[v2.6.34-stable 161/165] random: remove rand_initialize_irq()

From: Paul Gortmaker
Date: Wed Aug 15 2012 - 15:57:08 EST


From: Theodore Ts'o <tytso@xxxxxxx>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
If you see a problem with using this for longterm, please comment.
-------------------

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@xxxxxxx>
Signed-off-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
[PG: in .34 the irqdesc.h content is in irq.h instead.]
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
arch/ia64/kernel/irq_ia64.c | 1 -
drivers/char/random.c | 55 ---------------------------------------------
drivers/mfd/ab3100-core.c | 3 ---
include/linux/irq.h | 1 -
include/linux/random.h | 2 --
kernel/irq/manage.c | 17 --------------
6 files changed, 79 deletions(-)

diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c
index 6404793..73a3f5b 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 14f1f23..1644b8e 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -629,43 +629,6 @@ 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.
@@ -1134,24 +1097,6 @@ 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 2a193dc..5b7f5a90 100644
--- a/drivers/mfd/ab3100-core.c
+++ b/drivers/mfd/ab3100-core.c
@@ -890,9 +890,6 @@ static int __init 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/include/linux/irq.h b/include/linux/irq.h
index 707ab12..7c2e4bf 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -174,7 +174,6 @@ struct irq_2_iommu;
*/
struct irq_desc {
unsigned int irq;
- struct timer_rand_state *timer_rand_state;
unsigned int *kstat_irqs;
#ifdef CONFIG_INTR_REMAP
struct irq_2_iommu *irq_2_iommu;
diff --git a/include/linux/random.h b/include/linux/random.h
index 5a376bc..1864957 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -44,8 +44,6 @@ struct rand_pool_info {

#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 46f10b1..9080985 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -652,22 +652,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)

if (desc->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);
- }

/* Oneshot interrupts are not allowed with shared */
if ((new->flags & IRQF_ONESHOT) && (new->flags & IRQF_SHARED))
@@ -1040,7 +1024,6 @@ EXPORT_SYMBOL(free_irq);
*
* IRQF_SHARED Interrupt is shared
* IRQF_DISABLED Disable local interrupts while processing
- * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
* IRQF_TRIGGER_* Specify active edge(s) or level
*
*/
--
1.7.12.rc2

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