From 984e976f5382ff09351ddd3b023937611396d739 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Wed, 21 Nov 2007 12:24:45 +0800 Subject: [PATCH] [HWRNG]: move status polling loop to data_present callbacks Handle waiting for new random within the drivers themselves, this allows to use better suited timeouts for the individual rngs. Signed-off-by: Patrick McHardy Acked-by: Michael Buesch Signed-off-by: Herbert Xu --- drivers/char/hw_random/amd-rng.c | 12 ++++++++++-- drivers/char/hw_random/core.c | 24 ++++++------------------ drivers/char/hw_random/geode-rng.c | 12 ++++++++++-- drivers/char/hw_random/intel-rng.c | 15 ++++++++++++--- drivers/char/hw_random/omap-rng.c | 13 +++++++++++-- drivers/char/hw_random/pasemi-rng.c | 14 +++++++++++--- drivers/char/hw_random/via-rng.c | 19 ++++++++++++------- include/linux/hw_random.h | 2 +- 8 files changed, 73 insertions(+), 38 deletions(-) diff --git a/drivers/char/hw_random/amd-rng.c b/drivers/char/hw_random/amd-rng.c index 556fd81fa8..c422e870dc 100644 --- a/drivers/char/hw_random/amd-rng.c +++ b/drivers/char/hw_random/amd-rng.c @@ -28,6 +28,7 @@ #include #include #include +#include #include @@ -52,11 +53,18 @@ MODULE_DEVICE_TABLE(pci, pci_tbl); static struct pci_dev *amd_pdev; -static int amd_rng_data_present(struct hwrng *rng) +static int amd_rng_data_present(struct hwrng *rng, int wait) { u32 pmbase = (u32)rng->priv; + int data, i; - return !!(inl(pmbase + 0xF4) & 1); + for (i = 0; i < 20; i++) { + data = !!(inl(pmbase + 0xF4) & 1); + if (data || !wait) + break; + udelay(10); + } + return data; } static int amd_rng_data_read(struct hwrng *rng, u32 *data) diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 26a860adcb..0118b9817a 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -66,11 +66,11 @@ static inline void hwrng_cleanup(struct hwrng *rng) rng->cleanup(rng); } -static inline int hwrng_data_present(struct hwrng *rng) +static inline int hwrng_data_present(struct hwrng *rng, int wait) { if (!rng->data_present) return 1; - return rng->data_present(rng); + return rng->data_present(rng, wait); } static inline int hwrng_data_read(struct hwrng *rng, u32 *data) @@ -94,8 +94,7 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf, { u32 data; ssize_t ret = 0; - int i, err = 0; - int data_present; + int err = 0; int bytes_read; while (size) { @@ -107,21 +106,10 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf, err = -ENODEV; goto out; } - if (filp->f_flags & O_NONBLOCK) { - data_present = hwrng_data_present(current_rng); - } else { - /* Some RNG require some time between data_reads to gather - * new entropy. Poll it. - */ - for (i = 0; i < 20; i++) { - data_present = hwrng_data_present(current_rng); - if (data_present) - break; - udelay(10); - } - } + bytes_read = 0; - if (data_present) + if (hwrng_data_present(current_rng, + !(filp->f_flags & O_NONBLOCK))) bytes_read = hwrng_data_read(current_rng, &data); mutex_unlock(&rng_mutex); diff --git a/drivers/char/hw_random/geode-rng.c b/drivers/char/hw_random/geode-rng.c index 8e8658dcd2..fed4ef5569 100644 --- a/drivers/char/hw_random/geode-rng.c +++ b/drivers/char/hw_random/geode-rng.c @@ -28,6 +28,7 @@ #include #include #include +#include #include @@ -61,11 +62,18 @@ static int geode_rng_data_read(struct hwrng *rng, u32 *data) return 4; } -static int geode_rng_data_present(struct hwrng *rng) +static int geode_rng_data_present(struct hwrng *rng, int wait) { void __iomem *mem = (void __iomem *)rng->priv; + int data, i; - return !!(readl(mem + GEODE_RNG_STATUS_REG)); + for (i = 0; i < 20; i++) { + data = !!(readl(mem + GEODE_RNG_STATUS_REG)); + if (data || !wait) + break; + udelay(10); + } + return data; } diff --git a/drivers/char/hw_random/intel-rng.c b/drivers/char/hw_random/intel-rng.c index 753f46052b..5cc651ef75 100644 --- a/drivers/char/hw_random/intel-rng.c +++ b/drivers/char/hw_random/intel-rng.c @@ -29,6 +29,7 @@ #include #include #include +#include #include @@ -162,11 +163,19 @@ static inline u8 hwstatus_set(void __iomem *mem, return hwstatus_get(mem); } -static int intel_rng_data_present(struct hwrng *rng) +static int intel_rng_data_present(struct hwrng *rng, int wait) { void __iomem *mem = (void __iomem *)rng->priv; - - return !!(readb(mem + INTEL_RNG_STATUS) & INTEL_RNG_DATA_PRESENT); + int data, i; + + for (i = 0; i < 20; i++) { + data = !!(readb(mem + INTEL_RNG_STATUS) & + INTEL_RNG_DATA_PRESENT); + if (data || !wait) + break; + udelay(10); + } + return data; } static int intel_rng_data_read(struct hwrng *rng, u32 *data) diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c index 3f35a1c562..7e319951fa 100644 --- a/drivers/char/hw_random/omap-rng.c +++ b/drivers/char/hw_random/omap-rng.c @@ -29,6 +29,7 @@ #include #include #include +#include #include @@ -65,9 +66,17 @@ static void omap_rng_write_reg(int reg, u32 val) } /* REVISIT: Does the status bit really work on 16xx? */ -static int omap_rng_data_present(struct hwrng *rng) +static int omap_rng_data_present(struct hwrng *rng, int wait) { - return omap_rng_read_reg(RNG_STAT_REG) ? 0 : 1; + int data, i; + + for (i = 0; i < 20; i++) { + data = omap_rng_read_reg(RNG_STAT_REG) ? 0 : 1; + if (data || !wait) + break; + udelay(10); + } + return data; } static int omap_rng_data_read(struct hwrng *rng, u32 *data) diff --git a/drivers/char/hw_random/pasemi-rng.c b/drivers/char/hw_random/pasemi-rng.c index fa6040b6c8..621adf25e5 100644 --- a/drivers/char/hw_random/pasemi-rng.c +++ b/drivers/char/hw_random/pasemi-rng.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -44,9 +45,16 @@ static int pasemi_rng_data_present(struct hwrng *rng) { void __iomem *rng_regs = (void __iomem *)rng->priv; - - return (in_le32(rng_regs + SDCRNG_CTL_REG) - & SDCRNG_CTL_FVLD_M) ? 1 : 0; + int data, i; + + for (i = 0; i < 20; i++) { + data = (in_le32(rng_regs + SDCRNG_CTL_REG) + & SDCRNG_CTL_FVLD_M) ? 1 : 0; + if (data || !wait) + break; + udelay(10); + } + return data; } static int pasemi_rng_data_read(struct hwrng *rng, u32 *data) diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c index ec435cb25c..868e39fd42 100644 --- a/drivers/char/hw_random/via-rng.c +++ b/drivers/char/hw_random/via-rng.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -77,10 +78,11 @@ static inline u32 xstore(u32 *addr, u32 edx_in) return eax_out; } -static int via_rng_data_present(struct hwrng *rng) +static int via_rng_data_present(struct hwrng *rng, int wait) { u32 bytes_out; u32 *via_rng_datum = (u32 *)(&rng->priv); + int i; /* We choose the recommended 1-byte-per-instruction RNG rate, * for greater randomness at the expense of speed. Larger @@ -95,12 +97,15 @@ static int via_rng_data_present(struct hwrng *rng) * completes. */ - *via_rng_datum = 0; /* paranoia, not really necessary */ - bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1); - bytes_out &= VIA_XSTORE_CNT_MASK; - if (bytes_out == 0) - return 0; - return 1; + for (i = 0; i < 20; i++) { + *via_rng_datum = 0; /* paranoia, not really necessary */ + bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1); + bytes_out &= VIA_XSTORE_CNT_MASK; + if (bytes_out || !wait) + break; + udelay(10); + } + return bytes_out ? 1 : 0; } static int via_rng_data_read(struct hwrng *rng, u32 *data) diff --git a/include/linux/hw_random.h b/include/linux/hw_random.h index 21ea7610e1..85d11916e9 100644 --- a/include/linux/hw_random.h +++ b/include/linux/hw_random.h @@ -33,7 +33,7 @@ struct hwrng { const char *name; int (*init)(struct hwrng *rng); void (*cleanup)(struct hwrng *rng); - int (*data_present)(struct hwrng *rng); + int (*data_present)(struct hwrng *rng, int wait); int (*data_read)(struct hwrng *rng, u32 *data); unsigned long priv; -- 2.39.5