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: Dmitry Kalinkin <dmitry.kalinkin@gmail.com>
Cc: Igor Alekseev <igor.alekseev@itep.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dmitry Kalinkin 2015-09-18 02:01:44 +03:00 committed by Greg Kroah-Hartman
parent 472f16f33c
commit 0b04966257
4 changed files with 90 additions and 109 deletions

View File

@ -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);

View File

@ -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 @@ out:
* We check for saved errors in the written address range/space.
*/
if (!err_chk)
goto skip_chk;
if (err_chk) {
ioread16(bridge->flush_image->kern_base + 0x7F000);
/*
* 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);
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;

View File

@ -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;
struct vme_error_handler *handler;
bound = address + count;
handler = kmalloc(sizeof(*handler), GFP_KERNEL);
if (!handler)
return NULL;
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->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);
valid = vme_err;
break;
}
}
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)
{

View File

@ -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_ */