On Fri, Jul 22, 2016 at 03:23:36PM +1000, Russell Currey wrote:
>On EEH events the kernel will print a dump of relevant registers.
>If EEH is unavailable (i.e. CONFIG_EEH is disabled, a new platform
>doesn't have EEH support, etc) this information isn't readily available.
>
>Add a new debugfs handler to trigger a PHB register dump, so that this
>information can be made available on demand.
>
>Signed-off-by: Russell Currey <rus...@russell.cc>
Reviewed-by: Gavin Shan <gws...@linux.vnet.ibm.com>
>---
> arch/powerpc/platforms/powernv/pci-ioda.c | 35 +++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c
>b/arch/powerpc/platforms/powernv/pci-ioda.c
>index 891fc4a..ada2f3c 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -3018,6 +3018,38 @@ static void pnv_ioda_setup_pe_seg(struct pnv_ioda_pe
>*pe)
> }
> }
>
>+#ifdef CONFIG_DEBUG_FS
>+static ssize_t pnv_pci_debug_write(struct file *filp,
>+ const char __user *user_buf,
>+ size_t count, loff_t *ppos)
>+{
>+ struct pci_controller *hose = filp->private_data;
>+ struct pnv_phb *phb;
>+ int ret = 0;
Needn't initialize @ret in advance. The code might be simpler, but it's
only a personal preference:
struct pci_controller *hose = filp->private_data;
struct pnv_phb *phb = hose ? hose->private_data : NULL;
if (!phb)
return -ENODEV;
>+
>+ if (!hose)
>+ return -EFAULT;
>+
>+ phb = hose->private_data;
>+ if (!phb)
>+ return -EFAULT;
>+
>+ ret = opal_pci_get_phb_diag_data2(phb->opal_id, phb->diag.blob,
>+ PNV_PCI_DIAG_BUF_SIZE);
>+
>+ if (!ret)
>+ pnv_pci_dump_phb_diag_data(phb->hose, phb->diag.blob);
>+
>+ return ret < 0 ? ret : count;
return ret == OPAL_SUCCESS ? count : -EIO;
>+}
>+
>+static const struct file_operations pnv_pci_debug_ops = {
>+ .open = simple_open,
>+ .llseek = no_llseek,
>+ .write = pnv_pci_debug_write,
It might be reasonable to dump the diag-data on read if it is trying
to do it on write.
>+};
>+#endif /* CONFIG_DEBUG_FS */
>+
> static void pnv_pci_ioda_create_dbgfs(void)
> {
> #ifdef CONFIG_DEBUG_FS
>@@ -3036,6 +3068,9 @@ static void pnv_pci_ioda_create_dbgfs(void)
> if (!phb->dbgfs)
> pr_warning("%s: Error on creating debugfs on PHB#%x\n",
> __func__, hose->global_number);
>+
>+ debugfs_create_file("regdump", 0200, phb->dbgfs, hose,
>+ &pnv_pci_debug_ops);
"diag-data" might be indicating or a better one you can name :)
Thanks,
Gavin
> }
> #endif /* CONFIG_DEBUG_FS */
> }
>--
>2.9.0
>
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