Hari Bathini writes:
> diff --git a/arch/powerpc/kexec/file_load_64.c
> b/arch/powerpc/kexec/file_load_64.c
> index 2df6f4273ddd..8df085a22fd7 100644
> --- a/arch/powerpc/kexec/file_load_64.c
> +++ b/arch/powerpc/kexec/file_load_64.c
> @@ -17,9 +17,21 @@
> #include
> #include
> #include
> +#include
> #include
> +#include
> +#include
> #include
>
> +struct umem_info {
> + uint64_t *buf; /* data buffer for usable-memory property */
> + uint32_t idx; /* current index */
> + uint32_t size; /* size allocated for the data buffer */
Use kernel types please, u64, u32.
> + /* usable memory ranges to look up */
> + const struct crash_mem *umrngs;
"umrngs".
Given it's part of the umem_info struct could it just be "ranges"?
> +};
> +
> const struct kexec_file_ops * const kexec_file_loaders[] = {
> _elf64_ops,
> NULL
> @@ -74,6 +86,42 @@ static int get_exclude_memory_ranges(struct crash_mem
> **mem_ranges)
> return ret;
> }
>
> +/**
> + * get_usable_memory_ranges - Get usable memory ranges. This list includes
> + *regions like crashkernel, opal/rtas &
> tce-table,
> + *that kdump kernel could use.
> + * @mem_ranges: Range list to add the memory ranges to.
> + *
> + * Returns 0 on success, negative errno on error.
> + */
> +static int get_usable_memory_ranges(struct crash_mem **mem_ranges)
> +{
> + int ret;
> +
> + /*
> + * prom code doesn't take kindly to missing low memory. So, add
I don't know what that's referring to, "prom code" is too vague.
> + * [0, crashk_res.end] instead of [crashk_res.start, crashk_res.end]
> + * to keep it happy.
> + */
> + ret = add_mem_range(mem_ranges, 0, crashk_res.end + 1);
> + if (ret)
> + goto out;
> +
> + ret = add_rtas_mem_range(mem_ranges);
> + if (ret)
> + goto out;
> +
> + ret = add_opal_mem_range(mem_ranges);
> + if (ret)
> + goto out;
> +
> + ret = add_tce_mem_ranges(mem_ranges);
> +out:
> + if (ret)
> + pr_err("Failed to setup usable memory ranges\n");
> + return ret;
> +}
> +
> /**
> * __locate_mem_hole_top_down - Looks top down for a large enough memory hole
> * in the memory regions between buf_min &
> buf_max
> @@ -273,6 +321,382 @@ static int locate_mem_hole_bottom_up_ppc64(struct
> kexec_buf *kbuf,
> return ret;
> }
>
> +/**
> + * check_realloc_usable_mem - Reallocate buffer if it can't accommodate
> entries
> + * @um_info: Usable memory buffer and ranges info.
> + * @cnt: No. of entries to accommodate.
> + *
> + * Frees up the old buffer if memory reallocation fails.
> + *
> + * Returns buffer on success, NULL on error.
> + */
> +static uint64_t *check_realloc_usable_mem(struct umem_info *um_info, int cnt)
> +{
> + void *tbuf;
> +
> + if (um_info->size >=
> + ((um_info->idx + cnt) * sizeof(*(um_info->buf
> + return um_info->buf;
This is awkward.
AFAICS you only use um_info->size here, so instead why not store the
number of u64s you have space for, as num for example.
Then the above comparison becomes:
if (um_info->num >= (um_info->idx + count))
Then you only have to calculate the size internally here for the
realloc.
> +
> + um_info->size += MEM_RANGE_CHUNK_SZ;
new_size = um_info->size + MEM_RANGE_CHUNK_SZ;
tbuf = krealloc(um_info->buf, new_size, GFP_KERNEL);
> + tbuf = krealloc(um_info->buf, um_info->size, GFP_KERNEL);
> + if (!tbuf) {
> + um_info->size -= MEM_RANGE_CHUNK_SZ;
Then you can drop this.
> + return NULL;
> + }
um_info->size = new_size;
> +
> + memset(tbuf + um_info->idx, 0, MEM_RANGE_CHUNK_SZ);
Just pass __GFP_ZERO to krealloc?
> + return tbuf;
> +}
> +
> +/**
> + * add_usable_mem - Add the usable memory ranges within the given memory
> range
> + * to the buffer
> + * @um_info:Usable memory buffer and ranges info.
> + * @base: Base address of memory range to look for.
> + * @end:End address of memory range to look for.
> + * @cnt:No. of usable memory ranges added to buffer.
One caller never uses this AFAICS.
Couldn't the other caller just compare the um_info->idx before and after
the call, and avoid another pass by reference parameter.
> + *
> + * Returns 0 on success, negative errno on error.
> + */
> +static int add_usable_mem(struct umem_info *um_info, uint64_t base,
> + uint64_t end, int *cnt)
> +{
> + uint64_t loc_base, loc_end, *buf;
> + const struct crash_mem *umrngs;
> + int i, add;
add should be bool.
> + *cnt = 0;
> + umrngs = um_info->umrngs;
> + for (i = 0; i < umrngs->nr_ranges; i++) {
> + add = 0;
> + loc_base = umrngs->ranges[i].start;
> +
