From: Dan Williams Date: Fri, 28 Dec 2018 08:34:54 +0000 (-0800) Subject: mm, devm_memremap_pages: kill mapping "System RAM" support X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=298cf9b3308cfc6f3ab6c7a29b2d3df9e85cfe91;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git mm, devm_memremap_pages: kill mapping "System RAM" support commit 06489cfbd915ff36c8e36df27f1c2dc60f97ca56 upstream. Given the fact that devm_memremap_pages() requires a percpu_ref that is torn down by devm_memremap_pages_release() the current support for mapping RAM is broken. Support for remapping "System RAM" has been broken since the beginning and there is no existing user of this this code path, so just kill the support and make it an explicit error. This cleanup also simplifies a follow-on patch to fix the error path when setting a devm release action for devm_memremap_pages_release() fails. Link: http://lkml.kernel.org/r/154275557997.76910.14689813630968180480.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Reviewed-by: "Jérôme Glisse" Reviewed-by: Christoph Hellwig Reviewed-by: Logan Gunthorpe Cc: Balbir Singh Cc: Michal Hocko Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- diff --git a/kernel/memremap.c b/kernel/memremap.c index 602bf8aa4122..9a8b594fbbb6 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -305,15 +305,12 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, is_ram = region_intersects(align_start, align_size, IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); - if (is_ram == REGION_MIXED) { - WARN_ONCE(1, "%s attempted on mixed region %pr\n", - __func__, res); + if (is_ram != REGION_DISJOINT) { + WARN_ONCE(1, "%s attempted on %s region %pr\n", __func__, + is_ram == REGION_MIXED ? "mixed" : "ram", res); return ERR_PTR(-ENXIO); } - if (is_ram == REGION_INTERSECTS) - return __va(res->start); - if (!ref) return ERR_PTR(-EINVAL);