[PATCH v7 3/4] resource: add walk_system_ram_res_rev()
From: Baoquan He <bhe@redhat.com>
Date: 2018-07-18 02:53:01
Also in:
linux-devicetree, linux-input, linux-pci, lkml, nvdimm
Subsystem:
the rest · Maintainer:
Linus Torvalds
This function, being a variant of walk_system_ram_res() introduced in
commit 8c86e70acead ("resource: provide new functions to walk through
resources"), walks through a list of all the resources of System RAM
in reversed order, i.e., from higher to lower.
It will be used in kexec_file code.
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <redacted>
Cc: Brijesh Singh <redacted>
Cc: "Jérôme Glisse" <redacted>
Cc: Borislav Petkov <redacted>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Wei Yang <redacted>
---
include/linux/ioport.h | 3 +++
kernel/resource.c | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+)
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index b7456ae889dd..066cc263e2cc 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h@@ -279,6 +279,9 @@ extern int walk_system_ram_res(u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)); extern int +walk_system_ram_res_rev(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)); +extern int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, void *arg, int (*func)(struct resource *, void *));
diff --git a/kernel/resource.c b/kernel/resource.c
index c96e58d3d2f8..3e18f24b90c4 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c@@ -23,6 +23,8 @@ #include <linux/pfn.h> #include <linux/mm.h> #include <linux/resource_ext.h> +#include <linux/string.h> +#include <linux/vmalloc.h> #include <asm/io.h>
@@ -443,6 +445,44 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, } /* + * This function, being a variant of walk_system_ram_res(), calls the @func + * callback against all memory ranges of type System RAM which are marked as + * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from + * higher to lower. + */ +int walk_system_ram_res_rev(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)) +{ + unsigned long flags; + struct resource *res; + int ret = -1; + + flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + + read_lock(&resource_lock); + list_for_each_entry_reverse(res, &iomem_resource.child, sibling) { + if (start >= end) + break; + if ((res->flags & flags) != flags) + continue; + if (res->desc != IORES_DESC_NONE) + continue; + if (res->end < start) + break; + + if ((res->end >= start) && (res->start < end)) { + ret = (*func)(res, arg); + if (ret) + break; + } + end = res->start - 1; + + } + read_unlock(&resource_lock); + return ret; +} + +/* * This function calls the @func callback against all memory ranges, which * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY. */
--
2.13.6