Subject: Re: [PATCH] powerpc export rtas_set_slot_reset()

From: Brian King <[email-masked]>
Date: Tue, 19 Dec 2006 16:08:21 -0600

Linas Vepstas wrote:
> Hi Paul,
> A patch that provides an export for a bug being worked on the
> IPR evice driver.

This is not the API that I tested with... Here is the patch I
was using in my test. This is not ready to apply as we are
still working issues with various hardware...

Brian

-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center

The following patch adds a generic API to assert and deassert
PCI reset to a device on a pSeries machine. This is needed to
solve an issue with a new ipr PCI-E adapter which causes EEH
errors when running BIST. The only way to reset this adapter
without causing an EEH error is to use PCI reset.

Signed-off-by: Brian King <[email-masked]>
---

 linux-2.6-bjking1/arch/powerpc/platforms/pseries/eeh.c |   42 +++++++++++++++++
 linux-2.6-bjking1/include/asm-powerpc/ppc-pci.h        |    3 +
 2 files changed, 45 insertions(+)

diff -puN arch/powerpc/platforms/pseries/eeh.c~powerpc_slot_reset_api arch/powerpc/platforms/pseries/eeh.c
--- linux-2.6/arch/powerpc/platforms/pseries/eeh.c~powerpc_slot_reset_api	2006-12-18 15:58:56.000000000 -0600
+++ linux-2.6-bjking1/arch/powerpc/platforms/pseries/eeh.c	2006-12-18 15:58:57.000000000 -0600
@@ -591,6 +591,48 @@ static void __rtas_set_slot_reset(struct
 	msleep (PCI_BUS_SETTLE_TIME_MSEC);
 }
 
+/**
+ * pci_set_slot_reset - Assert PCI reset to the PCI slot
+ * @dev:	pci device struct
+ *
+ * After asserting PCI reset, the caller should wait for
+ * 100 milliseconds or longer.
+ *
+ * Return value:
+ * 	0 if success
+ **/
+int pci_set_slot_reset(struct pci_dev *dev)
+{
+	struct device_node *dn = pci_device_to_OF_node(dev);
+	struct pci_dn *pdn = PCI_DN(dn);
+
+	rtas_pci_slot_reset(pdn, 1);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_set_slot_reset);
+
+/**
+ * pci_clear_slot_reset - Clear PCI reset to the PCI slot
+ * @dev:	pci device struct
+ *
+ * After clearing PCI reset, the caller should wait 1.8 seconds
+ * or longer for the bus to stabilize and the device to come
+ * ready.
+ *
+ * Return value:
+ * 	0 if success
+ **/
+int pci_clear_slot_reset(struct pci_dev *dev)
+{
+	struct device_node *dn = pci_device_to_OF_node(dev);
+	struct pci_dn *pdn = PCI_DN(dn);
+
+	eeh_clear_slot (pdn->node, EEH_MODE_ISOLATED);
+	rtas_pci_slot_reset (pdn, 0);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_clear_slot_reset);
+
 int rtas_set_slot_reset(struct pci_dn *pdn)
 {
 	int i, rc;
diff -puN include/asm-powerpc/ppc-pci.h~powerpc_slot_reset_api include/asm-powerpc/ppc-pci.h
--- linux-2.6/include/asm-powerpc/ppc-pci.h~powerpc_slot_reset_api	2006-12-18 15:58:56.000000000 -0600
+++ linux-2.6-bjking1/include/asm-powerpc/ppc-pci.h	2006-12-18 15:58:57.000000000 -0600
@@ -124,6 +124,9 @@ void eeh_clear_slot (struct device_node 
 /* Find the associated "Partiationable Endpoint" PE */
 struct device_node * find_device_pe(struct device_node *dn);
 
+int pci_set_slot_reset(struct pci_dev *dev);
+int pci_clear_slot_reset(struct pci_dev *dev);
+
 #endif
 
 #endif /* __KERNEL__ */
_