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authorThomas Gleixner <tglx@linutronix.de>2007-10-11 11:12:29 +0200
committerThomas Gleixner <tglx@linutronix.de>2007-10-11 11:12:29 +0200
commitd4c3a41e9a1f72bb995a6fb89ad028eda9a14c3d (patch)
tree9349b4ef68d1074ec86fa279bbbb7a22eb7f3b44 /arch/i386/kernel/ioport.c
parent549c64ac41fd37236543143a4e92699958a3972e (diff)
downloadop-kernel-dev-d4c3a41e9a1f72bb995a6fb89ad028eda9a14c3d.zip
op-kernel-dev-d4c3a41e9a1f72bb995a6fb89ad028eda9a14c3d.tar.gz
i386: prepare shared kernel/ioport.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/i386/kernel/ioport.c')
-rw-r--r--arch/i386/kernel/ioport.c153
1 files changed, 0 insertions, 153 deletions
diff --git a/arch/i386/kernel/ioport.c b/arch/i386/kernel/ioport.c
deleted file mode 100644
index 3d310a9..0000000
--- a/arch/i386/kernel/ioport.c
+++ /dev/null
@@ -1,153 +0,0 @@
-/*
- * linux/arch/i386/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/smp.h>
-#include <linux/stddef.h>
-#include <linux/slab.h>
-#include <linux/thread_info.h>
-#include <linux/syscalls.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)
-{
- unsigned long mask;
- unsigned long *bitmap_base = bitmap + (base / BITS_PER_LONG);
- unsigned int low_index = base & (BITS_PER_LONG-1);
- int length = low_index + extent;
-
- if (low_index != 0) {
- mask = (~0UL << low_index);
- if (length < BITS_PER_LONG)
- mask &= ~(~0UL << length);
- if (new_value)
- *bitmap_base++ |= mask;
- else
- *bitmap_base++ &= ~mask;
- length -= BITS_PER_LONG;
- }
-
- mask = (new_value ? ~0UL : 0UL);
- while (length >= BITS_PER_LONG) {
- *bitmap_base++ = mask;
- length -= BITS_PER_LONG;
- }
-
- if (length > 0) {
- mask = ~(~0UL << length);
- if (new_value)
- *bitmap_base++ |= mask;
- else
- *bitmap_base++ &= ~mask;
- }
-}
-
-
-/*
- * this changes the io permissions bitmap in the current task.
- */
-asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
-{
- unsigned long i, max_long, bytes, bytes_updated;
- struct thread_struct * t = &current->thread;
- struct tss_struct * tss;
- unsigned long *bitmap;
-
- 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_thread_flag(TIF_IO_BITMAP);
- }
-
- /*
- * do it in the per-thread copy and in the TSS ...
- *
- * Disable preemption via get_cpu() - we must not switch away
- * because the ->io_bitmap_max value must match the bitmap
- * contents:
- */
- tss = &per_cpu(init_tss, get_cpu());
-
- set_bitmap(t->io_bitmap_ptr, from, num, !turn_on);
-
- /*
- * Search for a (possibly new) maximum. This is simple and stupid,
- * to keep it obviously correct:
- */
- max_long = 0;
- for (i = 0; i < IO_BITMAP_LONGS; i++)
- if (t->io_bitmap_ptr[i] != ~0UL)
- max_long = i;
-
- bytes = (max_long + 1) * sizeof(long);
- bytes_updated = max(bytes, t->io_bitmap_max);
-
- t->io_bitmap_max = bytes;
-
- /*
- * Sets the lazy trigger so that the next I/O operation will
- * reload the correct bitmap.
- * Reset the owner so that a process switch will not set
- * tss->io_bitmap_base to IO_BITMAP_OFFSET.
- */
- tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
- tss->io_bitmap_owner = NULL;
-
- put_cpu();
-
- 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.
- *
- * Here we just change the eflags value on the stack: we allow
- * only the super-user to do it. This depends on the stack-layout
- * on system-call entry - see also fork() and the signal handling
- * code.
- */
-
-asmlinkage long sys_iopl(unsigned long unused)
-{
- volatile struct pt_regs * regs = (struct pt_regs *) &unused;
- unsigned int level = regs->ebx;
- unsigned int old = (regs->eflags >> 12) & 3;
- struct thread_struct *t = &current->thread;
-
- if (level > 3)
- return -EINVAL;
- /* Trying to gain more privileges? */
- if (level > old) {
- if (!capable(CAP_SYS_RAWIO))
- return -EPERM;
- }
- t->iopl = level << 12;
- regs->eflags = (regs->eflags & ~X86_EFLAGS_IOPL) | t->iopl;
- set_iopl_mask(t->iopl);
- return 0;
-}
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