lib: logic_pio: Avoid possible overlap for unregistering regions

[linux-2.6-microblaze.git] / lib / logic_pio.c

diff --git a/lib/logic_pio.c b/lib/logic_pio.c
index feea48f..d0165c8 100644 (file)
--- a/lib/logic_pio.c
+++ b/lib/logic_pio.c
@@ -35,7 +35,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
        struct logic_pio_hwaddr *range;
        resource_size_t start;
        resource_size_t end;
-       resource_size_t mmio_sz = 0;
+       resource_size_t mmio_end = 0;
        resource_size_t iio_sz = MMIO_UPPER_LIMIT;
        int ret = 0;
 
@@ -46,7 +46,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
        end = new_range->hw_start + new_range->size;
 
        mutex_lock(&io_range_mutex);
-       list_for_each_entry_rcu(range, &io_range_list, list) {
+       list_for_each_entry(range, &io_range_list, list) {
                if (range->fwnode == new_range->fwnode) {
                        /* range already there */
                        goto end_register;
@@ -56,7 +56,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
                        /* for MMIO ranges we need to check for overlap */
                        if (start >= range->hw_start + range->size ||
                            end < range->hw_start) {
-                               mmio_sz += range->size;
+                               mmio_end = range->io_start + range->size;
                        } else {
                                ret = -EFAULT;
                                goto end_register;
@@ -69,16 +69,16 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
 
        /* range not registered yet, check for available space */
        if (new_range->flags == LOGIC_PIO_CPU_MMIO) {
-               if (mmio_sz + new_range->size - 1 > MMIO_UPPER_LIMIT) {
+               if (mmio_end + new_range->size - 1 > MMIO_UPPER_LIMIT) {
                        /* if it's too big check if 64K space can be reserved */
-                       if (mmio_sz + SZ_64K - 1 > MMIO_UPPER_LIMIT) {
+                       if (mmio_end + SZ_64K - 1 > MMIO_UPPER_LIMIT) {
                                ret = -E2BIG;
                                goto end_register;
                        }
                        new_range->size = SZ_64K;
                        pr_warn("Requested IO range too big, new size set to 64K\n");
                }
-               new_range->io_start = mmio_sz;
+               new_range->io_start = mmio_end;
        } else if (new_range->flags == LOGIC_PIO_INDIRECT) {
                if (iio_sz + new_range->size - 1 > IO_SPACE_LIMIT) {
                        ret = -E2BIG;
@@ -108,26 +108,38 @@ end_register:
  */
 struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode)
 {
-       struct logic_pio_hwaddr *range;
+       struct logic_pio_hwaddr *range, *found_range = NULL;
 
+       rcu_read_lock();
        list_for_each_entry_rcu(range, &io_range_list, list) {
-               if (range->fwnode == fwnode)
-                       return range;
+               if (range->fwnode == fwnode) {
+                       found_range = range;
+                       break;
+               }
        }
-       return NULL;
+       rcu_read_unlock();
+
+       return found_range;
 }
 
 /* Return a registered range given an input PIO token */
 static struct logic_pio_hwaddr *find_io_range(unsigned long pio)
 {
-       struct logic_pio_hwaddr *range;
+       struct logic_pio_hwaddr *range, *found_range = NULL;
 
+       rcu_read_lock();
        list_for_each_entry_rcu(range, &io_range_list, list) {
-               if (in_range(pio, range->io_start, range->size))
-                       return range;
+               if (in_range(pio, range->io_start, range->size)) {
+                       found_range = range;
+                       break;
+               }
        }
-       pr_err("PIO entry token %lx invalid\n", pio);
-       return NULL;
+       rcu_read_unlock();
+
+       if (!found_range)
+               pr_err("PIO entry token 0x%lx invalid\n", pio);
+
+       return found_range;
 }
 
 /**
@@ -180,14 +192,23 @@ unsigned long logic_pio_trans_cpuaddr(resource_size_t addr)
 {
        struct logic_pio_hwaddr *range;
 
+       rcu_read_lock();
        list_for_each_entry_rcu(range, &io_range_list, list) {
                if (range->flags != LOGIC_PIO_CPU_MMIO)
                        continue;
-               if (in_range(addr, range->hw_start, range->size))
-                       return addr - range->hw_start + range->io_start;
+               if (in_range(addr, range->hw_start, range->size)) {
+                       unsigned long cpuaddr;
+
+                       cpuaddr = addr - range->hw_start + range->io_start;
+
+                       rcu_read_unlock();
+                       return cpuaddr;
+               }
        }
-       pr_err("addr %llx not registered in io_range_list\n",
-              (unsigned long long) addr);
+       rcu_read_unlock();
+
+       pr_err("addr %pa not registered in io_range_list\n", &addr);
+
        return ~0UL;
 }