Re: [PATCH] kexec: force x86_64 arches to boot kdump kernels on boot cpu

[Eric W. Biederman]

Neil Horman <nhorman@xxxxxxxxxxxxx> writes:

> On Tue, Dec 11, 2007 at 08:29:20AM -0700, Eric W. Biederman wrote:
>> Neil Horman <nhorman@xxxxxxxxxxxxx> writes:
>> 
>> > On Mon, Dec 10, 2007 at 09:48:11PM -0700, Eric W. Biederman wrote:
>> >> Neil Horman <nhorman@xxxxxxxxxxxxx> writes:
>> 
>> Ok.  I just looked at read_pci_config.  It doesn't do the right thing for
>> a non-aligned 32bit access.  (Not that I am convinced there is a right
>> thing we can do).  Please make this read_pci_config_16 instead
>> and you won't need the shift.
>> 
>> Either that or as I earlier suggested just do a 32bit read from offset 0
>> and use shifts and masks to get vendor and device fields.
>> 
>
>
> The former seems like a reasonable solution to me.  Corrected in this updated
> patch.
>
>> You almost got YH's comment.  You need return 2 for the old functions
>> so we don't try and apply a per chipset fixup for every device in
>> the system.
>> 
>> I'm actually inclined to remove the return magic and just do something
>> like:
>> 	static fix_applied;
>> 	if (fix_applied++)
>>         	return;
>> In those functions that should be called only once.
>> 
>
> I like the latter approach better.  It seems less convoluted to me.
>
> New patch attached.

Ok. My only remaining nit to pick is that fix_hypertransport_config
is right in the middle of the nvidia quirks, which can be a bit
confusing when reading through the code.  Otherwise I think this
is a version that we can merge.

Let's get a clean description on this thing and send it to the
current x86 maintainers. Thomas, Ingo, and HPA


> Thanks & Regards
> Neil
>
> Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Acked-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>

>
>
>  early-quirks.c | 90 +++++++++++++++++++++++++++++++++++++++++++--------------
>  1 file changed, 69 insertions(+), 21 deletions(-)
>
>
> diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
> index 88bb83e..f307285 100644
> --- a/arch/x86/kernel/early-quirks.c
> +++ b/arch/x86/kernel/early-quirks.c
> @@ -21,8 +21,13 @@
>  #include <asm/gart.h>
>  #endif
>  
> -static void __init via_bugs(void)
> +static void __init via_bugs(int  num, int slot, int func)
>  {
> +	static int fix_applied = 0;
> +
> +	if (fix_applied++)
> +		return;
> +
>  #ifdef CONFIG_GART_IOMMU
>  	if ((end_pfn > MAX_DMA32_PFN ||  force_iommu) &&
>  	    !gart_iommu_aperture_allowed) {
> @@ -44,8 +49,36 @@ static int __init nvidia_hpet_check(struct acpi_table_header
> *header)
>  #endif /* CONFIG_X86_IO_APIC */
>  #endif /* CONFIG_ACPI */
>  
> -static void __init nvidia_bugs(void)
> +static void __init fix_hypertransport_config(int num, int slot, int func)
>  {
> +	u32 htcfg;
> +	/*
> +	 *we found a hypertransport bus
> +	 *make sure that are broadcasting
> +	 *interrupts to all cpus on the ht bus
> +	 *if we're using extended apic ids
> +	 */
> +	htcfg = read_pci_config(num, slot, func, 0x68);
> +	if (htcfg & (1 << 18)) {	
> + printk(KERN_INFO "Detected use of extended apic ids on hypertransport bus\n");
> +		if ((htcfg & (1 << 17)) == 0) {
> + printk(KERN_INFO "Enabling hypertransport extended apic interrupt
> broadcast\n");
> + printk(KERN_INFO "Note this is a bios bug, please contact your hw vendor\n");
> +			htcfg |= (1 << 17);
> +			write_pci_config(num, slot, func, 0x68, htcfg);
> +		}
> +	}
> +
> +	
> +}
> +
> +static void __init nvidia_bugs(int num, int slot, int func)
> +{
> +	static int fix_applied = 0;
> +
> +	if (fix_applied++)
> +		return;
> +
>  #ifdef CONFIG_ACPI
>  #ifdef CONFIG_X86_IO_APIC
>  	/*
> @@ -72,8 +105,13 @@ static void __init nvidia_bugs(void)
>  
>  }
>  
> -static void __init ati_bugs(void)
> +static void __init ati_bugs(int num, int slot, int func)
>  {
> +	static int fix_applied = 0;
> +
> +	if (fix_applied++)
> +		return;
> +
>  #ifdef CONFIG_X86_IO_APIC
>  	if (timer_over_8254 == 1) {
>  		timer_over_8254 = 0;
> @@ -84,14 +122,18 @@ static void __init ati_bugs(void)
>  }
>  
>  struct chipset {
> -	u16 vendor;
> -	void (*f)(void);
> +	u32 vendor;
> +	u32 device;
> +	u32 class;
> +	u32 class_mask;
> +	void (*f)(int num, int slot, int func);
>  };
>  
>  static struct chipset early_qrk[] __initdata = {
> -	{ PCI_VENDOR_ID_NVIDIA, nvidia_bugs },
> -	{ PCI_VENDOR_ID_VIA, via_bugs },
> -	{ PCI_VENDOR_ID_ATI, ati_bugs },
> + { PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID,
> nvidia_bugs },
> + { PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, via_bugs },
> + { PCI_VENDOR_ID_ATI, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, ati_bugs },
> + { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB, PCI_CLASS_BRIDGE_HOST,
> PCI_ANY_ID, fix_hypertransport_config },
>  	{}
>  };
>  
> @@ -106,27 +148,33 @@ void __init early_quirks(void)
>  	for (num = 0; num < 32; num++) {
>  		for (slot = 0; slot < 32; slot++) {
>  			for (func = 0; func < 8; func++) {
> -				u32 class;
> -				u32 vendor;
> +				u16 class;
> +				u16 vendor;
> +				u16 device;
>  				u8 type;
>  				int i;
> -				class = read_pci_config(num,slot,func,
> +
> +				class = read_pci_config_16(num,slot,func,
>  							PCI_CLASS_REVISION);
> -				if (class == 0xffffffff)
> +				if (class == 0xffff)
>  					break;
>  
> -				if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
> -					continue;
> -
> -				vendor = read_pci_config(num, slot, func,
> +				vendor = read_pci_config_16(num, slot, func,
>  							 PCI_VENDOR_ID);
> -				vendor &= 0xffff;
>  
> -				for (i = 0; early_qrk[i].f; i++)
> -					if (early_qrk[i].vendor == vendor) {
> -						early_qrk[i].f();
> -						return;
> +				device = read_pci_config_16(num, slot, func,
> +							PCI_DEVICE_ID);
> +
> +				for(i=0;early_qrk[i].f != NULL;i++) {
> + if (((early_qrk[i].vendor == PCI_ANY_ID) ||
> +					    (early_qrk[i].vendor == vendor)) &&
> + ((early_qrk[i].device == PCI_ANY_ID) ||
> +					    (early_qrk[i].device == device)) &&
> +					   (!((early_qrk[i].class ^ class) & 
> +					     early_qrk[i].class_mask))) {
> + early_qrk[i].f(num, slot, func);
>  					}
> +				}
>  
>  				type = read_pci_config_byte(num, slot, func,
>  							    PCI_HEADER_TYPE);
--
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