From 8e149e09f91098fd72bf9ac5b4a77a693abf721e Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 23 Apr 2008 14:56:30 -0700 Subject: [PATCH] pci/irq: restore mask_bits in msi shutdown -v3 [PATCH 1/2] pci/irq: restore mask_bits in msi shutdown -v3 Yinghai found that kexec'ing a RHEL 5.1 kernel with 2.6.25-rc3+ kernels prevents his NIC from working. He bisected to | commit 89d694b9dbe769ca1004e01db0ca43964806a611 | Author: Thomas Gleixner | Date: Mon Feb 18 18:25:17 2008 +0100 | | genirq: do not leave interupts enabled on free_irq | | The default_disable() function was changed in commit: | | 76d2160147f43f982dfe881404cfde9fd0a9da21 | genirq: do not mask interrupts by default | For MSI, default_shutdown will call mask_bit for msi device. All mask bits will left disabled after free_irq. Then in the kexec case, the next kernel can only use msi_enable bit, so all device's MSI can not be used. So lets to restore the mask bit to its pci reset defined value (enabled) when we disable the kernels use of msi to be a little friendlier to kexec'd kernels. Extend msi_set_mask_bit to msi_set_mask_bits to take mask, so we can fully restore that to 0x00 instead of 0xfe. Signed-off-by: Yinghai Lu Signed-off-by: Jesse Barnes --- drivers/pci/msi.c | 21 ++++++++++++++------- include/linux/msi.h | 1 + 2 files changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 26938da8f438..e3a05cc9a595 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -123,7 +123,7 @@ static void msix_flush_writes(unsigned int irq) } } -static void msi_set_mask_bit(unsigned int irq, int flag) +static void msi_set_mask_bits(unsigned int irq, u32 mask, u32 flag) { struct msi_desc *entry; @@ -137,8 +137,8 @@ static void msi_set_mask_bit(unsigned int irq, int flag) pos = (long)entry->mask_base; pci_read_config_dword(entry->dev, pos, &mask_bits); - mask_bits &= ~(1); - mask_bits |= flag; + mask_bits &= ~(mask); + mask_bits |= flag & mask; pci_write_config_dword(entry->dev, pos, mask_bits); } else { msi_set_enable(entry->dev, !flag); @@ -241,13 +241,13 @@ void write_msi_msg(unsigned int irq, struct msi_msg *msg) void mask_msi_irq(unsigned int irq) { - msi_set_mask_bit(irq, 1); + msi_set_mask_bits(irq, 1, 1); msix_flush_writes(irq); } void unmask_msi_irq(unsigned int irq) { - msi_set_mask_bit(irq, 0); + msi_set_mask_bits(irq, 1, 0); msix_flush_writes(irq); } @@ -291,7 +291,8 @@ static void __pci_restore_msi_state(struct pci_dev *dev) msi_set_enable(dev, 0); write_msi_msg(dev->irq, &entry->msg); if (entry->msi_attrib.maskbit) - msi_set_mask_bit(dev->irq, entry->msi_attrib.masked); + msi_set_mask_bits(dev->irq, entry->msi_attrib.maskbits_mask, + entry->msi_attrib.masked); pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control); control &= ~(PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE); @@ -315,7 +316,7 @@ static void __pci_restore_msix_state(struct pci_dev *dev) list_for_each_entry(entry, &dev->msi_list, list) { write_msi_msg(entry->irq, &entry->msg); - msi_set_mask_bit(entry->irq, entry->msi_attrib.masked); + msi_set_mask_bits(entry->irq, 1, entry->msi_attrib.masked); } BUG_ON(list_empty(&dev->msi_list)); @@ -382,6 +383,7 @@ static int msi_capability_init(struct pci_dev *dev) pci_write_config_dword(dev, msi_mask_bits_reg(pos, is_64bit_address(control)), maskbits); + entry->msi_attrib.maskbits_mask = temp; } list_add_tail(&entry->list, &dev->msi_list); @@ -583,6 +585,11 @@ void pci_disable_msi(struct pci_dev* dev) BUG_ON(list_empty(&dev->msi_list)); entry = list_entry(dev->msi_list.next, struct msi_desc, list); + /* Return the the pci reset with msi irqs unmasked */ + if (entry->msi_attrib.maskbit) { + u32 mask = entry->msi_attrib.maskbits_mask; + msi_set_mask_bits(dev->irq, mask, ~mask); + } if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) { return; } diff --git a/include/linux/msi.h b/include/linux/msi.h index 94bb46d82efd..8f2939227207 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -22,6 +22,7 @@ struct msi_desc { __u8 masked : 1; __u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */ __u8 pos; /* Location of the msi capability */ + __u32 maskbits_mask; /* mask bits mask */ __u16 entry_nr; /* specific enabled entry */ unsigned default_irq; /* default pre-assigned irq */ }msi_attrib; -- GitLab