lkml.org 
[lkml]   [2017]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4 03/21] ARM64: implement pci_remap_cfgspace() interface
On Wed, Apr 19, 2017 at 05:48:52PM +0100, Lorenzo Pieralisi wrote:
> The PCI bus specifications (rev 3.0, 3.2.5 "Transaction Ordering
> and Posting") defines rules for PCI configuration space transactions
> ordering and posting, that state that configuration writes
> are non-posted transactions.
>
> This rule is reinforced by the ARM v8 architecture reference manual
> (issue A.k, Early Write Acknowledgment) that explicitly recommends
> that No Early Write Acknowledgment attribute should be used to map
> PCI configuration (write) transactions.
>
> Current ioremap interface on ARM64 implements mapping functions
> where the Early Write Acknowledgment hint is enabled, so they
> cannot be used to map PCI configuration space in a PCI specs
> compliant way.
>
> Implement an ARM64 specific pci_remap_cfgspace() interface
> that allows to map PCI config region with nGnRnE attributes, providing
> a remap function that complies with PCI specifications and the ARMv8
> architecture reference manual recommendations.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

\
 
 \ /
  Last update: 2017-04-20 12:34    [W:0.270 / U:0.084 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site