From 9863be598ed068613996af8da71d9fd976a0ab2d Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Wed, 10 Jan 2007 23:15:41 -0800 Subject: [PATCH] intel-rng workarounds Add a load option to intel-rng to allow skipping the FWH detection, necessary in case the BIOS has locked read-only the firmware hub space. Also prevent any attempt to write to firmware space if it cannot be write enabled (apparently caused hangs on some systems not having an FWH and thus also not having a respective RNG). Signed-off-by: Jan Beulich Signed-off-by: Michael Buesch Cc: Jeff Garzik Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/hw_random/intel-rng.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) (limited to 'drivers/char') 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) -- cgit v1.2.3