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-rw-r--r--drivers/char/hw_random/intel-rng.c32
1 files changed, 30 insertions, 2 deletions
diff --git a/drivers/char/hw_random/intel-rng.c b/drivers/char/hw_random/intel-rng.c
index 8efbc9c0e54..154ce3e6b3c 100644
--- a/drivers/char/hw_random/intel-rng.c
+++ b/drivers/char/hw_random/intel-rng.c
@@ -143,6 +143,11 @@ static const struct pci_device_id pci_tbl[] = {
};
MODULE_DEVICE_TABLE(pci, pci_tbl);
+static __initdata int no_fwh_detect;
+module_param(no_fwh_detect, int, 0);
+MODULE_PARM_DESC(no_fwh_detect, "Skip FWH detection:\n"
+ " positive value - skip if FWH space locked read-only\n"
+ " negative value - skip always");
static inline u8 hwstatus_get(void __iomem *mem)
{
@@ -240,6 +245,11 @@ static int __init mod_init(void)
if (!dev)
goto out; /* Device not found. */
+ if (no_fwh_detect < 0) {
+ pci_dev_put(dev);
+ goto fwh_done;
+ }
+
/* Check for Intel 82802 */
if (dev->device < 0x2640) {
fwh_dec_en1_off = FWH_DEC_EN1_REG_OLD;
@@ -252,6 +262,23 @@ static int __init mod_init(void)
pci_read_config_byte(dev, fwh_dec_en1_off, &fwh_dec_en1_val);
pci_read_config_byte(dev, bios_cntl_off, &bios_cntl_val);
+ if ((bios_cntl_val &
+ (BIOS_CNTL_LOCK_ENABLE_MASK|BIOS_CNTL_WRITE_ENABLE_MASK))
+ == BIOS_CNTL_LOCK_ENABLE_MASK) {
+ static __initdata /*const*/ char warning[] =
+ KERN_WARNING PFX "Firmware space is locked read-only. If you can't or\n"
+ KERN_WARNING PFX "don't want to disable this in firmware setup, and if\n"
+ KERN_WARNING PFX "you are certain that your system has a functional\n"
+ KERN_WARNING PFX "RNG, try using the 'no_fwh_detect' option.\n";
+
+ pci_dev_put(dev);
+ if (no_fwh_detect)
+ goto fwh_done;
+ printk(warning);
+ err = -EBUSY;
+ goto out;
+ }
+
mem = ioremap_nocache(INTEL_FWH_ADDR, INTEL_FWH_ADDR_LEN);
if (mem == NULL) {
pci_dev_put(dev);
@@ -280,8 +307,7 @@ static int __init mod_init(void)
pci_write_config_byte(dev,
fwh_dec_en1_off,
fwh_dec_en1_val | FWH_F8_EN_MASK);
- if (!(bios_cntl_val &
- (BIOS_CNTL_LOCK_ENABLE_MASK|BIOS_CNTL_WRITE_ENABLE_MASK)))
+ if (!(bios_cntl_val & BIOS_CNTL_WRITE_ENABLE_MASK))
pci_write_config_byte(dev,
bios_cntl_off,
bios_cntl_val | BIOS_CNTL_WRITE_ENABLE_MASK);
@@ -315,6 +341,8 @@ static int __init mod_init(void)
goto out;
}
+fwh_done:
+
err = -ENOMEM;
mem = ioremap(INTEL_RNG_ADDR, INTEL_RNG_ADDR_LEN);
if (!mem)