From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.domeneshop.no ([194.63.252.54]:55401 "EHLO smtp.domeneshop.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755309Ab3K2N6I (ORCPT ); Fri, 29 Nov 2013 08:58:08 -0500 From: =?UTF-8?q?Bj=C3=B8rn=20Erik=20Nilsen?= To: jg1.han@samsung.com Cc: marex@denx.de, pratyush.anand@gmail.com, bhelgaas@google.com, linux-pci@vger.kernel.org, kishon@ti.com, Mohit.KUMAR@st.com, ajay.khandelwal@st.com, tharvey@gateworks.com, Eric.Nelson@boundarydevices.com, troy.kisky@boundarydevices.com, =?UTF-8?q?Bj=C3=B8rn=20Erik=20Nilsen?= Subject: [PATCH v5 1/2] PCI: designware: Fix crash in dw_msi_teardown_irq Date: Fri, 29 Nov 2013 14:35:24 +0100 Message-Id: <1385732125-28630-2-git-send-email-ben@datarespons.no> In-Reply-To: <1385732125-28630-1-git-send-email-ben@datarespons.no> References: <003101ceecd5$dd4e79e0$97eb6da0$%han@samsung.com> <1385732125-28630-1-git-send-email-ben@datarespons.no> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-pci-owner@vger.kernel.org List-ID: "PCI: designware: Add irq_create_mapping()" resulted in pre-allocated irq descs. Problem was that in assign_irq() these descs were explicitly allocated and hence also freed, resulting in a crash. We also need to clear the entire irq range in teardown. With this commit the teardown basically does exactly the opposite of what was done in setup. Signed-off-by: Bjørn Erik Nilsen --- drivers/pci/host/pcie-designware.c | 49 ++++++++++++++++++++++++++++---------- 1 file changed, 37 insertions(+), 12 deletions(-) diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c index e33b68b..61345a1 100644 --- a/drivers/pci/host/pcie-designware.c +++ b/drivers/pci/host/pcie-designware.c @@ -209,6 +209,25 @@ static int find_valid_pos0(struct pcie_port *pp, int msgvec, int pos, int *pos0) return 0; } +static void clear_irq_range(struct pcie_port *pp, unsigned int irq_base, + unsigned int nvec, unsigned int pos) +{ + unsigned int i, res, bit, val; + + i = 0; + while (i < nvec) { + irq_set_msi_desc_off(irq_base, i, NULL); + clear_bit(pos + i, pp->msi_irq_in_use); + /* Disable corresponding interrupt on MSI interrupt controller */ + res = ((pos + i) / 32) * 12; + bit = (pos + i) % 32; + dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val); + val &= ~(1 << bit); + dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val); + ++i; + } +} + static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos) { int res, bit, irq, pos0, pos1, i; @@ -242,11 +261,20 @@ static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos) if (!irq) goto no_valid_irq; + /* + * irq_create_mapping (called from dw_pcie_host_init) pre-allocates + * descs so there is no need to allocate descs here. We can therefore + * assume that if irq_find_mapping above returns non-zero, then the + * descs are also successfully allocated. + */ + i = 0; while (i < no_irqs) { + if (irq_set_msi_desc_off(irq, i, desc) != 0) { + clear_irq_range(pp, irq, i, pos0); + goto no_valid_irq; + } set_bit(pos0 + i, pp->msi_irq_in_use); - irq_alloc_descs((irq + i), (irq + i), 1, 0); - irq_set_msi_desc(irq + i, desc); /*Enable corresponding interrupt in MSI interrupt controller */ res = ((pos0 + i) / 32) * 12; bit = (pos0 + i) % 32; @@ -266,7 +294,7 @@ no_valid_irq: static void clear_irq(unsigned int irq) { - int res, bit, val, pos; + unsigned int pos, nvec; struct irq_desc *desc; struct msi_desc *msi; struct pcie_port *pp; @@ -281,18 +309,15 @@ static void clear_irq(unsigned int irq) return; } + /* undo what was done in assign_irq */ pos = data->hwirq; + nvec = 1 << msi->msi_attrib.multiple; - irq_free_desc(irq); - - clear_bit(pos, pp->msi_irq_in_use); + clear_irq_range(pp, irq, nvec, pos); - /* Disable corresponding interrupt on MSI interrupt controller */ - res = (pos / 32) * 12; - bit = pos % 32; - dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val); - val &= ~(1 << bit); - dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val); + /* all irqs cleared; reset attributes */ + msi->irq = 0; + msi->msi_attrib.multiple = 0; } static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev, -- 1.8.4.4