[PATCH v6 05/14] misc: bcm-vk: add triggers when host panic or reboots to notify card

[Scott Branden]

Pass down an interrupt to card in case of panic or reboot so
that card can take appropriate action to perform a clean reset.
Uses kernel notifier block either directly (register on panic list),
or implicitly (add shutdown method for PCI device).

Co-developed-by: Desmond Yan <desmond....@broadcom.com>
Signed-off-by: Desmond Yan <desmond....@broadcom.com>
Signed-off-by: Scott Branden <scott.bran...@broadcom.com>
---
 drivers/misc/bcm-vk/bcm_vk.h     |  2 ++
 drivers/misc/bcm-vk/bcm_vk_dev.c | 29 ++++++++++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/bcm-vk/bcm_vk.h b/drivers/misc/bcm-vk/bcm_vk.h
index 0a366db693c8..f428ad9a0c3d 100644
--- a/drivers/misc/bcm-vk/bcm_vk.h
+++ b/drivers/misc/bcm-vk/bcm_vk.h
@@ -223,6 +223,8 @@ struct bcm_vk {
        unsigned long wq_offload[1]; /* various flags on wq requested */
        void *tdma_vaddr; /* test dma segment virtual addr */
        dma_addr_t tdma_addr; /* test dma segment bus addr */
+
+       struct notifier_block panic_nb;
 };
 
 /* wq offload work items bits definitions */
diff --git a/drivers/misc/bcm-vk/bcm_vk_dev.c b/drivers/misc/bcm-vk/bcm_vk_dev.c
index c7bedd975609..1755493b3096 100644
--- a/drivers/misc/bcm-vk/bcm_vk_dev.c
+++ b/drivers/misc/bcm-vk/bcm_vk_dev.c
@@ -630,6 +630,16 @@ static int bcm_vk_trigger_reset(struct bcm_vk *vk)
        return 0;
 }
 
+static int bcm_vk_on_panic(struct notifier_block *nb,
+                          unsigned long e, void *p)
+{
+       struct bcm_vk *vk = container_of(nb, struct bcm_vk, panic_nb);
+
+       bcm_to_v_reset_doorbell(vk, VK_BAR0_RESET_DB_HARD);
+
+       return 0;
+}
+
 static int bcm_vk_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
        int err;
@@ -743,6 +753,15 @@ static int bcm_vk_probe(struct pci_dev *pdev, const struct 
pci_device_id *ent)
        /* sync other info */
        bcm_vk_sync_card_info(vk);
 
+       /* register for panic notifier */
+       vk->panic_nb.notifier_call = bcm_vk_on_panic;
+       err = atomic_notifier_chain_register(&panic_notifier_list,
+                                            &vk->panic_nb);
+       if (err) {
+               dev_err(dev, "Fail to register panic notifier\n");
+               goto err_destroy_workqueue;
+       }
+
        /*
         * lets trigger an auto download.  We don't want to do it serially here
         * because at probing time, it is not supposed to block for a long time.
@@ -751,7 +770,7 @@ static int bcm_vk_probe(struct pci_dev *pdev, const struct 
pci_device_id *ent)
        if (auto_load) {
                if ((boot_status & BOOT_STATE_MASK) == BROM_RUNNING) {
                        if (bcm_vk_trigger_autoload(vk))
-                               goto err_destroy_workqueue;
+                               goto err_unregister_panic_notifier;
                } else {
                        dev_err(dev,
                                "Auto-load skipped - BROM not in proper state 
(0x%x)\n",
@@ -763,6 +782,10 @@ static int bcm_vk_probe(struct pci_dev *pdev, const struct 
pci_device_id *ent)
 
        return 0;
 
+err_unregister_panic_notifier:
+       atomic_notifier_chain_unregister(&panic_notifier_list,
+                                        &vk->panic_nb);
+
 err_destroy_workqueue:
        destroy_workqueue(vk->wq_thread);
 
@@ -813,6 +836,10 @@ static void bcm_vk_remove(struct pci_dev *pdev)
        bcm_vk_trigger_reset(vk);
        usleep_range(BCM_VK_UCODE_BOOT_US, BCM_VK_UCODE_BOOT_MAX_US);
 
+       /* unregister panic notifier */
+       atomic_notifier_chain_unregister(&panic_notifier_list,
+                                        &vk->panic_nb);
+
        if (vk->tdma_vaddr)
                dma_free_coherent(&pdev->dev, nr_scratch_pages * PAGE_SIZE,
                                  vk->tdma_vaddr, vk->tdma_addr);
-- 
2.17.1