[patch 3/7] ps3: Use the HVs storage device notification mechanism properly

From: Geert Uytterhoeven
Date: Wed Nov 28 2007 - 09:36:24 EST

From: Geert Uytterhoeven <Geert.Uytterhoeven@xxxxxxxxxxx>

ps3: Use the HV's storage device notification mechanism properly

The hypervisor has a storage device notification mechanism to wait until a
storage device is ready. Unfortunately the storage device probing code used
this mechanism in an incorrect way, needing a polling loop and handling of
devices that are not yet ready.

This change corrects this by:
- First waiting for the reception of an asynchronous notification that a new
storage device became ready,
- Then looking up the storage device in the device repository.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@xxxxxxxxxxx>
---
arch/powerpc/platforms/ps3/device-init.c | 395 +++++++++++++++----------------
arch/powerpc/platforms/ps3/platform.h | 2
arch/powerpc/platforms/ps3/repository.c | 29 --
3 files changed, 194 insertions(+), 232 deletions(-)

--- a/arch/powerpc/platforms/ps3/device-init.c
+++ b/arch/powerpc/platforms/ps3/device-init.c
@@ -238,166 +238,6 @@ static int __init ps3_setup_vuart_device
return result;
}

-static int ps3stor_wait_for_completion(u64 dev_id, u64 tag,
- unsigned int timeout)
-{
- int result = -1;
- unsigned int retries = 0;
- u64 status;
-
- for (retries = 0; retries < timeout; retries++) {
- result = lv1_storage_check_async_status(dev_id, tag, &status);
- if (!result)
- break;
-
- msleep(1);
- }
-
- if (result)
- pr_debug("%s:%u: check_async_status: %s, status %lx\n",
- __func__, __LINE__, ps3_result(result), status);
-
- return result;
-}
-
-/**
- * ps3_storage_wait_for_device - Wait for a storage device to become ready.
- * @repo: The repository device to wait for.
- *
- * Uses the hypervisor's storage device notification mechanism to wait until
- * a storage device is ready. The device notification mechanism uses a
- * psuedo device (id = -1) to asynchronously notify the guest when storage
- * devices become ready. The notification device has a block size of 512
- * bytes.
- */
-
-static int ps3_storage_wait_for_device(const struct ps3_repository_device *repo)
-{
- int error = -ENODEV;
- int result;
- const u64 notification_dev_id = (u64)-1LL;
- const unsigned int timeout = HZ;
- u64 lpar;
- u64 tag;
- void *buf;
- enum ps3_notify_type {
- notify_device_ready = 0,
- notify_region_probe = 1,
- notify_region_update = 2,
- };
- struct {
- u64 operation_code; /* must be zero */
- u64 event_mask; /* OR of 1UL << enum ps3_notify_type */
- } *notify_cmd;
- struct {
- u64 event_type; /* enum ps3_notify_type */
- u64 bus_id;
- u64 dev_id;
- u64 dev_type;
- u64 dev_port;
- } *notify_event;
-
- pr_debug(" -> %s:%u: (%lu:%lu:%u)\n", __func__, __LINE__, repo->bus_id,
- repo->dev_id, repo->dev_type);
-
- buf = kzalloc(512, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- lpar = ps3_mm_phys_to_lpar(__pa(buf));
- notify_cmd = buf;
- notify_event = buf;
-
- result = lv1_open_device(repo->bus_id, notification_dev_id, 0);
- if (result) {
- printk(KERN_ERR "%s:%u: lv1_open_device %s\n", __func__,
- __LINE__, ps3_result(result));
- goto fail_free;
- }
-
- /* Setup and write the request for device notification. */
-
- notify_cmd->operation_code = 0; /* must be zero */
- notify_cmd->event_mask = 1UL << notify_region_probe;
-
- result = lv1_storage_write(notification_dev_id, 0, 0, 1, 0, lpar,
- &tag);
- if (result) {
- printk(KERN_ERR "%s:%u: write failed %s\n", __func__, __LINE__,
- ps3_result(result));
- goto fail_close;
- }
-
- /* Wait for the write completion */
-
- result = ps3stor_wait_for_completion(notification_dev_id, tag,
- timeout);
- if (result) {
- printk(KERN_ERR "%s:%u: write not completed %s\n", __func__,
- __LINE__, ps3_result(result));
- goto fail_close;
- }
-
- /* Loop here processing the requested notification events. */
-
- while (1) {
- memset(notify_event, 0, sizeof(*notify_event));
-
- result = lv1_storage_read(notification_dev_id, 0, 0, 1, 0,
- lpar, &tag);
- if (result) {
- printk(KERN_ERR "%s:%u: write failed %s\n", __func__,
- __LINE__, ps3_result(result));
- break;
- }
-
- result = ps3stor_wait_for_completion(notification_dev_id, tag,
- timeout);
- if (result) {
- printk(KERN_ERR "%s:%u: read not completed %s\n",
- __func__, __LINE__, ps3_result(result));
- break;
- }
-
- pr_debug("%s:%d: notify event (%u:%u:%u): event_type 0x%lx, "
- "port %lu\n", __func__, __LINE__, repo->bus_index,
- repo->dev_index, repo->dev_type,
- notify_event->event_type, notify_event->dev_port);
-
- if (notify_event->event_type != notify_region_probe ||
- notify_event->bus_id != repo->bus_id) {
- pr_debug("%s:%u: bad notify_event: event %lu, "
- "dev_id %lu, dev_type %lu\n",
- __func__, __LINE__, notify_event->event_type,
- notify_event->dev_id, notify_event->dev_type);
- break;
- }
-
- if (notify_event->dev_id == repo->dev_id &&
- notify_event->dev_type == repo->dev_type) {
- pr_debug("%s:%u: device ready (%u:%u:%u)\n", __func__,
- __LINE__, repo->bus_index, repo->dev_index,
- repo->dev_type);
- error = 0;
- break;
- }
-
- if (notify_event->dev_id == repo->dev_id &&
- notify_event->dev_type == PS3_DEV_TYPE_NOACCESS) {
- pr_debug("%s:%u: no access: dev_id %lu\n", __func__,
- __LINE__, repo->dev_id);
- break;
- }
- }
-
-fail_close:
- lv1_close_device(repo->bus_id, notification_dev_id);
-fail_free:
- kfree(buf);
- pr_debug(" <- %s:%u\n", __func__, __LINE__);
- return error;
-}
-
static int ps3_setup_storage_dev(const struct ps3_repository_device *repo,
enum ps3_match_id match_id)
{
@@ -449,16 +289,6 @@ static int ps3_setup_storage_dev(const s
goto fail_find_interrupt;
}

- /* FIXME: Arrange to only do this on a 'cold' boot */
-
- result = ps3_storage_wait_for_device(repo);
- if (result) {
- printk(KERN_ERR "%s:%u: storage_notification failed %d\n",
- __func__, __LINE__, result);
- result = -ENODEV;
- goto fail_probe_notification;
- }
-
for (i = 0; i < num_regions; i++) {
unsigned int id;
u64 start, size;
@@ -494,7 +324,6 @@ static int ps3_setup_storage_dev(const s

fail_device_register:
fail_read_region:
-fail_probe_notification:
fail_find_interrupt:
kfree(p);
fail_malloc:
@@ -659,56 +488,219 @@ static int ps3_register_repository_devic
return result;
}

+
+#define PS3_NOTIFICATION_DEV_ID ULONG_MAX
+#define PS3_NOTIFICATION_INTERRUPT_ID 0
+
+struct ps3_notification_device {
+ struct ps3_system_bus_device sbd;
+ spinlock_t lock;
+ u64 tag;
+ u64 lv1_status;
+ struct completion done;
+};
+
+enum ps3_notify_type {
+ notify_device_ready = 0,
+ notify_region_probe = 1,
+ notify_region_update = 2,
+};
+
+struct ps3_notify_cmd {
+ u64 operation_code; /* must be zero */
+ u64 event_mask; /* OR of 1UL << enum ps3_notify_type */
+};
+
+struct ps3_notify_event {
+ u64 event_type; /* enum ps3_notify_type */
+ u64 bus_id;
+ u64 dev_id;
+ u64 dev_type;
+ u64 dev_port;
+};
+
+static irqreturn_t ps3_notification_interrupt(int irq, void *data)
+{
+ struct ps3_notification_device *dev = data;
+ int res;
+ u64 tag, status;
+
+ spin_lock(&dev->lock);
+ res = lv1_storage_get_async_status(PS3_NOTIFICATION_DEV_ID, &tag,
+ &status);
+ if (tag != dev->tag)
+ pr_err("%s:%u: tag mismatch, got %lx, expected %lx\n",
+ __func__, __LINE__, tag, dev->tag);
+
+ if (res) {
+ pr_err("%s:%u: res %d status 0x%lx\n", __func__, __LINE__, res,
+ status);
+ } else {
+ pr_debug("%s:%u: completed, status 0x%lx\n", __func__,
+ __LINE__, status);
+ dev->lv1_status = status;
+ complete(&dev->done);
+ }
+ spin_unlock(&dev->lock);
+ return IRQ_HANDLED;
+}
+
+static int ps3_notification_read_write(struct ps3_notification_device *dev,
+ u64 lpar, int write)
+{
+ const char *op = write ? "write" : "read";
+ unsigned long flags;
+ int res;
+
+ init_completion(&dev->done);
+ spin_lock_irqsave(&dev->lock, flags);
+ res = write ? lv1_storage_write(dev->sbd.dev_id, 0, 0, 1, 0, lpar,
+ &dev->tag)
+ : lv1_storage_read(dev->sbd.dev_id, 0, 0, 1, 0, lpar,
+ &dev->tag);
+ spin_unlock_irqrestore(&dev->lock, flags);
+ if (res) {
+ pr_err("%s:%u: %s failed %d\n", __func__, __LINE__, op, res);
+ return -EPERM;
+ }
+ pr_debug("%s:%u: notification %s issued\n", __func__, __LINE__, op);
+
+ res = wait_for_completion_interruptible(&dev->done);
+ if (res) {
+ pr_debug("%s:%u: interrupted %s\n", __func__, __LINE__, op);
+ return res;
+ }
+
+ if (dev->lv1_status) {
+ pr_err("%s:%u: %s not completed, status 0x%lx\n", __func__,
+ __LINE__, op, dev->lv1_status);
+ return -EIO;
+ }
+ pr_debug("%s:%u: notification %s completed\n", __func__, __LINE__, op);
+
+ return 0;
+}
+
+
/**
* ps3_probe_thread - Background repository probing at system startup.
*
* This implementation only supports background probing on a single bus.
+ * It uses the hypervisor's storage device notification mechanism to wait until
+ * a storage device is ready. The device notification mechanism uses a
+ * pseudo device to asynchronously notify the guest when storage devices become
+ * ready. The notification device has a block size of 512 bytes.
*/

static int ps3_probe_thread(void *data)
{
- struct ps3_repository_device *repo = data;
- int result;
- unsigned int ms = 250;
+ struct ps3_notification_device dev;
+ struct ps3_repository_device repo;
+ int res;
+ unsigned int irq;
+ u64 lpar;
+ void *buf;
+ struct ps3_notify_cmd *notify_cmd;
+ struct ps3_notify_event *notify_event;

pr_debug(" -> %s:%u: kthread started\n", __func__, __LINE__);

- do {
- try_to_freeze();
+ buf = kzalloc(512, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ lpar = ps3_mm_phys_to_lpar(__pa(buf));
+ notify_cmd = buf;
+ notify_event = buf;
+
+ /* dummy system bus device */
+ dev.sbd.bus_id = (u64)data;
+ dev.sbd.dev_id = PS3_NOTIFICATION_DEV_ID;
+ dev.sbd.interrupt_id = PS3_NOTIFICATION_INTERRUPT_ID;
+
+ res = lv1_open_device(dev.sbd.bus_id, dev.sbd.dev_id, 0);
+ if (res) {
+ pr_err("%s:%u: lv1_open_device %s\n", __func__, __LINE__,
+ ps3_result(res));
+ goto fail_free;
+ }
+
+ res = ps3_sb_event_receive_port_setup(&dev.sbd, PS3_BINDING_CPU_ANY,
+ &irq);
+ if (res) {
+ pr_err("%s:%u: ps3_sb_event_receive_port_setup failed %d\n",
+ __func__, __LINE__, res);
+ goto fail_close_device;
+ }
+
+ spin_lock_init(&dev.lock);
+
+ res = request_irq(irq, ps3_notification_interrupt, IRQF_DISABLED,
+ "ps3_notification", &dev);
+ if (res) {
+ pr_err("%s:%u: request_irq failed %d\n", __func__, __LINE__,
+ res);
+ goto fail_sb_event_receive_port_destroy;
+ }

- pr_debug("%s:%u: probing...\n", __func__, __LINE__);
+ /* Setup and write the request for device notification. */
+ notify_cmd->operation_code = 0; /* must be zero */
+ notify_cmd->event_mask = 1UL << notify_region_probe;

- do {
- result = ps3_repository_find_device(repo);
+ res = ps3_notification_read_write(&dev, lpar, 1);
+ if (res)
+ goto fail_free_irq;

- if (result == -ENODEV)
- pr_debug("%s:%u: nothing new\n", __func__,
- __LINE__);
- else if (result)
- pr_debug("%s:%u: find device error.\n",
- __func__, __LINE__);
- else {
- pr_debug("%s:%u: found device (%u:%u:%u)\n",
- __func__, __LINE__, repo->bus_index,
- repo->dev_index, repo->dev_type);
- ps3_register_repository_device(repo);
- ps3_repository_bump_device(repo);
- ms = 250;
- }
- } while (!result);
+ /* Loop here processing the requested notification events. */
+ do {
+ try_to_freeze();

- pr_debug("%s:%u: ms %u\n", __func__, __LINE__, ms);
+ memset(notify_event, 0, sizeof(*notify_event));

- if ( ms > 60000)
+ res = ps3_notification_read_write(&dev, lpar, 0);
+ if (res)
break;

- msleep_interruptible(ms);
+ pr_debug("%s:%u: notify event type 0x%lx bus id %lu dev id %lu"
+ " type %lu port %lu\n", __func__, __LINE__,
+ notify_event->event_type, notify_event->bus_id,
+ notify_event->dev_id, notify_event->dev_type,
+ notify_event->dev_port);

- /* An exponential backoff. */
- ms <<= 1;
+ if (notify_event->event_type != notify_region_probe ||
+ notify_event->bus_id != dev.sbd.bus_id) {
+ pr_warning("%s:%u: bad notify_event: event %lu, "
+ "dev_id %lu, dev_type %lu\n",
+ __func__, __LINE__, notify_event->event_type,
+ notify_event->dev_id,
+ notify_event->dev_type);
+ continue;
+ }
+
+ res = ps3_repository_find_device_by_id(&repo, dev.sbd.bus_id,
+ notify_event->dev_id);
+ if (res) {
+ pr_warning("%s:%u: device %lu:%lu not found\n",
+ __func__, __LINE__, dev.sbd.bus_id,
+ notify_event->dev_id);
+ continue;
+ }
+
+ pr_debug("%s:%u: device %lu:%lu found\n", __func__, __LINE__,
+ dev.sbd.bus_id, notify_event->dev_id);
+ ps3_register_repository_device(&repo);

} while (!kthread_should_stop());

+fail_free_irq:
+ free_irq(irq, &dev);
+fail_sb_event_receive_port_destroy:
+ ps3_sb_event_receive_port_destroy(&dev.sbd, irq);
+fail_close_device:
+ lv1_close_device(dev.sbd.bus_id, dev.sbd.dev_id);
+fail_free:
+ kfree(buf);
+
pr_debug(" <- %s:%u: kthread finished\n", __func__, __LINE__);

return 0;
@@ -723,7 +715,7 @@ static int __init ps3_start_probe_thread
{
int result;
struct task_struct *task;
- static struct ps3_repository_device repo; /* must be static */
+ struct ps3_repository_device repo;

pr_debug(" -> %s:%d\n", __func__, __LINE__);

@@ -746,7 +738,8 @@ static int __init ps3_start_probe_thread
return -ENODEV;
}

- task = kthread_run(ps3_probe_thread, &repo, "ps3-probe-%u", bus_type);
+ task = kthread_run(ps3_probe_thread, (void *)repo.bus_id,
+ "ps3-probe-%u", bus_type);

if (IS_ERR(task)) {
result = PTR_ERR(task);
--- a/arch/powerpc/platforms/ps3/platform.h
+++ b/arch/powerpc/platforms/ps3/platform.h
@@ -89,8 +89,6 @@ enum ps3_dev_type {
PS3_DEV_TYPE_STOR_ROM = TYPE_ROM, /* 5 */
PS3_DEV_TYPE_SB_GPIO = 6,
PS3_DEV_TYPE_STOR_FLASH = TYPE_RBC, /* 14 */
- PS3_DEV_TYPE_STOR_DUMMY = 32,
- PS3_DEV_TYPE_NOACCESS = 255,
};

int ps3_repository_read_bus_str(unsigned int bus_index, const char *bus_str,
--- a/arch/powerpc/platforms/ps3/repository.c
+++ b/arch/powerpc/platforms/ps3/repository.c
@@ -344,35 +344,6 @@ int ps3_repository_find_device(struct ps
return result;
}

- if (tmp.bus_type == PS3_BUS_TYPE_STORAGE) {
- /*
- * A storage device may show up in the repository before the
- * hypervisor has finished probing its type and regions
- */
- unsigned int num_regions;
-
- if (tmp.dev_type == PS3_DEV_TYPE_STOR_DUMMY) {
- pr_debug("%s:%u storage device not ready\n", __func__,
- __LINE__);
- return -ENODEV;
- }
-
- result = ps3_repository_read_stor_dev_num_regions(tmp.bus_index,
- tmp.dev_index,
- &num_regions);
- if (result) {
- pr_debug("%s:%d read_stor_dev_num_regions failed\n",
- __func__, __LINE__);
- return result;
- }
-
- if (!num_regions) {
- pr_debug("%s:%u storage device has no regions yet\n",
- __func__, __LINE__);
- return -ENODEV;
- }
- }
-
result = ps3_repository_read_dev_id(tmp.bus_index, tmp.dev_index,
&tmp.dev_id);


--
With kind regards,

Geert Uytterhoeven
Software Architect

Sony Network and Software Technology Center Europe
The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium

Phone: +32 (0)2 700 8453
Fax: +32 (0)2 700 8622
E-mail: Geert.Uytterhoeven@xxxxxxxxxxx
Internet: http://www.sony-europe.com/

Sony Network and Software Technology Center Europe
A division of Sony Service Centre (Europe) N.V.
Registered office: Technologielaan 7 · B-1840 Londerzeel · Belgium
VAT BE 0413.825.160 · RPR Brussels
Fortis Bank Zaventem · Swift GEBABEBB08A · IBAN BE39001382358619

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