reserve_region_with_split: Fix GFP_KERNEL usage under spinlock

[linux-2.6-omap-h63xx.git] / kernel / resource.c

diff --git a/kernel/resource.c b/kernel/resource.c
index 03d796c1b2e980c1ea55c5f1dc3bbfed64b0233e..4337063663efe39f8de666d16c591c84f66db0f7 100644 (file)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -17,6 +17,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/device.h>
+#include <linux/pfn.h>
 #include <asm/io.h>
 
 
@@ -38,10 +39,6 @@ EXPORT_SYMBOL(iomem_resource);
 
 static DEFINE_RWLOCK(resource_lock);
 
-#ifdef CONFIG_PROC_FS
-
-enum { MAX_IORES_LEVEL = 5 };
-
 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
 {
        struct resource *p = v;
@@ -53,6 +50,10 @@ static void *r_next(struct seq_file *m, void *v, loff_t *pos)
        return p->sibling;
 }
 
+#ifdef CONFIG_PROC_FS
+
+enum { MAX_IORES_LEVEL = 5 };
+
 static void *r_start(struct seq_file *m, loff_t *pos)
        __acquires(resource_lock)
 {
@@ -516,6 +517,70 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t
        return result;
 }
 
+static void __init __reserve_region_with_split(struct resource *root,
+               resource_size_t start, resource_size_t end,
+               const char *name)
+{
+       struct resource *parent = root;
+       struct resource *conflict;
+       struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
+
+       if (!res)
+               return;
+
+       res->name = name;
+       res->start = start;
+       res->end = end;
+       res->flags = IORESOURCE_BUSY;
+
+       for (;;) {
+               conflict = __request_resource(parent, res);
+               if (!conflict)
+                       break;
+               if (conflict != parent) {
+                       parent = conflict;
+                       if (!(conflict->flags & IORESOURCE_BUSY))
+                               continue;
+               }
+
+               /* Uhhuh, that didn't work out.. */
+               kfree(res);
+               res = NULL;
+               break;
+       }
+
+       if (!res) {
+               /* failed, split and try again */
+
+               /* conflict covered whole area */
+               if (conflict->start <= start && conflict->end >= end)
+                       return;
+
+               if (conflict->start > start)
+                       __reserve_region_with_split(root, start, conflict->start-1, name);
+               if (!(conflict->flags & IORESOURCE_BUSY)) {
+                       resource_size_t common_start, common_end;
+
+                       common_start = max(conflict->start, start);
+                       common_end = min(conflict->end, end);
+                       if (common_start < common_end)
+                               __reserve_region_with_split(root, common_start, common_end, name);
+               }
+               if (conflict->end < end)
+                       __reserve_region_with_split(root, conflict->end+1, end, name);
+       }
+
+}
+
+void __init reserve_region_with_split(struct resource *root,
+               resource_size_t start, resource_size_t end,
+               const char *name)
+{
+       write_lock(&resource_lock);
+       __reserve_region_with_split(root, start, end, name);
+       write_unlock(&resource_lock);
+}
+
 EXPORT_SYMBOL(adjust_resource);
 
 /**
@@ -562,33 +627,34 @@ struct resource * __request_region(struct resource *parent,
 {
        struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 
-       if (res) {
-               res->name = name;
-               res->start = start;
-               res->end = start + n - 1;
-               res->flags = IORESOURCE_BUSY;
+       if (!res)
+               return NULL;
 
-               write_lock(&resource_lock);
+       res->name = name;
+       res->start = start;
+       res->end = start + n - 1;
+       res->flags = IORESOURCE_BUSY;
 
-               for (;;) {
-                       struct resource *conflict;
+       write_lock(&resource_lock);
 
-                       conflict = __request_resource(parent, res);
-                       if (!conflict)
-                               break;
-                       if (conflict != parent) {
-                               parent = conflict;
-                               if (!(conflict->flags & IORESOURCE_BUSY))
-                                       continue;
-                       }
+       for (;;) {
+               struct resource *conflict;
 
-                       /* Uhhuh, that didn't work out.. */
-                       kfree(res);
-                       res = NULL;
+               conflict = __request_resource(parent, res);
+               if (!conflict)
                        break;
+               if (conflict != parent) {
+                       parent = conflict;
+                       if (!(conflict->flags & IORESOURCE_BUSY))
+                               continue;
                }
-               write_unlock(&resource_lock);
+
+               /* Uhhuh, that didn't work out.. */
+               kfree(res);
+               res = NULL;
+               break;
        }
+       write_unlock(&resource_lock);
        return res;
 }
 EXPORT_SYMBOL(__request_region);
@@ -763,3 +829,41 @@ static int __init reserve_setup(char *str)
 }
 
 __setup("reserve=", reserve_setup);
+
+/*
+ * Check if the requested addr and size spans more than any slot in the
+ * iomem resource tree.
+ */
+int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
+{
+       struct resource *p = &iomem_resource;
+       int err = 0;
+       loff_t l;
+
+       read_lock(&resource_lock);
+       for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+               /*
+                * We can probably skip the resources without
+                * IORESOURCE_IO attribute?
+                */
+               if (p->start >= addr + size)
+                       continue;
+               if (p->end < addr)
+                       continue;
+               if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
+                   PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
+                       continue;
+               printk(KERN_WARNING "resource map sanity check conflict: "
+                      "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
+                      (unsigned long long)addr,
+                      (unsigned long long)(addr + size - 1),
+                      (unsigned long long)p->start,
+                      (unsigned long long)p->end,
+                      p->name);
+               err = -1;
+               break;
+       }
+       read_unlock(&resource_lock);
+
+       return err;
+}