From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BEC21C433FE for ; Sun, 7 Nov 2021 08:33:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1CDD61378 for ; Sun, 7 Nov 2021 08:33:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235240AbhKGIf5 (ORCPT ); Sun, 7 Nov 2021 03:35:57 -0500 Received: from smtp04.smtpout.orange.fr ([80.12.242.126]:65038 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235231AbhKGIf4 (ORCPT ); Sun, 7 Nov 2021 03:35:56 -0500 Received: from pop-os.home ([86.243.171.122]) by smtp.orange.fr with ESMTPA id jdbymh7FXsoWhjdbym9Yyc; Sun, 07 Nov 2021 09:33:12 +0100 X-ME-Helo: pop-os.home X-ME-Auth: YWZlNiIxYWMyZDliZWIzOTcwYTEyYzlhMmU3ZiQ1M2U2MzfzZDfyZTMxZTBkMTYyNDBjNDJlZmQ3ZQ== X-ME-Date: Sun, 07 Nov 2021 09:33:12 +0100 X-ME-IP: 86.243.171.122 From: Christophe JAILLET To: nsaenz@kernel.org, jim2101024@gmail.com, f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com, lorenzo.pieralisi@arm.com, robh@kernel.org, kw@linux.com, bhelgaas@google.com Cc: linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET Subject: [PATCH] PCI: brcmstb: Declare a bitmap as a bitmap, not as a plain 'unsigned long' Date: Sun, 7 Nov 2021 09:32:58 +0100 Message-Id: X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The 'used' field of 'struct brcm_msi' is used as a bitmap. So it should be declared as so (i.e. unsigned long *). This fixes an harmless Coverity warning about array vs singleton usage. This bitmap can be BRCM_INT_PCI_MSI_LEGACY_NR or BRCM_INT_PCI_MSI_NR long. So, while at it, document it, should it help someone in the future. Addresses-Coverity: "Out-of-bounds access (ARRAY_VS_SINGLETON)" Suggested-by: Krzysztof Wilczynski Signed-off-by: Christophe JAILLET --- The BUILD_BUG_ON is surely a bit to much of paranoia :) I'm also not really pleased about the layout of the DECLARE_BITMAP. This looks odd, but I couldn't find something nicer :( --- drivers/pci/controller/pcie-brcmstb.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 1fc7bd49a7ad..15d394ac7478 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -266,8 +266,9 @@ struct brcm_msi { struct mutex lock; /* guards the alloc/free operations */ u64 target_addr; int irq; - /* used indicates which MSI interrupts have been alloc'd */ - unsigned long used; + /* Used indicates which MSI interrupts have been alloc'd. 'nr' bellow is + the real size of the bitmap. It depends on the chip. */ + DECLARE_BITMAP (used, BRCM_INT_PCI_MSI_NR); bool legacy; /* Some chips have MSIs in bits [31..24] of a shared register. */ int legacy_shift; @@ -534,7 +535,7 @@ static int brcm_msi_alloc(struct brcm_msi *msi) int hwirq; mutex_lock(&msi->lock); - hwirq = bitmap_find_free_region(&msi->used, msi->nr, 0); + hwirq = bitmap_find_free_region(msi->used, msi->nr, 0); mutex_unlock(&msi->lock); return hwirq; @@ -543,7 +544,7 @@ static int brcm_msi_alloc(struct brcm_msi *msi) static void brcm_msi_free(struct brcm_msi *msi, unsigned long hwirq) { mutex_lock(&msi->lock); - bitmap_release_region(&msi->used, hwirq, 0); + bitmap_release_region(msi->used, hwirq, 0); mutex_unlock(&msi->lock); } @@ -661,6 +662,12 @@ static int brcm_pcie_enable_msi(struct brcm_pcie *pcie) msi->irq = irq; msi->legacy = pcie->hw_rev < BRCM_PCIE_HW_REV_33; + /* + * Sanity check to make sure that the 'used' bitmap in struct brcm_msi + * is large enough. + */ + BUILD_BUG_ON(BRCM_INT_PCI_MSI_LEGACY_NR > BRCM_INT_PCI_MSI_NR); + if (msi->legacy) { msi->intr_base = msi->base + PCIE_INTR2_CPU_BASE; msi->nr = BRCM_INT_PCI_MSI_LEGACY_NR; -- 2.30.2