Merge branches 'x86/early-printk', 'x86/microcode' and 'core/objtool' into x86/urgent...

[sfrench/cifs-2.6.git] / arch / x86 / kernel / early_printk.c

diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 5e801c8c8ce7cfaf191505fc9feaae5414f7270b..374a52fa529694f7399ad59e0b4ec2c1d598c636 100644 (file)
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -213,8 +213,9 @@ static unsigned int mem32_serial_in(unsigned long addr, int offset)
  * early_pci_serial_init()
  *
  * This function is invoked when the early_printk param starts with "pciserial"
- * The rest of the param should be ",B:D.F,baud" where B, D & F describe the
- * location of a PCI device that must be a UART device.
+ * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe
+ * the location of a PCI device that must be a UART device. "force" is optional
+ * and overrides the use of an UART device with a wrong PCI class code.
  */
 static __init void early_pci_serial_init(char *s)
 {
@@ -224,17 +225,23 @@ static __init void early_pci_serial_init(char *s)
        u32 classcode, bar0;
        u16 cmdreg;
        char *e;
+       int force = 0;
 
-
-       /*
-        * First, part the param to get the BDF values
-        */
        if (*s == ',')
                ++s;
 
        if (*s == 0)
                return;
 
+       /* Force the use of an UART device with wrong class code */
+       if (!strncmp(s, "force,", 6)) {
+               force = 1;
+               s += 6;
+       }
+
+       /*
+        * Part the param to get the BDF values
+        */
        bus = (u8)simple_strtoul(s, &e, 16);
        s = e;
        if (*s != ':')
@@ -253,7 +260,7 @@ static __init void early_pci_serial_init(char *s)
                s++;
 
        /*
-        * Second, find the device from the BDF
+        * Find the device from the BDF
         */
        cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
        classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
@@ -264,8 +271,10 @@ static __init void early_pci_serial_init(char *s)
         */
        if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
             (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
-          (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */
-               return;
+          (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
+               if (!force)
+                       return;
+       }
 
        /*
         * Determine if it is IO or memory mapped
@@ -289,7 +298,7 @@ static __init void early_pci_serial_init(char *s)
        }
 
        /*
-        * Lastly, initialize the hardware
+        * Initialize the hardware
         */
        if (*s) {
                if (strcmp(s, "nocfg") == 0)