Instead of iterating over the PCI config window and performing individual ioremap() calls on all the adjacent slices, perform a single ioremap() to map the entire region, and divvy it up later. This not only prevents leaving some of it mapped if we fail half way through, it also ensures that archs that support huge-vmap can use section mappings to perform the mapping. On my Seattle A0 box, this transforms 128 separate 1 MB mappings that are mapped down to 4 KB pages into a single 128 MB mapping using 2 MB sections, saving 512 KB worth of page tables. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- huge-vmap for arm64 proposed here: http://article.gmane.org/gmane.linux.kernel.hardened.devel/1661 drivers/pci/host/pci-host-generic.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c index 1652bc70b145..3251cd779278 100644 --- a/drivers/pci/host/pci-host-generic.c +++ b/drivers/pci/host/pci-host-generic.c @@ -161,6 +161,7 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci) struct device *dev = pci->host.dev.parent; struct device_node *np = dev->of_node; u32 sz = 1 << pci->cfg.ops->bus_shift; + void *window; err = of_address_to_resource(np, 0, &pci->cfg.res); if (err) { @@ -186,14 +187,15 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci) return -ENOMEM; bus_range = pci->cfg.bus_range; + window = devm_ioremap(dev, pci->cfg.res.start, + (bus_range->end - bus_range->start + 1) * sz); + if (!window) + return -ENOMEM; + for (busn = bus_range->start; busn <= bus_range->end; ++busn) { u32 idx = busn - bus_range->start; - pci->cfg.win[idx] = devm_ioremap(dev, - pci->cfg.res.start + idx * sz, - sz); - if (!pci->cfg.win[idx]) - return -ENOMEM; + pci->cfg.win[idx] = window + idx * sz; } return 0; -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
