From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/arch/s390/crypto/arch_random.c | 111 -------------------------------------------------------
1 files changed, 1 insertions(+), 110 deletions(-)
diff --git a/kernel/arch/s390/crypto/arch_random.c b/kernel/arch/s390/crypto/arch_random.c
index 4cbb4b6..1f2d409 100644
--- a/kernel/arch/s390/crypto/arch_random.c
+++ b/kernel/arch/s390/crypto/arch_random.c
@@ -2,126 +2,17 @@
/*
* s390 arch random implementation.
*
- * Copyright IBM Corp. 2017, 2018
+ * Copyright IBM Corp. 2017, 2020
* Author(s): Harald Freudenberger
- *
- * The s390_arch_random_generate() function may be called from random.c
- * in interrupt context. So this implementation does the best to be very
- * fast. There is a buffer of random data which is asynchronously checked
- * and filled by a workqueue thread.
- * If there are enough bytes in the buffer the s390_arch_random_generate()
- * just delivers these bytes. Otherwise false is returned until the
- * worker thread refills the buffer.
- * The worker fills the rng buffer by pulling fresh entropy from the
- * high quality (but slow) true hardware random generator. This entropy
- * is then spread over the buffer with an pseudo random generator PRNG.
- * As the arch_get_random_seed_long() fetches 8 bytes and the calling
- * function add_interrupt_randomness() counts this as 1 bit entropy the
- * distribution needs to make sure there is in fact 1 bit entropy contained
- * in 8 bytes of the buffer. The current values pull 32 byte entropy
- * and scatter this into a 2048 byte buffer. So 8 byte in the buffer
- * will contain 1 bit of entropy.
- * The worker thread is rescheduled based on the charge level of the
- * buffer but at least with 500 ms delay to avoid too much CPU consumption.
- * So the max. amount of rng data delivered via arch_get_random_seed is
- * limited to 4k bytes per second.
*/
#include <linux/kernel.h>
#include <linux/atomic.h>
#include <linux/random.h>
-#include <linux/slab.h>
#include <linux/static_key.h>
-#include <linux/workqueue.h>
#include <asm/cpacf.h>
DEFINE_STATIC_KEY_FALSE(s390_arch_random_available);
atomic64_t s390_arch_random_counter = ATOMIC64_INIT(0);
EXPORT_SYMBOL(s390_arch_random_counter);
-
-#define ARCH_REFILL_TICKS (HZ/2)
-#define ARCH_PRNG_SEED_SIZE 32
-#define ARCH_RNG_BUF_SIZE 2048
-
-static DEFINE_SPINLOCK(arch_rng_lock);
-static u8 *arch_rng_buf;
-static unsigned int arch_rng_buf_idx;
-
-static void arch_rng_refill_buffer(struct work_struct *);
-static DECLARE_DELAYED_WORK(arch_rng_work, arch_rng_refill_buffer);
-
-bool s390_arch_random_generate(u8 *buf, unsigned int nbytes)
-{
- /* max hunk is ARCH_RNG_BUF_SIZE */
- if (nbytes > ARCH_RNG_BUF_SIZE)
- return false;
-
- /* lock rng buffer */
- if (!spin_trylock(&arch_rng_lock))
- return false;
-
- /* try to resolve the requested amount of bytes from the buffer */
- arch_rng_buf_idx -= nbytes;
- if (arch_rng_buf_idx < ARCH_RNG_BUF_SIZE) {
- memcpy(buf, arch_rng_buf + arch_rng_buf_idx, nbytes);
- atomic64_add(nbytes, &s390_arch_random_counter);
- spin_unlock(&arch_rng_lock);
- return true;
- }
-
- /* not enough bytes in rng buffer, refill is done asynchronously */
- spin_unlock(&arch_rng_lock);
-
- return false;
-}
-EXPORT_SYMBOL(s390_arch_random_generate);
-
-static void arch_rng_refill_buffer(struct work_struct *unused)
-{
- unsigned int delay = ARCH_REFILL_TICKS;
-
- spin_lock(&arch_rng_lock);
- if (arch_rng_buf_idx > ARCH_RNG_BUF_SIZE) {
- /* buffer is exhausted and needs refill */
- u8 seed[ARCH_PRNG_SEED_SIZE];
- u8 prng_wa[240];
- /* fetch ARCH_PRNG_SEED_SIZE bytes of entropy */
- cpacf_trng(NULL, 0, seed, sizeof(seed));
- /* blow this entropy up to ARCH_RNG_BUF_SIZE with PRNG */
- memset(prng_wa, 0, sizeof(prng_wa));
- cpacf_prno(CPACF_PRNO_SHA512_DRNG_SEED,
- &prng_wa, NULL, 0, seed, sizeof(seed));
- cpacf_prno(CPACF_PRNO_SHA512_DRNG_GEN,
- &prng_wa, arch_rng_buf, ARCH_RNG_BUF_SIZE, NULL, 0);
- arch_rng_buf_idx = ARCH_RNG_BUF_SIZE;
- }
- delay += (ARCH_REFILL_TICKS * arch_rng_buf_idx) / ARCH_RNG_BUF_SIZE;
- spin_unlock(&arch_rng_lock);
-
- /* kick next check */
- queue_delayed_work(system_long_wq, &arch_rng_work, delay);
-}
-
-static int __init s390_arch_random_init(void)
-{
- /* all the needed PRNO subfunctions available ? */
- if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG) &&
- cpacf_query_func(CPACF_PRNO, CPACF_PRNO_SHA512_DRNG_GEN)) {
-
- /* alloc arch random working buffer */
- arch_rng_buf = kmalloc(ARCH_RNG_BUF_SIZE, GFP_KERNEL);
- if (!arch_rng_buf)
- return -ENOMEM;
-
- /* kick worker queue job to fill the random buffer */
- queue_delayed_work(system_long_wq,
- &arch_rng_work, ARCH_REFILL_TICKS);
-
- /* enable arch random to the outside world */
- static_branch_enable(&s390_arch_random_available);
- }
-
- return 0;
-}
-arch_initcall(s390_arch_random_init);
--
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