From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965162AbcFMH3r (ORCPT ); Mon, 13 Jun 2016 03:29:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56365 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964986AbcFMH3p (ORCPT ); Mon, 13 Jun 2016 03:29:45 -0400 Date: Mon, 13 Jun 2016 15:29:39 +0800 From: Dave Young To: Thiago Jung Bauermann Cc: linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Eric Biederman Subject: Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer. Message-ID: <20160613072939.GD4974@dhcp-128-65.nay.redhat.com> References: <1465701022-11601-1-git-send-email-bauerman@linux.vnet.ibm.com> <1465701022-11601-3-git-send-email-bauerman@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1465701022-11601-3-git-send-email-bauerman@linux.vnet.ibm.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 13 Jun 2016 07:29:44 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote: > Allow architectures to specify different memory walking functions for > kexec_add_buffer. Intel uses iomem to track reserved memory ranges, > but PowerPC uses the memblock subsystem. Can the crashk_res be inserted to iomem_resource so that only one weak function for system ram is needed? > > Also, factor kexec_locate_mem_hole out of kexec_add_buffer. It will be > used by the PowerPC kexec_file_load implementation to find free memory > for the purgatory stack. > > Cc: Eric Biederman > Cc: kexec@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > --- > include/linux/kexec.h | 10 ++++++ > kernel/kexec_file.c | 96 +++++++++++++++++++++++++++++++++++++-------------- > 2 files changed, 81 insertions(+), 25 deletions(-) > > diff --git a/include/linux/kexec.h b/include/linux/kexec.h > index e8acb2b43dd9..920e2cbe5bdd 100644 > --- a/include/linux/kexec.h > +++ b/include/linux/kexec.h > @@ -210,6 +210,10 @@ extern asmlinkage long sys_kexec_load(unsigned long entry, > struct kexec_segment __user *segments, > unsigned long flags); > extern int kernel_kexec(void); > +int kexec_locate_mem_hole(struct kimage *image, unsigned long size, > + unsigned long align, unsigned long start, > + unsigned long end, bool top_down, > + unsigned long *addr); > extern int kexec_add_buffer(struct kimage *image, char *buffer, > unsigned long bufsz, unsigned long memsz, > unsigned long buf_align, unsigned long buf_min, > @@ -315,6 +319,12 @@ int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, > Elf_Shdr *sechdrs, unsigned int relsec); > int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, > unsigned int relsec); > +int __weak arch_walk_iomem(unsigned long desc, unsigned long start, > + unsigned long end, bool top_down, void *data, > + int (*func)(u64, u64, void *)); > +int __weak arch_walk_system_ram(unsigned long start, unsigned long end, > + bool top_down, void *data, > + int (*func)(u64, u64, void *)); > void arch_kexec_protect_crashkres(void); > void arch_kexec_unprotect_crashkres(void); > > diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c > index b6eec7527e9f..300f71cb4f72 100644 > --- a/kernel/kexec_file.c > +++ b/kernel/kexec_file.c > @@ -428,6 +428,68 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg) > return locate_mem_hole_bottom_up(start, end, kbuf); > } > > +int __weak arch_walk_iomem(unsigned long desc, unsigned long start, > + unsigned long end, bool top_down, void *data, > + int (*func)(u64, u64, void *)) > +{ > + return walk_iomem_res_desc(desc, > + IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, > + start, end, data, func); > +} > + > +int __weak arch_walk_system_ram(unsigned long start, unsigned long end, > + bool top_down, void *data, > + int (*func)(u64, u64, void *)) > +{ > + return walk_system_ram_res(start, end, data, func); > +} > + > +/** > + * kexec_locate_mem_hole - find free memory to load segment or use in purgatory > + * @image: kexec image being updated. > + * @size: Memory size. > + * @align: Minimum alignment needed. > + * @start: Minimum starting address. > + * @end: Maximum end address. > + * @top_down Find the highest free memory region? > + * @addr On success, will have start address of the memory region found. > + * > + * Return: 0 on success, negative erro on failure. > + */ > +int kexec_locate_mem_hole(struct kimage *image, unsigned long size, > + unsigned long align, unsigned long start, > + unsigned long end, bool top_down, unsigned long *addr) > +{ > + int ret; > + struct kexec_buf buf; > + > + memset(&buf, 0, sizeof(struct kexec_buf)); > + buf.image = image; > + > + buf.memsz = size; > + buf.buf_align = align; > + buf.buf_min = start; > + buf.buf_max = end; > + buf.top_down = top_down; > + > + /* Walk the RAM ranges and allocate a suitable range for the buffer */ > + if (image->type == KEXEC_TYPE_CRASH) > + ret = arch_walk_iomem(crashk_res.desc, crashk_res.start, > + crashk_res.end, top_down, &buf, > + locate_mem_hole_callback); > + else > + ret = arch_walk_system_ram(0, -1, top_down, &buf, > + locate_mem_hole_callback); > + if (ret != 1) { > + /* A suitable memory range could not be found for buffer */ > + return -EADDRNOTAVAIL; > + } > + > + *addr = buf.mem; > + > + return 0; > +} > + > /* > * Helper function for placing a buffer in a kexec segment. This assumes > * that kexec_mutex is held. > @@ -439,8 +501,8 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, > { > > struct kexec_segment *ksegment; > - struct kexec_buf buf, *kbuf; > int ret; > + unsigned long addr, align, size; > > /* Currently adding segment this way is allowed only in file mode */ > if (!image->file_mode) > @@ -461,36 +523,20 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, > return -EINVAL; > } > > - memset(&buf, 0, sizeof(struct kexec_buf)); > - kbuf = &buf; > - kbuf->image = image; > - > - kbuf->memsz = ALIGN(memsz, PAGE_SIZE); > - kbuf->buf_align = max(buf_align, PAGE_SIZE); > - kbuf->buf_min = buf_min; > - kbuf->buf_max = buf_max; > - kbuf->top_down = top_down; > + size = ALIGN(memsz, PAGE_SIZE); > + align = max(buf_align, PAGE_SIZE); > > - /* Walk the RAM ranges and allocate a suitable range for the buffer */ > - if (image->type == KEXEC_TYPE_CRASH) > - ret = walk_iomem_res_desc(crashk_res.desc, > - IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, > - crashk_res.start, crashk_res.end, kbuf, > - locate_mem_hole_callback); > - else > - ret = walk_system_ram_res(0, -1, kbuf, > - locate_mem_hole_callback); > - if (ret != 1) { > - /* A suitable memory range could not be found for buffer */ > - return -EADDRNOTAVAIL; > - } > + ret = kexec_locate_mem_hole(image, size, align, buf_min, buf_max, > + top_down, &addr); > + if (ret) > + return ret; > > /* Found a suitable memory range */ > ksegment = &image->segment[image->nr_segments]; > ksegment->kbuf = buffer; > ksegment->bufsz = bufsz; > - ksegment->mem = kbuf->mem; > - ksegment->memsz = kbuf->memsz; > + ksegment->mem = addr; > + ksegment->memsz = size; > image->nr_segments++; > *load_addr = ksegment->mem; > return 0; > -- > 1.9.1 > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec