Re: [PATCH v2] EDAC, sb_edac: Add support for systems with segmented PCI buses

[Masayoshi Mizuma]

Hi Boris,

On 07/25/2018 05:22 AM, Borislav Petkov wrote:
> On Tue, Jul 24, 2018 at 03:02:13PM -0400, Masayoshi Mizuma wrote:
>> [*] KASAN report is as follows.
> 
> That KASAN report is an arbitrary side-effect from the missing segmented
> support so I ripped it out from the commit message and ended up
> committing this:

Thank you so much!

- Masa

> 
> ---
> From: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
> Date: Tue, 24 Jul 2018 15:02:13 -0400
> Subject: [PATCH] EDAC, sb_edac: Add support for systems with segmented PCI buses
> 
> Extend the driver to check whether segment number and bus number matches
> when deciding how to group memory controller PCI devices to CPU sockets.
> 
> Signed-off-by: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
> Cc: linux-edac <linux-edac@xxxxxxxxxxxxxxx>
> Link: http://lkml.kernel.org/r/20180724190213.26359-1-msys.mizuma@xxxxxxxxx
> [ Cleanup commit message. ]
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> ---
>  drivers/edac/sb_edac.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
> index 4a89c8093307..07726fb00321 100644
> --- a/drivers/edac/sb_edac.c
> +++ b/drivers/edac/sb_edac.c
> @@ -352,6 +352,7 @@ struct pci_id_table {
>  
>  struct sbridge_dev {
>  	struct list_head	list;
> +	int			seg;
>  	u8			bus, mc;
>  	u8			node_id, source_id;
>  	struct pci_dev		**pdev;
> @@ -729,7 +730,8 @@ static inline int numcol(u32 mtr)
>  	return 1 << cols;
>  }
>  
> -static struct sbridge_dev *get_sbridge_dev(u8 bus, enum domain dom, int multi_bus,
> +static struct sbridge_dev *get_sbridge_dev(int seg, u8 bus, enum domain dom,
> +					   int multi_bus,
>  					   struct sbridge_dev *prev)
>  {
>  	struct sbridge_dev *sbridge_dev;
> @@ -747,14 +749,15 @@ static struct sbridge_dev *get_sbridge_dev(u8 bus, enum domain dom, int multi_bu
>  				      : sbridge_edac_list.next, struct sbridge_dev, list);
>  
>  	list_for_each_entry_from(sbridge_dev, &sbridge_edac_list, list) {
> -		if (sbridge_dev->bus == bus && (dom == SOCK || dom == sbridge_dev->dom))
> +		if ((sbridge_dev->seg == seg) && (sbridge_dev->bus == bus) &&
> +				(dom == SOCK || dom == sbridge_dev->dom))
>  			return sbridge_dev;
>  	}
>  
>  	return NULL;
>  }
>  
> -static struct sbridge_dev *alloc_sbridge_dev(u8 bus, enum domain dom,
> +static struct sbridge_dev *alloc_sbridge_dev(int seg, u8 bus, enum domain dom,
>  					     const struct pci_id_table *table)
>  {
>  	struct sbridge_dev *sbridge_dev;
> @@ -771,6 +774,7 @@ static struct sbridge_dev *alloc_sbridge_dev(u8 bus, enum domain dom,
>  		return NULL;
>  	}
>  
> +	sbridge_dev->seg = seg;
>  	sbridge_dev->bus = bus;
>  	sbridge_dev->dom = dom;
>  	sbridge_dev->n_devs = table->n_devs_per_imc;
> @@ -2246,6 +2250,7 @@ static int sbridge_get_onedevice(struct pci_dev **prev,
>  	struct sbridge_dev *sbridge_dev = NULL;
>  	const struct pci_id_descr *dev_descr = &table->descr[devno];
>  	struct pci_dev *pdev = NULL;
> +	int seg = 0;
>  	u8 bus = 0;
>  	int i = 0;
>  
> @@ -2276,10 +2281,12 @@ static int sbridge_get_onedevice(struct pci_dev **prev,
>  		/* End of list, leave */
>  		return -ENODEV;
>  	}
> +	seg = pci_domain_nr(pdev->bus);
>  	bus = pdev->bus->number;
>  
>  next_imc:
> -	sbridge_dev = get_sbridge_dev(bus, dev_descr->dom, multi_bus, sbridge_dev);
> +	sbridge_dev = get_sbridge_dev(seg, bus, dev_descr->dom,
> +				      multi_bus, sbridge_dev);
>  	if (!sbridge_dev) {
>  		/* If the HA1 wasn't found, don't create EDAC second memory controller */
>  		if (dev_descr->dom == IMC1 && devno != 1) {
> @@ -2292,7 +2299,7 @@ static int sbridge_get_onedevice(struct pci_dev **prev,
>  		if (dev_descr->dom == SOCK)
>  			goto out_imc;
>  
> -		sbridge_dev = alloc_sbridge_dev(bus, dev_descr->dom, table);
> +		sbridge_dev = alloc_sbridge_dev(seg, bus, dev_descr->dom, table);
>  		if (!sbridge_dev) {
>  			pci_dev_put(pdev);
>  			return -ENOMEM;
>