[PATCH] powerpc: IBMEBUS bus support

This patch adds the necessary core bus support used by device drivers
that sit on the IBM GX bus on modern pSeries machines like the Galaxy
infiniband for example. It provide transparent DMA ops (the low level
driver works with virtual addresses directly) along with a simple bus
layer using the Open Firmware matching routines.

Signed-off-by: Heiko J Schick <schickhj@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 396 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
new file mode 100644
index 000000000000..e47d40ac6f39
--- /dev/null
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -0,0 +1,396 @@
+/*
+ * IBM PowerPC IBM eBus Infrastructure Support.
+ *
+ * Copyright (c) 2005 IBM Corporation
+ *  Heiko J Schick <schickhj@de.ibm.com>
+ *    
+ * All rights reserved.
+ *
+ * This source code is distributed under a dual license of GPL v2.0 and OpenIB 
+ * BSD. 
+ *
+ * OpenIB BSD License
+ *
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions are met: 
+ *
+ * Redistributions of source code must retain the above copyright notice, this 
+ * list of conditions and the following disclaimer. 
+ *
+ * Redistributions in binary form must reproduce the above copyright notice, 
+ * this list of conditions and the following disclaimer in the documentation 
+ * and/or other materials
+ * provided with the distribution. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/kobject.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <asm/ibmebus.h>
+#include <asm/abs_addr.h>
+
+static struct ibmebus_dev ibmebus_bus_device = { /* fake "parent" device */
+        .name = ibmebus_bus_device.ofdev.dev.bus_id,
+        .ofdev.dev.bus_id = "ibmebus",
+        .ofdev.dev.bus    = &ibmebus_bus_type,
+};
+
+static void *ibmebus_alloc_coherent(struct device *dev,
+                                    size_t size,
+                                    dma_addr_t *dma_handle,
+                                    gfp_t flag)
+{
+        void *mem;
+        
+        mem = kmalloc(size, flag);
+        *dma_handle = (dma_addr_t)mem;
+
+        return mem;
+}
+
+static void ibmebus_free_coherent(struct device *dev,
+                                  size_t size, void *vaddr, 
+                                  dma_addr_t dma_handle)
+{
+        kfree(vaddr);
+}
+
+static dma_addr_t ibmebus_map_single(struct device *dev,
+                                     void *ptr,
+                                     size_t size,
+                                     enum dma_data_direction direction)
+{
+        return (dma_addr_t)(ptr);
+}
+
+static void ibmebus_unmap_single(struct device *dev,
+                                 dma_addr_t dma_addr,
+                                 size_t size, 
+                                 enum dma_data_direction direction)
+{
+        return;
+}
+
+static int ibmebus_map_sg(struct device *dev,
+                          struct scatterlist *sg,
+                          int nents, enum dma_data_direction direction)
+{
+        int i;
+        
+        for (i = 0; i < nents; i++) {
+                sg[i].dma_address = (dma_addr_t)page_address(sg[i].page) 
+                        + sg[i].offset;
+                sg[i].dma_length = sg[i].length;
+        }
+        
+        return nents;
+}
+
+static void ibmebus_unmap_sg(struct device *dev,
+                             struct scatterlist *sg,
+                             int nents, enum dma_data_direction direction)
+{
+        return;
+}
+
+static int ibmebus_dma_supported(struct device *dev, u64 mask)
+{
+        return 1;
+}
+
+struct dma_mapping_ops ibmebus_dma_ops = {
+        .alloc_coherent = ibmebus_alloc_coherent,
+        .free_coherent  = ibmebus_free_coherent,
+        .map_single     = ibmebus_map_single,
+        .unmap_single   = ibmebus_unmap_single,
+        .map_sg         = ibmebus_map_sg,
+        .unmap_sg       = ibmebus_unmap_sg,
+        .dma_supported  = ibmebus_dma_supported,
+};
+
+static int ibmebus_bus_probe(struct device *dev)
+{
+        struct ibmebus_dev *ibmebusdev    = to_ibmebus_dev(dev);
+        struct ibmebus_driver *ibmebusdrv = to_ibmebus_driver(dev->driver);
+        const struct of_device_id *id;
+        int error = -ENODEV;
+        
+        if (!ibmebusdrv->probe)
+                return error;
+        
+        id = of_match_device(ibmebusdrv->id_table, &ibmebusdev->ofdev);
+        if (id) {
+                error = ibmebusdrv->probe(ibmebusdev, id);
+        }
+        
+        return error;
+}
+
+static int ibmebus_bus_remove(struct device *dev)
+{
+        struct ibmebus_dev *ibmebusdev    = to_ibmebus_dev(dev);
+        struct ibmebus_driver *ibmebusdrv = to_ibmebus_driver(dev->driver);
+        
+        if (ibmebusdrv->remove) {
+                return ibmebusdrv->remove(ibmebusdev);
+        }
+        
+        return 0;
+}
+
+static void __devinit ibmebus_dev_release(struct device *dev)
+{
+        of_node_put(to_ibmebus_dev(dev)->ofdev.node);
+        kfree(to_ibmebus_dev(dev));
+}
+
+static ssize_t ibmebusdev_show_name(struct device *dev, 
+                                    struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%s\n", to_ibmebus_dev(dev)->name);
+}
+static DEVICE_ATTR(name, S_IRUSR | S_IRGRP | S_IROTH, ibmebusdev_show_name, 
+                   NULL);
+
+static struct ibmebus_dev* __devinit ibmebus_register_device_common(
+        struct ibmebus_dev *dev, char *name)
+{
+        int err = 0;
+
+        dev->name = name;
+        dev->ofdev.dev.parent  = &ibmebus_bus_device.ofdev.dev;
+        dev->ofdev.dev.bus     = &ibmebus_bus_type;
+        dev->ofdev.dev.release = ibmebus_dev_release;
+
+        /* An ibmebusdev is based on a of_device. We have to change the
+         * bus type to use our own DMA mapping operations. 
+         */       
+        if ((err = of_device_register(&dev->ofdev)) != 0) {
+                printk(KERN_ERR "%s: failed to register device (%d).\n",
+                       __FUNCTION__, err);
+                return NULL;
+        }
+        
+        device_create_file(&dev->ofdev.dev, &dev_attr_name);
+        
+        return dev;
+}
+
+static struct ibmebus_dev* __devinit ibmebus_register_device_node(
+        struct device_node *dn)
+{
+        struct ibmebus_dev *dev;
+        char *loc_code;
+        int length;
+
+        loc_code = (char *)get_property(dn, "ibm,loc-code", NULL);
+        if (!loc_code) {
+                printk(KERN_WARNING "%s: node %s missing 'ibm,loc-code'\n",
+                       __FUNCTION__, dn->name ? dn->name : "<unknown>");
+                return NULL;
+        }
+        
+        if (strlen(loc_code) == 0) {
+                printk(KERN_WARNING "%s: 'ibm,loc-code' is invalid\n",
+                       __FUNCTION__);
+                return NULL;
+        }
+
+        dev = kmalloc(sizeof(struct ibmebus_dev), GFP_KERNEL);
+        if (!dev) {
+                return NULL;
+        }
+        memset(dev, 0, sizeof(struct ibmebus_dev));
+
+        dev->ofdev.node = of_node_get(dn);
+       
+        length = strlen(loc_code);
+        memcpy(dev->ofdev.dev.bus_id, loc_code 
+                + (length - min(length, BUS_ID_SIZE - 1)), 
+                min(length, BUS_ID_SIZE - 1));
+
+        /* Register with generic device framework. */
+        if (ibmebus_register_device_common(dev, dn->name) == NULL) {
+                kfree(dev);
+                return NULL;
+        }
+
+        return dev;
+}
+
+static void ibmebus_probe_of_nodes(char* name)
+{
+        struct device_node *dn = NULL;
+        
+        while ((dn = of_find_node_by_name(dn, name))) {
+                if (ibmebus_register_device_node(dn) == NULL) {
+                        of_node_put(dn);
+                        
+                        return;
+                }
+        }
+        
+        of_node_put(dn);
+        
+        return;
+}
+
+static void ibmebus_add_devices_by_id(struct of_device_id *idt)
+{
+        while (strlen(idt->name) > 0) {
+                ibmebus_probe_of_nodes(idt->name);
+                idt++;
+        }
+
+        return;
+}
+
+static int ibmebus_match_helper(struct device *dev, void *data)
+{
+        if (strcmp((char*)data, to_ibmebus_dev(dev)->name) == 0)
+                return 1;
+        
+        return 0;
+}
+
+static int ibmebus_unregister_device(struct device *dev)
+{
+        device_remove_file(dev, &dev_attr_name);
+        of_device_unregister(to_of_device(dev));
+
+        return 0;
+}
+
+static void ibmebus_remove_devices_by_id(struct of_device_id *idt)
+{
+        struct device *dev;
+        
+        while (strlen(idt->name) > 0) {
+                while ((dev = bus_find_device(&ibmebus_bus_type, NULL, 
+                                              (void*)idt->name,
+                                              ibmebus_match_helper))) {
+                        ibmebus_unregister_device(dev);
+                }
+                idt++;
+                
+        }
+        
+        return;
+}
+
+int ibmebus_register_driver(struct ibmebus_driver *drv)
+{
+        int err = 0;
+
+        drv->driver.name   = drv->name;
+        drv->driver.bus    = &ibmebus_bus_type;
+        drv->driver.probe  = ibmebus_bus_probe;
+        drv->driver.remove = ibmebus_bus_remove;
+
+        if ((err = driver_register(&drv->driver) != 0))
+                return err;
+
+        ibmebus_add_devices_by_id(drv->id_table);
+        
+        return 0;
+}
+EXPORT_SYMBOL(ibmebus_register_driver);
+
+void ibmebus_unregister_driver(struct ibmebus_driver *drv)
+{       
+        driver_unregister(&drv->driver);
+        ibmebus_remove_devices_by_id(drv->id_table);
+}
+EXPORT_SYMBOL(ibmebus_unregister_driver);
+
+int ibmebus_request_irq(struct ibmebus_dev *dev,
+                        u32 ist, 
+                        irqreturn_t (*handler)(int, void*, struct pt_regs *),
+                        unsigned long irq_flags, const char * devname,
+                        void *dev_id)
+{
+        unsigned int irq = virt_irq_create_mapping(ist);
+        
+        if (irq == NO_IRQ)
+                return -EINVAL;
+        
+        irq = irq_offset_up(irq);
+        
+        return request_irq(irq, handler,
+                           irq_flags, devname, dev_id);
+}
+EXPORT_SYMBOL(ibmebus_request_irq);
+
+void ibmebus_free_irq(struct ibmebus_dev *dev, u32 ist, void *dev_id)
+{
+        unsigned int irq = virt_irq_create_mapping(ist);
+        
+        irq = irq_offset_up(irq);
+        free_irq(irq, dev_id);
+        
+        return;
+}
+EXPORT_SYMBOL(ibmebus_free_irq);
+
+static int ibmebus_bus_match(struct device *dev, struct device_driver *drv)
+{       
+        const struct ibmebus_dev *ebus_dev = to_ibmebus_dev(dev);
+        struct ibmebus_driver *ebus_drv    = to_ibmebus_driver(drv);
+        const struct of_device_id *ids     = ebus_drv->id_table;
+        const struct of_device_id *found_id;
+        
+        if (!ids)
+                return 0;
+        
+        found_id = of_match_device(ids, &ebus_dev->ofdev);
+        if (found_id)
+                return 1;
+        
+        return 0;
+}
+
+struct bus_type ibmebus_bus_type = {
+        .name = "ibmebus",
+        .match = ibmebus_bus_match,
+};
+EXPORT_SYMBOL(ibmebus_bus_type);
+
+static int __init ibmebus_bus_init(void)
+{
+        int err;
+        
+        printk(KERN_INFO "IBM eBus Device Driver\n");
+        
+        err = bus_register(&ibmebus_bus_type);
+        if (err) {
+                printk(KERN_ERR ":%s: failed to register IBM eBus.\n",
+                       __FUNCTION__);
+                return err;
+        }
+        
+        err = device_register(&ibmebus_bus_device.ofdev.dev);
+        if (err) {
+                printk(KERN_WARNING "%s: device_register returned %i\n", 
+                       __FUNCTION__, err);
+                bus_unregister(&ibmebus_bus_type);
+
+                return err;
+        }
+        
+        return 0;
+}
+__initcall(ibmebus_bus_init);