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

[Neil Horman <nhorman@tuxdriver.com>]

On Fri, Dec 07, 2007 at 12:58:32PM -0500, Neil Horman wrote:
> 
> Ok, New patch attached.  It preforms the same function as previously described,
> but is more restricted in its application.  As Yinghai pointed out, the
> broadcast mask bit (bit 17 in the htcfg register) should only be enabled, if the
> extened apic id bit (bit 18 in the same register) is also set.  So this patch
> now check for that bit to be turned on first.  Also, this patch now adds an
> independent quirk check for all AMD hypertransport host controllers, since its
> possible for this misconfiguration to be present in systems other than nvidias.
> The net effect of these changes is, that its now applicable to all AMD systems
> containing hypertransport busses, and is only activated if extended apic ids are
> in use, meaning that this quirk guarantees that all processors in a system are
> elligible to receive interrupts from the ioapic, even if their apicid extends
> beyond the nominal 4 bit limitation.  Tested successfully by me.
> 
> Thanks & Regards
> Neil
> 
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> 
> 
>  early-quirks.c |   83 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 76 insertions(+), 7 deletions(-)
> 
> 
> 
> diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
> index 88bb83e..d5a7b30 100644
> --- a/arch/x86/kernel/early-quirks.c
> +++ b/arch/x86/kernel/early-quirks.c
> @@ -44,6 +44,50 @@ static int __init nvidia_hpet_check(struct acpi_table_header *header)
>  #endif /* CONFIG_X86_IO_APIC */
>  #endif /* CONFIG_ACPI */
>  
> +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)) == 1) {	
> +		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");
> +			htcfg |= (1 << 17);
> +			write_pci_config(num, slot, func, 0x68, htcfg);
> +		}
> +	}
> +	
> +}
> +
> +static void __init check_hypertransport_config()
> +{
> +	int num, slot, func;
> +	u32 device, vendor;
> +	func = 0;
> +	for (num = 0; num < 32; num++) {
> +		for (slot = 0; slot < 32; slot++) {
> +			vendor = read_pci_config(num,slot,func,
> +						PCI_VENDOR_ID); 
> +			device = read_pci_config(num,slot,func,
> +						PCI_DEVICE_ID);
> +			vendor &= 0x0000ffff;
> +			device >>= 16;
> +			if ((vendor == PCI_VENDOR_ID_AMD) &&
> +			    (device == PCI_DEVICE_ID_AMD_K8_NB))
> +				fix_hypertransport_config(num,slot,func);
> +		}
> +	}
> +
> +	return;
> +
> +}
> +
>  static void __init nvidia_bugs(void)
>  {
>  #ifdef CONFIG_ACPI
> @@ -83,6 +127,12 @@ static void __init ati_bugs(void)
>  #endif
>  }
>  
> +static void __init amd_host_bugs(void)
> +{
> +	printk(KERN_CRIT "IN AMD_HOST_BUGS\n");
> +	check_hypertransport_config();
> +}
> +
>  struct chipset {
>  	u16 vendor;
>  	void (*f)(void);
> @@ -95,9 +145,16 @@ static struct chipset early_qrk[] __initdata = {
>  	{}
>  };
>  
> +static struct chipset early_host_qrk[] __initdata = {
> +	{ PCI_VENDOR_ID_AMD, amd_host_bugs},
> +	{}
> +};
> +
>  void __init early_quirks(void)
>  {
>  	int num, slot, func;
> +	u8 found_bridge = 0;
> +	u8 found_host = 0;
>  
>  	if (!early_pci_allowed())
>  		return;
> @@ -115,18 +172,30 @@ void __init early_quirks(void)
>  				if (class == 0xffffffff)
>  					break;
>  
> -				if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
> +				class >>= 16;
> +				if ((class != PCI_CLASS_BRIDGE_PCI) &&
> +				    (class != PCI_CLASS_BRIDGE_HOST))
>  					continue;
>  
>  				vendor = read_pci_config(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;
> -					}
> +				if ((class == PCI_CLASS_BRIDGE_PCI) && (!found_bridge)) {
> +					for (i = 0; early_qrk[i].f; i++)
> +						if (early_qrk[i].vendor == vendor) {
> +							early_qrk[i].f();
> +							found_bridge = 1;;
> +						}
> +				} else if (!found_host) {
> +					for (i = 0; early_host_qrk[i].f; i++)
> +						if (early_host_qrk[i].vendor == vendor) {
> +							early_host_qrk[i].f();
> +							found_host = 1;
> +						}
> +				}
> +
> +				if (found_bridge && found_host)
> +					return;
>  
>  				type = read_pci_config_byte(num, slot, func,
>  							    PCI_HEADER_TYPE);
> 
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

Sorry to reply to myself, but do we have consensus on this patch?  I'd like to
figure out its disposition if possible.  

Thanks & Regards
Neil