Re: [PATCH] x86: x86_{phys,virt}_bits field also for i386 (v2)

From: Jan Beulich
Date: Mon Sep 08 2008 - 06:50:10 EST


>>> Ingo Molnar <mingo@xxxxxxx> 05.09.08 17:00 >>>
>
>* Jan Beulich <jbeulich@xxxxxxxxxx> wrote:
>
>> Make the x86_{phys,virt}_bits common for 32- and 64-bits, and use the
>> former in ioremap's phys_addr_valid() check also on 32bit/PAE.
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
>>
>> ---
>> arch/x86/kernel/cpu/common.c | 17 +++++++++++++++++
>> arch/x86/mm/ioremap.c | 15 ++++++---------
>> include/asm-x86/processor.h | 4 ++--
>> 3 files changed, 25 insertions(+), 11 deletions(-)
>
>hm, the cpu/common.c bits just got reworked massively in tip/master.
>I've tried a blind merge (see the patch below) but at least the first
>hunk looks wrong. Mind looking at how to merge this?

This is my take at it:

Make the x86_{phys,virt}_bits common for 32- and 64-bits, and use the
former in ioremap's phys_addr_valid() check also on 32bit/PAE.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

---
arch/x86/kernel/cpu/common.c | 22 +++++++++++++++++++++-
arch/x86/mm/ioremap.c | 13 ++++++-------
include/asm-x86/processor.h | 4 ++--
3 files changed, 29 insertions(+), 10 deletions(-)

--- linux-x86.orig/arch/x86/kernel/cpu/common.c
+++ linux-x86/arch/x86/kernel/cpu/common.c
@@ -472,14 +472,20 @@ static void __cpuinit get_cpu_cap(struct
if (xlvl >= 0x80860001)
c->x86_capability[2] = cpuid_edx(0x80860001);
}
+#endif

if (c->extended_cpuid_level >= 0x80000008) {
u32 eax = cpuid_eax(0x80000008);

c->x86_virt_bits = (eax >> 8) & 0xff;
c->x86_phys_bits = eax & 0xff;
+ /* CPUID workaround for Intel 0F33/0F34 CPU */
+ if (c->x86_vendor == X86_VENDOR_INTEL
+ && c->x86 == 0xF && c->x86_model == 0x3
+ && (c->x86_mask == 0x3
+ || c->x86_mask == 0x4))
+ c->x86_phys_bits = 36;
}
-#endif

if (c->extended_cpuid_level >= 0x80000007)
c->x86_power = cpuid_edx(0x80000007);
@@ -500,6 +506,8 @@ static void __init early_identify_cpu(st
c->x86_clflush_size = 64;
#else
c->x86_clflush_size = 32;
+ c->x86_phys_bits = 32;
+ c->x86_virt_bits = 32;
#endif
c->x86_cache_alignment = c->x86_clflush_size;

@@ -512,6 +520,11 @@ static void __init early_identify_cpu(st

cpu_detect(c);

+#ifdef CONFIG_X86_32
+ if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
+ c->x86_phys_bits = 36;
+#endif
+
get_cpu_vendor(c);

get_cpu_cap(c);
@@ -635,6 +648,8 @@ static void __cpuinit identify_cpu(struc
#else
c->cpuid_level = -1; /* CPUID not detected */
c->x86_clflush_size = 32;
+ c->x86_phys_bits = 32;
+ c->x86_virt_bits = 32;
#endif
c->x86_cache_alignment = c->x86_clflush_size;
memset(&c->x86_capability, 0, sizeof c->x86_capability);
@@ -652,6 +667,11 @@ static void __cpuinit identify_cpu(struc

generic_identify(c);

+#ifdef CONFIG_X86_32
+ if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
+ c->x86_phys_bits = 36;
+#endif
+
if (this_cpu->c_identify)
this_cpu->c_identify(c);

--- linux-x86.orig/arch/x86/mm/ioremap.c
+++ linux-x86/arch/x86/mm/ioremap.c
@@ -22,13 +22,17 @@
#include <asm/pgalloc.h>
#include <asm/pat.h>

-#ifdef CONFIG_X86_64
-
static inline int phys_addr_valid(unsigned long addr)
{
+#ifdef CONFIG_RESOURCES_64BIT
return addr < (1UL << boot_cpu_data.x86_phys_bits);
+#else
+ return 1;
+#endif
}

+#ifdef CONFIG_X86_64
+
unsigned long __phys_addr(unsigned long x)
{
if (x >= __START_KERNEL_map) {
@@ -47,11 +51,6 @@ EXPORT_SYMBOL(__phys_addr);

#else

-static inline int phys_addr_valid(unsigned long addr)
-{
- return 1;
-}
-
#ifdef CONFIG_DEBUG_VIRTUAL
unsigned long __phys_addr(unsigned long x)
{
--- linux-x86.orig/include/asm-x86/processor.h
+++ linux-x86/include/asm-x86/processor.h
@@ -74,8 +74,6 @@ struct cpuinfo_x86 {
#else
/* Number of 4K pages in DTLB/ITLB combined(in pages): */
int x86_tlbsize;
- __u8 x86_virt_bits;
- __u8 x86_phys_bits;
/* CPUID returned core id bits: */
__u8 x86_coreid_bits;
#endif
@@ -100,6 +98,8 @@ struct cpuinfo_x86 {
u16 apicid;
u16 initial_apicid;
u16 x86_clflush_size;
+ u8 x86_virt_bits;
+ u8 x86_phys_bits;
#ifdef CONFIG_SMP
/* number of cores as seen by the OS: */
u16 booted_cores;


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