powerpc/eeh: Device bars restore based on PE
The patch introduces the function to traverse the devices of the
specified PE and its child PEs. Also, the restore on device bars
is implemented based on the traverse function.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/pseries/eeh_pe.c b/arch/powerpc/platforms/pseries/eeh_pe.c
index 0dac1b6..2b7e85b 100644
--- a/arch/powerpc/platforms/pseries/eeh_pe.c
+++ b/arch/powerpc/platforms/pseries/eeh_pe.c
@@ -172,6 +172,38 @@
}
/**
+ * eeh_pe_dev_traverse - Traverse the devices from the PE
+ * @root: EEH PE
+ * @fn: function callback
+ * @flag: extra parameter to callback
+ *
+ * The function is used to traverse the devices of the specified
+ * PE and its child PEs.
+ */
+void *eeh_pe_dev_traverse(struct eeh_pe *root,
+ eeh_traverse_func fn, void *flag)
+{
+ struct eeh_pe *pe;
+ struct eeh_dev *edev;
+ void *ret;
+
+ if (!root) {
+ pr_warning("%s: Invalid PE %p\n", __func__, root);
+ return NULL;
+ }
+
+ /* Traverse root PE */
+ for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
+ eeh_pe_for_each_dev(pe, edev) {
+ ret = fn(edev, flag);
+ if (ret) return ret;
+ }
+ }
+
+ return NULL;
+}
+
+/**
* __eeh_pe_get - Check the PE address
* @data: EEH PE
* @flag: EEH device
@@ -467,3 +499,65 @@
{
eeh_pe_traverse(pe, __eeh_pe_state_clear, &state);
}
+
+/**
+ * eeh_restore_one_device_bars - Restore the Base Address Registers for one device
+ * @data: EEH device
+ * @flag: Unused
+ *
+ * Loads the PCI configuration space base address registers,
+ * the expansion ROM base address, the latency timer, and etc.
+ * from the saved values in the device node.
+ */
+static void *eeh_restore_one_device_bars(void *data, void *flag)
+{
+ int i;
+ u32 cmd;
+ struct eeh_dev *edev = (struct eeh_dev *)data;
+ struct device_node *dn = eeh_dev_to_of_node(edev);
+
+ for (i = 4; i < 10; i++)
+ eeh_ops->write_config(dn, i*4, 4, edev->config_space[i]);
+ /* 12 == Expansion ROM Address */
+ eeh_ops->write_config(dn, 12*4, 4, edev->config_space[12]);
+
+#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
+#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)])
+
+ eeh_ops->write_config(dn, PCI_CACHE_LINE_SIZE, 1,
+ SAVED_BYTE(PCI_CACHE_LINE_SIZE));
+ eeh_ops->write_config(dn, PCI_LATENCY_TIMER, 1,
+ SAVED_BYTE(PCI_LATENCY_TIMER));
+
+ /* max latency, min grant, interrupt pin and line */
+ eeh_ops->write_config(dn, 15*4, 4, edev->config_space[15]);
+
+ /*
+ * Restore PERR & SERR bits, some devices require it,
+ * don't touch the other command bits
+ */
+ eeh_ops->read_config(dn, PCI_COMMAND, 4, &cmd);
+ if (edev->config_space[1] & PCI_COMMAND_PARITY)
+ cmd |= PCI_COMMAND_PARITY;
+ else
+ cmd &= ~PCI_COMMAND_PARITY;
+ if (edev->config_space[1] & PCI_COMMAND_SERR)
+ cmd |= PCI_COMMAND_SERR;
+ else
+ cmd &= ~PCI_COMMAND_SERR;
+ eeh_ops->write_config(dn, PCI_COMMAND, 4, cmd);
+
+ return NULL;
+}
+
+/**
+ * eeh_pe_restore_bars - Restore the PCI config space info
+ * @pe: EEH PE
+ *
+ * This routine performs a recursive walk to the children
+ * of this device as well.
+ */
+void eeh_pe_restore_bars(struct eeh_pe *pe)
+{
+ eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL);
+}