From patchwork Fri Nov 8 13:01:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rasmus Villemoes X-Patchwork-Id: 1191956 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 478kD335PXz9s4Y for ; Sat, 9 Nov 2019 02:08:03 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=rasmusvillemoes.dk Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=rasmusvillemoes.dk header.i=@rasmusvillemoes.dk header.b="Wd8jlhlr"; dkim-atps=neutral Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 478kD26pnPzF5n5 for ; Sat, 9 Nov 2019 02:08:02 +1100 (AEDT) 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=rasmusvillemoes.dk (client-ip=2a00:1450:4864:20::243; helo=mail-lj1-x243.google.com; envelope-from=linux@rasmusvillemoes.dk; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=rasmusvillemoes.dk Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=rasmusvillemoes.dk header.i=@rasmusvillemoes.dk header.b="Wd8jlhlr"; dkim-atps=neutral Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) (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 lists.ozlabs.org (Postfix) with ESMTPS id 478gQv3xq9zF6t8 for ; Sat, 9 Nov 2019 00:02:15 +1100 (AEDT) Received: by mail-lj1-x243.google.com with SMTP id k15so6146406lja.3 for ; Fri, 08 Nov 2019 05:02:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rasmusvillemoes.dk; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=sKXWGKE2hJnX3KS13PAL5ShHJjGXx4HK2hpojfTk/KY=; b=Wd8jlhlrNoR8vSP62k5UaqWRiK+nvDs5ICXuM6pcJ1syXOE5Uy6SdSPnRaqleX/18p xnht3FCO06C6nQXwtjVdIjwIQ3VWoJ2FnTK0saZ2Cq2J6kEz5BOGnM/0MkJq9oJZc2CJ syO7hxAtxdvkTZ4UCegVO6iXF14ExTffno5PM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=sKXWGKE2hJnX3KS13PAL5ShHJjGXx4HK2hpojfTk/KY=; b=UhJmA8v8o5Z1GN7qXWuIbFOwGvTrM4O1wi3H9RTmh9pNOl6fqB+C0711PQx5u7gpMv u065JJjRXzJl4gZkWahlv2WyC5lJckuMIRh4zBNZZ1kSexpucIIb8D2FENIL1XIni0tn JLxrPej1RICFuE6VVYHGJCp/ClrILjn0aVir0/kbRrm8wTq4A3GPFhuEqgIzo9WDA039 fu6WvFQDil0QVtAvd9306lgj4gqo/ZkvaclNd2QHwk5x+2xLTMh9Ukw+g1x2gt8uQNAn C/Wn2MHT39SsmJ6EoE1UTEOvAIKWSlOKUGsw3lDfI/acbW2sUYy9qHRI5nGG1E3KFwis LfhA== X-Gm-Message-State: APjAAAWI2UwhM1rVU2+wM0OODpp4uvKNur5rsw2SHmwR7s9APxxh7i9i N3sHHO7YSo0aOq5cT8C6g3Xw0A== X-Google-Smtp-Source: APXvYqzQt94JN6S91SYODDE7DWrTPiopp9NX09dPKGBykjy6EmJomIkdbCDQ1O1wLfaGhH99Gg0u2A== X-Received: by 2002:a05:651c:209:: with SMTP id y9mr6416091ljn.65.1573218131200; Fri, 08 Nov 2019 05:02:11 -0800 (PST) Received: from prevas-ravi.prevas.se ([81.216.59.226]) by smtp.gmail.com with ESMTPSA id d28sm2454725lfn.33.2019.11.08.05.02.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Nov 2019 05:02:10 -0800 (PST) From: Rasmus Villemoes To: Qiang Zhao , Li Yang , Christophe Leroy Subject: [PATCH v4 34/47] soc: fsl: qe: change return type of cpm_muram_alloc() to s32 Date: Fri, 8 Nov 2019 14:01:10 +0100 Message-Id: <20191108130123.6839-35-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191108130123.6839-1-linux@rasmusvillemoes.dk> References: <20191108130123.6839-1-linux@rasmusvillemoes.dk> 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: Scott Wood , Rasmus Villemoes , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" There are a number of problems with cpm_muram_alloc() and its callers. Most callers assign the return value to some variable and then use IS_ERR_VALUE to check for allocation failure. However, when that variable is not sizeof(long), this leads to warnings - and it is indeed broken to do e.g. u32 foo = cpm_muram_alloc(); if (IS_ERR_VALUE(foo)) on a 64-bit platform, since the condition foo >= (unsigned long)-ENOMEM is tautologically false. There are also callers that ignore the possibility of error, and then there are those that check for error by comparing the return value to 0... One could fix that by changing all callers to store the return value temporarily in an "unsigned long" and test that. However, use of IS_ERR_VALUE() is error-prone and should be restricted to things which are inherently long-sized (stuff in pt_regs etc.). Instead, let's aim for changing to the standard kernel style int foo = cpm_muram_alloc(); if (foo < 0) deal_with_it() some->where = foo; Changing the return type from unsigned long to s32 (aka signed int) doesn't change the value that gets stored into any of the callers' variables except if the caller was storing the result in a u64 _and_ the allocation failed, so in itself this patch should be a no-op. Another problem with cpm_muram_alloc() is that it can certainly validly return 0 - and except if some cpm_muram_alloc_fixed() call interferes, the very first cpm_muram_alloc() call will return just that. But that shows that both ucc_slow_free() and ucc_fast_free() are buggy, since they assume that a value of 0 means "that field was never allocated". We'll later change cpm_muram_free() to accept (and ignore) a negative offset, so callers can use a sentinel of -1 instead of 0 and just unconditionally call cpm_muram_free(). Signed-off-by: Rasmus Villemoes --- drivers/soc/fsl/qe/qe_common.c | 29 ++++++++++++++++------------- include/soc/fsl/qe/qe.h | 16 ++++++++-------- 2 files changed, 24 insertions(+), 21 deletions(-) diff --git a/drivers/soc/fsl/qe/qe_common.c b/drivers/soc/fsl/qe/qe_common.c index 83e85e61669f..50be59678903 100644 --- a/drivers/soc/fsl/qe/qe_common.c +++ b/drivers/soc/fsl/qe/qe_common.c @@ -32,7 +32,7 @@ static phys_addr_t muram_pbase; struct muram_block { struct list_head head; - unsigned long start; + s32 start; int size; }; @@ -110,13 +110,14 @@ int cpm_muram_init(void) * @algo: algorithm for alloc. * @data: data for genalloc's algorithm. * - * This function returns an offset into the muram area. + * This function returns a non-negative offset into the muram area, or + * a negative errno on failure. */ -static unsigned long cpm_muram_alloc_common(unsigned long size, - genpool_algo_t algo, void *data) +static s32 cpm_muram_alloc_common(unsigned long size, + genpool_algo_t algo, void *data) { struct muram_block *entry; - unsigned long start; + s32 start; if (!muram_pool && cpm_muram_init()) goto out2; @@ -137,7 +138,7 @@ static unsigned long cpm_muram_alloc_common(unsigned long size, out1: gen_pool_free(muram_pool, start, size); out2: - return (unsigned long)-ENOMEM; + return -ENOMEM; } /* @@ -145,13 +146,14 @@ static unsigned long cpm_muram_alloc_common(unsigned long size, * @size: number of bytes to allocate * @align: requested alignment, in bytes * - * This function returns an offset into the muram area. + * This function returns a non-negative offset into the muram area, or + * a negative errno on failure. * Use cpm_dpram_addr() to get the virtual address of the area. * Use cpm_muram_free() to free the allocation. */ -unsigned long cpm_muram_alloc(unsigned long size, unsigned long align) +s32 cpm_muram_alloc(unsigned long size, unsigned long align) { - unsigned long start; + s32 start; unsigned long flags; struct genpool_data_align muram_pool_data; @@ -168,7 +170,7 @@ EXPORT_SYMBOL(cpm_muram_alloc); * cpm_muram_free - free a chunk of multi-user ram * @offset: The beginning of the chunk as returned by cpm_muram_alloc(). */ -int cpm_muram_free(unsigned long offset) +int cpm_muram_free(s32 offset) { unsigned long flags; int size; @@ -194,13 +196,14 @@ EXPORT_SYMBOL(cpm_muram_free); * cpm_muram_alloc_fixed - reserve a specific region of multi-user ram * @offset: offset of allocation start address * @size: number of bytes to allocate - * This function returns an offset into the muram area + * This function returns @offset if the area was available, a negative + * errno otherwise. * Use cpm_dpram_addr() to get the virtual address of the area. * Use cpm_muram_free() to free the allocation. */ -unsigned long cpm_muram_alloc_fixed(unsigned long offset, unsigned long size) +s32 cpm_muram_alloc_fixed(unsigned long offset, unsigned long size) { - unsigned long start; + long start; unsigned long flags; struct genpool_data_fixed muram_pool_data_fixed; diff --git a/include/soc/fsl/qe/qe.h b/include/soc/fsl/qe/qe.h index 521fa3a177e0..f589ae3f1216 100644 --- a/include/soc/fsl/qe/qe.h +++ b/include/soc/fsl/qe/qe.h @@ -98,26 +98,26 @@ static inline void qe_reset(void) {} int cpm_muram_init(void); #if defined(CONFIG_CPM) || defined(CONFIG_QUICC_ENGINE) -unsigned long cpm_muram_alloc(unsigned long size, unsigned long align); -int cpm_muram_free(unsigned long offset); -unsigned long cpm_muram_alloc_fixed(unsigned long offset, unsigned long size); +s32 cpm_muram_alloc(unsigned long size, unsigned long align); +int cpm_muram_free(s32 offset); +s32 cpm_muram_alloc_fixed(unsigned long offset, unsigned long size); void __iomem *cpm_muram_addr(unsigned long offset); unsigned long cpm_muram_offset(void __iomem *addr); dma_addr_t cpm_muram_dma(void __iomem *addr); #else -static inline unsigned long cpm_muram_alloc(unsigned long size, - unsigned long align) +static inline s32 cpm_muram_alloc(unsigned long size, + unsigned long align) { return -ENOSYS; } -static inline int cpm_muram_free(unsigned long offset) +static inline int cpm_muram_free(s32 offset) { return -ENOSYS; } -static inline unsigned long cpm_muram_alloc_fixed(unsigned long offset, - unsigned long size) +static inline s32 cpm_muram_alloc_fixed(unsigned long offset, + unsigned long size) { return -ENOSYS; }