random: remove rand_initialize_irq()

commit c5857ccf293968348e5eb4ebedc68074de3dcda6 upstream.

With the new interrupt sampling system, we are no longer using the
timer_rand_state structure in the irq descriptor, so we can stop
initializing it now.

[ Merged in fixes from Sedat to find some last missing references to
  rand_initialize_irq() ]

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

7 files changed, 0 insertions, 81 deletions

diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c
index 782c3a357f2..3540c5e8042 100644
--- a/arch/ia64/kernel/irq_ia64.c
+++ b/arch/ia64/kernel/irq_ia64.c
@@ -23,7 +23,6 @@
 #include <linux/ioport.h>
 #include <linux/kernel_stat.h>
 #include <linux/ptrace.h>
-#include <linux/random.h>       /* for rand_initialize_irq() */
 #include <linux/signal.h>
 #include <linux/smp.h>
 #include <linux/threads.h>
diff --git a/drivers/char/random.c b/drivers/char/random.c
index e70701ec3b0..5df09b014ea 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -634,43 +634,6 @@ struct timer_rand_state {
         unsigned dont_count_entropy:1;
 };
 
-#ifndef CONFIG_GENERIC_HARDIRQS
-
-static struct timer_rand_state *irq_timer_state[NR_IRQS];
-
-static struct timer_rand_state *get_timer_rand_state(unsigned int irq)
-{
-        return irq_timer_state[irq];
-}
-
-static void set_timer_rand_state(unsigned int irq,
-                                 struct timer_rand_state *state)
-{
-        irq_timer_state[irq] = state;
-}
-
-#else
-
-static struct timer_rand_state *get_timer_rand_state(unsigned int irq)
-{
-        struct irq_desc *desc;
-
-        desc = irq_to_desc(irq);
-
-        return desc->timer_rand_state;
-}
-
-static void set_timer_rand_state(unsigned int irq,
-                                 struct timer_rand_state *state)
-{
-        struct irq_desc *desc;
-
-        desc = irq_to_desc(irq);
-
-        desc->timer_rand_state = state;
-}
-#endif
-
 /*
  * Add device- or boot-specific data to the input and nonblocking
  * pools to help initialize them to unique values.
@@ -1133,24 +1096,6 @@ static int rand_initialize(void)
 }
 module_init(rand_initialize);
 
-void rand_initialize_irq(int irq)
-{
-        struct timer_rand_state *state;
-
-        state = get_timer_rand_state(irq);
-
-        if (state)
-                return;
-
-        /*
-         * If kzalloc returns null, we just won't use that entropy
-         * source.
-         */
-        state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
-        if (state)
-                set_timer_rand_state(irq, state);
-}
-
 #ifdef CONFIG_BLOCK
 void rand_initialize_disk(struct gendisk *disk)
 {
diff --git a/drivers/mfd/ab3100-core.c b/drivers/mfd/ab3100-core.c
index c0befd3ad98..ccd81b1540a 100644
--- a/drivers/mfd/ab3100-core.c
+++ b/drivers/mfd/ab3100-core.c
@@ -936,9 +936,6 @@ static int __devinit ab3100_probe(struct i2c_client *client,
 
         err = request_threaded_irq(client->irq, NULL, ab3100_irq_handler,
                                 IRQF_ONESHOT, "ab3100-core", ab3100);
-        /* This real unpredictable IRQ is of course sampled for entropy */
-        rand_initialize_irq(client->irq);
-
         if (err)
                 goto exit_no_irq;
 
diff --git a/drivers/mfd/ab3550-core.c b/drivers/mfd/ab3550-core.c
index 3d7dce671b9..d69dc4bf8bb 100644
--- a/drivers/mfd/ab3550-core.c
+++ b/drivers/mfd/ab3550-core.c
@@ -1309,8 +1309,6 @@ static int __init ab3550_probe(struct i2c_client *client,
 
         err = request_threaded_irq(client->irq, NULL, ab3550_irq_handler,
                 IRQF_ONESHOT, "ab3550-core", ab);
-        /* This real unpredictable IRQ is of course sampled for entropy */
-        rand_initialize_irq(client->irq);
 
         if (err)
                 goto exit_no_irq;
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 2d921b35212..d0a3100b406 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -38,7 +38,6 @@ struct timer_rand_state;
  */
 struct irq_desc {
         struct irq_data         irq_data;
-        struct timer_rand_state *timer_rand_state;
         unsigned int __percpu   *kstat_irqs;
         irq_flow_handler_t      handle_irq;
 #ifdef CONFIG_IRQ_PREFLOW_FASTEOI
diff --git a/include/linux/random.h b/include/linux/random.h
index 29e217a7e6d..ac621ce886c 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -48,8 +48,6 @@ struct rnd_state {
 
 #ifdef __KERNEL__
 
-extern void rand_initialize_irq(int irq);
-
 extern void add_device_randomness(const void *, unsigned int);
 extern void add_input_randomness(unsigned int type, unsigned int code,
                                  unsigned int value);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index df8136fff8c..fa4a70ee272 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -886,22 +886,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 
         if (desc->irq_data.chip == &no_irq_chip)
                 return -ENOSYS;
-        /*
-         * Some drivers like serial.c use request_irq() heavily,
-         * so we have to be careful not to interfere with a
-         * running system.
-         */
-        if (new->flags & IRQF_SAMPLE_RANDOM) {
-                /*
-                 * This function might sleep, we want to call it first,
-                 * outside of the atomic block.
-                 * Yes, this might clear the entropy pool if the wrong
-                 * driver is attempted to be loaded, without actually
-                 * installing a new handler, but is this really a problem,
-                 * only the sysadmin is able to do this.
-                 */
-                rand_initialize_irq(irq);
-        }
 
         /*
          * Check whether the interrupt nests into another interrupt
@@ -1325,7 +1309,6 @@ EXPORT_SYMBOL(free_irq);
  *      Flags:
  *
  *      IRQF_SHARED             Interrupt is shared
- *      IRQF_SAMPLE_RANDOM      The interrupt can be used for entropy
  *      IRQF_TRIGGER_*          Specify active edge(s) or level
  *
  */