From 386ced19e9a348e8131d20f009e692fa8fcc4568 Mon Sep 17 00:00:00 2001 From: Vivian Wang Date: Thu, 29 Jan 2026 09:56:06 +0800 Subject: [PATCH] PCI/MSI: Convert the boolean no_64bit_msi flag to a DMA address mask Some PCI devices have PCI_MSI_FLAGS_64BIT in the MSI capability, but implement less than 64 address bits. This breaks on platforms where such a device is assigned an MSI address higher than what's supported. Currently, no_64bit_msi bit is set for these devices, meaning that only 32-bit MSI addresses are allowed for them. However, on some platforms the MSI doorbell address is above the 32-bit limit but within the addressable range of the device. As a first step to enable MSI on those combinations of devices and platforms, convert the boolean no_64bit_msi flag to a DMA mask and fixup the affected usage sites: - no_64bit_msi = 1 -> msi_addr_mask = DMA_BIT_MASK(32) - no_64bit_msi = 0 -> msi_addr_mask = DMA_BIT_MASK(64) - if (no_64bit_msi) -> if (msi_addr_mask < DMA_BIT_MASK(64)) Since no values other than DMA_BIT_MASK(32) and DMA_BIT_MASK(64) are used, this is functionally equivalent. This prepares for changing the binary decision between 32 and 64 bit to a DMA mask based decision which allows to support systems which have a DMA address space less than 64bit but a MSI doorbell address above the 32-bit limit. [ tglx: Massaged changelog ] Signed-off-by: Vivian Wang Signed-off-by: Thomas Gleixner Reviewed-by: Brett Creeley # ionic Reviewed-by: Thomas Gleixner Acked-by: Takashi Iwai # sound Link: https://patch.msgid.link/20260129-pci-msi-addr-mask-v4-1-70da998f2750@iscas.ac.cn --- arch/powerpc/platforms/powernv/pci-ioda.c | 2 +- arch/powerpc/platforms/pseries/msi.c | 4 ++-- drivers/gpu/drm/radeon/radeon_irq_kms.c | 2 +- drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c | 2 +- drivers/pci/msi/msi.c | 2 +- drivers/pci/msi/pcidev_msi.c | 2 +- drivers/pci/probe.c | 7 +++++++ include/linux/pci.h | 8 +++++++- sound/hda/controllers/intel.c | 2 +- 9 files changed, 22 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index b0c1d9d16fb52..1c78fdfb7b036 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -1666,7 +1666,7 @@ static int __pnv_pci_ioda_msi_setup(struct pnv_phb *phb, struct pci_dev *dev, return -ENXIO; /* Force 32-bit MSI on some broken devices */ - if (dev->no_64bit_msi) + if (dev->msi_addr_mask < DMA_BIT_MASK(64)) is_64 = 0; /* Assign XIVE to PE */ diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c index a82aaa786e9e0..7473c7ca1db07 100644 --- a/arch/powerpc/platforms/pseries/msi.c +++ b/arch/powerpc/platforms/pseries/msi.c @@ -383,7 +383,7 @@ static int rtas_prepare_msi_irqs(struct pci_dev *pdev, int nvec_in, int type, */ again: if (type == PCI_CAP_ID_MSI) { - if (pdev->no_64bit_msi) { + if (pdev->msi_addr_mask < DMA_BIT_MASK(64)) { rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec); if (rc < 0) { /* @@ -409,7 +409,7 @@ again: if (use_32bit_msi_hack && rc > 0) rtas_hack_32bit_msi_gen2(pdev); } else { - if (pdev->no_64bit_msi) + if (pdev->msi_addr_mask < DMA_BIT_MASK(64)) rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSIX_FN, nvec); else rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c index 9961251b44ba0..d550554a6f3f2 100644 --- a/drivers/gpu/drm/radeon/radeon_irq_kms.c +++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c @@ -252,7 +252,7 @@ static bool radeon_msi_ok(struct radeon_device *rdev) */ if (rdev->family < CHIP_BONAIRE) { dev_info(rdev->dev, "radeon: MSI limited to 32-bit\n"); - rdev->pdev->no_64bit_msi = 1; + rdev->pdev->msi_addr_mask = DMA_BIT_MASK(32); } /* force MSI on */ diff --git a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c index 70d86c5f52fbb..0671deae9a286 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c +++ b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c @@ -331,7 +331,7 @@ static int ionic_probe(struct pci_dev *pdev, const struct pci_device_id *ent) #ifdef CONFIG_PPC64 /* Ensure MSI/MSI-X interrupts lie within addressable physical memory */ - pdev->no_64bit_msi = 1; + pdev->msi_addr_mask = DMA_BIT_MASK(32); #endif err = ionic_setup_one(ionic); diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c index e010ecd9f90dd..fb9a42bec62eb 100644 --- a/drivers/pci/msi/msi.c +++ b/drivers/pci/msi/msi.c @@ -322,7 +322,7 @@ static int msi_verify_entries(struct pci_dev *dev) { struct msi_desc *entry; - if (!dev->no_64bit_msi) + if (dev->msi_addr_mask == DMA_BIT_MASK(64)) return 0; msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) { diff --git a/drivers/pci/msi/pcidev_msi.c b/drivers/pci/msi/pcidev_msi.c index 5520aff53b567..0b03468130926 100644 --- a/drivers/pci/msi/pcidev_msi.c +++ b/drivers/pci/msi/pcidev_msi.c @@ -24,7 +24,7 @@ void pci_msi_init(struct pci_dev *dev) } if (!(ctrl & PCI_MSI_FLAGS_64BIT)) - dev->no_64bit_msi = 1; + dev->msi_addr_mask = DMA_BIT_MASK(32); } void pci_msix_init(struct pci_dev *dev) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 41183aed8f5d9..a2bff57176a37 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2047,6 +2047,13 @@ int pci_setup_device(struct pci_dev *dev) */ dev->dma_mask = 0xffffffff; + /* + * Assume 64-bit addresses for MSI initially. Will be changed to 32-bit + * if MSI (rather than MSI-X) capability does not have + * PCI_MSI_FLAGS_64BIT. Can also be overridden by driver. + */ + dev->msi_addr_mask = DMA_BIT_MASK(64); + dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus), dev->bus->number, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn)); diff --git a/include/linux/pci.h b/include/linux/pci.h index 864775651c6fa..0fe32fef03315 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -377,6 +377,13 @@ struct pci_dev { 0xffffffff. You only need to change this if your device has broken DMA or supports 64-bit transfers. */ + u64 msi_addr_mask; /* Mask of the bits of bus address for + MSI that this device implements. + Normally set based on device + capabilities. You only need to + change this if your device claims + to support 64-bit MSI but implements + fewer than 64 address bits. */ struct device_dma_parameters dma_parms; @@ -441,7 +448,6 @@ struct pci_dev { unsigned int is_busmaster:1; /* Is busmaster */ unsigned int no_msi:1; /* May not use MSI */ - unsigned int no_64bit_msi:1; /* May only use 32-bit MSIs */ unsigned int block_cfg_access:1; /* Config space access blocked */ unsigned int broken_parity_status:1; /* Generates false positive parity */ unsigned int irq_reroute_variant:2; /* Needs IRQ rerouting variant */ diff --git a/sound/hda/controllers/intel.c b/sound/hda/controllers/intel.c index 1e8e3d61291a1..c9542ebdf7e2b 100644 --- a/sound/hda/controllers/intel.c +++ b/sound/hda/controllers/intel.c @@ -1905,7 +1905,7 @@ static int azx_first_init(struct azx *chip) if (chip->msi && chip->driver_caps & AZX_DCAPS_NO_MSI64) { dev_dbg(card->dev, "Disabling 64bit MSI\n"); - pci->no_64bit_msi = true; + pci->msi_addr_mask = DMA_BIT_MASK(32); } pci_set_master(pci); -- 2.47.3