fix Intel RNG detection (take 2)
PATCH 1/1 fix Intel RNG detection (take 2)
Previously, since determination whether there was an Intel random number generator was based on a single bit, on systems with a matching bridge device but without a firmware hub, there was a 50% chance that the code would incorrectly decide that the system had an RNG. This patch adds detection of the firmware hub to better qualify the existence of an RNG.
There is one issue with the patch: I was unable to determine the LPC equivalent for the PCI bridge 8086:2430 (since the old code didn't care about which of the many devices provided by the ICH/ESB it was chose to use the PCI bridge device, but the FWH settings live in the LPC device, so the device list needed to be changed).
Signed-off-by Jan Beulich <[email protected]>
Cc Michael Buesch <[email protected]>
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +178 -10
@@ -50,6 +50,43 @@#define INTEL_RNG_ADDR_LEN 3/* +* LPC bridge PCI config space registers +*/ +#define FWH_DEC_EN1_REG_OLD 0xe3 +#define FWH_DEC_EN1_REG_NEW 0xd9/* high byte of 16-bit register */ +#define FWH_F8_EN_MASK 0x80 + +#define BIOS_CNTL_REG_OLD 0x4e +#define BIOS_CNTL_REG_NEW 0xdc +#define BIOS_CNTL_WRITE_ENABLE_MASK 0x01 +#define BIOS_CNTL_LOCK_ENABLE_MASK 0x02 + +/* +* Magic address at which Intel Firmware Hubs get accessed +*/ +#define INTEL_FWH_ADDR 0xffff0000 +#define INTEL_FWH_ADDR_LEN 2 + +/* +* Intel Firmware Hub command codes (write to any address inside the device) +*/ +#define INTEL_FWH_RESET_CMD 0xff/* aka READ_ARRAY */ +#define INTEL_FWH_READ_ID_CMD 0x90 + +/* +* Intel Firmware Hub Read ID command result addresses +*/ +#define INTEL_FWH_MANUFACTURER_CODE_ADDRESS 0x000000 +#define INTEL_FWH_DEVICE_CODE_ADDRESS 0x000001 + +/* +* Intel Firmware Hub Read ID command result values +*/ +#define INTEL_FWH_MANUFACTURER_CODE 0x89 +#define INTEL_FWH_DEVICE_CODE_8M 0xac +#define INTEL_FWH_DEVICE_CODE_4M 0xad + +/* * Data for PCI driver interface * * This data only exists for exporting the supported
@@ -58,12 +95,50 @@* want to register another driver on the same PCI id. */ static const struct pci_device_id pci_tbl[] = { - {0x8086 ,0x2418 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x2428 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x2430 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x2448 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x244e ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x245e ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, +/* AA +{ 0x8086, 0x2418, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x2410 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* AA */ +/* AB +{ 0x8086, 0x2428, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x2420 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* AB */ +/* ?? +{ 0x8086, 0x2430, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ +/* BAM, CAM, DBM, FBM, GxM +{ 0x8086, 0x2448, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x244c ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* BAM */ + {0x8086 ,0x248c ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* CAM */ + {0x8086 ,0x24cc ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* DBM */ + {0x8086 ,0x2641 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* FBM */ + {0x8086 ,0x27b9 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* GxM */ + {0x8086 ,0x27bd ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* GxM DH */ +/* BA, CA, DB, Ex, 6300, Fx, 631x/632x, Gx +{ 0x8086, 0x244e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x2440 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* BA */ + {0x8086 ,0x2480 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* CA */ + {0x8086 ,0x24c0 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* DB */ + {0x8086 ,0x24d0 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* Ex */ + {0x8086 ,0x25a1 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 6300 */ + {0x8086 ,0x2640 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* Fx */ + {0x8086 ,0x2670 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2671 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2672 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2673 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2674 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2675 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2676 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2677 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2678 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2679 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267a ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267b ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267c ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267d ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267e ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267f ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x27b8 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* Gx */ +/* E +{ 0x8086, 0x245e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x2450 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* E */ {0 , },/* terminate list */ };MODULE_DEVICE_TABLE (pci, pci_tbl);
@@ -138,22 +213,115 @@ static struct hwrng intel_rng = { }; +#ifdef CONFIG_SMP +static char __initdata waitflag; + +static void __init intel_init_wait (void *unused) +{ +while (waitflag) { +cpu_relax (); +smp_rmb (); + } +} +#endif +static int __init mod_init (void ) {int err = -ENODEV ; +unsigned i; +struct pci_dev *dev =NULL ;void __iomem *mem; -u8 hw_status; - -if (!pci_dev_present (pci_tbl)) +unsigned long flags; +u8 bios_cntl_off, fwh_dec_en1_off; +u8 bios_cntl_val =0xff , fwh_dec_en1_val =0xff ; +u8 hw_status, mfc, dvc; + +for (i =0 ; !dev && pci_tbl[i].vendor; ++i) + dev =pci_get_device (pci_tbl[i].vendor, pci_tbl[i].device,NULL ); + +if (!dev) goto out;/* Device not found. */ +/* Check for Intel 82802 */ +if (dev->device <0x2640 ) { + fwh_dec_en1_off =FWH_DEC_EN1_REG_OLD ; + bios_cntl_off =BIOS_CNTL_REG_OLD ; + } +else { + fwh_dec_en1_off =FWH_DEC_EN1_REG_NEW ; + bios_cntl_off =BIOS_CNTL_REG_NEW ; + } + +pci_read_config_byte (dev, fwh_dec_en1_off, &fwh_dec_en1_val); +pci_read_config_byte (dev, bios_cntl_off, &bios_cntl_val); + + mem =ioremap_nocache (INTEL_FWH_ADDR ,INTEL_FWH_ADDR_LEN ); +if (mem ==NULL ) { +pci_dev_put (dev); + err = -EBUSY ; + goto out; + } + +#ifdef CONFIG_SMP + waitflag =1 ; +smp_wmb (); +if (smp_call_function (intel_init_wait,NULL ,1 ,0 ) !=0 ) { + waitflag =0 ; +smp_wmb (); +pci_dev_put (dev); + printk(KERN_ERR PFX "cannot run on all processors\n"); + err = -EAGAIN ; + goto err_unmap; + } +#else +#define waitflag err +#endif +local_irq_save (flags); + +if (!(fwh_dec_en1_val &FWH_F8_EN_MASK )) +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 ))) +pci_write_config_byte (dev, + bios_cntl_off, + bios_cntl_val |BIOS_CNTL_WRITE_ENABLE_MASK ); + +writeb (INTEL_FWH_RESET_CMD , mem); +writeb (INTEL_FWH_READ_ID_CMD , mem); + mfc =readb (mem +INTEL_FWH_MANUFACTURER_CODE_ADDRESS ); + dvc =readb (mem +INTEL_FWH_DEVICE_CODE_ADDRESS ); +writeb (INTEL_FWH_RESET_CMD , mem); + +if (!(bios_cntl_val + & (BIOS_CNTL_LOCK_ENABLE_MASK |BIOS_CNTL_WRITE_ENABLE_MASK ))) +pci_write_config_byte (dev, bios_cntl_off, bios_cntl_val); +if (!(fwh_dec_en1_val &FWH_F8_EN_MASK )) +pci_write_config_byte (dev, fwh_dec_en1_off, fwh_dec_en1_val); + +local_irq_restore (flags); + waitflag =0 ; +smp_wmb (); + +iounmap (mem); +pci_dev_put (dev); + +if (mfc !=INTEL_FWH_MANUFACTURER_CODE + || (dvc !=INTEL_FWH_DEVICE_CODE_8M + && dvc !=INTEL_FWH_DEVICE_CODE_4M )) { + printk(KERN_ERR PFX "FWH not detected\n"); + err = -ENODEV ; + goto out; + } + err = -ENOMEM ; mem =ioremap (INTEL_RNG_ADDR ,INTEL_RNG_ADDR_LEN );if (!mem) goto out; intel_rng.priv = (unsigned long )mem; -/* Check for Intel 82802 */ +/* Check for Random Number Generator */ err = -ENODEV ; hw_status =hwstatus_get (mem);if ((hw_status &INTEL_RNG_PRESENT ) ==0 )
Quoted 7 lines · Jan Beulich
Previously, since determination whether there was an Intel random number generator was based on a single bit, on systems with a matching bridge device but without a firmware hub, there was a 50% chance that the code would incorrectly decide that the system had an RNG. This patch adds detection of the firmware hub to better qualify the existence of an RNG.
Quoted 8 lines
There is one issue with the patch: I was unable to determine the LPC equivalent for the PCI bridge 8086:2430 (since the old code didn't care about which of the many devices provided by the ICH/ESB it was chose to use the PCI bridge device, but the FWH settings live in the LPC device, so the device list needed to be changed).
Signed-off-by Jan Beulich <[email protected]>Cc Michael Buesch <[email protected]>
Acked-by Michael Buesch <[email protected]>
If noone else complains, Andrew please apply to -mm and queue for the next kernel.
Quoted 225 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +178
-10@@ -50,6 +50,43 @@#define INTEL_RNG_ADDR_LEN 3/* +* LPC bridge PCI config space registers +*/ +#define FWH_DEC_EN1_REG_OLD 0xe3 +#define FWH_DEC_EN1_REG_NEW 0xd9/* high byte of 16-bit register */ +#define FWH_F8_EN_MASK 0x80 + +#define BIOS_CNTL_REG_OLD 0x4e +#define BIOS_CNTL_REG_NEW 0xdc +#define BIOS_CNTL_WRITE_ENABLE_MASK 0x01 +#define BIOS_CNTL_LOCK_ENABLE_MASK 0x02 + +/* +* Magic address at which Intel Firmware Hubs get accessed +*/ +#define INTEL_FWH_ADDR 0xffff0000 +#define INTEL_FWH_ADDR_LEN 2 + +/* +* Intel Firmware Hub command codes (write to any address inside the device) +*/ +#define INTEL_FWH_RESET_CMD 0xff/* aka READ_ARRAY */ +#define INTEL_FWH_READ_ID_CMD 0x90 + +/* +* Intel Firmware Hub Read ID command result addresses +*/ +#define INTEL_FWH_MANUFACTURER_CODE_ADDRESS 0x000000 +#define INTEL_FWH_DEVICE_CODE_ADDRESS 0x000001 + +/* +* Intel Firmware Hub Read ID command result values +*/ +#define INTEL_FWH_MANUFACTURER_CODE 0x89 +#define INTEL_FWH_DEVICE_CODE_8M 0xac +#define INTEL_FWH_DEVICE_CODE_4M 0xad + +/* * Data for PCI driver interface * * This data only exists for exporting the supported @@ -58,12 +95,50 @@* want to register another driver on the same PCI id. */ static const struct pci_device_id pci_tbl[] = { - {0x8086 ,0x2418 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x2428 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x2430 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x2448 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x244e ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, - {0x8086 ,0x245e ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , }, +/* AA +{ 0x8086, 0x2418, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x2410 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* AA */ +/* AB +{ 0x8086, 0x2428, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x2420 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* AB */ +/* ?? +{ 0x8086, 0x2430, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ +/* BAM, CAM, DBM, FBM, GxM +{ 0x8086, 0x2448, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x244c ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* BAM */ + {0x8086 ,0x248c ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* CAM */ + {0x8086 ,0x24cc ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* DBM */ + {0x8086 ,0x2641 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* FBM */ + {0x8086 ,0x27b9 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* GxM */ + {0x8086 ,0x27bd ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* GxM DH */ +/* BA, CA, DB, Ex, 6300, Fx, 631x/632x, Gx +{ 0x8086, 0x244e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x2440 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* BA */ + {0x8086 ,0x2480 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* CA */ + {0x8086 ,0x24c0 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* DB */ + {0x8086 ,0x24d0 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* Ex */ + {0x8086 ,0x25a1 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 6300 */ + {0x8086 ,0x2640 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* Fx */ + {0x8086 ,0x2670 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2671 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2672 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2673 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2674 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2675 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2676 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2677 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2678 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x2679 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267a ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267b ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267c ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267d ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267e ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x267f ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* 631x/632x */ + {0x8086 ,0x27b8 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* Gx */ +/* E +{ 0x8086, 0x245e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */ + {0x8086 ,0x2450 ,PCI_ANY_ID ,PCI_ANY_ID ,0 ,0 ,0 , },/* E */ {0 , },/* terminate list */ };MODULE_DEVICE_TABLE (pci, pci_tbl);@@ -138,22 +213,115 @@ static struct hwrng intel_rng = { }; +#ifdef CONFIG_SMP +static char __initdata waitflag; + +static void __init intel_init_wait (void *unused) +{ +while (waitflag) { +cpu_relax (); +smp_rmb (); + } +} +#endif +static int __init mod_init (void ) {int err = -ENODEV ; +unsigned i; +struct pci_dev *dev =NULL ;void __iomem *mem; -u8 hw_status; - -if (!pci_dev_present (pci_tbl)) +unsigned long flags; +u8 bios_cntl_off, fwh_dec_en1_off; +u8 bios_cntl_val =0xff , fwh_dec_en1_val =0xff ; +u8 hw_status, mfc, dvc; + +for (i =0 ; !dev && pci_tbl[i].vendor; ++i) + dev =pci_get_device (pci_tbl[i].vendor, pci_tbl[i].device,NULL ); + +if (!dev) goto out;/* Device not found. */ +/* Check for Intel 82802 */ +if (dev->device <0x2640 ) { + fwh_dec_en1_off =FWH_DEC_EN1_REG_OLD ; + bios_cntl_off =BIOS_CNTL_REG_OLD ; + } +else { + fwh_dec_en1_off =FWH_DEC_EN1_REG_NEW ; + bios_cntl_off =BIOS_CNTL_REG_NEW ; + } + +pci_read_config_byte (dev, fwh_dec_en1_off, &fwh_dec_en1_val); +pci_read_config_byte (dev, bios_cntl_off, &bios_cntl_val); + + mem =ioremap_nocache (INTEL_FWH_ADDR ,INTEL_FWH_ADDR_LEN ); +if (mem ==NULL ) { +pci_dev_put (dev); + err = -EBUSY ; + goto out; + } + +#ifdef CONFIG_SMP + waitflag =1 ; +smp_wmb (); +if (smp_call_function (intel_init_wait,NULL ,1 ,0 ) !=0 ) { + waitflag =0 ; +smp_wmb (); +pci_dev_put (dev); + printk(KERN_ERR PFX "cannot run on all processors\n"); + err = -EAGAIN ; + goto err_unmap; + } +#else +#define waitflag err +#endif +local_irq_save (flags); + +if (!(fwh_dec_en1_val &FWH_F8_EN_MASK )) +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 ))) +pci_write_config_byte (dev, + bios_cntl_off, + bios_cntl_val |BIOS_CNTL_WRITE_ENABLE_MASK ); + +writeb (INTEL_FWH_RESET_CMD , mem); +writeb (INTEL_FWH_READ_ID_CMD , mem); + mfc =readb (mem +INTEL_FWH_MANUFACTURER_CODE_ADDRESS ); + dvc =readb (mem +INTEL_FWH_DEVICE_CODE_ADDRESS ); +writeb (INTEL_FWH_RESET_CMD , mem); + +if (!(bios_cntl_val + & (BIOS_CNTL_LOCK_ENABLE_MASK |BIOS_CNTL_WRITE_ENABLE_MASK ))) +pci_write_config_byte (dev, bios_cntl_off, bios_cntl_val); +if (!(fwh_dec_en1_val &FWH_F8_EN_MASK )) +pci_write_config_byte (dev, fwh_dec_en1_off, fwh_dec_en1_val); + +local_irq_restore (flags); + waitflag =0 ; +smp_wmb (); + +iounmap (mem); +pci_dev_put (dev); + +if (mfc !=INTEL_FWH_MANUFACTURER_CODE + || (dvc !=INTEL_FWH_DEVICE_CODE_8M + && dvc !=INTEL_FWH_DEVICE_CODE_4M )) { + printk(KERN_ERR PFX "FWH not detected\n"); + err = -ENODEV ; + goto out; + } + err = -ENOMEM ; mem =ioremap (INTEL_RNG_ADDR ,INTEL_RNG_ADDR_LEN );if (!mem) goto out; intel_rng.priv = (unsigned long )mem; -/* Check for Intel 82802 */ +/* Check for Random Number Generator */ err = -ENODEV ; hw_status =hwstatus_get (mem);if ((hw_status &INTEL_RNG_PRESENT ) ==0 )
Signature · 1 line
Greetings Michael.
Quoted 16 lines · On Mon, 31 Jul 2006 12:41:36 +0200 Jan Beulich <[email protected]> wrote:
Previously, since determination whether there was an Intel random number generator was based on a single bit, on systems with a matching bridge device but without a firmware hub, there was a 50% chance that the code would incorrectly decide that the system had an RNG. This patch adds detection of the firmware hub to better qualify the existence of an RNG.
There is one issue with the patch: I was unable to determine the LPC equivalent for the PCI bridge 8086:2430 (since the old code didn't care about which of the many devices provided by the ICH/ESB it was chose to use the PCI bridge device, but the FWH settings live in the LPC device, so the device list needed to be changed).
...
drivers/char/hw_random/intel-rng.c static struct hwrng intel_rng = { · line 219
Quoted 4 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +4
-0+#ifdef CONFIG_SMP +static char __initdata waitflag; + +static void __init intel_init_wait (void *unused)
No space before the (, please.
drivers/char/hw_random/intel-rng.c static struct hwrng intel_rng = { · line 224
Quoted 5 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +5
-0+{ +while (waitflag) { +cpu_relax (); +smp_rmb (); + }
I believe we decided that cpu_relax() implies a barrier.
Quoted 18 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +11
-3+#endif +static int __init mod_init (void ) {int err = -ENODEV ; +unsigned i; +struct pci_dev *dev =NULL ;void __iomem *mem; -u8 hw_status; - -if (!pci_dev_present (pci_tbl)) +unsigned long flags; +u8 bios_cntl_off, fwh_dec_en1_off; +u8 bios_cntl_val =0xff , fwh_dec_en1_val =0xff ; +u8 hw_status, mfc, dvc; + +for (i =0 ; !dev && pci_tbl[i].vendor; ++i) + dev =pci_get_device (pci_tbl[i].vendor, pci_tbl[i].device,NULL );
drivers/char/hw_random/intel-rng.c static struct hwrng intel_rng = { · line 250
Quoted 10 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +8
-0+ +if (!dev) goto out;/* Device not found. */ +/* Check for Intel 82802 */ +if (dev->device <0x2640 ) { + fwh_dec_en1_off =FWH_DEC_EN1_REG_OLD ; + bios_cntl_off =BIOS_CNTL_REG_OLD ; + } +else {
Please do
} else {Quoted 18 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +18
-0+ fwh_dec_en1_off =FWH_DEC_EN1_REG_NEW ; + bios_cntl_off =BIOS_CNTL_REG_NEW ; + } + +pci_read_config_byte (dev, fwh_dec_en1_off, &fwh_dec_en1_val); +pci_read_config_byte (dev, bios_cntl_off, &bios_cntl_val); + + mem =ioremap_nocache (INTEL_FWH_ADDR ,INTEL_FWH_ADDR_LEN ); +if (mem ==NULL ) { +pci_dev_put (dev); + err = -EBUSY ; + goto out; + } + +#ifdef CONFIG_SMP + waitflag =1 ; +smp_wmb (); +if (smp_call_function (intel_init_wait,NULL ,1 ,0 ) !=0 ) {
drivers/char/hw_random/intel-rng.c static struct hwrng intel_rng = { · line 278
Quoted 10 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +10
-0+ waitflag =0 ; +smp_wmb (); +pci_dev_put (dev); + printk(KERN_ERR PFX "cannot run on all processors\n"); + err = -EAGAIN ; + goto err_unmap; + } +#else +#define waitflag err +#endif
awww man, this is nasty. We're #defining the name of a file-global variable to that it puns a local? On uniproc only?
Please, not in Linux. Let's find a better way.
drivers/char/hw_random/intel-rng.c static struct hwrng intel_rng = { · line 279
Quoted 1 line
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +1
-0+local_irq_save (flags);
I think the code needs a comment explaining the local_irq_save(). Its reasoning is not apparent from reading the implementation.
Quoted 8 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +8
-0+if (!(fwh_dec_en1_val &FWH_F8_EN_MASK )) +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 ))) + pci_write_config_byte(dev, + bios_cntl_off,
drivers/char/hw_random/intel-rng.c static struct hwrng intel_rng = { · line 298
Quoted 10 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +10
-0+ bios_cntl_val | BIOS_CNTL_WRITE_ENABLE_MASK); + +writeb (INTEL_FWH_RESET_CMD , mem); +writeb (INTEL_FWH_READ_ID_CMD , mem); + mfc =readb (mem +INTEL_FWH_MANUFACTURER_CODE_ADDRESS ); + dvc =readb (mem +INTEL_FWH_DEVICE_CODE_ADDRESS ); +writeb (INTEL_FWH_RESET_CMD , mem); + +if (!(bios_cntl_val + & (BIOS_CNTL_LOCK_ENABLE_MASK |BIOS_CNTL_WRITE_ENABLE_MASK )))
It would be (a little) more conventional to do
if (!(bios_cntl_val &
drivers/char/hw_random/intel-rng.c static struct hwrng intel_rng = { · line 305
Quoted 7 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +7
-0+pci_write_config_byte (dev, bios_cntl_off, bios_cntl_val); +if (!(fwh_dec_en1_val &FWH_F8_EN_MASK )) +pci_write_config_byte (dev, fwh_dec_en1_off, fwh_dec_en1_val); + +local_irq_restore (flags); + waitflag =0 ; +smp_wmb ();
Again, the barrier is hard to understand. Pretty much all open-coded barriers should have an explanatory comment.
drivers/char/hw_random/intel-rng.c static struct hwrng intel_rng = { · line 312
Quoted 6 lines
drivers/char/hw_random/intel-rng.c renamed from home/jbeulich/tmp/linux-2.6.18-rc3/drivers/char/hw_random/intel-rng.c +6
-0+iounmap (mem); +pci_dev_put (dev); + +if (mfc !=INTEL_FWH_MANUFACTURER_CODE + || (dvc !=INTEL_FWH_DEVICE_CODE_8M + && dvc !=INTEL_FWH_DEVICE_CODE_4M )) {
Again,
if (mfc != INTEL_FWH_MANUFACTURER_CODE ||
(dvc != INTEL_FWH_DEVICE_CODE_8M &&
dvc != INTEL_FWH_DEVICE_CODE_4M)) {would be more typical.