This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / x86_64 / kernel / ioport-xen.c

diff --git a/arch/x86_64/kernel/ioport-xen.c b/arch/x86_64/kernel/ioport-xen.c
new file mode 100644 (file)
index 0000000..1fcbb20
--- /dev/null
+++ b/arch/x86_64/kernel/ioport-xen.c
@@ -0,0 +1,99 @@
+/*
+ *     linux/arch/x86_64/kernel/ioport.c
+ *
+ * This contains the io-permission bitmap code - written by obz, with changes
+ * by Linus.
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/stddef.h>
+#include <linux/slab.h>
+#include <linux/thread_info.h>
+#include <xen/interface/physdev.h>
+
+/* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */
+static void set_bitmap(unsigned long *bitmap, unsigned int base, unsigned int extent, int new_value)
+{
+       int i;
+
+       if (new_value)
+               for (i = base; i < base + extent; i++)
+                       __set_bit(i, bitmap);
+       else
+               for (i = base; i < base + extent; i++)
+                       clear_bit(i, bitmap);
+}
+
+/*
+ * this changes the io permissions bitmap in the current task.
+ */
+asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
+{
+       struct thread_struct * t = &current->thread;
+       unsigned long *bitmap;
+       struct physdev_set_iobitmap set_iobitmap;
+
+       if ((from + num <= from) || (from + num > IO_BITMAP_BITS))
+               return -EINVAL;
+       if (turn_on && !capable(CAP_SYS_RAWIO))
+               return -EPERM;
+
+       /*
+        * If it's the first ioperm() call in this thread's lifetime, set the
+        * IO bitmap up. ioperm() is much less timing critical than clone(),
+        * this is why we delay this operation until now:
+        */
+       if (!t->io_bitmap_ptr) {
+               bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
+               if (!bitmap)
+                       return -ENOMEM;
+
+               memset(bitmap, 0xff, IO_BITMAP_BYTES);
+               t->io_bitmap_ptr = bitmap;
+
+               set_iobitmap.bitmap   = (char *)bitmap;
+               set_iobitmap.nr_ports = IO_BITMAP_BITS;
+               HYPERVISOR_physdev_op(PHYSDEVOP_set_iobitmap, &set_iobitmap);
+       }
+
+       set_bitmap(t->io_bitmap_ptr, from, num, !turn_on);
+
+       return 0;
+}
+
+/*
+ * sys_iopl has to be used when you want to access the IO ports
+ * beyond the 0x3ff range: to get the full 65536 ports bitmapped
+ * you'd need 8kB of bitmaps/process, which is a bit excessive.
+ *
+ */
+
+asmlinkage long sys_iopl(unsigned int new_iopl, struct pt_regs *regs)
+{
+       unsigned int old_iopl = current->thread.iopl;
+       struct physdev_set_iopl set_iopl;
+
+       if (new_iopl > 3)
+               return -EINVAL;
+
+       /* Need "raw I/O" privileges for direct port access. */
+       if ((new_iopl > old_iopl) && !capable(CAP_SYS_RAWIO))
+               return -EPERM;
+
+       /* Change our version of the privilege levels. */
+       current->thread.iopl = new_iopl;
+
+       /* Force the change at ring 0. */
+       set_iopl.iopl = (new_iopl == 0) ? 1 : new_iopl;
+       HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
+
+       return 0;
+}