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Message-Id: <2060648.f0n9OPAato@hactar>
Date: Tue, 28 Jun 2016 19:18:18 -0300
From: Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>
To: Dave Young <dyoung@...hat.com>
Cc: kexec@...ts.infradead.org, linuxppc-dev@...ts.ozlabs.org,
linux-kernel@...r.kernel.org,
Eric Biederman <ebiederm@...ssion.com>
Subject: Re: [PATCH v3 2/9] kexec_file: Generalize kexec_add_buffer.
Am Donnerstag, 23 Juni 2016, 10:25:06 schrieb Dave Young:
> On 06/22/16 at 08:30pm, Thiago Jung Bauermann wrote:
> > Am Mittwoch, 22 Juni 2016, 18:20:47 schrieb Dave Young:
> > > The patch looks good, but could the subject be more specific?
> > >
> > > For example just like the first sentence of the patch descriotion:
> > > Allow architectures to specify their own memory walking function
> >
> > Ok, What about this? I also changed the description to refer to x86 arch
> > instead of Intel arch.
>
> It looks good to me.
This version has the struct kexec_buf documentation comments that were
in patch 3/9. I fixed the names of the struct members, and changed their
descriptions to try to be clearer.
--
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center
Subject: [PATCH 2/9] kexec_file: Allow arch-specific memory walking for
kexec_add_buffer
Allow architectures to specify a different memory walking function for
kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but
PowerPC uses the memblock subsystem.
Signed-off-by: Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@...ssion.com>
Cc: Dave Young <dyoung@...hat.com>
Cc: kexec@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org
---
include/linux/kexec.h | 25 ++++++++++++++++++++++++-
kernel/kexec_file.c | 30 ++++++++++++++++++++++--------
kernel/kexec_internal.h | 14 --------------
3 files changed, 46 insertions(+), 23 deletions(-)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index e8acb2b43dd9..e16d845d587f 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -146,7 +146,30 @@ struct kexec_file_ops {
kexec_verify_sig_t *verify_sig;
#endif
};
-#endif
+
+/**
+ * struct kexec_buf - parameters for finding a place for a buffer in memory
+ * @image: kexec image in which memory to search.
+ * @mem: On return will have address of the buffer in memory.
+ * @memsz: Size for the buffer in memory.
+ * @buf_align: Minimum alignment needed.
+ * @buf_min: The buffer can't be placed below this address.
+ * @buf_max: The buffer can't be placed above this address.
+ * @top_down: Allocate from top of memory.
+ */
+struct kexec_buf {
+ struct kimage *image;
+ unsigned long mem;
+ unsigned long memsz;
+ unsigned long buf_align;
+ unsigned long buf_min;
+ unsigned long buf_max;
+ bool top_down;
+};
+
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+ int (*func)(u64, u64, void *));
+#endif /* CONFIG_KEXEC_FILE */
struct kimage {
kimage_entry_t head;
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b6eec7527e9f..b1f1f6402518 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -428,6 +428,27 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
return locate_mem_hole_bottom_up(start, end, kbuf);
}
+/**
+ * arch_kexec_walk_mem - call func(data) on free memory regions
+ * @kbuf: Context info for the search. Also passed to @func.
+ * @func: Function to call for each memory region.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+ int (*func)(u64, u64, void *))
+{
+ if (kbuf->image->type == KEXEC_TYPE_CRASH)
+ return walk_iomem_res_desc(crashk_res.desc,
+ IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+ crashk_res.start, crashk_res.end,
+ kbuf, func);
+ else
+ return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
/*
* Helper function for placing a buffer in a kexec segment. This assumes
* that kexec_mutex is held.
@@ -472,14 +493,7 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
kbuf->top_down = top_down;
/* 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);
+ ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
if (ret != 1) {
/* A suitable memory range could not be found for buffer */
return -EADDRNOTAVAIL;
diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h
index eefd5bf960c2..4cef7e4706b0 100644
--- a/kernel/kexec_internal.h
+++ b/kernel/kexec_internal.h
@@ -20,20 +20,6 @@ struct kexec_sha_region {
unsigned long len;
};
-/*
- * Keeps track of buffer parameters as provided by caller for requesting
- * memory placement of buffer.
- */
-struct kexec_buf {
- struct kimage *image;
- unsigned long mem;
- unsigned long memsz;
- unsigned long buf_align;
- unsigned long buf_min;
- unsigned long buf_max;
- bool top_down; /* allocate from top of memory hole */
-};
-
void kimage_file_post_load_cleanup(struct kimage *image);
#else /* CONFIG_KEXEC_FILE */
static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
--
1.9.1
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