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Message-Id: <1465701022-11601-3-git-send-email-bauerman@linux.vnet.ibm.com>
Date: Sun, 12 Jun 2016 00:10:16 -0300
From: Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>
To: linuxppc-dev@...ts.ozlabs.org
Cc: kexec@...ts.infradead.org, linux-kernel@...r.kernel.org,
Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>,
Eric Biederman <ebiederm@...ssion.com>
Subject: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.
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.
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 <ebiederm@...ssion.com>
Cc: kexec@...ts.infradead.org
Cc: linux-kernel@...r.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
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