Re: [RFC PATCH v2 02/11] PCI/P2PDMA: Avoid pci_get_slot() which sleeps

2021-03-12 Thread Logan Gunthorpe
On 2021-03-12 1:57 p.m., Bjorn Helgaas wrote: > On Thu, Mar 11, 2021 at 04:31:32PM -0700, Logan Gunthorpe wrote: >> In order to use upstream_bridge_distance_warn() from a dma_map function, >> it must not sleep. However, pci_get_slot() takes the pci_bus_sem so it >> might sleep. >> >> In order to

Re: [RFC PATCH v2 02/11] PCI/P2PDMA: Avoid pci_get_slot() which sleeps

2021-03-12 Thread Bjorn Helgaas
On Thu, Mar 11, 2021 at 04:31:32PM -0700, Logan Gunthorpe wrote: > In order to use upstream_bridge_distance_warn() from a dma_map function, > it must not sleep. However, pci_get_slot() takes the pci_bus_sem so it > might sleep. > > In order to avoid this, try to get the host bridge's device from >

[RFC PATCH v2 02/11] PCI/P2PDMA: Avoid pci_get_slot() which sleeps

2021-03-11 Thread Logan Gunthorpe
In order to use upstream_bridge_distance_warn() from a dma_map function, it must not sleep. However, pci_get_slot() takes the pci_bus_sem so it might sleep. In order to avoid this, try to get the host bridge's device from bus->self, and if that is not set just get the first element in the list. It