORE
-                               winchip2_unprotect_mcr();
-                               winchip2_create_optimal_mcr();
-                               rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
-                               /* Enable
-                                       write combining on non-stack, non-string
-                                       write combining on string, all types
-                                       weak write ordering 
-                               */
-                               lo|=31;                         
-                               wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
-                               winchip2_protect_mcr();
-#endif
-                               break;
-                       case 9:
-                               name="3";
-                               
fcr_set=ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|E2MMX|EAMD3D;
-                               fcr_clr=DPDC;
-#ifdef CONFIG_X86_OOSTORE
-                               winchip2_unprotect_mcr();
-                               winchip2_create_optimal_mcr();
-                               rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
-                               /* Enable
-                                       write combining on non-stack, non-string
-                                       write combining on string, all types
-                                       weak write ordering 
-                               */
-                               lo|=31;                         
-                               wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
-                               winchip2_protect_mcr();
-#endif
-                               break;
-                       case 10:
-                               name="4";
-                               /* no info on the WC4 yet */
-                               break;
-                       default:
-                               name="??";
-                       }
-
-                       rdmsr(MSR_IDT_FCR1, lo, hi);
-                       newlo=(lo|fcr_set) & (~fcr_clr);
-
-                       if (newlo!=lo) {
-                               printk(KERN_INFO "Centaur FCR was 0x%X now 
0x%X\n", lo, newlo );
-                               wrmsr(MSR_IDT_FCR1, newlo, hi );
-                       } else {
-                               printk(KERN_INFO "Centaur FCR is 0x%X\n",lo);
-                       }
-                       /* Emulate MTRRs using Centaur's MCR. */
-                       set_bit(X86_FEATURE_CENTAUR_MCR, c->x86_capability);
-                       /* Report CX8 */
-                       set_bit(X86_FEATURE_CX8, c->x86_capability);
-                       /* Set 3DNow! on Winchip 2 and above. */
-                       if (c->x86_model >=8)
-                               set_bit(X86_FEATURE_3DNOW, c->x86_capability);
-                       /* See if we can find out some more. */
-                       if ( cpuid_eax(0x80000000) >= 0x80000005 ) {
-                               /* Yes, we can. */
-                               cpuid(0x80000005,&aa,&bb,&cc,&dd);
-                               /* Add L1 data and code cache sizes. */
-                               c->x86_cache_size = (cc>>24)+(dd>>24);
-                       }
-                       snprintf( c->x86_model_id, sizeof(c->x86_model_id),
-                               "WinChip %s", name );
-                       break;
-
-               case 6:
-                       init_c3(c);
-                       break;
-       }
+       if (c->x86 == 6)
+               init_c3(c);
 }
 
 static unsigned int centaur_size_cache(struct cpuinfo_x86 * c, unsigned int 
size)
diff -r 86a02b7148fa -r 79053138b35c xen/arch/x86/cpu/mtrr/Makefile
--- a/xen/arch/x86/cpu/mtrr/Makefile    Wed Aug 29 11:34:01 2007 +0100
+++ b/xen/arch/x86/cpu/mtrr/Makefile    Wed Aug 29 14:40:00 2007 +0100
@@ -1,5 +1,4 @@ obj-$(x86_32) += amd.o
 obj-$(x86_32) += amd.o
-obj-$(x86_32) += centaur.o
 obj-$(x86_32) += cyrix.o
 obj-y += generic.o
 obj-y += main.o
diff -r 86a02b7148fa -r 79053138b35c xen/arch/x86/cpu/mtrr/centaur.c
--- a/xen/arch/x86/cpu/mtrr/centaur.c   Wed Aug 29 11:34:01 2007 +0100
+++ /dev/null   Thu Jan 01 00:00:00 1970 +0000
@@ -1,223 +0,0 @@
-#include <xen/init.h>
-#include <xen/mm.h>
-#include <asm/mtrr.h>
-#include <asm/msr.h>
-#include "mtrr.h"
-
-static struct {
-       unsigned long high;
-       unsigned long low;
-} centaur_mcr[8];
-
-static u8 centaur_mcr_reserved;
-static u8 centaur_mcr_type;    /* 0 for winchip, 1 for winchip2 */
-
-/*
- *     Report boot time MCR setups 
- */
-
-static int
-centaur_get_free_region(unsigned long base, unsigned long size)
-/*  [SUMMARY] Get a free MTRR.
-    <base> The starting (base) address of the region.
-    <size> The size (in bytes) of the region.
-    [RETURNS] The index of the region on success, else -1 on error.
-*/
-{
-       int i, max;
-       mtrr_type ltype;
-       unsigned long lbase;
-       unsigned int lsize;
-
-       max = num_var_ranges;
-       for (i = 0; i < max; ++i) {
-               if (centaur_mcr_reserved & (1 << i))
-                       continue;
-               mtrr_if->get(i, &lbase, &lsize, &ltype);
-               if (lsize == 0)
-                       return i;
-       }
-       return -ENOSPC;
-}
-
-void
-mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
-{
-       centaur_mcr[mcr].low = lo;
-       centaur_mcr[mcr].high = hi;
-}
-
-static void
-centaur_get_mcr(unsigned int reg, unsigned long *base,
-               unsigned int *size, mtrr_type * type)
-{
-       *base = centaur_mcr[reg].high >> PAGE_SHIFT;
-       *size = -(centaur_mcr[reg].low & 0xfffff000) >> PAGE_SHIFT;
-       *type = MTRR_TYPE_WRCOMB;       /*  If it is there, it is 
write-combining  */
-       if (centaur_mcr_type == 1 && ((centaur_mcr[reg].low & 31) & 2))
-               *type = MTRR_TYPE_UNCACHABLE;
-       if (centaur_mcr_type == 1 && (centaur_mcr[reg].low & 31) == 25)
-               *type = MTRR_TYPE_WRBACK;
-       if (centaur_mcr_type == 0 && (centaur_mcr[reg].low & 31) == 31)
-               *type = MTRR_TYPE_WRBACK;
-
-}
-
-static void centaur_set_mcr(unsigned int reg, unsigned long base,
-                           unsigned long size, mtrr_type type)
-{
-       unsigned long low, high;
-
-       if (size == 0) {
-               /*  Disable  */
-               high = low = 0;
-       } else {
-               high = base << PAGE_SHIFT;
-               if (centaur_mcr_type == 0)
-                       low = -size << PAGE_SHIFT | 0x1f;       /* only support 
write-combining... */
-               else {
-                       if (type == MTRR_TYPE_UNCACHABLE)
-                               low = -size << PAGE_SHIFT | 0x02;       /* NC */
-                       else
-                               low = -size << PAGE_SHIFT | 0x09;       /* 
WWO,WC */
-               }
-       }
-       centaur_mcr[reg].high = high;
-       centaur_mcr[reg].low = low;
-       wrmsr(MSR_IDT_MCR0 + reg, low, high);
-}
-
-#if 0
-/*
- *     Initialise the later (saner) Winchip MCR variant. In this version
- *     the BIOS can pass us the registers it has used (but not their values)
- *     and the control register is read/write
- */
-
-static void __init
-centaur_mcr1_init(void)
-{
-       unsigned i;
-       u32 lo, hi;
-
-       /* Unfortunately, MCR's are read-only, so there is no way to
-        * find out what the bios might have done.
-        */
-
-       rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
-       if (((lo >> 17) & 7) == 1) {    /* Type 1 Winchip2 MCR */
-               lo &= ~0x1C0;   /* clear key */
-               lo |= 0x040;    /* set key to 1 */
-               wrmsr(MSR_IDT_MCR_CTRL, lo, hi);        /* unlock MCR */
-       }
-
-       centaur_mcr_type = 1;
-
-       /*
-        *  Clear any unconfigured MCR's.
-        */
-
-       for (i = 0; i < 8; ++i) {
-               if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0) {
-                       if (!(lo & (1 << (9 + i))))
-                               wrmsr(MSR_IDT_MCR0 + i, 0, 0);
-                       else
-                               /*
-                                *      If the BIOS set up an MCR we cannot see 
it
-                                *      but we don't wish to obliterate it
-                                */
-                               centaur_mcr_reserved |= (1 << i);
-               }
-       }
-       /*  
-        *  Throw the main write-combining switch... 
-        *  However if OOSTORE is enabled then people have already done far
-        *  cleverer things and we should behave. 
-        */
-
-       lo |= 15;               /* Write combine enables */
-       wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
-}
-
-/*
- *     Initialise the original winchip with read only MCR registers
- *     no used bitmask for the BIOS to pass on and write only control
- */
-
-static void __init
-centaur_mcr0_init(void)
-{
-       unsigned i;
-
-       /* Unfortunately, MCR's are read-only, so there is no way to
-        * find out what the bios might have done.
-        */
-
-       /* Clear any unconfigured MCR's.
-        * This way we are sure that the centaur_mcr array contains the actual
-        * values. The disadvantage is that any BIOS tweaks are thus undone.
-        *
-        */
-       for (i = 0; i < 8; ++i) {
-               if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0)
-                       wrmsr(MSR_IDT_MCR0 + i, 0, 0);
-       }
-
-       wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0); /* Write only */
-}
-
-/*
- *     Initialise Winchip series MCR registers
- */
-
-static void __init
-centaur_mcr_init(void)
-{
-       struct set_mtrr_context ctxt;
-
-       set_mtrr_prepare_save(&ctxt);
-       set_mtrr_cache_disable(&ctxt);
-
-       if (boot_cpu_data.x86_model == 4)
-               centaur_mcr0_init();
-       else if (boot_cpu_data.x86_model == 8 || boot_cpu_data.x86_model == 9)
-               centaur_mcr1_init();
-
-       set_mtrr_done(&ctxt);
-}
-#endif
-
-static int centaur_validate_add_page(unsigned long base, 
-                                    unsigned long size, unsigned int type)
-{
-       /*
-        *  FIXME: Winchip2 supports uncached
-        */
-       if (type != MTRR_TYPE_WRCOMB && 
-           (centaur_mcr_type == 0 || type != MTRR_TYPE_UNCACHABLE)) {
-               printk(KERN_WARNING
-                      "mtrr: only write-combining%s supported\n",
-                      centaur_mcr_type ? " and uncacheable are"
-                      : " is");
-               return -EINVAL;
-       }
-       return 0;
-}
-
-static struct mtrr_ops centaur_mtrr_ops = {
-       .vendor            = X86_VENDOR_CENTAUR,
-//     .init              = centaur_mcr_init,
-       .set               = centaur_set_mcr,
-       .get               = centaur_get_mcr,
-       .get_free_region   = centaur_get_free_region,
-       .validate_add_page = centaur_validate_add_page,
-       .have_wrcomb       = positive_have_wrcomb,
-};
-
-int __init centaur_init_mtrr(void)
-{
-       set_mtrr_ops(&centaur_mtrr_ops);
-       return 0;
-}
-
-//arch_initcall(centaur_init_mtrr);
diff -r 86a02b7148fa -r 79053138b35c xen/arch/x86/cpu/mtrr/main.c
--- a/xen/arch/x86/cpu/mtrr/main.c      Wed Aug 29 11:34:01 2007 +0100
+++ b/xen/arch/x86/cpu/mtrr/main.c      Wed Aug 29 14:40:00 2007 +0100
@@ -539,14 +539,12 @@ EXPORT_SYMBOL(mtrr_del);
  */
 extern void amd_init_mtrr(void);
 extern void cyrix_init_mtrr(void);
-extern void centaur_init_mtrr(void);
 
 static void __init init_ifs(void)
 {
 #ifndef CONFIG_X86_64
        amd_init_mtrr();
        cyrix_init_mtrr();
-       centaur_init_mtrr();
 #endif
 }
 
@@ -609,13 +607,6 @@ void __init mtrr_bp_init(void)
                                size_and_mask = 0;
                        }
                        break;
-               case X86_VENDOR_CENTAUR:
-                       if (cpu_has_centaur_mcr) {
-                               mtrr_if = mtrr_ops[X86_VENDOR_CENTAUR];
-                               size_or_mask = 0xfff00000;      /* 32 bits */
-                               size_and_mask = 0;
-                       }
-                       break;
                case X86_VENDOR_CYRIX:
                        if (cpu_has_cyrix_arr) {
                                mtrr_if = mtrr_ops[X86_VENDOR_CYRIX];
diff -r 86a02b7148fa -r 79053138b35c xen/include/asm-x86/spinlock.h
--- a/xen/include/asm-x86/spinlock.h    Wed Aug 29 11:34:01 2007 +0100
+++ b/xen/include/asm-x86/spinlock.h    Wed Aug 29 14:40:00 2007 +0100
@@ -33,18 +33,10 @@ static inline void _raw_spin_lock(spinlo
 
 static inline void _raw_spin_unlock(spinlock_t *lock)
 {
-#if !defined(CONFIG_X86_OOSTORE)
     ASSERT(spin_is_locked(lock));
     __asm__ __volatile__ (
        "movb $1,%0" 
         : "=m" (lock->lock) : : "memory" );
-#else
-    char oldval = 1;
-    ASSERT(spin_is_locked(lock));
-    __asm__ __volatile__ (
-       "xchgb %b0, %1"
-        : "=q" (oldval), "=m" (lock->lock) : "0" (oldval) : "memory" );
-#endif
 }
 
 static inline int _raw_spin_trylock(spinlock_t *lock)
diff -r 86a02b7148fa -r 79053138b35c xen/include/asm-x86/system.h
--- a/xen/include/asm-x86/system.h      Wed Aug 29 11:34:01 2007 +0100
+++ b/xen/include/asm-x86/system.h      Wed Aug 29 14:40:00 2007 +0100
@@ -253,40 +253,14 @@ static always_inline unsigned long long 
 })
 #endif
 
-/*
- * Force strict CPU ordering.
- * And yes, this is required on UP too when we're talking
- * to devices.
- *
- * For now, "wmb()" doesn't actually do anything, as all
- * Intel CPU's follow what Intel calls a *Processor Order*,
- * in which all writes are seen in the program order even
- * outside the CPU.
- *
- * I expect future Intel CPU's to have a weaker ordering,
- * but I'd also expect them to finally get their act together
- * and add some real memory barriers if so.
- *
- * Some non intel clones support out of order store. wmb() ceases to be a
- * nop for these.
- */
 #if defined(__i386__)
 #define mb()   __asm__ __volatile__ ("lock; addl $0,0(%%esp)": : :"memory")
 #define rmb()  __asm__ __volatile__ ("lock; addl $0,0(%%esp)": : :"memory")
-#ifdef CONFIG_X86_OOSTORE
-#define wmb()  __asm__ __volatile__ ("lock; addl $0,0(%%esp)": : :"memory")
-#endif
 #elif defined(__x86_64__)
 #define mb()    __asm__ __volatile__ ("mfence":::"memory")
 #define rmb()   __asm__ __volatile__ ("lfence":::"memory")
-#ifdef CONFIG_X86_OOSTORE
-#define wmb()   __asm__ __volatile__ ("sfence":::"memory")
-#endif
-#endif
-
-#ifndef CONFIG_X86_OOSTORE
+#endif
 #define wmb()  __asm__ __volatile__ ("": : :"memory")
-#endif
 
 #ifdef CONFIG_SMP
 #define smp_mb()       mb()

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