[PATCH v3 1/8] arm64: identify PHYS_OFFSET correctly

[Pratyush Anand]

On Wed, Sep 7, 2016 at 10:03 AM, AKASHI Takahiro
<takahiro.akashi at linaro.org> wrote:
> Due to the kernel patch[1], the current code will not be able to identify

[1] is mentioned in cover letter only, not here.

> the correct value of PHYS_OFFSET if some "reserved" memory region, which
> is likely to be UEFI runtime services code/data, exists at an address below
> the first "System RAM" regions.
>
> This patch fixes this issue.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>  kexec/arch/arm64/iomem.h       |  7 +++++++
>  kexec/arch/arm64/kexec-arm64.c | 22 +++++++++++++++++-----
>  2 files changed, 24 insertions(+), 5 deletions(-)
>  create mode 100644 kexec/arch/arm64/iomem.h
>
> diff --git a/kexec/arch/arm64/iomem.h b/kexec/arch/arm64/iomem.h
> new file mode 100644
> index 0000000..7fd66eb
> --- /dev/null
> +++ b/kexec/arch/arm64/iomem.h
> @@ -0,0 +1,7 @@
> +#ifndef IOMEM_H
> +#define IOMEM_H
> +
> +#define SYSTEM_RAM             "System RAM\n"
> +#define IOMEM_RESERVED         "reserved\n"
> +
> +#endif
> diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
> index 7183dac..bc96c76 100644
> --- a/kexec/arch/arm64/kexec-arm64.c
> +++ b/kexec/arch/arm64/kexec-arm64.c
> @@ -21,6 +21,7 @@
>  #include "crashdump-arm64.h"
>  #include "dt-ops.h"
>  #include "fs2dt.h"
> +#include "iomem.h"
>  #include "kexec-syscall.h"
>  #include "arch/options.h"
>
> @@ -465,18 +466,28 @@ void add_segment(struct kexec_info *info, const void *buf, size_t bufsz,
>   * get_memory_ranges_iomem_cb - Helper for get_memory_ranges_iomem.
>   */
>
> +static int count_memory_ranges;

IMHO improving definition of kexec_iomem_for_each_line() and
callback() for handling NULL match case would have been a better
choice than introducing a new static variable. callback() can return
-ve in case of error, 0 in case of no match and 1 in case of (one)
match.

~Pratyush

> +
>  static int get_memory_ranges_iomem_cb(void *data, int nr, char *str,
>         unsigned long long base, unsigned long long length)
>  {
>         struct memory_range *r;
>
> -       if (nr >= KEXEC_SEGMENT_MAX)
> +       if (count_memory_ranges >= KEXEC_SEGMENT_MAX)
>                 return -1;
>
> -       r = (struct memory_range *)data + nr;
> -       r->type = RANGE_RAM;
> +       r = (struct memory_range *)data + count_memory_ranges;
> +
> +       if (!strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)))
> +               r->type = RANGE_RAM;
> +       else if (!strncmp(str, IOMEM_RESERVED, strlen(IOMEM_RESERVED)))
> +               r->type = RANGE_RESERVED;
> +       else
> +               return 0;
> +
>         r->start = base;
>         r->end = base + length - 1;
> +       count_memory_ranges++;
>
>         set_phys_offset(r->start);
>
> @@ -493,9 +504,10 @@ static int get_memory_ranges_iomem_cb(void *data, int nr, char *str,
>  static int get_memory_ranges_iomem(struct memory_range *array,
>         unsigned int *count)
>  {
> -       *count = kexec_iomem_for_each_line("System RAM\n",
> -               get_memory_ranges_iomem_cb, array);
> +       count_memory_ranges = 0;
> +       kexec_iomem_for_each_line(NULL, get_memory_ranges_iomem_cb, array);
>
> +       *count = count_memory_ranges;
>         if (!*count) {
>                 dbgprintf("%s: failed: No RAM found.\n", __func__);
>                 return -EFAILED;
> --
> 2.9.0
>