rapidio: make enumeration/discovery configurable

Systems that use RapidIO fabric may need to implement their own
enumeration and discovery methods which are better suitable for needs of
a target application.

The following set of patches is intended to simplify process of
introduction of new RapidIO fabric enumeration/discovery methods.

The first patch offers ability to add new RapidIO enumeration/discovery
methods using kernel configuration options.  This new configuration
option mechanism allows to select statically linked or modular
enumeration/discovery method(s) from the list of existing methods or use
external module(s).

This patch also updates the currently existing enumeration/discovery
code to be used as a statically linked or modular method.

The corresponding configuration option is named "Basic
enumeration/discovery" method.  This is the only one configuration
option available today but new methods are expected to be introduced
after adoption of provided patches.

The second patch address a long time complaint of RapidIO subsystem
users regarding fabric enumeration/discovery start sequence.  Existing
implementation offers only a boot-time enumeration/discovery start which
requires synchronized boot of all endpoints in RapidIO network.  While
it works for small closed configurations with limited number of
endpoints, using this approach in systems with large number of endpoints
is quite challenging.

To eliminate requirement for synchronized start the second patch
introduces RapidIO enumeration/discovery start from user space.

For compatibility with the existing RapidIO subsystem implementation,
automatic boot time enumeration/discovery start can be configured in by
specifying "rio-scan.scan=1" command line parameter if statically linked
basic enumeration method is selected.

This patch:

Rework to implement RapidIO enumeration/discovery method selection
combined with ability to use enumeration/discovery as a kernel module.

This patch adds ability to introduce new RapidIO enumeration/discovery
methods using kernel configuration options.  Configuration option
mechanism allows to select statically linked or modular
enumeration/discovery method from the list of existing methods or use
external modules.  If a modular enumeration/discovery is selected each
RapidIO mport device can have its own method attached to it.

The existing enumeration/discovery code was updated to be used as
statically linked or modular method.  This configuration option is named
"Basic enumeration/discovery" method.

Several common routines have been moved from rio-scan.c to make them
available to other enumeration methods and reduce number of exported
symbols.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 215 insertions, 7 deletions

diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index d553b5d13722..6e75dda34799 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -31,7 +31,11 @@
 
 #include "rio.h"
 
+static LIST_HEAD(rio_devices);
+static DEFINE_SPINLOCK(rio_global_list_lock);
+
 static LIST_HEAD(rio_mports);
+static DEFINE_MUTEX(rio_mport_list_lock);
 static unsigned char next_portid;
 static DEFINE_SPINLOCK(rio_mmap_lock);
 
@@ -53,6 +57,32 @@ u16 rio_local_get_device_id(struct rio_mport *port)
 }
 
 /**
+ * rio_add_device- Adds a RIO device to the device model
+ * @rdev: RIO device
+ *
+ * Adds the RIO device to the global device list and adds the RIO
+ * device to the RIO device list.  Creates the generic sysfs nodes
+ * for an RIO device.
+ */
+int rio_add_device(struct rio_dev *rdev)
+{
+        int err;
+
+        err = device_add(&rdev->dev);
+        if (err)
+                return err;
+
+        spin_lock(&rio_global_list_lock);
+        list_add_tail(&rdev->global_list, &rio_devices);
+        spin_unlock(&rio_global_list_lock);
+
+        rio_create_sysfs_dev_files(rdev);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(rio_add_device);
+
+/**
  * rio_request_inb_mbox - request inbound mailbox service
  * @mport: RIO master port from which to allocate the mailbox resource
  * @dev_id: Device specific pointer to pass on event
@@ -489,6 +519,7 @@ rio_mport_get_physefb(struct rio_mport *port, int local,
 
         return ext_ftr_ptr;
 }
+EXPORT_SYMBOL_GPL(rio_mport_get_physefb);
 
 /**
  * rio_get_comptag - Begin or continue searching for a RIO device by component tag
@@ -521,6 +552,7 @@ exit:
         spin_unlock(&rio_global_list_lock);
         return rdev;
 }
+EXPORT_SYMBOL_GPL(rio_get_comptag);
 
 /**
  * rio_set_port_lockout - Sets/clears LOCKOUT bit (RIO EM 1.3) for a switch port.
@@ -545,6 +577,107 @@ int rio_set_port_lockout(struct rio_dev *rdev, u32 pnum, int lock)
                                   regval);
         return 0;
 }
+EXPORT_SYMBOL_GPL(rio_set_port_lockout);
+
+/**
+ * rio_switch_init - Sets switch operations for a particular vendor switch
+ * @rdev: RIO device
+ * @do_enum: Enumeration/Discovery mode flag
+ *
+ * Searches the RIO switch ops table for known switch types. If the vid
+ * and did match a switch table entry, then call switch initialization
+ * routine to setup switch-specific routines.
+ */
+void rio_switch_init(struct rio_dev *rdev, int do_enum)
+{
+        struct rio_switch_ops *cur = __start_rio_switch_ops;
+        struct rio_switch_ops *end = __end_rio_switch_ops;
+
+        while (cur < end) {
+                if ((cur->vid == rdev->vid) && (cur->did == rdev->did)) {
+                        pr_debug("RIO: calling init routine for %s\n",
+                                 rio_name(rdev));
+                        cur->init_hook(rdev, do_enum);
+                        break;
+                }
+                cur++;
+        }
+
+        if ((cur >= end) && (rdev->pef & RIO_PEF_STD_RT)) {
+                pr_debug("RIO: adding STD routing ops for %s\n",
+                        rio_name(rdev));
+                rdev->rswitch->add_entry = rio_std_route_add_entry;
+                rdev->rswitch->get_entry = rio_std_route_get_entry;
+                rdev->rswitch->clr_table = rio_std_route_clr_table;
+        }
+
+        if (!rdev->rswitch->add_entry || !rdev->rswitch->get_entry)
+                printk(KERN_ERR "RIO: missing routing ops for %s\n",
+                       rio_name(rdev));
+}
+EXPORT_SYMBOL_GPL(rio_switch_init);
+
+/**
+ * rio_enable_rx_tx_port - enable input receiver and output transmitter of
+ * given port
+ * @port: Master port associated with the RIO network
+ * @local: local=1 select local port otherwise a far device is reached
+ * @destid: Destination ID of the device to check host bit
+ * @hopcount: Number of hops to reach the target
+ * @port_num: Port (-number on switch) to enable on a far end device
+ *
+ * Returns 0 or 1 from on General Control Command and Status Register
+ * (EXT_PTR+0x3C)
+ */
+int rio_enable_rx_tx_port(struct rio_mport *port,
+                          int local, u16 destid,
+                          u8 hopcount, u8 port_num)
+{
+#ifdef CONFIG_RAPIDIO_ENABLE_RX_TX_PORTS
+        u32 regval;
+        u32 ext_ftr_ptr;
+
+        /*
+        * enable rx input tx output port
+        */
+        pr_debug("rio_enable_rx_tx_port(local = %d, destid = %d, hopcount = "
+                 "%d, port_num = %d)\n", local, destid, hopcount, port_num);
+
+        ext_ftr_ptr = rio_mport_get_physefb(port, local, destid, hopcount);
+
+        if (local) {
+                rio_local_read_config_32(port, ext_ftr_ptr +
+                                RIO_PORT_N_CTL_CSR(0),
+                                &regval);
+        } else {
+                if (rio_mport_read_config_32(port, destid, hopcount,
+                ext_ftr_ptr + RIO_PORT_N_CTL_CSR(port_num), &regval) < 0)
+                        return -EIO;
+        }
+
+        if (regval & RIO_PORT_N_CTL_P_TYP_SER) {
+                /* serial */
+                regval = regval | RIO_PORT_N_CTL_EN_RX_SER
+                                | RIO_PORT_N_CTL_EN_TX_SER;
+        } else {
+                /* parallel */
+                regval = regval | RIO_PORT_N_CTL_EN_RX_PAR
+                                | RIO_PORT_N_CTL_EN_TX_PAR;
+        }
+
+        if (local) {
+                rio_local_write_config_32(port, ext_ftr_ptr +
+                                          RIO_PORT_N_CTL_CSR(0), regval);
+        } else {
+                if (rio_mport_write_config_32(port, destid, hopcount,
+                    ext_ftr_ptr + RIO_PORT_N_CTL_CSR(port_num), regval) < 0)
+                        return -EIO;
+        }
+#endif
+        return 0;
+}
+EXPORT_SYMBOL_GPL(rio_enable_rx_tx_port);
+
 
 /**
  * rio_chk_dev_route - Validate route to the specified device.
@@ -610,6 +743,7 @@ rio_mport_chk_dev_access(struct rio_mport *mport, u16 destid, u8 hopcount)
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(rio_mport_chk_dev_access);
 
 /**
  * rio_chk_dev_access - Validate access to the specified device.
@@ -941,6 +1075,7 @@ rio_mport_get_efb(struct rio_mport *port, int local, u16 destid,
                 return RIO_GET_BLOCK_ID(reg_val);
         }
 }
+EXPORT_SYMBOL_GPL(rio_mport_get_efb);
 
 /**
  * rio_mport_get_feature - query for devices' extended features
@@ -997,6 +1132,7 @@ rio_mport_get_feature(struct rio_mport * port, int local, u16 destid,
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(rio_mport_get_feature);
 
 /**
  * rio_get_asm - Begin or continue searching for a RIO device by vid/did/asm_vid/asm_did
@@ -1246,6 +1382,71 @@ EXPORT_SYMBOL_GPL(rio_dma_prep_slave_sg);
 
 #endif /* CONFIG_RAPIDIO_DMA_ENGINE */
 
+/**
+ * rio_register_scan - enumeration/discovery method registration interface
+ * @mport_id: mport device ID for which fabric scan routine has to be set
+ *            (RIO_MPORT_ANY = set for all available mports)
+ * @scan_ops: enumeration/discovery control structure
+ *
+ * Assigns enumeration or discovery method to the specified mport device (or all
+ * available mports if RIO_MPORT_ANY is specified).
+ * Returns error if the mport already has an enumerator attached to it.
+ * In case of RIO_MPORT_ANY ignores ports with valid scan routines and returns
+ * an error if was unable to find at least one available mport.
+ */
+int rio_register_scan(int mport_id, struct rio_scan *scan_ops)
+{
+        struct rio_mport *port;
+        int rc = -EBUSY;
+
+        mutex_lock(&rio_mport_list_lock);
+        list_for_each_entry(port, &rio_mports, node) {
+                if (port->id == mport_id || mport_id == RIO_MPORT_ANY) {
+                        if (port->nscan && mport_id == RIO_MPORT_ANY)
+                                continue;
+                        else if (port->nscan)
+                                break;
+
+                        port->nscan = scan_ops;
+                        rc = 0;
+
+                        if (mport_id != RIO_MPORT_ANY)
+                                break;
+                }
+        }
+        mutex_unlock(&rio_mport_list_lock);
+
+        return rc;
+}
+EXPORT_SYMBOL_GPL(rio_register_scan);
+
+/**
+ * rio_unregister_scan - removes enumeration/discovery method from mport
+ * @mport_id: mport device ID for which fabric scan routine has to be
+ *            unregistered (RIO_MPORT_ANY = set for all available mports)
+ *
+ * Removes enumeration or discovery method assigned to the specified mport
+ * device (or all available mports if RIO_MPORT_ANY is specified).
+ */
+int rio_unregister_scan(int mport_id)
+{
+        struct rio_mport *port;
+
+        mutex_lock(&rio_mport_list_lock);
+        list_for_each_entry(port, &rio_mports, node) {
+                if (port->id == mport_id || mport_id == RIO_MPORT_ANY) {
+                        if (port->nscan)
+                                port->nscan = NULL;
+                        if (mport_id != RIO_MPORT_ANY)
+                                break;
+                }
+        }
+        mutex_unlock(&rio_mport_list_lock);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(rio_unregister_scan);
+
 static void rio_fixup_device(struct rio_dev *dev)
 {
 }
@@ -1274,7 +1475,7 @@ static void disc_work_handler(struct work_struct *_work)
         work = container_of(_work, struct rio_disc_work, work);
         pr_debug("RIO: discovery work for mport %d %s\n",
                  work->mport->id, work->mport->name);
-        rio_disc_mport(work->mport);
+        work->mport->nscan->discover(work->mport);
 }
 
 int rio_init_mports(void)
@@ -1290,12 +1491,15 @@ int rio_init_mports(void)
          * First, run enumerations and check if we need to perform discovery
          * on any of the registered mports.
          */
+        mutex_lock(&rio_mport_list_lock);
         list_for_each_entry(port, &rio_mports, node) {
-                if (port->host_deviceid >= 0)
-                        rio_enum_mport(port);
-                else
+                if (port->host_deviceid >= 0) {
+                        if (port->nscan)
+                                port->nscan->enumerate(port);
+                } else
                         n++;
         }
+        mutex_unlock(&rio_mport_list_lock);
 
         if (!n)
                 goto no_disc;
@@ -1322,14 +1526,16 @@ int rio_init_mports(void)
         }
 
         n = 0;
+        mutex_lock(&rio_mport_list_lock);
         list_for_each_entry(port, &rio_mports, node) {
-                if (port->host_deviceid < 0) {
+                if (port->host_deviceid < 0 && port->nscan) {
                         work[n].mport = port;
                         INIT_WORK(&work[n].work, disc_work_handler);
                         queue_work(rio_wq, &work[n].work);
                         n++;
                 }
         }
+        mutex_unlock(&rio_mport_list_lock);
 
         flush_workqueue(rio_wq);
         pr_debug("RIO: destroy discovery workqueue\n");
@@ -1342,8 +1548,6 @@ no_disc:
         return 0;
 }
 
-device_initcall_sync(rio_init_mports);
-
 static int hdids[RIO_MAX_MPORTS + 1];
 
 static int rio_get_hdid(int index)
@@ -1371,7 +1575,10 @@ int rio_register_mport(struct rio_mport *port)
 
         port->id = next_portid++;
         port->host_deviceid = rio_get_hdid(port->id);
+        port->nscan = NULL;
+        mutex_lock(&rio_mport_list_lock);
         list_add_tail(&port->node, &rio_mports);
+        mutex_unlock(&rio_mport_list_lock);
         return 0;
 }
 
@@ -1386,3 +1593,4 @@ EXPORT_SYMBOL_GPL(rio_request_inb_mbox);
 EXPORT_SYMBOL_GPL(rio_release_inb_mbox);
 EXPORT_SYMBOL_GPL(rio_request_outb_mbox);
 EXPORT_SYMBOL_GPL(rio_release_outb_mbox);
+EXPORT_SYMBOL_GPL(rio_init_mports);