Re: [PATCH v2 2/9] kexec_file: Generalize kexec_add_buffer.
From: Thiago Jung Bauermann <hidden>
Date: 2016-06-17 20:51:19
Also in:
kexec, lkml
Subsystem:
kexec, the rest · Maintainers:
Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Linus Torvalds
Am Freitag, 17 Juni 2016, 15:35:23 schrieb Dave Young:
On 06/16/16 at 05:39pm, Thiago Jung Bauermann wrote:quoted
Am Donnerstag, 16 Juni 2016, 09:58:53 schrieb Dave Young:quoted
On 06/15/16 at 01:21pm, Thiago Jung Bauermann wrote:quoted
+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 [off-list ref]
Cc: Eric Biederman [off-list ref]
Cc: Dave Young [off-list ref]
Cc: kexec@lists.infradead.org
Cc: linux-kernel@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) { }