PCI: xilinx: Don't allocate extra memory for the MSI capture address
authorMarc Zyngier <maz@kernel.org>
Tue, 30 Mar 2021 15:11:35 +0000 (16:11 +0100)
committerLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tue, 20 Apr 2021 13:11:21 +0000 (14:11 +0100)
commit161260e7f7bc58d6a0972eb41a6072e82d0b58a5
treec41a541a0d86ba776fe8cd3c6c66ab8758401135
parent83ed8d4fa656d37d17bb83203485e3f7a2360e7a
PCI: xilinx: Don't allocate extra memory for the MSI capture address

A long cargo-culted behaviour of PCI drivers is to allocate memory
to obtain an address that is fed to the controller as the MSI
capture address (i.e. the MSI doorbell).

But there is no actual requirement for this address to be RAM.
All it needs to be is a suitable aligned address that will
*not* be DMA'd to.

Use the physical address of the 'port' data structure as the MSI
capture address, aligned on a 4K boundary.

Link: https://lore.kernel.org/r/20210330151145.997953-5-maz@kernel.org
Tested-by: Bharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
drivers/pci/controller/pcie-xilinx.c