From patchwork Mon Jun 20 12:45:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 1645497 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=zx2c4.com header.i=@zx2c4.com header.a=rsa-sha256 header.s=20210105 header.b=Bd10BB7n; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4LRTsW1mBmz9sFw for ; Mon, 20 Jun 2022 22:46:07 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4LRTsT1qfwz3c7q for ; Mon, 20 Jun 2022 22:46:05 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=zx2c4.com header.i=@zx2c4.com header.a=rsa-sha256 header.s=20210105 header.b=Bd10BB7n; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2604:1380:4601:e00::1; helo=ams.source.kernel.org; envelope-from=srs0=ylcv=w3=zx2c4.com=jason@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=zx2c4.com header.i=@zx2c4.com header.a=rsa-sha256 header.s=20210105 header.b=Bd10BB7n; dkim-atps=neutral Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4LRTs852yQz3bkv for ; Mon, 20 Jun 2022 22:45:48 +1000 (AEST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 84678B8119E; Mon, 20 Jun 2022 12:45:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A902FC3411B; Mon, 20 Jun 2022 12:45:41 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="Bd10BB7n" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1655729140; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2IX05eBKqb4vnKKc2MkH1ad0v14O9oH9GsjOTm7oDzk=; b=Bd10BB7nPPAr46mIN//9Vx0qcZnResZwi0ahy4t9BLnm/DiUy7ga6Ezgsc/3ObcfPcuN1r kbwMaJIoSnEpP7sw5f2xDEBMj1hBx9fTIQnwIoKjIKU7boA5tWYPRiZLn+1zi0kCI3Cox2 YlV8J5L+NoHiD+1M3ZfIRE/AWb32s30= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 956417d4 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Mon, 20 Jun 2022 12:45:39 +0000 (UTC) From: "Jason A. Donenfeld" To: Michael Ellerman , linuxppc-dev@lists.ozlabs.org, LKML , stable , Christophe Leroy Subject: [PATCH v4] powerpc/powernv: wire up rng during setup_arch Date: Mon, 20 Jun 2022 14:45:31 +0200 Message-Id: <20220620124531.78075-1-Jason@zx2c4.com> In-Reply-To: References: MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Jason A. Donenfeld" Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The platform's RNG must be available before random_init() in order to be useful for initial seeding, which in turn means that it needs to be called from setup_arch(), rather than from an init call. Fortunately, each platform already has a setup_arch function pointer, which means we can wire it up that way. Complicating things, however, is that POWER8 systems need some per-cpu state and kmalloc, which isn't available at this stage. So we split things into an early phase and a late phase, with the early phase working well enough to seed the RNG with a spinlock, before later getting fast per-cpu allocations. This commit also removes some noisy log messages that don't add much. Cc: stable@vger.kernel.org Cc: Michael Ellerman Reviewed-by: Christophe Leroy Fixes: a4da0d50b2a0 ("powerpc: Implement arch_get_random_long/int() for powernv") Signed-off-by: Jason A. Donenfeld --- arch/powerpc/platforms/powernv/powernv.h | 2 + arch/powerpc/platforms/powernv/rng.c | 68 ++++++++++++++++++------ arch/powerpc/platforms/powernv/setup.c | 2 + 3 files changed, 55 insertions(+), 17 deletions(-) diff --git a/arch/powerpc/platforms/powernv/powernv.h b/arch/powerpc/platforms/powernv/powernv.h index e297bf4abfcb..fd3f5e1eb10b 100644 --- a/arch/powerpc/platforms/powernv/powernv.h +++ b/arch/powerpc/platforms/powernv/powernv.h @@ -42,4 +42,6 @@ ssize_t memcons_copy(struct memcons *mc, char *to, loff_t pos, size_t count); u32 __init memcons_get_size(struct memcons *mc); struct memcons *__init memcons_init(struct device_node *node, const char *mc_prop_name); +void powernv_rng_init(void); + #endif /* _POWERNV_H */ diff --git a/arch/powerpc/platforms/powernv/rng.c b/arch/powerpc/platforms/powernv/rng.c index e3d44b36ae98..c1beced9c32c 100644 --- a/arch/powerpc/platforms/powernv/rng.c +++ b/arch/powerpc/platforms/powernv/rng.c @@ -17,6 +17,7 @@ #include #include #include +#include "powernv.h" #define DARN_ERR 0xFFFFFFFFFFFFFFFFul @@ -28,6 +29,12 @@ struct powernv_rng { static DEFINE_PER_CPU(struct powernv_rng *, powernv_rng); +static struct { + struct powernv_rng rng; + spinlock_t lock; +} early_state __initdata = { + .lock = __SPIN_LOCK_UNLOCKED(powernv_early_rng) +}; int powernv_hwrng_present(void) { @@ -84,7 +91,7 @@ static int powernv_get_random_darn(unsigned long *v) return 1; } -static int __init initialise_darn(void) +static int __init initialize_darn(void) { unsigned long val; int i; @@ -98,10 +105,18 @@ static int __init initialise_darn(void) return 0; } } + return -EIO; +} - pr_warn("Unable to use DARN for get_random_seed()\n"); +static int __init powernv_get_random_long_early(unsigned long *v) +{ + unsigned long flags; - return -EIO; + spin_lock_irqsave(&early_state.lock, flags); + *v = rng_whiten(&early_state.rng, in_be64(early_state.rng.regs)); + spin_unlock_irqrestore(&early_state.lock, flags); + + return 1; } int powernv_get_random_long(unsigned long *v) @@ -163,32 +178,51 @@ static __init int rng_create(struct device_node *dn) 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) +void __init powernv_rng_init(void) +{ + struct device_node *dn; + struct resource res; + + /* Prefer darn over the rest. */ + if (!initialize_darn()) + return; + + dn = of_find_compatible_node(NULL, NULL, "ibm,power-rng"); + if (!dn) + return; + if (of_address_to_resource(dn, 0, &res)) + return; + early_state.rng.regs_real = (void __iomem *)res.start; + early_state.rng.regs = of_iomap(dn, 0); + if (!early_state.rng.regs) + return; + early_state.rng.mask = in_be64(early_state.rng.regs); + ppc_md.get_random_seed = powernv_get_random_long_early; +} + +static __init int powernv_rng_late_init(void) { struct device_node *dn; - int rc; + + /* + * If this didn't get initialized early on, then we're using darn, + * or this isn't available at all, so return early. + */ + if (ppc_md.get_random_seed != powernv_get_random_long_early) + return 0; + ppc_md.get_random_seed = NULL; 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); + if (rng_create(dn)) continue; - } - /* Create devices for hwrng driver */ of_platform_device_create(dn, NULL, NULL); } - - initialise_darn(); - return 0; } -machine_subsys_initcall(powernv, rng_init); +machine_subsys_initcall(powernv, powernv_rng_late_init); diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c index 824c3ad7a0fa..a5fcb6796b22 100644 --- a/arch/powerpc/platforms/powernv/setup.c +++ b/arch/powerpc/platforms/powernv/setup.c @@ -203,6 +203,8 @@ static void __init pnv_setup_arch(void) pnv_check_guarded_cores(); /* XXX PMCS */ + + powernv_rng_init(); } static void __init pnv_init(void)