| Message ID | 1445506922-6005-2-git-send-email-eric.auger@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thursday 22 October 2015 11:41:57 Eric Auger wrote: > In preparation for subsequent changes in reset function lookup, > lets introduce a dynamic list of reset combos (compat string, > reset module, reset function). The list can be populated/voided with > two new functions, vfio_platform_register/unregister_reset. Those are > not yet used in this patch. > > Signed-off-by: Eric Auger <eric.auger@linaro.org> Looks correct to me now, just a little style comments. > drivers/vfio/platform/vfio_platform_common.c | 77 +++++++++++++++++++++++++++ > drivers/vfio/platform/vfio_platform_private.h | 7 +++ > 2 files changed, 84 insertions(+) > > diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c > index e43efb5..52a4c7b 100644 > --- a/drivers/vfio/platform/vfio_platform_common.c > +++ b/drivers/vfio/platform/vfio_platform_common.c > @@ -23,6 +23,15 @@ > > #include "vfio_platform_private.h" > > +struct vfio_platform_reset_node { > + struct list_head link; > + char *compat; > + struct module *owner; > + vfio_platform_reset_fn_t reset; > +}; > + > +static LIST_HEAD(reset_list); > +static DEFINE_MUTEX(reset_lock); > static DEFINE_MUTEX(driver_lock); I wonder if having a single mutex here would be enough. If you don't expect drivers to register/unregister a lot, you could just use driver_lock here as well. > static const struct vfio_platform_reset_combo reset_lookup_table[] = { > @@ -573,3 +582,71 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) > return vdev; > } > EXPORT_SYMBOL_GPL(vfio_platform_remove_common); > + > +int vfio_platform_register_reset(struct module *reset_owner, > + const char *compat, > + vfio_platform_reset_fn_t reset) > +{ > + struct vfio_platform_reset_node *node, *iter; > + bool found = false; > + > + mutex_lock(&reset_lock); > + list_for_each_entry(iter, &reset_list, link) { > + if (!strcmp(iter->compat, compat)) { > + found = true; > + break; > + } > + } > + if (found) { > + mutex_unlock(&reset_lock); > + return -EINVAL; > + } This seems to be an unnecesssary safeguard. I would not bother with the search, or otherwise do a WARN_ON here. > + node = kmalloc(sizeof(*node), GFP_KERNEL); > + if (!node) { > + mutex_unlock(&reset_lock); > + return -ENOMEM; > + } > + > + node->compat = kstrdup(compat, GFP_KERNEL); > + if (!node->compat) { > + kfree(node); > + mutex_unlock(&reset_lock); > + return -ENOMEM; > + } If you hold a lock, it's better to use a goto for handling errors and put the unlock and kfree there. I think it can be avoided entirely here though: It should be safe to define the interface as keeping a reference on the string and not do a kstrdup here. I would expect users to pass a string literal. We could even go as far as defining the entire interface as a shim, like #define vfio_platform_register_reset(__compat, __reset) \ static struct vfio_platform_reset_node __reset ## _node = { \ .owner = THIS_MODULE, \ .compat = __compat, \ .reset = __reset, \ }; \ __vfio_platform_register_reset(&__reset ## node); to make the function really simple. Arnd
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index e43efb5..52a4c7b 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -23,6 +23,15 @@ #include "vfio_platform_private.h" +struct vfio_platform_reset_node { + struct list_head link; + char *compat; + struct module *owner; + vfio_platform_reset_fn_t reset; +}; + +static LIST_HEAD(reset_list); +static DEFINE_MUTEX(reset_lock); static DEFINE_MUTEX(driver_lock); static const struct vfio_platform_reset_combo reset_lookup_table[] = { @@ -573,3 +582,71 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) return vdev; } EXPORT_SYMBOL_GPL(vfio_platform_remove_common); + +int vfio_platform_register_reset(struct module *reset_owner, + const char *compat, + vfio_platform_reset_fn_t reset) +{ + struct vfio_platform_reset_node *node, *iter; + bool found = false; + + mutex_lock(&reset_lock); + list_for_each_entry(iter, &reset_list, link) { + if (!strcmp(iter->compat, compat)) { + found = true; + break; + } + } + if (found) { + mutex_unlock(&reset_lock); + return -EINVAL; + } + + node = kmalloc(sizeof(*node), GFP_KERNEL); + if (!node) { + mutex_unlock(&reset_lock); + return -ENOMEM; + } + + node->compat = kstrdup(compat, GFP_KERNEL); + if (!node->compat) { + kfree(node); + mutex_unlock(&reset_lock); + return -ENOMEM; + } + + node->owner = reset_owner; + node->reset = reset; + + list_add(&node->link, &reset_list); + mutex_unlock(&reset_lock); + return 0; +} +EXPORT_SYMBOL_GPL(vfio_platform_register_reset); + +int vfio_platform_unregister_reset(const char *compat) +{ + struct vfio_platform_reset_node *iter; + bool found = false; + + mutex_lock(&reset_lock); + list_for_each_entry(iter, &reset_list, link) { + if (!strcmp(iter->compat, compat)) { + found = true; + break; + } + } + if (!found) { + mutex_unlock(&reset_lock); + return -EINVAL; + } + + list_del(&iter->link); + kfree(iter->compat); + kfree(iter); + mutex_unlock(&reset_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset); + diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h index 1c9b3d5..1fb1410 100644 --- a/drivers/vfio/platform/vfio_platform_private.h +++ b/drivers/vfio/platform/vfio_platform_private.h @@ -89,4 +89,11 @@ extern int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev, unsigned start, unsigned count, void *data); +typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev); + +extern int vfio_platform_register_reset(struct module *owner, + const char *compat, + vfio_platform_reset_fn_t reset); +extern int vfio_platform_unregister_reset(const char *compat); + #endif /* VFIO_PLATFORM_PRIVATE_H */
In preparation for subsequent changes in reset function lookup, lets introduce a dynamic list of reset combos (compat string, reset module, reset function). The list can be populated/voided with two new functions, vfio_platform_register/unregister_reset. Those are not yet used in this patch. Signed-off-by: Eric Auger <eric.auger@linaro.org> --- v1 -> v2: - reset_list becomes static - vfio_platform_register/unregister_reset take a const char * as compat - fix node leak - add reset_lock to protect the reset list manipulation - move vfio_platform_reset_node declaration in vfio_platform_common.c --- drivers/vfio/platform/vfio_platform_common.c | 77 +++++++++++++++++++++++++++ drivers/vfio/platform/vfio_platform_private.h | 7 +++ 2 files changed, 84 insertions(+)