[PATCH 3/3] powerpc/powernv/pci: Track TCE tables in debugfs

[Russell Currey]

Add a new debugfs entry to trigger dumping out the TCEs for a
given PE using pseudo-bypass, for example PE 0x4 of PHB 2:

echo 0x4 > /sys/kernel/debug/powerpc/PCI0002/dump_tces

This will result in the table being dumped out in dmesg.

Signed-off-by: Russell Currey <rus...@russell.cc>
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 34 +++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c 
b/arch/powerpc/platforms/powernv/pci-ioda.c
index d2ca214610fd..91316d3c26dc 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -3314,6 +3314,38 @@ static int pnv_pci_diag_data_set(void *data, u64 val)
 DEFINE_SIMPLE_ATTRIBUTE(pnv_pci_diag_data_fops, NULL,
                        pnv_pci_diag_data_set, "%llu\n");
 
+static int pnv_pci_dump_tces_set(void *data, u64 val)
+{
+       struct pci_controller *hose;
+       struct pnv_ioda_pe *pe;
+       struct pnv_phb *phb;
+       int i;
+
+       hose = (struct pci_controller *)data;
+       if (!hose || !hose->private_data)
+               return -ENODEV;
+
+       phb = hose->private_data;
+       pe = &phb->ioda.pe_array[val];
+
+       if (!pe)
+               return -EINVAL;
+
+       if (!pe->tces)
+               return -EIO;
+
+       for (i = 0; i < pe->tce_count; i++) {
+               if (i > 16 && pe->tces[i] == 0)
+                       break;
+               pr_info("TCE %3d: %016llx\n", i, be64_to_cpu(pe->tces[i]));
+       }
+       return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(pnv_pci_dump_tces_fops, NULL,
+                       pnv_pci_dump_tces_set, "%llu\n");
+
+
 #endif /* CONFIG_DEBUG_FS */
 
 static void pnv_pci_ioda_create_dbgfs(void)
@@ -3339,6 +3371,8 @@ static void pnv_pci_ioda_create_dbgfs(void)
 
                debugfs_create_file("dump_diag_regs", 0200, phb->dbgfs, hose,
                                    &pnv_pci_diag_data_fops);
+               debugfs_create_file("dump_tces", 0200, phb->dbgfs, hose,
+                                   &pnv_pci_dump_tces_fops);
        }
 #endif /* CONFIG_DEBUG_FS */
 }
-- 
2.17.1