tree c2d9127a35e7a0615c3983f9051c29dc2fff2265
parent 93e01a5039915048e6b0be559ca4bfba1cce6f71
author Gavin Shan <gwshan@linux.vnet.ibm.com> 1463726495 +1000
committer Michael Ellerman <mpe@ellerman.id.au> 1466487055 +1000

powerpc/powernv: Dynamically release PE

This supports releasing PEs dynamically. A reference count is
introduced to PE representing number of PCI devices associated
with the PE. The reference count is increased when PCI device
joins the PE and decreased when PCI device leaves the PE in
pnv_pci_release_device(). When the count becomes zero, the PE
and its consumed resources are released. Note that the count
is accessed concurrently. So a counter with "int" type is enough
here.

In order to release the sources consumed by the PE, couple of
helper functions are introduced as below:

   * pnv_pci_ioda1_unset_window() - Unset IODA1 DMA32 window
   * pnv_pci_ioda1_release_dma_pe() - Release IODA1 DMA32 segments
   * pnv_pci_ioda2_release_dma_pe() - Release IODA2 DMA resource
   * pnv_ioda_release_pe_seg() - Unmap IO/M32/M64 segments

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>