1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c
new file mode 100644
index 000000000000..c071790cc983
--- /dev/null
+++ b/drivers/pci/syscall.c
@@ -0,0 +1,145 @@
+/*
+ *	pci_syscall.c
+ *
+ * For architectures where we want to allow direct access
+ * to the PCI config stuff - it would probably be preferable
+ * on PCs too, but there people just do it by hand with the
+ * magic northbridge registers..
+ */
+
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/pci.h>
+#include <linux/smp_lock.h>
+#include <linux/syscalls.h>
+#include <asm/uaccess.h>
+
+
+asmlinkage long
+sys_pciconfig_read(unsigned long bus, unsigned long dfn,
+		   unsigned long off, unsigned long len,
+		   void __user *buf)
+{
+	struct pci_dev *dev;
+	u8 byte;
+	u16 word;
+	u32 dword;
+	long err, cfg_ret;
+
+	err = -EPERM;
+	if (!capable(CAP_SYS_ADMIN))
+		goto error;
+
+	err = -ENODEV;
+	dev = pci_find_slot(bus, dfn);
+	if (!dev)
+		goto error;
+
+	lock_kernel();
+	switch (len) {
+	case 1:
+		cfg_ret = pci_read_config_byte(dev, off, &byte);
+		break;
+	case 2:
+		cfg_ret = pci_read_config_word(dev, off, &word);
+		break;
+	case 4:
+		cfg_ret = pci_read_config_dword(dev, off, &dword);
+		break;
+	default:
+		err = -EINVAL;
+		unlock_kernel();
+		goto error;
+	};
+	unlock_kernel();
+
+	err = -EIO;
+	if (cfg_ret != PCIBIOS_SUCCESSFUL)
+		goto error;
+
+	switch (len) {
+	case 1:
+		err = put_user(byte, (unsigned char __user *)buf);
+		break;
+	case 2:
+		err = put_user(word, (unsigned short __user *)buf);
+		break;
+	case 4:
+		err = put_user(dword, (unsigned int __user *)buf);
+		break;
+	};
+	return err;
+
+error:
+	/* ??? XFree86 doesn't even check the return value.  They
+	   just look for 0xffffffff in the output, since that's what
+	   they get instead of a machine check on x86.  */
+	switch (len) {
+	case 1:
+		put_user(-1, (unsigned char __user *)buf);
+		break;
+	case 2:
+		put_user(-1, (unsigned short __user *)buf);
+		break;
+	case 4:
+		put_user(-1, (unsigned int __user *)buf);
+		break;
+	};
+	return err;
+}
+
+asmlinkage long
+sys_pciconfig_write(unsigned long bus, unsigned long dfn,
+		    unsigned long off, unsigned long len,
+		    void __user *buf)
+{
+	struct pci_dev *dev;
+	u8 byte;
+	u16 word;
+	u32 dword;
+	int err = 0;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	dev = pci_find_slot(bus, dfn);
+	if (!dev)
+		return -ENODEV;
+
+	lock_kernel();
+	switch(len) {
+	case 1:
+		err = get_user(byte, (u8 __user *)buf);
+		if (err)
+			break;
+		err = pci_write_config_byte(dev, off, byte);
+		if (err != PCIBIOS_SUCCESSFUL)
+			err = -EIO;
+		break;
+
+	case 2:
+		err = get_user(word, (u16 __user *)buf);
+		if (err)
+			break;
+		err = pci_write_config_word(dev, off, word);
+		if (err != PCIBIOS_SUCCESSFUL)
+			err = -EIO;
+		break;
+
+	case 4:
+		err = get_user(dword, (u32 __user *)buf);
+		if (err)
+			break;
+		err = pci_write_config_dword(dev, off, dword);
+		if (err != PCIBIOS_SUCCESSFUL)
+			err = -EIO;
+		break;
+
+	default:
+		err = -EINVAL;
+		break;
+	};
+	unlock_kernel();
+
+	return err;
+}