From 386ced19e9a348e8131d20f009e692fa8fcc4568 Mon Sep 17 00:00:00 2001 From: Vivian Wang Date: Thu, 29 Jan 2026 09:56:06 +0800 Subject: 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 --- include/linux/pci.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/pci.h b/include/linux/pci.h index 864775651c6f..0fe32fef0331 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 */ -- cgit v1.2.3