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Commit 0b049662 authored by Dmitry Kalinkin's avatar Dmitry Kalinkin Committed by Greg Kroah-Hartman
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vme: change bus error handling scheme 



The current VME bus error handler adds errors to the bridge error list.
vme_master_{read,write} then traverses that list to look for relevant
errors.

Such scheme didn't work well for accesses going through vme_master_mmap
because they would also allocate a vme_bus_error, but have no way to do
vme_clear_errors call to free that memory.

This changes the error handling process to be other way around: now
vme_master_{read,write} defines a window in VME address space that will
catch possible errors.  VME bus error interrupt only traverses these
windows and marks those that had errors in them.

Signed-off-by: default avatarDmitry Kalinkin <dmitry.kalinkin@gmail.com>
Cc: Igor Alekseev <igor.alekseev@itep.ru>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 472f16f3

drivers/vme/bridges/vme_ca91cx42.c

+1 −2
Original line number Diff line number Diff line
@@ -204,8 +204,7 @@ static int ca91cx42_irq_init(struct vme_bridge *ca91cx42_bridge) 
	/* Need pdev */

	pdev = container_of(ca91cx42_bridge->parent, struct pci_dev, dev);



	/* Initialise list for VME bus errors */

	INIT_LIST_HEAD(&ca91cx42_bridge->vme_errors);

	INIT_LIST_HEAD(&ca91cx42_bridge->vme_error_handlers);



	mutex_init(&ca91cx42_bridge->irq_mtx);

drivers/vme/bridges/vme_tsi148.c

+42 −41
Original line number Diff line number Diff line
@@ -314,8 +314,7 @@ static int tsi148_irq_init(struct vme_bridge *tsi148_bridge) 


	bridge = tsi148_bridge->driver_priv;



	/* Initialise list for VME bus errors */

	INIT_LIST_HEAD(&tsi148_bridge->vme_errors);

	INIT_LIST_HEAD(&tsi148_bridge->vme_error_handlers);



	mutex_init(&tsi148_bridge->irq_mtx);
@@ -1187,7 +1186,7 @@ static ssize_t tsi148_master_read(struct vme_master_resource *image, void *buf, 
	int retval, enabled;

	unsigned long long vme_base, size;

	u32 aspace, cycle, dwidth;

	struct vme_bus_error *vme_err = NULL;

	struct vme_error_handler *handler;

	struct vme_bridge *tsi148_bridge;

	void __iomem *addr = image->kern_base + offset;

	unsigned int done = 0;
@@ -1197,6 +1196,17 @@ static ssize_t tsi148_master_read(struct vme_master_resource *image, void *buf, 


	spin_lock(&image->lock);



	if (err_chk) {

		__tsi148_master_get(image, &enabled, &vme_base, &size, &aspace,

				    &cycle, &dwidth);

		handler = vme_register_error_handler(tsi148_bridge, aspace,

						     vme_base + offset, count);

		if (!handler) {

			spin_unlock(&image->lock);

			return -ENOMEM;

		}

	}



	/* The following code handles VME address alignment. We cannot use

	 * memcpy_xxx here because it may cut data transfers in to 8-bit

	 * cycles when D16 or D32 cycles are required on the VME bus.
@@ -1240,24 +1250,16 @@ static ssize_t tsi148_master_read(struct vme_master_resource *image, void *buf, 
out:

	retval = count;



	if (!err_chk)

		goto skip_chk;



	__tsi148_master_get(image, &enabled, &vme_base, &size, &aspace, &cycle,

		&dwidth);



	vme_err = vme_find_error(tsi148_bridge, aspace, vme_base + offset,

		count);

	if (vme_err != NULL) {

		dev_err(image->parent->parent, "First VME read error detected "

			"an at address 0x%llx\n", vme_err->address);

		retval = vme_err->address - (vme_base + offset);

		/* Clear down save errors in this address range */

		vme_clear_errors(tsi148_bridge, aspace, vme_base + offset,

			count);

	if (err_chk) {

		if (handler->num_errors) {

			dev_err(image->parent->parent,

				"First VME read error detected an at address 0x%llx\n",

				handler->first_error);

			retval = handler->first_error - (vme_base + offset);

		}

		vme_unregister_error_handler(handler);

	}



skip_chk:

	spin_unlock(&image->lock);



	return retval;
@@ -1274,7 +1276,7 @@ static ssize_t tsi148_master_write(struct vme_master_resource *image, void *buf, 
	unsigned int done = 0;

	unsigned int count32;



	struct vme_bus_error *vme_err = NULL;

	struct vme_error_handler *handler;

	struct vme_bridge *tsi148_bridge;

	struct tsi148_driver *bridge;
@@ -1284,6 +1286,17 @@ static ssize_t tsi148_master_write(struct vme_master_resource *image, void *buf, 


	spin_lock(&image->lock);



	if (err_chk) {

		__tsi148_master_get(image, &enabled, &vme_base, &size, &aspace,

				    &cycle, &dwidth);

		handler = vme_register_error_handler(tsi148_bridge, aspace,

						     vme_base + offset, count);

		if (!handler) {

			spin_unlock(&image->lock);

			return -ENOMEM;

		}

	}



	/* Here we apply for the same strategy we do in master_read

	 * function in order to assure the correct cycles.

	 */
@@ -1333,30 +1346,18 @@ static ssize_t tsi148_master_write(struct vme_master_resource *image, void *buf, 
	 * We check for saved errors in the written address range/space.

	 */



	if (!err_chk)

		goto skip_chk;



	/*

	 * Get window info first, to maximise the time that the buffers may

	 * fluch on their own

	 */

	__tsi148_master_get(image, &enabled, &vme_base, &size, &aspace, &cycle,

		&dwidth);



	if (err_chk) {

		ioread16(bridge->flush_image->kern_base + 0x7F000);



	vme_err = vme_find_error(tsi148_bridge, aspace, vme_base + offset,

		count);

	if (vme_err != NULL) {

		dev_warn(tsi148_bridge->parent, "First VME write error detected"

			" an at address 0x%llx\n", vme_err->address);

		retval = vme_err->address - (vme_base + offset);

		/* Clear down save errors in this address range */

		vme_clear_errors(tsi148_bridge, aspace, vme_base + offset,

			count);

		if (handler->num_errors) {

			dev_warn(tsi148_bridge->parent,

				 "First VME write error detected an at address 0x%llx\n",

				 handler->first_error);

			retval = handler->first_error - (vme_base + offset);

		}

		vme_unregister_error_handler(handler);

	}



skip_chk:

	spin_unlock(&image->lock);



	return retval;

drivers/vme/vme.c

+34 −58
Original line number Diff line number Diff line
@@ -1026,76 +1026,52 @@ EXPORT_SYMBOL(vme_dma_free); 
void vme_bus_error_handler(struct vme_bridge *bridge,

			   unsigned long long address, int am)

{

	struct vme_bus_error *error;

	struct list_head *handler_pos = NULL;

	struct vme_error_handler *handler;

	u32 aspace = vme_get_aspace(am);



	error = kmalloc(sizeof(struct vme_bus_error), GFP_ATOMIC);

	if (error) {

		error->aspace = vme_get_aspace(am);

		error->address = address;

		list_add_tail(&error->list, &bridge->vme_errors);

	} else {

		dev_err(bridge->parent,

			"Unable to alloc memory for VMEbus Error reporting\n");

	list_for_each(handler_pos, &bridge->vme_error_handlers) {

		handler = list_entry(handler_pos, struct vme_error_handler,

				     list);

		if ((aspace == handler->aspace) &&

		    (address >= handler->start) &&

		    (address < handler->end)) {

			if (!handler->num_errors)

				handler->first_error = address;

			if (handler->num_errors != UINT_MAX)

				handler->num_errors++;

		}

	}

}

EXPORT_SYMBOL(vme_bus_error_handler);



/*

 * Find the first error in this address range

 */

struct vme_bus_error *vme_find_error(struct vme_bridge *bridge, u32 aspace,

				     unsigned long long address, size_t count)

struct vme_error_handler *vme_register_error_handler(

	struct vme_bridge *bridge, u32 aspace,

	unsigned long long address, size_t len)

{

	struct list_head *err_pos;

	struct vme_bus_error *vme_err, *valid = NULL;

	unsigned long long bound;



	bound = address + count;

	struct vme_error_handler *handler;



	err_pos = NULL;

	/* Iterate through errors */

	list_for_each(err_pos, &bridge->vme_errors) {

		vme_err = list_entry(err_pos, struct vme_bus_error, list);

		if ((vme_err->aspace == aspace) &&

		    (vme_err->address >= address) &&

		    (vme_err->address < bound)) {

	handler = kmalloc(sizeof(*handler), GFP_KERNEL);

	if (!handler)

		return NULL;



			valid = vme_err;

			break;

		}

	}

	handler->aspace = aspace;

	handler->start = address;

	handler->end = address + len;

	handler->num_errors = 0;

	handler->first_error = 0;

	list_add_tail(&handler->list, &bridge->vme_error_handlers);



	return valid;

	return handler;

}

EXPORT_SYMBOL(vme_find_error);

EXPORT_SYMBOL(vme_register_error_handler);



/*

 * Clear errors in the provided address range.

 */

void vme_clear_errors(struct vme_bridge *bridge, u32 aspace,

		      unsigned long long address, size_t count)

void vme_unregister_error_handler(struct vme_error_handler *handler)

{

	struct list_head *err_pos, *temp;

	struct vme_bus_error *vme_err;

	unsigned long long bound;



	bound = address + count;



	err_pos = NULL;

	/* Iterate through errors */

	list_for_each_safe(err_pos, temp, &bridge->vme_errors) {

		vme_err = list_entry(err_pos, struct vme_bus_error, list);



		if ((vme_err->aspace == aspace) &&

		    (vme_err->address >= address) &&

		    (vme_err->address < bound)) {



			list_del(err_pos);

			kfree(vme_err);

		}

	}

	list_del(&handler->list);

	kfree(handler);

}

EXPORT_SYMBOL(vme_clear_errors);

EXPORT_SYMBOL(vme_unregister_error_handler);



void vme_irq_handler(struct vme_bridge *bridge, int level, int statid)

{

drivers/vme/vme_bridge.h

+14 −9
Original line number Diff line number Diff line
@@ -75,10 +75,13 @@ struct vme_lm_resource { 
	int monitors;

};



struct vme_bus_error {

struct vme_error_handler {

	struct list_head list;

	u32 aspace;

	unsigned long long address;

	unsigned long long start;	/* Beginning of error window */

	unsigned long long end;		/* End of error window */

	unsigned long long first_error;	/* Address of the first error */

	u32 aspace;			/* Address space of error window*/

	unsigned num_errors;		/* Number of errors */

};



struct vme_callback {
@@ -106,8 +109,10 @@ struct vme_bridge { 
	struct list_head dma_resources;

	struct list_head lm_resources;



	struct list_head vme_errors;	/* List for errors generated on VME */

	struct list_head devices;	/* List of devices on this bridge */

	/* List for registered errors handlers */

	struct list_head vme_error_handlers;

	/* List of devices on this bridge */

	struct list_head devices;



	/* Bridge Info - XXX Move to private structure? */

	struct device *parent;	/* Parent device (eg. pdev->dev for PCI) */
@@ -168,13 +173,13 @@ struct vme_bridge { 


void vme_bus_error_handler(struct vme_bridge *bridge,

			   unsigned long long address, int am);

struct vme_bus_error *vme_find_error(struct vme_bridge *bridge, u32 aspace,

				     unsigned long long address, size_t count);

void vme_clear_errors(struct vme_bridge *bridge, u32 aspace,

		      unsigned long long address, size_t count);

void vme_irq_handler(struct vme_bridge *, int, int);



int vme_register_bridge(struct vme_bridge *);

void vme_unregister_bridge(struct vme_bridge *);

struct vme_error_handler *vme_register_error_handler(

	struct vme_bridge *bridge, u32 aspace,

	unsigned long long address, size_t len);

void vme_unregister_error_handler(struct vme_error_handler *handler);



#endif /* _VME_BRIDGE_H_ */