random: de-duplicate INPUT_POOL constants

We already had the POOL_* constants, so deduplicate the older INPUT_POOL
ones. As well, fold EXTRACT_SIZE into the poolinfo enum, since it's
related.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

drivers/char/random.c

@@ -358,13 +358,6 @@
 
 /* #define ADD_INTERRUPT_BENCH */
 
-/*
- * Configuration information
- */
-#define INPUT_POOL_SHIFT	12
-#define INPUT_POOL_WORDS	(1 << (INPUT_POOL_SHIFT-5))
-#define EXTRACT_SIZE		(BLAKE2S_HASH_SIZE / 2)
-
 /*
  * To allow fractional bits to be tracked, the entropy_count field is
  * denominated in units of 1/8th bits.
@@ -440,7 +433,9 @@ enum poolinfo {
 	POOL_TAP2 = 76,
 	POOL_TAP3 = 51,
 	POOL_TAP4 = 25,
-	POOL_TAP5 = 1
+	POOL_TAP5 = 1,
+
+	EXTRACT_SIZE = BLAKE2S_HASH_SIZE / 2
 };
 
 /*
@@ -503,7 +498,7 @@ MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression");
  *
  **********************************************************************/
 
-static u32 input_pool_data[INPUT_POOL_WORDS] __latent_entropy;
+static u32 input_pool_data[POOL_WORDS] __latent_entropy;
 
 static struct {
 	/* read-only data: */
@@ -1961,7 +1956,7 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
 #include <linux/sysctl.h>
 
 static int min_write_thresh;
-static int max_write_thresh = INPUT_POOL_WORDS * 32;
+static int max_write_thresh = POOL_BITS;
 static int random_min_urandom_seed = 60;
 static char sysctl_bootid[16];
 
@@ -2018,7 +2013,7 @@ static int proc_do_entropy(struct ctl_table *table, int write,
 	return proc_dointvec(&fake_table, write, buffer, lenp, ppos);
 }
 
-static int sysctl_poolsize = INPUT_POOL_WORDS * 32;
+static int sysctl_poolsize = POOL_BITS;
 extern struct ctl_table random_table[];
 struct ctl_table random_table[] = {
 	{