Re: [PATCH] x86: x86_{phys,virt}_bits field also for i386 (v3)

From: Jan Beulich
Date: Thu Sep 18 2008 - 05:30:35 EST


>>> Ingo Molnar <mingo@xxxxxxx> 18.09.08 11:10 >>>
>* Ingo Molnar <mingo@xxxxxxx> 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>
>>
>> applied to tip/x86/core, thanks Jan.
>
>hm, this commit quickly broke a -tip testsystem. The system booted up
>fine but had no networking afterwards. (the eth0 interface came up fine
>but no interrupts were emitted)
>
>i've pushed out the bad tree into tip/tmp.virt_bits.bad. The bad config
>is attached.
>
>just check out tip/tmp.virt_bits.bad, boot into the kernel and see
>forcedeth networking break (if you have a box with forcedeth). It's
>reproducible. I've attached a 'good' and a 'bad' boot log as well.

I'm really sorry for that, yet another merge oversight (not caught because
only re-tested on x86-64). Here's a better one.

********************************************************

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 | 17 ++++++++---------
include/asm-x86/processor.h | 4 ++--
3 files changed, 25 insertions(+), 13 deletions(-)

--- linux-tip.orig/arch/x86/kernel/cpu/common.c
+++ linux-tip/arch/x86/kernel/cpu/common.c
@@ -439,6 +439,11 @@ void __cpuinit cpu_detect(struct cpuinfo
c->x86_cache_alignment = c->x86_clflush_size;
}
}
+
+#ifdef CONFIG_X86_32
+ if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
+ c->x86_phys_bits = 36;
+#endif
}

static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
@@ -464,14 +469,18 @@ static void __cpuinit get_cpu_cap(struct
}
}

-#ifdef CONFIG_X86_64
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);
@@ -519,6 +528,8 @@ 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;

@@ -641,6 +652,8 @@ 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);
--- linux-tip.orig/arch/x86/mm/ioremap.c
+++ linux-tip/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)
+static inline int phys_addr_valid(resource_size_t addr)
{
- return addr < (1UL << boot_cpu_data.x86_phys_bits);
+#ifdef CONFIG_RESOURCES_64BIT
+ return !(addr >> 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-tip.orig/include/asm-x86/processor.h
+++ linux-tip/include/asm-x86/processor.h
@@ -74,9 +74,9 @@ 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;
#endif
+ u8 x86_virt_bits;
+ u8 x86_phys_bits;
/* CPUID returned core id bits: */
__u8 x86_coreid_bits;
/* Max extended CPUID function supported: */


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