Hi Andrew,
On 11/15/23 at 09:00pm, Baoquan He wrote:
> This function, being a variant of walk_system_ram_res() introduced in
> commit 8c86e70acead ("resource: provide new functions to walk through
> resources"), walks through a list of all the resources of System RAM
> in reversed order, i.e., from higher to lower.
>
> It will be used in kexec_file code to load kernel, initrd etc when
> preparing kexec reboot.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> ---
> v1->v2:
> - Use kvrealloc() to reallocate memory instead of kvcalloc(), this
> simplifies code. Suggested by Andrew.
>
> include/linux/ioport.h | 3 +++
> kernel/resource.c | 57 ++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 60 insertions(+)
Gentle ping.
Could you pick this patchset into next tree so that it can be run on
testing robots?
Thanks
Baoquan
>
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index 14f5cfabbbc8..db7fe25f3370 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -331,6 +331,9 @@ extern int
> walk_system_ram_res(u64 start, u64 end, void *arg,
> int (*func)(struct resource *, void *));
> extern int
> +walk_system_ram_res_rev(u64 start, u64 end, void *arg,
> + int (*func)(struct resource *, void *));
> +extern int
> walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end,
> void *arg, int (*func)(struct resource *, void *));
>
> diff --git a/kernel/resource.c b/kernel/resource.c
> index 866ef3663a0b..e8a244300e5b 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -27,6 +27,8 @@
> #include <linux/mount.h>
> #include <linux/resource_ext.h>
> #include <uapi/linux/magic.h>
> +#include <linux/string.h>
> +#include <linux/vmalloc.h>
> #include <asm/io.h>
>
>
> @@ -429,6 +431,61 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
> func);
> }
>
> +/*
> + * This function, being a variant of walk_system_ram_res(), calls the @func
> + * callback against all memory ranges of type System RAM which are marked as
> + * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from
> + * higher to lower.
> + */
> +int walk_system_ram_res_rev(u64 start, u64 end, void *arg,
> + int (*func)(struct resource *, void *))
> +{
> + struct resource res, *rams;
> + int rams_size = 16, i;
> + unsigned long flags;
> + int ret = -1;
> +
> + /* create a list */
> + rams = kvcalloc(rams_size, sizeof(struct resource), GFP_KERNEL);
> + if (!rams)
> + return ret;
> +
> + flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
> + i = 0;
> + while ((start < end) &&
> + (!find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res))) {
> + if (i >= rams_size) {
> + /* re-alloc */
> + struct resource *rams_new;
> +
> + rams_new = kvrealloc(rams, rams_size * sizeof(struct resource),
> + (rams_size + 16) * sizeof(struct resource),
> + GFP_KERNEL);
> + if (!rams_new)
> + goto out;
> +
> + rams = rams_new;
> + rams_size += 16;
> + }
> +
> + rams[i].start = res.start;
> + rams[i++].end = res.end;
> +
> + start = res.end + 1;
> + }
> +
> + /* go reverse */
> + for (i--; i >= 0; i--) {
> + ret = (*func)(&rams[i], arg);
> + if (ret)
> + break;
> + }
> +
> +out:
> + kvfree(rams);
> + return ret;
> +}
> +
> /*
> * This function calls the @func callback against all memory ranges, which
> * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
> --
> 2.41.0
>
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