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Subject[PATCH] random: use IS_ENABLED(CONFIG_NUMA) instead of ifdefs
Date
Rather than an awkward combination of ifdefs and __maybe_unused, we can
ensure more source gets parsed, regardless of the configuration, by
using IS_ENABLED for the CONFIG_NUMA conditional code. This makes things
cleaner and easier to follow.

I've confirmed that on !CONFIG_NUMA, we don't wind up with excess code
by accident; the generated object file is the same.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
drivers/char/random.c | 30 +++++++++++-------------------
1 file changed, 11 insertions(+), 19 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 9b5eb6cf82ce..54086e9da05b 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -759,7 +759,6 @@ static int credit_entropy_bits_safe(struct entropy_store *r, int nbits)

static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);

-#ifdef CONFIG_NUMA
/*
* Hack to deal with crazy userspace progams when they are all trying
* to access /dev/urandom in parallel. The programs are almost
@@ -767,7 +766,6 @@ static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);
* their brain damage.
*/
static struct crng_state **crng_node_pool __read_mostly;
-#endif

static void invalidate_batched_entropy(void);
static void numa_crng_init(void);
@@ -815,7 +813,7 @@ static bool __init crng_init_try_arch_early(struct crng_state *crng)
return arch_init;
}

-static void __maybe_unused crng_initialize_secondary(struct crng_state *crng)
+static void crng_initialize_secondary(struct crng_state *crng)
{
chacha_init_consts(crng->state);
_get_random_bytes(&crng->state[4], sizeof(__u32) * 12);
@@ -866,7 +864,6 @@ static void crng_finalize_init(struct crng_state *crng)
}
}

-#ifdef CONFIG_NUMA
static void do_numa_crng_init(struct work_struct *work)
{
int i;
@@ -893,29 +890,24 @@ static DECLARE_WORK(numa_crng_init_work, do_numa_crng_init);

static void numa_crng_init(void)
{
- schedule_work(&numa_crng_init_work);
+ if (IS_ENABLED(CONFIG_NUMA))
+ schedule_work(&numa_crng_init_work);
}

static struct crng_state *select_crng(void)
{
- struct crng_state **pool;
- int nid = numa_node_id();
-
- /* pairs with cmpxchg_release() in do_numa_crng_init() */
- pool = READ_ONCE(crng_node_pool);
- if (pool && pool[nid])
- return pool[nid];
+ if (IS_ENABLED(CONFIG_NUMA)) {
+ struct crng_state **pool;
+ int nid = numa_node_id();

- return &primary_crng;
-}
-#else
-static void numa_crng_init(void) {}
+ /* pairs with cmpxchg_release() in do_numa_crng_init() */
+ pool = READ_ONCE(crng_node_pool);
+ if (pool && pool[nid])
+ return pool[nid];
+ }

-static struct crng_state *select_crng(void)
-{
return &primary_crng;
}
-#endif

/*
* crng_fast_load() can be called by code in the interrupt service
--
2.34.1
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