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authorJan Glauber <jang@linux.vnet.ibm.com>2012-11-29 14:35:47 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-11-30 17:47:25 +0100
commit7441b0627e2251370902305a204e1330a696ca04 (patch)
treed3a36466a8517f8b889b6f0037f15280e33302d4 /drivers/pci
parentcbc0dd1f856b52b59c2c73a477b6cb210c8c66ad (diff)
downloadop-kernel-dev-7441b0627e2251370902305a204e1330a696ca04.zip
op-kernel-dev-7441b0627e2251370902305a204e1330a696ca04.tar.gz
s390/pci: PCI hotplug support via SCLP
Add SCLP PCI configure/deconfigure and implement a PCI hotplug controller (s390_pci_hpc). The hotplug controller creates a slot for every PCI function in stand-by or configured state. The PCI functions are named after the PCI function ID (fid). By writing to the power attribute in /sys/bus/pci/slots/<fid>/power the PCI function is moved to stand-by or configured state. If moved to the configured state the device is automatically scanned by the s390 PCI layer. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/hotplug/Kconfig11
-rw-r--r--drivers/pci/hotplug/Makefile1
-rw-r--r--drivers/pci/hotplug/s390_pci_hpc.c252
3 files changed, 264 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig
index b0e46de..13e9e63 100644
--- a/drivers/pci/hotplug/Kconfig
+++ b/drivers/pci/hotplug/Kconfig
@@ -151,4 +151,15 @@ config HOTPLUG_PCI_SGI
When in doubt, say N.
+config HOTPLUG_PCI_S390
+ tristate "System z PCI Hotplug Support"
+ depends on S390 && 64BIT
+ help
+ Say Y here if you want to use the System z PCI Hotplug
+ driver for PCI devices. Without this driver it is not
+ possible to access stand-by PCI functions nor to deconfigure
+ PCI functions.
+
+ When in doubt, say Y.
+
endif # HOTPLUG_PCI
diff --git a/drivers/pci/hotplug/Makefile b/drivers/pci/hotplug/Makefile
index c459cd4..47ec8c8 100644
--- a/drivers/pci/hotplug/Makefile
+++ b/drivers/pci/hotplug/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_HOTPLUG_PCI_RPA) += rpaphp.o
obj-$(CONFIG_HOTPLUG_PCI_RPA_DLPAR) += rpadlpar_io.o
obj-$(CONFIG_HOTPLUG_PCI_SGI) += sgi_hotplug.o
obj-$(CONFIG_HOTPLUG_PCI_ACPI) += acpiphp.o
+obj-$(CONFIG_HOTPLUG_PCI_S390) += s390_pci_hpc.o
# acpiphp_ibm extends acpiphp, so should be linked afterwards.
diff --git a/drivers/pci/hotplug/s390_pci_hpc.c b/drivers/pci/hotplug/s390_pci_hpc.c
new file mode 100644
index 0000000..dee68e0
--- /dev/null
+++ b/drivers/pci/hotplug/s390_pci_hpc.c
@@ -0,0 +1,252 @@
+/*
+ * PCI Hot Plug Controller Driver for System z
+ *
+ * Copyright 2012 IBM Corp.
+ *
+ * Author(s):
+ * Jan Glauber <jang@linux.vnet.ibm.com>
+ */
+
+#define COMPONENT "zPCI hpc"
+#define pr_fmt(fmt) COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
+#include <linux/init.h>
+#include <asm/sclp.h>
+
+#define SLOT_NAME_SIZE 10
+static LIST_HEAD(s390_hotplug_slot_list);
+
+MODULE_AUTHOR("Jan Glauber <jang@linux.vnet.ibm.com");
+MODULE_DESCRIPTION("Hot Plug PCI Controller for System z");
+MODULE_LICENSE("GPL");
+
+static int zpci_fn_configured(enum zpci_state state)
+{
+ return state == ZPCI_FN_STATE_CONFIGURED ||
+ state == ZPCI_FN_STATE_ONLINE;
+}
+
+/*
+ * struct slot - slot information for each *physical* slot
+ */
+struct slot {
+ struct list_head slot_list;
+ struct hotplug_slot *hotplug_slot;
+ struct zpci_dev *zdev;
+};
+
+static int enable_slot(struct hotplug_slot *hotplug_slot)
+{
+ struct slot *slot = hotplug_slot->private;
+ int rc;
+
+ if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
+ return -EIO;
+
+ rc = sclp_pci_configure(slot->zdev->fid);
+ if (!rc) {
+ slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
+ /* automatically scan the device after is was configured */
+ zpci_enable_device(slot->zdev);
+ zpci_scan_device(slot->zdev);
+ }
+ return rc;
+}
+
+static int disable_slot(struct hotplug_slot *hotplug_slot)
+{
+ struct slot *slot = hotplug_slot->private;
+ int rc;
+
+ if (!zpci_fn_configured(slot->zdev->state))
+ return -EIO;
+
+ /* TODO: we rely on the user to unbind/remove the device, is that plausible
+ * or do we need to trigger that here?
+ */
+ rc = sclp_pci_deconfigure(slot->zdev->fid);
+ if (!rc) {
+ /* Fixme: better call List-PCI to find the disabled FH
+ for the FID since the FH should be opaque... */
+ slot->zdev->fh &= 0x7fffffff;
+ slot->zdev->state = ZPCI_FN_STATE_STANDBY;
+ }
+ return rc;
+}
+
+static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
+{
+ struct slot *slot = hotplug_slot->private;
+
+ switch (slot->zdev->state) {
+ case ZPCI_FN_STATE_STANDBY:
+ *value = 0;
+ break;
+ default:
+ *value = 1;
+ break;
+ }
+ return 0;
+}
+
+static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
+{
+ /* if the slot exits it always contains a function */
+ *value = 1;
+ return 0;
+}
+
+static void release_slot(struct hotplug_slot *hotplug_slot)
+{
+ struct slot *slot = hotplug_slot->private;
+
+ pr_debug("%s - physical_slot = %s\n", __func__, hotplug_slot_name(hotplug_slot));
+ kfree(slot->hotplug_slot->info);
+ kfree(slot->hotplug_slot);
+ kfree(slot);
+}
+
+static struct hotplug_slot_ops s390_hotplug_slot_ops = {
+ .enable_slot = enable_slot,
+ .disable_slot = disable_slot,
+ .get_power_status = get_power_status,
+ .get_adapter_status = get_adapter_status,
+};
+
+static int init_pci_slot(struct zpci_dev *zdev)
+{
+ struct hotplug_slot *hotplug_slot;
+ struct hotplug_slot_info *info;
+ char name[SLOT_NAME_SIZE];
+ struct slot *slot;
+ int rc;
+
+ if (!zdev)
+ return 0;
+
+ slot = kzalloc(sizeof(*slot), GFP_KERNEL);
+ if (!slot)
+ goto error;
+
+ hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
+ if (!hotplug_slot)
+ goto error_hp;
+ hotplug_slot->private = slot;
+
+ slot->hotplug_slot = hotplug_slot;
+ slot->zdev = zdev;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ goto error_info;
+ hotplug_slot->info = info;
+
+ hotplug_slot->ops = &s390_hotplug_slot_ops;
+ hotplug_slot->release = &release_slot;
+
+ get_power_status(hotplug_slot, &info->power_status);
+ get_adapter_status(hotplug_slot, &info->adapter_status);
+
+ snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
+ rc = pci_hp_register(slot->hotplug_slot, zdev->bus,
+ ZPCI_DEVFN, name);
+ if (rc) {
+ pr_err("pci_hp_register failed with error %d\n", rc);
+ goto error_reg;
+ }
+ list_add(&slot->slot_list, &s390_hotplug_slot_list);
+ return 0;
+
+error_reg:
+ kfree(info);
+error_info:
+ kfree(hotplug_slot);
+error_hp:
+ kfree(slot);
+error:
+ return -ENOMEM;
+}
+
+static int __init init_pci_slots(void)
+{
+ struct zpci_dev *zdev;
+ int device = 0;
+
+ /*
+ * Create a structure for each slot, and register that slot
+ * with the pci_hotplug subsystem.
+ */
+ mutex_lock(&zpci_list_lock);
+ list_for_each_entry(zdev, &zpci_list, entry) {
+ init_pci_slot(zdev);
+ device++;
+ }
+
+ mutex_unlock(&zpci_list_lock);
+ return (device) ? 0 : -ENODEV;
+}
+
+static void exit_pci_slot(struct zpci_dev *zdev)
+{
+ struct list_head *tmp, *n;
+ struct slot *slot;
+
+ list_for_each_safe(tmp, n, &s390_hotplug_slot_list) {
+ slot = list_entry(tmp, struct slot, slot_list);
+ if (slot->zdev != zdev)
+ continue;
+ list_del(&slot->slot_list);
+ pci_hp_deregister(slot->hotplug_slot);
+ }
+}
+
+static void __exit exit_pci_slots(void)
+{
+ struct list_head *tmp, *n;
+ struct slot *slot;
+
+ /*
+ * Unregister all of our slots with the pci_hotplug subsystem.
+ * Memory will be freed in release_slot() callback after slot's
+ * lifespan is finished.
+ */
+ list_for_each_safe(tmp, n, &s390_hotplug_slot_list) {
+ slot = list_entry(tmp, struct slot, slot_list);
+ list_del(&slot->slot_list);
+ pci_hp_deregister(slot->hotplug_slot);
+ }
+}
+
+static int __init pci_hotplug_s390_init(void)
+{
+ /*
+ * Do specific initialization stuff for your driver here
+ * like initializing your controller hardware (if any) and
+ * determining the number of slots you have in the system
+ * right now.
+ */
+
+ if (!pci_probe)
+ return -EOPNOTSUPP;
+
+ /* register callbacks for slot handling from arch code */
+ mutex_lock(&zpci_list_lock);
+ hotplug_ops.create_slot = init_pci_slot;
+ hotplug_ops.remove_slot = exit_pci_slot;
+ mutex_unlock(&zpci_list_lock);
+ pr_info("registered hotplug slot callbacks\n");
+ return init_pci_slots();
+}
+
+static void __exit pci_hotplug_s390_exit(void)
+{
+ exit_pci_slots();
+}
+
+module_init(pci_hotplug_s390_init);
+module_exit(pci_hotplug_s390_exit);
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