Am Freitag, 17 Juni 2016, 15:35:23 schrieb Dave Young:
> On 06/16/16 at 05:39pm, Thiago Jung Bauermann wrote:
> > Am Donnerstag, 16 Juni 2016, 09:58:53 schrieb Dave Young:
> > > On 06/15/16 at 01:21pm, Thiago Jung Bauermann wrote:
> > > > +int __weak arch_kexec_walk_mem(unsigned int image_type, bool
> > > > top_down,
> > > > + void *data, int (*func)(u64, u64, void *))
> > > > +{
> > >
> > > top_down is also not used?
> >
> > It's unused in the default implementation, but the powerpc implementation
> > in patch 8 uses it:
> Well, arch_kexec_walk_mem use kbuf as "data", you can even drop
> "image_type" since kbuf has all you want kbuf->image->type, and
> kbuf->top_down
>
> int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
> int (*func)(u64, u64, void *))
Sounds good to me, but I had to move struct kexec_buf from
kernel/kexec_internal.h to include/linux/kexec.h.
Here's the updated patch. What do you think?
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center
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.
Signed-off-by: Thiago Jung Bauermann <bauerman at linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm at xmission.com>
Cc: Dave Young <dyoung at redhat.com>
Cc: kexec at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index e8acb2b43dd9..d8df01107ae2 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -201,6 +201,20 @@ struct kimage {
#endif
};
+/*
+ * 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 */
+};
+
/* kexec interface functions */
extern void machine_kexec(struct kimage *image);
extern int machine_kexec_prepare(struct kimage *image);
@@ -315,6 +329,8 @@ 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_kexec_walk_mem(struct kexec_buf *kbuf,
+ 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..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) { }
