diff options
| -rw-r--r-- | drivers/acpi/osl.c | 62 |
1 files changed, 51 insertions, 11 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 32826893c2e6..885e222bcabd 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -104,6 +104,7 @@ struct acpi_ioremap { void __iomem *virt; acpi_physical_address phys; acpi_size size; + struct kref ref; }; static LIST_HEAD(acpi_ioremaps); @@ -245,15 +246,28 @@ acpi_physical_address __init acpi_os_get_root_pointer(void) } /* Must be called with 'acpi_ioremap_lock' or RCU read lock held. */ -static void __iomem * -acpi_map_vaddr_lookup(acpi_physical_address phys, acpi_size size) +static struct acpi_ioremap * +acpi_map_lookup(acpi_physical_address phys, acpi_size size) { struct acpi_ioremap *map; list_for_each_entry_rcu(map, &acpi_ioremaps, list) if (map->phys <= phys && phys + size <= map->phys + map->size) - return map->virt + (phys - map->phys); + return map; + + return NULL; +} + +/* Must be called with 'acpi_ioremap_lock' or RCU read lock held. */ +static void __iomem * +acpi_map_vaddr_lookup(acpi_physical_address phys, unsigned int size) +{ + struct acpi_ioremap *map; + + map = acpi_map_lookup(phys, size); + if (map) + return map->virt + (phys - map->phys); return NULL; } @@ -265,7 +279,8 @@ acpi_map_lookup_virt(void __iomem *virt, acpi_size size) struct acpi_ioremap *map; list_for_each_entry_rcu(map, &acpi_ioremaps, list) - if (map->virt == virt && map->size == size) + if (map->virt <= virt && + virt + size <= map->virt + map->size) return map; return NULL; @@ -274,9 +289,10 @@ acpi_map_lookup_virt(void __iomem *virt, acpi_size size) void __iomem *__init_refok acpi_os_map_memory(acpi_physical_address phys, acpi_size size) { - struct acpi_ioremap *map; - unsigned long flags; + struct acpi_ioremap *map, *tmp_map; + unsigned long flags, pg_sz; void __iomem *virt; + phys_addr_t pg_off; if (phys > ULONG_MAX) { printk(KERN_ERR PREFIX "Cannot map memory that high\n"); @@ -290,7 +306,9 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size) if (!map) return NULL; - virt = ioremap(phys, size); + pg_off = round_down(phys, PAGE_SIZE); + pg_sz = round_up(phys + size, PAGE_SIZE) - pg_off; + virt = ioremap(pg_off, pg_sz); if (!virt) { kfree(map); return NULL; @@ -298,21 +316,40 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size) INIT_LIST_HEAD(&map->list); map->virt = virt; - map->phys = phys; - map->size = size; + map->phys = pg_off; + map->size = pg_sz; + kref_init(&map->ref); spin_lock_irqsave(&acpi_ioremap_lock, flags); + /* Check if page has already been mapped. */ + tmp_map = acpi_map_lookup(phys, size); + if (tmp_map) { + kref_get(&tmp_map->ref); + spin_unlock_irqrestore(&acpi_ioremap_lock, flags); + iounmap(map->virt); + kfree(map); + return tmp_map->virt + (phys - tmp_map->phys); + } list_add_tail_rcu(&map->list, &acpi_ioremaps); spin_unlock_irqrestore(&acpi_ioremap_lock, flags); - return virt; + return map->virt + (phys - map->phys); } EXPORT_SYMBOL_GPL(acpi_os_map_memory); +static void acpi_kref_del_iomap(struct kref *ref) +{ + struct acpi_ioremap *map; + + map = container_of(ref, struct acpi_ioremap, ref); + list_del_rcu(&map->list); +} + void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size) { struct acpi_ioremap *map; unsigned long flags; + int del; if (!acpi_gbl_permanent_mmap) { __acpi_unmap_table(virt, size); @@ -328,9 +365,12 @@ void __ref acpi_os_unmap_memory(void __iomem *virt, acpi_size size) return; } - list_del_rcu(&map->list); + del = kref_put(&map->ref, acpi_kref_del_iomap); spin_unlock_irqrestore(&acpi_ioremap_lock, flags); + if (!del) + return; + synchronize_rcu(); iounmap(map->virt); kfree(map); |