misc: mic: Remove COSM functionality from the MIC card driver

Since card side COSM functionality, to trigger MIC device shutdowns
and communicate shutdown status to the host, is now moved into a
separate COSM client driver, this patch removes this functionality
from the base MIC card driver. The mic_bus driver is also updated to
use the device index provided by COSM rather than maintain its own
device index.

Reviewed-by: Nikhil Rao <[e-mail]>
Reviewed-by: Sudeep Dutt <[e-mail]>
Signed-off-by: Ashutosh Dixit <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/mic/bus/mic_bus.c

···
 #include <linux/idr.h>
 #include <linux/mic_bus.h>
 
-/* Unique numbering for mbus devices. */
-static DEFINE_IDA(mbus_index_ida);
-
 static ssize_t device_show(struct device *d,
 			   struct device_attribute *attr, char *buf)
 {
···
 
 struct mbus_device *
 mbus_register_device(struct device *pdev, int id, struct dma_map_ops *dma_ops,
-		     struct mbus_hw_ops *hw_ops, void __iomem *mmio_va)
+		     struct mbus_hw_ops *hw_ops, int index,
+		     void __iomem *mmio_va)
 {
 	int ret;
 	struct mbus_device *mbdev;
···
 	mbdev->dev.release = mbus_release_dev;
 	mbdev->hw_ops = hw_ops;
 	mbdev->dev.bus = &mic_bus;
-
-	/* Assign a unique device index and hence name. */
-	ret = ida_simple_get(&mbus_index_ida, 0, 0, GFP_KERNEL);
-	if (ret < 0)
-		goto free_mbdev;
-
-	mbdev->index = ret;
+	mbdev->index = index;
 	dev_set_name(&mbdev->dev, "mbus-dev%u", mbdev->index);
 	/*
 	 * device_register() causes the bus infrastructure to look for a
···
 	 */
 	ret = device_register(&mbdev->dev);
 	if (ret)
-		goto ida_remove;
+		goto free_mbdev;
 	return mbdev;
-ida_remove:
-	ida_simple_remove(&mbus_index_ida, mbdev->index);
 free_mbdev:
 	kfree(mbdev);
 	return ERR_PTR(ret);
···
 
 void mbus_unregister_device(struct mbus_device *mbdev)
 {
-	int index = mbdev->index; /* save for after device release */
-
 	device_unregister(&mbdev->dev);
-	ida_simple_remove(&mbus_index_ida, index);
 }
 EXPORT_SYMBOL_GPL(mbus_unregister_device);
 
···
 static void __exit mbus_exit(void)
 {
 	bus_unregister(&mic_bus);
-	ida_destroy(&mbus_index_ida);
 }
 
 core_initcall(mbus_init);

drivers/misc/mic/card/mic_device.c

···
 #include "mic_virtio.h"
 
 static struct mic_driver *g_drv;
-static struct mic_irq *shutdown_cookie;
-
-static void mic_notify_host(u8 state)
-{
-	struct mic_driver *mdrv = g_drv;
-	struct mic_bootparam __iomem *bootparam = mdrv->dp;
-
-	iowrite8(state, &bootparam->shutdown_status);
-	dev_dbg(mdrv->dev, "%s %d system_state %d\n",
-		__func__, __LINE__, state);
-	mic_send_intr(&mdrv->mdev, ioread8(&bootparam->c2h_shutdown_db));
-}
-
-static int mic_panic_event(struct notifier_block *this, unsigned long event,
-		void *ptr)
-{
-	struct mic_driver *mdrv = g_drv;
-	struct mic_bootparam __iomem *bootparam = mdrv->dp;
-
-	iowrite8(-1, &bootparam->h2c_config_db);
-	iowrite8(-1, &bootparam->h2c_shutdown_db);
-	mic_notify_host(MIC_CRASHED);
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block mic_panic = {
-	.notifier_call  = mic_panic_event,
-};
-
-static irqreturn_t mic_shutdown_isr(int irq, void *data)
-{
-	struct mic_driver *mdrv = g_drv;
-	struct mic_bootparam __iomem *bootparam = mdrv->dp;
-
-	mic_ack_interrupt(&g_drv->mdev);
-	if (ioread8(&bootparam->shutdown_card))
-		orderly_poweroff(true);
-	return IRQ_HANDLED;
-}
-
-static int mic_shutdown_init(void)
-{
-	int rc = 0;
-	struct mic_driver *mdrv = g_drv;
-	struct mic_bootparam __iomem *bootparam = mdrv->dp;
-	int shutdown_db;
-
-	shutdown_db = mic_next_card_db();
-	shutdown_cookie = mic_request_card_irq(mic_shutdown_isr, NULL,
-					       "Shutdown", mdrv, shutdown_db);
-	if (IS_ERR(shutdown_cookie))
-		rc = PTR_ERR(shutdown_cookie);
-	else
-		iowrite8(shutdown_db, &bootparam->h2c_shutdown_db);
-	return rc;
-}
-
-static void mic_shutdown_uninit(void)
-{
-	struct mic_driver *mdrv = g_drv;
-	struct mic_bootparam __iomem *bootparam = mdrv->dp;
-
-	iowrite8(-1, &bootparam->h2c_shutdown_db);
-	mic_free_card_irq(shutdown_cookie, mdrv);
-}
 
 static int __init mic_dp_init(void)
 {
···
 	u8 node_id;
 
 	g_drv = mdrv;
-	/*
-	 * Unloading the card module is not supported. The MIC card module
-	 * handles fundamental operations like host/card initiated shutdowns
-	 * and informing the host about card crashes and cannot be unloaded.
-	 */
+	/* Unloading the card module is not supported. */
 	if (!try_module_get(mdrv->dev->driver->owner)) {
 		rc = -ENODEV;
 		goto done;
···
 	rc = mic_init_irq();
 	if (rc)
 		goto dp_uninit;
-	rc = mic_shutdown_init();
-	if (rc)
-		goto irq_uninit;
 	if (!mic_request_dma_chans(mdrv)) {
 		rc = -ENODEV;
-		goto shutdown_uninit;
+		goto irq_uninit;
 	}
 	rc = mic_devices_init(mdrv);
 	if (rc)
···
 					   NULL, &scif_hw_ops,
 					   0, node_id, &mdrv->mdev.mmio, NULL,
 					   NULL, mdrv->dp, mdrv->dma_ch,
-					   mdrv->num_dma_ch);
+					   mdrv->num_dma_ch, true);
 	if (IS_ERR(mdrv->scdev)) {
 		rc = PTR_ERR(mdrv->scdev);
 		goto device_uninit;
 	}
 	mic_create_card_debug_dir(mdrv);
-	atomic_notifier_chain_register(&panic_notifier_list, &mic_panic);
 done:
 	return rc;
 device_uninit:
 	mic_devices_uninit(mdrv);
 dma_free:
 	mic_free_dma_chans(mdrv);
-shutdown_uninit:
-	mic_shutdown_uninit();
 irq_uninit:
 	mic_uninit_irq();
 dp_uninit:
···
 	scif_unregister_device(mdrv->scdev);
 	mic_devices_uninit(mdrv);
 	mic_free_dma_chans(mdrv);
-	/*
-	 * Inform the host about the shutdown status i.e. poweroff/restart etc.
-	 * The module cannot be unloaded so the only code path to call
-	 * mic_devices_uninit(..) is the shutdown callback.
-	 */
-	mic_notify_host(system_state);
-	mic_shutdown_uninit();
 	mic_uninit_irq();
 	mic_dp_uninit();
 	module_put(mdrv->dev->driver->owner);

drivers/misc/mic/card/mic_x100.c

···
 	mic_hw_intr_init(mdrv);
 	platform_set_drvdata(pdev, mdrv);
 	mdrv->dma_mbdev = mbus_register_device(mdrv->dev, MBUS_DEV_DMA_MIC,
-					       NULL, &mbus_hw_ops,
+					       NULL, &mbus_hw_ops, 0,
 					       mdrv->mdev.mmio.va);
 	if (IS_ERR(mdrv->dma_mbdev)) {
 		rc = PTR_ERR(mdrv->dma_mbdev);

drivers/misc/mic/common/mic_dev.h

···
 #ifndef __MIC_DEV_H__
 #define __MIC_DEV_H__
 
+/* The maximum number of MIC devices supported in a single host system. */
+#define MIC_MAX_NUM_DEVS 128
+
+/**
+ * enum mic_hw_family - The hardware family to which a device belongs.
+ */
+enum mic_hw_family {
+	MIC_FAMILY_X100 = 0,
+	MIC_FAMILY_X200,
+	MIC_FAMILY_UNKNOWN,
+	MIC_FAMILY_LAST
+};
+
 /**
  * struct mic_mw - MIC memory window
  *

include/linux/mic_bus.h

···
 
 struct mbus_device *
 mbus_register_device(struct device *pdev, int id, struct dma_map_ops *dma_ops,
-		     struct mbus_hw_ops *hw_ops, void __iomem *mmio_va);
+		     struct mbus_hw_ops *hw_ops, int index,
+		     void __iomem *mmio_va);
 void mbus_unregister_device(struct mbus_device *mbdev);
 
 int mbus_register_driver(struct mbus_driver *drv);