From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 08:20:59 +0000
Subject: [PATCH] kernel_5.10 no rt
---
kernel/arch/powerpc/platforms/powernv/rng.c | 80 ++++++++++++++++++++++++++-------------
1 files changed, 53 insertions(+), 27 deletions(-)
diff --git a/kernel/arch/powerpc/platforms/powernv/rng.c b/kernel/arch/powerpc/platforms/powernv/rng.c
index 718f50e..a99033c 100644
--- a/kernel/arch/powerpc/platforms/powernv/rng.c
+++ b/kernel/arch/powerpc/platforms/powernv/rng.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2013, Michael Ellerman, IBM Corporation.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) "powernv-rng: " fmt
@@ -21,6 +17,7 @@
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/smp.h>
+#include "powernv.h"
#define DARN_ERR 0xFFFFFFFFFFFFFFFFul
@@ -31,7 +28,6 @@
};
static DEFINE_PER_CPU(struct powernv_rng *, powernv_rng);
-
int powernv_hwrng_present(void)
{
@@ -47,7 +43,11 @@
unsigned long parity;
/* Calculate the parity of the value */
- asm ("popcntd %0,%1" : "=r" (parity) : "r" (val));
+ asm (".machine push; \
+ .machine power7; \
+ popcntd %0,%1; \
+ .machine pop;"
+ : "=r" (parity) : "r" (val));
/* xor our value with the previous mask */
val ^= rng->mask;
@@ -63,13 +63,15 @@
struct powernv_rng *rng;
rng = raw_cpu_read(powernv_rng);
+ if (!rng)
+ return 0;
*v = rng_whiten(rng, __raw_rm_readq(rng->regs_real));
return 1;
}
-int powernv_get_random_darn(unsigned long *v)
+static int powernv_get_random_darn(unsigned long *v)
{
unsigned long val;
@@ -98,9 +100,6 @@
return 0;
}
}
-
- pr_warn("Unable to use DARN for get_random_seed()\n");
-
return -EIO;
}
@@ -163,32 +162,59 @@
rng_init_per_cpu(rng, dn);
- pr_info_once("Registering arch random hook.\n");
-
ppc_md.get_random_seed = powernv_get_random_long;
return 0;
}
-static __init int rng_init(void)
+static int __init pnv_get_random_long_early(unsigned long *v)
{
struct device_node *dn;
- int rc;
- for_each_compatible_node(dn, NULL, "ibm,power-rng") {
- rc = rng_create(dn);
- if (rc) {
- pr_err("Failed creating rng for %pOF (%d).\n",
- dn, rc);
- continue;
- }
+ if (!slab_is_available())
+ return 0;
- /* Create devices for hwrng driver */
- of_platform_device_create(dn, NULL, NULL);
+ if (cmpxchg(&ppc_md.get_random_seed, pnv_get_random_long_early,
+ NULL) != pnv_get_random_long_early)
+ return 0;
+
+ for_each_compatible_node(dn, NULL, "ibm,power-rng")
+ rng_create(dn);
+
+ if (!ppc_md.get_random_seed)
+ return 0;
+ return ppc_md.get_random_seed(v);
+}
+
+void __init pnv_rng_init(void)
+{
+ struct device_node *dn;
+
+ /* Prefer darn over the rest. */
+ if (!initialise_darn())
+ return;
+
+ dn = of_find_compatible_node(NULL, NULL, "ibm,power-rng");
+ if (dn)
+ ppc_md.get_random_seed = pnv_get_random_long_early;
+
+ of_node_put(dn);
+}
+
+static int __init pnv_rng_late_init(void)
+{
+ struct device_node *dn;
+ unsigned long v;
+
+ /* In case it wasn't called during init for some other reason. */
+ if (ppc_md.get_random_seed == pnv_get_random_long_early)
+ pnv_get_random_long_early(&v);
+
+ if (ppc_md.get_random_seed == powernv_get_random_long) {
+ for_each_compatible_node(dn, NULL, "ibm,power-rng")
+ of_platform_device_create(dn, NULL, NULL);
}
-
- initialise_darn();
return 0;
}
-machine_subsys_initcall(powernv, rng_init);
+machine_subsys_initcall(powernv, pnv_rng_late_init);
--
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