[PATCH 12/16] cciss: do soft reset if hard reset is broken

Stephen M. Cameron
2011-05-03T20:02:54Z

on driver load, if reset_devices is set, and the hard reset
attempts fail, try to bring up the controller to the point that
a command can be sent, and send it a soft reset command, then
after the reset undo whatever driver initialization was done to get
it to the point to take a command, and re-do it after the reset.

This is to get kdump to work on all the "non-resettable" controllers
(except 64xx controllers which can't be reset due to the potentially
shared cache module.)

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
---
drivers/block/cciss.c | 236 ++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 221 insertions(+), 15 deletions(-)

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index df58c59..23b0ba4 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -2477,6 +2477,31 @@ static int deregister_disk(ctlr_info_t *h, int drv_index,
return 0;
}

+static int __devinit cciss_send_reset(ctlr_info_t *h, unsigned char *scsi3addr,
+ u8 reset_type)
+{
+ CommandList_struct *c;
+ int return_status;
+
+ c = cmd_alloc(h);
+ if (!c)
+ return -ENOMEM;
+ return_status = fill_cmd(h, c, CCISS_RESET_MSG, NULL, 0, 0,
+ CTLR_LUNID, TYPE_MSG);
+ c->Request.CDB[1] = reset_type; /* fill_cmd defaults to target reset */
+ if (return_status != IO_OK) {
+ cmd_special_free(h, c);
+ return return_status;
+ }
+ c->waiting = NULL;
+ enqueue_cmd_and_start_io(h, c);
+ /* Don't wait for completion, the reset won't complete. Don't free
+ * the command either. This is the last command we will send before
+ * re-initializing everything, so it doesn't matter and won't leak.
+ */
+ return 0;
+}
+
static int fill_cmd(ctlr_info_t *h, CommandList_struct *c, __u8 cmd, void *buff,
size_t size, __u8 page_code, unsigned char *scsi3addr,
int cmd_type)
@@ -3463,6 +3488,63 @@ static inline u32 process_nonindexed_cmd(ctlr_info_t *h, u32 raw_tag)
return next_command(h);
}

+/* Some controllers, like p400, will give us one interrupt
+ * after a soft reset, even if we turned interrupts off.
+ * Only need to check for this in the cciss_xxx_discard_completions
+ * functions.
+ */
+static int ignore_bogus_interrupt(ctlr_info_t *h)
+{
+ if (likely(!reset_devices))
+ return 0;
+
+ if (likely(h->interrupts_enabled))
+ return 0;
+
+ dev_info(&h->pdev->dev, "Received interrupt while interrupts disabled "
+ "(known firmware bug.) Ignoring.\n");
+
+ return 1;
+}
+
+static irqreturn_t cciss_intx_discard_completions(int irq, void *dev_id)
+{
+ ctlr_info_t *h = dev_id;
+ unsigned long flags;
+ u32 raw_tag;
+
+ if (ignore_bogus_interrupt(h))
+ return IRQ_NONE;
+
+ if (interrupt_not_for_us(h))
+ return IRQ_NONE;
+ spin_lock_irqsave(&h->lock, flags);
+ while (interrupt_pending(h)) {
+ raw_tag = get_next_completion(h);
+ while (raw_tag != FIFO_EMPTY)
+ raw_tag = next_command(h);
+ }
+ spin_unlock_irqrestore(&h->lock, flags);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t cciss_msix_discard_completions(int irq, void *dev_id)
+{
+ ctlr_info_t *h = dev_id;
+ unsigned long flags;
+ u32 raw_tag;
+
+ if (ignore_bogus_interrupt(h))
+ return IRQ_NONE;
+
+ spin_lock_irqsave(&h->lock, flags);
+ raw_tag = get_next_completion(h);
+ while (raw_tag != FIFO_EMPTY)
+ raw_tag = next_command(h);
+ spin_unlock_irqrestore(&h->lock, flags);
+ return IRQ_HANDLED;
+}
+
static irqreturn_t do_cciss_intx(int irq, void *dev_id)
{
ctlr_info_t *h = dev_id;
@@ -4380,7 +4462,6 @@ static __devinit int cciss_message(struct pci_dev *pdev, unsigned char opcode, u
return 0;
}

-#define cciss_soft_reset_controller(p) cciss_message(p, 1, 0)
#define cciss_noop(p) cciss_message(p, 3, 0)

static int cciss_controller_hard_reset(struct pci_dev *pdev,
@@ -4591,13 +4672,17 @@ static __devinit int cciss_kdump_hard_reset_controller(struct pci_dev *pdev)
/* Wait for board to become not ready, then ready. */
dev_info(&pdev->dev, "Waiting for board to reset.\n");
rc = cciss_wait_for_board_state(pdev, vaddr, BOARD_NOT_READY);
- if (rc) /* Don't bail, might be E500, etc. which can't be reset */
- dev_warn(&pdev->dev,
- "failed waiting for board to reset\n");
+ if (rc) {
+ dev_warn(&pdev->dev, "Failed waiting for board to hard reset."
+ " Will try soft reset.\n");
+ rc = -ENOTSUPP; /* Not expected, but try soft reset later */
+ goto unmap_cfgtable;
+ }
rc = cciss_wait_for_board_state(pdev, vaddr, BOARD_READY);
if (rc) {
dev_warn(&pdev->dev,
- "failed waiting for board to become ready\n");
+ "failed waiting for board to become ready "
+ "after hard reset\n");
goto unmap_cfgtable;
}

@@ -4605,16 +4690,13 @@ static __devinit int cciss_kdump_hard_reset_controller(struct pci_dev *pdev)
if (rc < 0)
goto unmap_cfgtable;
if (rc) {
- dev_warn(&pdev->dev, "Unable to successfully reset controller,"
- " Ignoring controller.\n");
- rc = -ENODEV;
- goto unmap_cfgtable;
+ dev_warn(&pdev->dev, "Unable to successfully hard reset "
+ "controller. Will try soft reset.\n");
+ rc = -ENOTSUPP; /* Not expected, but try soft reset later */
} else {
- dev_info(&pdev->dev, "board ready.\n");
+ dev_info(&pdev->dev, "Board ready after hard reset.\n");
}

- dev_info(&pdev->dev, "board ready.\n");
-
unmap_cfgtable:
iounmap(cfgtable);

@@ -4639,7 +4721,7 @@ static __devinit int cciss_init_reset_devices(struct pci_dev *pdev)
* due to concerns about shared bbwc between 6402/6404 pair.
*/
if (rc == -ENOTSUPP)
- return 0; /* just try to do the kdump anyhow. */
+ return rc; /* just try to do the kdump anyhow. */
if (rc)
return -ENODEV;

@@ -4745,6 +4827,60 @@ static int cciss_request_irq(ctlr_info_t *h,
return -1;
}

+static int __devinit cciss_kdump_soft_reset(ctlr_info_t *h)
+{
+ if (cciss_send_reset(h, CTLR_LUNID, CCISS_RESET_TYPE_CONTROLLER)) {
+ dev_warn(&h->pdev->dev, "Resetting array controller failed.\n");
+ return -EIO;
+ }
+
+ dev_info(&h->pdev->dev, "Waiting for board to soft reset.\n");
+ if (cciss_wait_for_board_state(h->pdev, h->vaddr, BOARD_NOT_READY)) {
+ dev_warn(&h->pdev->dev, "Soft reset had no effect.\n");
+ return -1;
+ }
+
+ dev_info(&h->pdev->dev, "Board reset, awaiting READY status.\n");
+ if (cciss_wait_for_board_state(h->pdev, h->vaddr, BOARD_READY)) {
+ dev_warn(&h->pdev->dev, "Board failed to become ready "
+ "after soft reset.\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static void cciss_undo_allocations_after_kdump_soft_reset(ctlr_info_t *h)
+{
+ int ctlr = h->ctlr;
+
+ free_irq(h->intr[PERF_MODE_INT], h);
+#ifdef CONFIG_PCI_MSI
+ if (h->msix_vector)
+ pci_disable_msix(h->pdev);
+ else if (h->msi_vector)
+ pci_disable_msi(h->pdev);
+#endif /* CONFIG_PCI_MSI */
+ cciss_free_sg_chain_blocks(h->cmd_sg_list, h->nr_cmds);
+ cciss_free_scatterlists(h);
+ cciss_free_cmd_pool(h);
+ kfree(h->blockFetchTable);
+ if (h->reply_pool)
+ pci_free_consistent(h->pdev, h->max_commands * sizeof(__u64),
+ h->reply_pool, h->reply_pool_dhandle);
+ if (h->transtable)
+ iounmap(h->transtable);
+ if (h->cfgtable)
+ iounmap(h->cfgtable);
+ if (h->vaddr)
+ iounmap(h->vaddr);
+ unregister_blkdev(h->major, h->devname);
+ cciss_destroy_hba_sysfs_entry(h);
+ pci_release_regions(h->pdev);
+ kfree(h);
+ hba[ctlr] = NULL;
+}
+
/*
* This is it. Find all the controllers and register them. I really hate
* stealing all these major device numbers.
@@ -4756,13 +4892,27 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
int i;
int j = 0;
int rc;
+ int try_soft_reset = 0;
int dac, return_code;
InquiryData_struct *inq_buff;
ctlr_info_t *h;
+ unsigned long flags;

rc = cciss_init_reset_devices(pdev);
- if (rc)
- return rc;
+ if (rc) {
+ if (rc != -ENOTSUPP)
+ return rc;
+ /* If the reset fails in a particular way (it has no way to do
+ * a proper hard reset, so returns -ENOTSUPP) we can try to do
+ * a soft reset once we get the controller configured up to the
+ * point that it can accept a command.
+ */
+ try_soft_reset = 1;
+ rc = 0;
+ }
+
+reinit_after_soft_reset:
+
i = alloc_cciss_hba(pdev);
if (i < 0)
return -1;
@@ -4852,6 +5002,62 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
h->gendisk[j] = NULL;
}

+ /* At this point, the controller is ready to take commands.
+ * Now, if reset_devices and the hard reset didn't work, try
+ * the soft reset and see if that works.
+ */
+ if (try_soft_reset) {
+
+ /* This is kind of gross. We may or may not get a completion
+ * from the soft reset command, and if we do, then the value
+ * from the fifo may or may not be valid. So, we wait 10 secs
+ * after the reset throwing away any completions we get during
+ * that time. Unregister the interrupt handler and register
+ * fake ones to scoop up any residual completions.
+ */
+ spin_lock_irqsave(&h->lock, flags);
+ h->access.set_intr_mask(h, CCISS_INTR_OFF);
+ spin_unlock_irqrestore(&h->lock, flags);
+ free_irq(h->intr[PERF_MODE_INT], h);
+ rc = cciss_request_irq(h, cciss_msix_discard_completions,
+ cciss_intx_discard_completions);
+ if (rc) {
+ dev_warn(&h->pdev->dev, "Failed to request_irq after "
+ "soft reset.\n");
+ goto clean4;
+ }
+
+ rc = cciss_kdump_soft_reset(h);
+ if (rc) {
+ dev_warn(&h->pdev->dev, "Soft reset failed.\n");
+ goto clean4;
+ }
+
+ dev_info(&h->pdev->dev, "Board READY.\n");
+ dev_info(&h->pdev->dev,
+ "Waiting for stale completions to drain.\n");
+ h->access.set_intr_mask(h, CCISS_INTR_ON);
+ msleep(10000);
+ h->access.set_intr_mask(h, CCISS_INTR_OFF);
+
+ rc = controller_reset_failed(h->cfgtable);
+ if (rc)
+ dev_info(&h->pdev->dev,
+ "Soft reset appears to have failed.\n");
+
+ /* since the controller's reset, we have to go back and re-init
+ * everything. Easiest to just forget what we've done and do it
+ * all over again.
+ */
+ cciss_undo_allocations_after_kdump_soft_reset(h);
+ try_soft_reset = 0;
+ if (rc)
+ /* don't go to clean4, we already unallocated */
+ return -ENODEV;
+
+ goto reinit_after_soft_reset;
+ }
+
cciss_scsi_setup(h);

/* Turn the interrupts on so we can service requests */