[PATCH 3/4] powerpc: EEH: capture and log pci state on error

[linas@austin.ibm.com (Linas Vepstas)]

If an EEH event is observed, capture PCI config space info about 
the device, wrap it up and pass it to the event logger.  This
pach just slots in the basic logging function. A later patch
will provide for more through data gathering. 

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>

----
 arch/powerpc/platforms/pseries/eeh.c |   43 +++++++++++++++++++++++++++++++++--
 1 file changed, 41 insertions(+), 2 deletions(-)

Index: linux-2.6.21-rc7-mm2/arch/powerpc/platforms/pseries/eeh.c
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/powerpc/platforms/pseries/eeh.c	2007-04-26 15:37:32.000000000 -0500
+++ linux-2.6.21-rc7-mm2/arch/powerpc/platforms/pseries/eeh.c	2007-04-26 16:19:28.000000000 -0500
@@ -100,6 +100,9 @@ static unsigned char slot_errbuf[RTAS_ER
 static DEFINE_SPINLOCK(slot_errbuf_lock);
 static int eeh_error_buf_size;
 
+#define EEH_PCI_REGS_LOG_LEN 4096
+static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN];
+
 /* System monitoring statistics */
 static unsigned long no_device;
 static unsigned long no_dn;
@@ -115,7 +118,8 @@ static unsigned long slot_resets;
 /* --------------------------------------------------------------- */
 /* Below lies the EEH event infrastructure */
 
-void eeh_slot_error_detail (struct pci_dn *pdn, int severity)
+static void rtas_slot_error_detail(struct pci_dn *pdn, int severity,
+                                   char *driver_log, size_t loglen)
 {
 	int config_addr;
 	unsigned long flags;
@@ -133,7 +137,8 @@ void eeh_slot_error_detail (struct pci_d
 	rc = rtas_call(ibm_slot_error_detail,
 	               8, 1, NULL, config_addr,
 	               BUID_HI(pdn->phb->buid),
-	               BUID_LO(pdn->phb->buid), NULL, 0,
+	               BUID_LO(pdn->phb->buid),
+	               virt_to_phys(driver_log), loglen,
 	               virt_to_phys(slot_errbuf),
 	               eeh_error_buf_size,
 	               severity);
@@ -144,6 +149,40 @@ void eeh_slot_error_detail (struct pci_d
 }
 
 /**
+ * gather_pci_data - copy assorted PCI config space registers to buff
+ * @pdn: device to report data for
+ * @buf: point to buffer in which to log
+ * @len: amount of room in buffer
+ *
+ * This routine captures assorted PCI configuration space data,
+ * and puts them into a buffer for RTAS error logging.
+ */
+static size_t gather_pci_data(struct pci_dn *pdn, char * buf, size_t len)
+{
+	u32 cfg;
+	int n = 0;
+
+	n += scnprintf(buf+n, len-n, "%s\n", pdn->node->name);
+	rtas_read_config(pdn, PCI_VENDOR_ID, 4, &cfg);
+	n += scnprintf(buf+n, len-n, "dev/vend:%x\n", cfg);
+	rtas_read_config(pdn, PCI_COMMAND, 4, &cfg);
+	n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg);
+
+	return n;
+}
+
+void eeh_slot_error_detail(struct pci_dn *pdn, int severity)
+{
+	size_t loglen = 0;
+	memset(pci_regs_buf, 0, EEH_PCI_REGS_LOG_LEN);
+
+	rtas_pci_enable(pdn, EEH_THAW_MMIO);
+	loglen = gather_pci_data(pdn, pci_regs_buf, EEH_PCI_REGS_LOG_LEN);
+
+	rtas_slot_error_detail(pdn, severity, pci_regs_buf, loglen);
+}
+
+/**
  * read_slot_reset_state - Read the reset state of a device node's slot
  * @dn: device node to read
  * @rets: array to return results in