Re: [PATCH v2 2/9] kexec_file: Generalize kexec_add_buffer.
From: Thiago Jung Bauermann <hidden>
Date: 2016-06-16 20:39:34
Also in:
kexec, lkml
Subsystem:
kexec, the rest · Maintainers:
Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Linus Torvalds
Am Donnerstag, 16 Juni 2016, 09:58:53 schrieb Dave Young:
On 06/15/16 at 01:21pm, Thiago Jung Bauermann wrote:quoted
+/** + * arch_kexec_walk_mem - call func(data) on free memory regions + * @image_type: kimage.type + * @top_down: Start from the highest address? + * @data: Argument to pass 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(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:
int arch_kexec_walk_mem(unsigned int type, bool top_down, void *data,
int (*func)(u64, u64, void *))
{
int ret = 0;
u64 i;
phys_addr_t mstart, mend;
if (top_down) {
for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
&mstart, &mend, NULL) {
ret = func(mstart, mend, data);
if (ret)
break;
}
} else {
for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
NULL) {
ret = func(mstart, mend, data);
if (ret)
break;
}
}
return ret;
}
Rethink about the argument name type should be better than image_type, it is obvious in the comments and the code and simpler.
Ok, renamed in the patch below.
[]'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..42b31f2e1d88 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h@@ -315,6 +315,8 @@ 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(unsigned int type, 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..989647a324f2 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c@@ -428,6 +428,29 @@ 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 + * @type: kimage.type + * @top_down: Start from the highest address? + * @data: Argument to pass 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(unsigned int type, bool top_down, void *data, + int (*func)(u64, u64, void *)) +{ + if (type == KEXEC_TYPE_CRASH) + return walk_iomem_res_desc(crashk_res.desc, + IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, + crashk_res.start, crashk_res.end, + data, func); + else + return walk_system_ram_res(0, ULONG_MAX, data, func); +} + /* * Helper function for placing a buffer in a kexec segment. This assumes * that kexec_mutex is held.
@@ -472,14 +495,8 @@ 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(image->type, top_down, kbuf, + locate_mem_hole_callback); if (ret != 1) { /* A suitable memory range could not be found for buffer */ return -EADDRNOTAVAIL;