diff options
| author | Vivian Wang <wangruikang@iscas.ac.cn> | 2026-01-29 09:56:06 +0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@kernel.org> | 2026-01-31 01:11:48 +0100 |
| commit | 386ced19e9a348e8131d20f009e692fa8fcc4568 (patch) | |
| tree | 07e95b5949b774feba691dae8d8408ecb9aab05f /include/linux | |
| parent | 37f9d5026cd78fbe80a124edbbadab382b26545f (diff) | |
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 <wangruikang@iscas.ac.cn>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Brett Creeley <brett.creeley@amd.com> # ionic
Reviewed-by: Thomas Gleixner <tglx@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de> # sound
Link: https://patch.msgid.link/20260129-pci-msi-addr-mask-v4-1-70da998f2750@iscas.ac.cn
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/pci.h | 8 |
1 files changed, 7 insertions, 1 deletions
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 */ |