[PATCH v8 01/13] resource: add walk_system_ram_res_rev()
From: AKASHI Takahiro <hidden>
Date: 2018-02-22 11:18:58
Also in:
kexec, lkml
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 implementation on arm64.
Signed-off-by: AKASHI Takahiro <redacted>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/ioport.h | 3 +++
kernel/resource.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 60 insertions(+)
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index da0ebaec25f0..f12d95fe038b 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h@@ -277,6 +277,9 @@ 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 e270b5048988..bdaa93407f4c 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>
@@ -486,6 +488,61 @@ int walk_mem_res(u64 start, u64 end, void *arg, arg, func); } +int walk_system_ram_res_rev(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)) +{ + struct resource res, *rams; + int rams_size = 16, i; + int ret = -1; + + /* create a list */ + rams = vmalloc(sizeof(struct resource) * rams_size); + if (!rams) + return ret; + + res.start = start; + res.end = end; + res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + i = 0; + while ((res.start < res.end) && + (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) { + if (i >= rams_size) { + /* re-alloc */ + struct resource *rams_new; + int rams_new_size; + + rams_new_size = rams_size + 16; + rams_new = vmalloc(sizeof(struct resource) + * rams_new_size); + if (!rams_new) + goto out; + + memcpy(rams_new, rams, + sizeof(struct resource) * rams_size); + vfree(rams); + rams = rams_new; + rams_size = rams_new_size; + } + + rams[i].start = res.start; + rams[i++].end = res.end; + + res.start = res.end + 1; + res.end = end; + } + + /* go reverse */ + for (i--; i >= 0; i--) { + ret = (*func)(&rams[i], arg); + if (ret) + break; + } + +out: + vfree(rams); + return ret; +} + #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) /*
--
2.16.2