Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761034AbYGKVUg (ORCPT ); Fri, 11 Jul 2008 17:20:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760425AbYGKVS6 (ORCPT ); Fri, 11 Jul 2008 17:18:58 -0400 Received: from mail.tor.primus.ca ([216.254.136.21]:36953 "EHLO mail-07.primus.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760252AbYGKVSx (ORCPT ); Fri, 11 Jul 2008 17:18:53 -0400 From: Matthew Wilcox To: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Cc: grundler@parisc-linux.org, mingo@elte.hu, tglx@linutronix.de, jgarzik@pobox.com, linux-ide@vger.kernel.org, suresh.b.siddha@intel.com, benh@kernel.crashing.org, jbarnes@virtuousgeek.org, rdunlap@xenotime.net, mtk.manpages@gmail.com, ebiederm@xmission.com, Matthew Wilcox , Matthew Wilcox Subject: [PATCH 3/6] PCI MSI: Add support for multiple messages Date: Fri, 11 Jul 2008 17:16:55 -0400 Message-Id: <1215811018-15270-3-git-send-email-matthew@wil.cx> X-Mailer: git-send-email 1.5.5.4 In-Reply-To: <20080711211559.GV14894@parisc-linux.org> References: <20080711211559.GV14894@parisc-linux.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8249 Lines: 222 Add the new API pci_enable_msi_block() to allow drivers to request multiple MSI and reimplement pci_enable_msi in terms of pci_enable_msi_block. Ensure that the architecture back ends don't have to know about multiple MSI. Signed-off-by: Matthew Wilcox --- arch/powerpc/kernel/msi.c | 4 ++ drivers/pci/msi.c | 69 +++++++++++++++++++++++++++++++------------- drivers/pci/msi.h | 4 -- include/linux/msi.h | 1 + include/linux/pci.h | 6 ++- 5 files changed, 57 insertions(+), 27 deletions(-) diff --git a/arch/powerpc/kernel/msi.c b/arch/powerpc/kernel/msi.c index c62d101..5bc8dda 100644 --- a/arch/powerpc/kernel/msi.c +++ b/arch/powerpc/kernel/msi.c @@ -19,6 +19,10 @@ int arch_msi_check_device(struct pci_dev* dev, int nvec, int type) return -ENOSYS; } + /* PowerPC doesn't support multiple MSI yet */ + if (type == PCI_CAP_ID_MSI && nvec > 1) + return 1; + if (ppc_md.msi_check_device) { pr_debug("msi: Using platform check routine.\n"); return ppc_md.msi_check_device(dev, nvec, type); diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 104f297..853a0f2 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -45,6 +45,13 @@ arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) struct msi_desc *entry; int ret; + /* + * If an architecture wants to support multiple MSI, it needs to + * override arch_setup_msi_irqs() + */ + if (type == PCI_CAP_ID_MSI && nvec > 1) + return 1; + list_for_each_entry(entry, &dev->msi_list, list) { ret = arch_setup_msi_irq(dev, entry); if (ret) @@ -186,6 +193,12 @@ void write_msi_msg(unsigned int irq, struct msi_msg *msg) } else { struct pci_dev *dev = entry->dev; int pos = entry->msi_attrib.pos; + u16 msgctl; + + pci_read_config_word(dev, msi_control_reg(pos), &msgctl); + msgctl &= ~PCI_MSI_FLAGS_QSIZE; + msgctl |= entry->msi_attrib.multiple << 4; + pci_write_config_word(dev, msi_control_reg(pos), msgctl); pci_write_config_dword(dev, msi_lower_address_reg(pos), msg->address_lo); @@ -301,13 +314,15 @@ EXPORT_SYMBOL_GPL(pci_restore_msi_state); /** * msi_capability_init - configure device's MSI capability structure * @dev: pointer to the pci_dev data structure of MSI device function + * @nvec: number of interrupts to allocate * - * Setup the MSI capability structure of device function with a single - * MSI irq, regardless of device function is capable of handling - * multiple messages. A return of zero indicates the successful setup - * of an entry zero with the new MSI irq or non-zero for otherwise. - **/ -static int msi_capability_init(struct pci_dev *dev) + * Setup the MSI capability structure of the device with the requested + * number of interrupts. A return value of zero indicates the successful + * setup of an entry with the new MSI irq. A negative return value indicates + * an error, and a positive return value indicates the number of interrupts + * which could have been allocated. + */ +static int msi_capability_init(struct pci_dev *dev, int nvec) { struct msi_desc *entry; int pos, ret; @@ -351,7 +366,7 @@ static int msi_capability_init(struct pci_dev *dev) list_add_tail(&entry->list, &dev->msi_list); /* Configure MSI capability structure */ - ret = arch_setup_msi_irqs(dev, 1, PCI_CAP_ID_MSI); + ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI); if (ret) { msi_free_irqs(dev); return ret; @@ -503,36 +518,48 @@ static int pci_msi_check_device(struct pci_dev* dev, int nvec, int type) } /** - * pci_enable_msi - configure device's MSI capability structure - * @dev: pointer to the pci_dev data structure of MSI device function + * pci_enable_msi_block - configure device's MSI capability structure + * @dev: device to configure + * @nvec: number of interrupts to configure * - * Setup the MSI capability structure of device function with - * a single MSI irq upon its software driver call to request for - * MSI mode enabled on its hardware device function. A return of zero - * indicates the successful setup of an entry zero with the new MSI - * irq or non-zero for otherwise. - **/ -int pci_enable_msi(struct pci_dev* dev) + * Allocate IRQs for a device with the MSI capability. + * This function returns a negative errno if an error occurs. If it + * is unable to allocate the number of interrupts requested, it returns + * the number of interrupts it might be able to allocate. If it successfully + * allocates at least the number of interrupt vectors requested, it returns + * 0 and updates the @dev's irq member to the new interrupt number. + */ +int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec) { - int status; + int status, pos, maxvec; + u16 msgctl; + + pos = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (!pos) + return -EINVAL; + pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl); + maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1); + if (nvec > maxvec) + return maxvec; - status = pci_msi_check_device(dev, 1, PCI_CAP_ID_MSI); + status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI); if (status) return status; WARN_ON(!!dev->msi_enabled); - /* Check whether driver already requested for MSI-X irqs */ + /* Check whether driver already requested MSI-X irqs */ if (dev->msix_enabled) { printk(KERN_INFO "PCI: %s: Can't enable MSI. " "Device already has MSI-X enabled\n", pci_name(dev)); return -EINVAL; } - status = msi_capability_init(dev); + + status = msi_capability_init(dev, nvec); return status; } -EXPORT_SYMBOL(pci_enable_msi); +EXPORT_SYMBOL(pci_enable_msi_block); void pci_msi_shutdown(struct pci_dev* dev) { diff --git a/drivers/pci/msi.h b/drivers/pci/msi.h index 3898f52..b72e0bd 100644 --- a/drivers/pci/msi.h +++ b/drivers/pci/msi.h @@ -22,12 +22,8 @@ #define msi_disable(control) control &= ~PCI_MSI_FLAGS_ENABLE #define multi_msi_capable(control) \ (1 << ((control & PCI_MSI_FLAGS_QMASK) >> 1)) -#define multi_msi_enable(control, num) \ - control |= (((num >> 1) << 4) & PCI_MSI_FLAGS_QSIZE); #define is_64bit_address(control) (!!(control & PCI_MSI_FLAGS_64BIT)) #define is_mask_bit_support(control) (!!(control & PCI_MSI_FLAGS_MASKBIT)) -#define msi_enable(control, num) multi_msi_enable(control, num); \ - control |= PCI_MSI_FLAGS_ENABLE #define msix_table_offset_reg(base) (base + 0x04) #define msix_pba_offset_reg(base) (base + 0x08) diff --git a/include/linux/msi.h b/include/linux/msi.h index 13a8a1b..70fcebc 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -18,6 +18,7 @@ extern void write_msi_msg(unsigned int irq, struct msi_msg *msg); struct msi_desc { struct { __u8 is_msix : 1; + __u8 multiple: 3; /* log2 number of messages */ __u8 maskbit : 1; /* mask-pending bit supported ? */ __u8 masked : 1; __u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */ diff --git a/include/linux/pci.h b/include/linux/pci.h index d18b1dd..16df5f9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -699,7 +699,7 @@ struct msix_entry { #ifndef CONFIG_PCI_MSI -static inline int pci_enable_msi(struct pci_dev *dev) +static inline int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec) { return -1; } @@ -726,7 +726,7 @@ static inline void msi_remove_pci_irq_vectors(struct pci_dev *dev) static inline void pci_restore_msi_state(struct pci_dev *dev) { } #else -extern int pci_enable_msi(struct pci_dev *dev); +extern int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec); extern void pci_msi_shutdown(struct pci_dev *dev); extern void pci_disable_msi(struct pci_dev *dev); extern int pci_enable_msix(struct pci_dev *dev, @@ -737,6 +737,8 @@ extern void msi_remove_pci_irq_vectors(struct pci_dev *dev); extern void pci_restore_msi_state(struct pci_dev *dev); #endif +#define pci_enable_msi(pdev) pci_enable_msi_block(pdev, 1) + #ifdef CONFIG_HT_IRQ /* The functions a driver should call */ int ht_create_irq(struct pci_dev *dev, int idx); -- 1.5.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/