From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Mon, 2 Oct 2017 15:14:23 +0900 Subject: [PATCH v4 02/10] resource: add walk_system_ram_res_rev() In-Reply-To: <20171002061431.11117-1-takahiro.akashi@linaro.org> References: <20171002061431.11117-1-takahiro.akashi@linaro.org> Message-ID: <20171002061431.11117-3-takahiro.akashi@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 Cc: Vivek Goyal Cc: Andrew Morton Cc: Linus Torvalds --- include/linux/ioport.h | 3 +++ kernel/resource.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index f5cf32e80041..62eb62b98118 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -273,6 +273,9 @@ extern int walk_system_ram_res(u64 start, u64 end, void *arg, int (*func)(u64, u64, void *)); extern int +walk_system_ram_res_rev(u64 start, u64 end, void *arg, + int (*func)(u64, u64, void *)); +extern int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, void *arg, int (*func)(u64, u64, void *)); diff --git a/kernel/resource.c b/kernel/resource.c index 9b5f04404152..572f2f91ce9c 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -23,6 +23,8 @@ #include #include #include +#include +#include #include @@ -469,6 +471,63 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, return ret; } +int walk_system_ram_res_rev(u64 start, u64 end, void *arg, + int (*func)(u64, u64, void *)) +{ + struct resource res, *rams; + u64 orig_end; + int count, i; + int ret = -1; + + count = 16; /* initial */ + + /* create a list */ + rams = vmalloc(sizeof(struct resource) * count); + if (!rams) + return ret; + + res.start = start; + res.end = end; + res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + orig_end = res.end; + i = 0; + while ((res.start < res.end) && + (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) { + if (i >= count) { + /* re-alloc */ + struct resource *rams_new; + int count_new; + + count_new = count + 16; + rams_new = vmalloc(sizeof(struct resource) * count_new); + if (!rams_new) + goto out; + + memcpy(rams_new, rams, count); + vfree(rams); + rams = rams_new; + count = count_new; + } + + rams[i].start = res.start; + rams[i++].end = res.end; + + res.start = res.end + 1; + res.end = orig_end; + } + + /* go reverse */ + for (i--; i >= 0; i--) { + ret = (*func)(rams[i].start, rams[i].end, arg); + if (ret) + break; + } + +out: + vfree(rams); + return ret; +} + #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) /* -- 2.14.1