MN10300: Introduce barriers to replace removed volatiles in gdbstub

[linux-2.6-omap-h63xx.git] / drivers / firewire / fw-device.c

diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index 2b6586341635b9ed57dafc5f6ebb977924177010..de9066e69adfbeea440d31cec1c0945f337db728 100644 (file)
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -27,6 +27,7 @@
 #include <linux/idr.h>
 #include <linux/rwsem.h>
 #include <asm/semaphore.h>
+#include <asm/system.h>
 #include <linux/ctype.h>
 #include "fw-transaction.h"
 #include "fw-topology.h"
@@ -130,23 +131,16 @@ static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 }
 
 static int
-fw_unit_uevent(struct device *dev, char **envp, int num_envp,
-              char *buffer, int buffer_size)
+fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
        struct fw_unit *unit = fw_unit(dev);
        char modalias[64];
-       int length = 0;
-       int i = 0;
 
        get_modalias(unit, modalias, sizeof(modalias));
 
-       if (add_uevent_var(envp, num_envp, &i,
-                          buffer, buffer_size, &length,
-                          "MODALIAS=%s", modalias))
+       if (add_uevent_var(env, "MODALIAS=%s", modalias))
                return -ENOMEM;
 
-       envp[i] = NULL;
-
        return 0;
 }
 
@@ -189,9 +183,14 @@ static void fw_device_release(struct device *dev)
 
 int fw_device_enable_phys_dma(struct fw_device *device)
 {
+       int generation = device->generation;
+
+       /* device->node_id, accessed below, must not be older than generation */
+       smp_rmb();
+
        return device->card->driver->enable_phys_dma(device->card,
                                                     device->node_id,
-                                                    device->generation);
+                                                    generation);
 }
 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 
@@ -391,17 +390,21 @@ complete_transaction(struct fw_card *card, int rcode,
        complete(&callback_data->done);
 }
 
-static int read_rom(struct fw_device *device, int index, u32 * data)
+static int
+read_rom(struct fw_device *device, int generation, int index, u32 *data)
 {
        struct read_quadlet_callback_data callback_data;
        struct fw_transaction t;
        u64 offset;
 
+       /* device->node_id, accessed below, must not be older than generation */
+       smp_rmb();
+
        init_completion(&callback_data.done);
 
        offset = 0xfffff0000400ULL + index * 4;
        fw_send_request(device->card, &t, TCODE_READ_QUADLET_REQUEST,
-                       device->node_id, device->generation, device->max_speed,
+                       device->node_id, generation, device->max_speed,
                        offset, NULL, 4, complete_transaction, &callback_data);
 
        wait_for_completion(&callback_data.done);
@@ -411,7 +414,14 @@ static int read_rom(struct fw_device *device, int index, u32 * data)
        return callback_data.rcode;
 }
 
-static int read_bus_info_block(struct fw_device *device)
+/*
+ * Read the bus info block, perform a speed probe, and read all of the rest of
+ * the config ROM.  We do all this with a cached bus generation.  If the bus
+ * generation changes under us, read_bus_info_block will fail and get retried.
+ * It's better to start all over in this case because the node from which we
+ * are reading the ROM may have changed the ROM during the reset.
+ */
+static int read_bus_info_block(struct fw_device *device, int generation)
 {
        static u32 rom[256];
        u32 stack[16], sp, key;
@@ -421,7 +431,7 @@ static int read_bus_info_block(struct fw_device *device)
 
        /* First read the bus info block. */
        for (i = 0; i < 5; i++) {
-               if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+               if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
                        return -1;
                /*
                 * As per IEEE1212 7.2, during power-up, devices can
@@ -456,7 +466,8 @@ static int read_bus_info_block(struct fw_device *device)
                        device->max_speed = device->card->link_speed;
 
                while (device->max_speed > SCODE_100) {
-                       if (read_rom(device, 0, &dummy) == RCODE_COMPLETE)
+                       if (read_rom(device, generation, 0, &dummy) ==
+                           RCODE_COMPLETE)
                                break;
                        device->max_speed--;
                }
@@ -489,7 +500,7 @@ static int read_bus_info_block(struct fw_device *device)
                        return -1;
 
                /* Read header quadlet for the block to get the length. */
-               if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+               if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
                        return -1;
                end = i + (rom[i] >> 16) + 1;
                i++;
@@ -508,7 +519,8 @@ static int read_bus_info_block(struct fw_device *device)
                 * it references another block, and push it in that case.
                 */
                while (i < end) {
-                       if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+                       if (read_rom(device, generation, i, &rom[i]) !=
+                           RCODE_COMPLETE)
                                return -1;
                        if ((key >> 30) == 3 && (rom[i] >> 30) > 1 &&
                            sp < ARRAY_SIZE(stack))
@@ -655,7 +667,7 @@ static void fw_device_init(struct work_struct *work)
         * device.
         */
 
-       if (read_bus_info_block(device) < 0) {
+       if (read_bus_info_block(device, device->generation) < 0) {
                if (device->config_rom_retries < MAX_RETRIES) {
                        device->config_rom_retries++;
                        schedule_delayed_work(&device->work, RETRY_DELAY);
@@ -808,6 +820,7 @@ void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
 
                device = node->data;
                device->node_id = node->node_id;
+               smp_wmb();  /* update node_id before generation */
                device->generation = card->generation;
                if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
                        PREPARE_DELAYED_WORK(&device->work, fw_device_update);