From 2b107d93635616db0c3f893c8cc2e6d5cd8d77b2 Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Fri, 7 May 2010 14:59:45 -0700 Subject: [PATCH 1/3] x86: Avoid check hlt for newer cpus Check hlt instruction was targeted for some older CPUs. It is an expensive operation in that it takes 4 ticks to break out the check. We can avoid such check completely for newer x86 cpus (family >= 5). [ hpa: corrected family > 5 to family >= 5 ] Signed-off-by: Jacob Pan LKML-Reference: <1273269585-14346-1-git-send-email-jacob.jun.pan@linux.intel.com> Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/bugs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 01a265212395..c39576cb3018 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -86,7 +86,7 @@ static void __init check_fpu(void) static void __init check_hlt(void) { - if (paravirt_enabled()) + if (boot_cpu_data.x86 >= 5 || paravirt_enabled()) return; printk(KERN_INFO "Checking 'hlt' instruction... "); From e4af4268a34d8cd28c46a03161fc017cbd2db887 Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Fri, 14 May 2010 14:41:14 -0700 Subject: [PATCH 2/3] x86, mrst, pci: return 0 for non-present pci bars Moorestown PCI code has special handling of devices with fixed BARs. In case of BAR sizing writes, we need to update the fake PCI MMCFG space with real size decode value. When a BAR is not present, we need to return 0 instead of ~0. ~0 will be treated as device error per bugzilla 12006. Signed-off-by: Jacob Pan LKML-Reference: <1273873281-17489-2-git-send-email-jacob.jun.pan@linux.intel.com> Acked-by: Jesse Barnes Acked-by: Thomas Gleixner Signed-off-by: H. Peter Anvin --- arch/x86/pci/mrst.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/pci/mrst.c b/arch/x86/pci/mrst.c index 8bf2fcb88d04..d5c7aefe56ff 100644 --- a/arch/x86/pci/mrst.c +++ b/arch/x86/pci/mrst.c @@ -109,7 +109,7 @@ static int pci_device_update_fixed(struct pci_bus *bus, unsigned int devfn, decode++; decode = ~(decode - 1); } else { - decode = ~0; + decode = 0; } /* From fea24e28c663e62663097f0ed3b8ff1f9a87f15e Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Fri, 14 May 2010 14:41:20 -0700 Subject: [PATCH 3/3] x86, mrst: add nop functions to x86_init mpparse functions Moorestown does not have BIOS provided MP tables, we can save some time by avoiding scaning of these tables. e.g. [ 0.000000] Scan SMP from c0000000 for 1024 bytes. [ 0.000000] Scan SMP from c009fc00 for 1024 bytes. [ 0.000000] Scan SMP from c00f0000 for 65536 bytes. [ 0.000000] Scan SMP from c00bfff0 for 1024 bytes. Searching EBDA with the base at 0x40E will also result in random pointer deferencing within 1MB. This can be a problem in Lincroft if the pointer hits VGA area and VGA mode is not enabled. Signed-off-by: Jacob Pan LKML-Reference: <1273873281-17489-8-git-send-email-jacob.jun.pan@linux.intel.com> Acked-by: Thomas Gleixner Signed-off-by: H. Peter Anvin --- arch/x86/kernel/mrst.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/mrst.c b/arch/x86/kernel/mrst.c index 0aad8670858e..e796448f0eb5 100644 --- a/arch/x86/kernel/mrst.c +++ b/arch/x86/kernel/mrst.c @@ -237,4 +237,9 @@ void __init x86_mrst_early_setup(void) x86_init.pci.fixup_irqs = x86_init_noop; legacy_pic = &null_legacy_pic; + + /* Avoid searching for BIOS MP tables */ + x86_init.mpparse.find_smp_config = x86_init_noop; + x86_init.mpparse.get_smp_config = x86_init_uint_noop; + }