/*
* The PCI Library -- Access to i386 I/O ports on Linux
*
- * Copyright (c) 1997--2003 Martin Mares <mj@ucw.cz>
+ * Copyright (c) 1997--2006 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
-#ifdef __GLIBC__
#include <sys/io.h>
-#else
-#include <asm/io.h>
-#endif
+#include <errno.h>
-static int intel_iopl_set = -1;
+static int ioperm_enabled;
+static int iopl_enabled;
static int
-intel_setup_io(void)
+intel_setup_io(struct pci_access *a UNUSED)
{
- if (intel_iopl_set < 0)
- intel_iopl_set = (iopl(3) < 0) ? 0 : 1;
- return intel_iopl_set;
+ if (ioperm_enabled || iopl_enabled)
+ return 1;
+
+ /*
+ * Before Linux 2.6.8, only the first 0x3ff I/O ports permissions can be
+ * modified via ioperm(). Since 2.6.8 all ports are supported.
+ * Since Linux 5.5, EFLAGS-based iopl() implementation was removed and
+ * replaced by new TSS-IOPB-map-all-based emulator. Before Linux 5.5,
+ * EFLAGS-based iopl() allowed userspace to enable/disable interrupts,
+ * which is dangerous. So prefer usage of ioperm() and fallback to iopl().
+ */
+ if (ioperm(0xcf8, 8, 1) < 0) /* conf1 + conf2 ports */
+ {
+ if (errno == EINVAL) /* ioperm() unsupported */
+ {
+ if (iopl(3) < 0)
+ return 0;
+ iopl_enabled = 1;
+ return 1;
+ }
+ return 0;
+ }
+ if (ioperm(0xc000, 0xfff, 1) < 0) /* remaining conf2 ports */
+ {
+ ioperm(0xcf8, 8, 0);
+ return 0;
+ }
+
+ ioperm_enabled = 1;
+ return 1;
}
static inline void
-intel_cleanup_io(void)
+intel_cleanup_io(struct pci_access *a UNUSED)
+{
+ if (ioperm_enabled)
+ {
+ ioperm(0xcf8, 8, 0);
+ ioperm(0xc000, 0xfff, 0);
+ ioperm_enabled = 0;
+ }
+
+ if (iopl_enabled)
+ {
+ iopl(0);
+ iopl_enabled = 0;
+ }
+}
+
+static inline void intel_io_lock(void)
+{
+}
+
+static inline void intel_io_unlock(void)
{
- if (intel_iopl_set > 0)
- iopl(3);
- intel_iopl_set = -1;
}