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path: root/drivers/pci/syscall.c
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Diffstat (limited to 'drivers/pci/syscall.c')
-rw-r--r--drivers/pci/syscall.c145
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;
+}