Re: [PATCH v2] powernv: eeh: add buffer for P7IOC hub error data

[Gavin Shan <shangw@linux.vnet.ibm.com>]

On Fri, Dec 20, 2013 at 01:06:01PM -0600, Brian W Hart wrote:
>V2: Replace driver-global 'hub_diag' with a per-PHB hub diag structure.
>
>Prevent ioda_eeh_hub_diag() from clobbering itself when called by supplying
>a per-PHB buffer for P7IOC hub diagnostic data.  Take care to inform OPAL of
>the correct size for the buffer.
>
>Signed-off-by: Brian W Hart <hartb@linux.vnet.ibm.com>

Acked-by: Gavin Shan <shangw@linux.vnet.ibm.com>

We also need backport it to stable kernel 3.11+

>---
> arch/powerpc/platforms/powernv/eeh-ioda.c | 15 ++-------------
> arch/powerpc/platforms/powernv/pci.h      |  4 +++-
> 2 files changed, 5 insertions(+), 14 deletions(-)
>
>diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c
>index 8184ef5..4790275 100644
>--- a/arch/powerpc/platforms/powernv/eeh-ioda.c
>+++ b/arch/powerpc/platforms/powernv/eeh-ioda.c
>@@ -36,7 +36,6 @@
> #include "powernv.h"
> #include "pci.h"
>
>-static char *hub_diag = NULL;
> static int ioda_eeh_nb_init = 0;
>
> static int ioda_eeh_event(struct notifier_block *nb,
>@@ -140,15 +139,6 @@ static int ioda_eeh_post_init(struct pci_controller *hose)
> 		ioda_eeh_nb_init = 1;
> 	}
>
>-	/* We needn't HUB diag-data on PHB3 */
>-	if (phb->type == PNV_PHB_IODA1 && !hub_diag) {
>-		hub_diag = (char *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
>-		if (!hub_diag) {
>-			pr_err("%s: Out of memory !\n", __func__);
>-			return -ENOMEM;
>-		}
>-	}
>-
> #ifdef CONFIG_DEBUG_FS
> 	if (phb->dbgfs) {
> 		debugfs_create_file("err_injct_outbound", 0600,
>@@ -633,11 +623,10 @@ static void ioda_eeh_hub_diag_common(struct OpalIoP7IOCErrorData *data)
> static void ioda_eeh_hub_diag(struct pci_controller *hose)
> {
> 	struct pnv_phb *phb = hose->private_data;
>-	struct OpalIoP7IOCErrorData *data;
>+	struct OpalIoP7IOCErrorData *data = &phb->diag.hub_diag;
> 	long rc;
>
>-	data = (struct OpalIoP7IOCErrorData *)ioda_eeh_hub_diag;
>-	rc = opal_pci_get_hub_diag_data(phb->hub_id, data, PAGE_SIZE);
>+	rc = opal_pci_get_hub_diag_data(phb->hub_id, data, sizeof *data);
> 	if (rc != OPAL_SUCCESS) {
> 		pr_warning("%s: Failed to get HUB#%llx diag-data (%ld)\n",
> 			   __func__, phb->hub_id, rc);
>diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>index 911c24e..1ed8d5f 100644
>--- a/arch/powerpc/platforms/powernv/pci.h
>+++ b/arch/powerpc/platforms/powernv/pci.h
>@@ -172,11 +172,13 @@ struct pnv_phb {
> 		} ioda;
> 	};
>
>-	/* PHB status structure */
>+	/* PHB and hub status structure */
> 	union {
> 		unsigned char			blob[PNV_PCI_DIAG_BUF_SIZE];
> 		struct OpalIoP7IOCPhbErrorData	p7ioc;
>+		struct OpalIoP7IOCErrorData 	hub_diag;
> 	} diag;
>+
> };
>
> extern struct pci_ops pnv_pci_ops;

Thanks,
Gavin