On Thu, 18 Sep 2014 17:25:12 +0800, "Wang, Yalin" <Yalin.Wang@xxxxxxxxxxxxxx> wrote:
> This patch make some change to unflatten_dt_node(), make sure the
> device_node don't reference to fdt raw blob memory, so that we can
> free the raw blob reserved memory after initcalls.
>
> Signed-off-by: Yalin Wang <yalin.wang@xxxxxxxxxxxxxx>
Do you have any measurements showing a change in available memory before
and after the patch?
g.
> ---
> drivers/of/fdt.c | 27 +++++++++++++++++++++++----
> include/linux/of_fdt.h | 2 ++
> 2 files changed, 25 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 79cb831..e891ef6 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -240,6 +240,7 @@ static void * unflatten_dt_node(void *blob,
> (offset = fdt_next_property_offset(blob, offset))) {
> const char *pname;
> u32 sz;
> + int name_len;
>
> if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) {
> offset = -FDT_ERR_INTERNAL;
> @@ -250,10 +251,12 @@ static void * unflatten_dt_node(void *blob,
> pr_info("Can't find property name in list !\n");
> break;
> }
> + name_len = strlen(pname);
> if (strcmp(pname, "name") == 0)
> has_name = 1;
> - pp = unflatten_dt_alloc(&mem, sizeof(struct property),
> - __alignof__(struct property));
> + pp = unflatten_dt_alloc(&mem,
> + ALIGN(sizeof(struct property) + name_len + 1, 4)
> + + sz, __alignof__(struct property));
> if (allnextpp) {
> /* We accept flattened tree phandles either in
> * ePAPR-style "phandle" properties, or the
> @@ -270,9 +273,11 @@ static void * unflatten_dt_node(void *blob,
> * stuff */
> if (strcmp(pname, "ibm,phandle") == 0)
> np->phandle = be32_to_cpup(p);
> - pp->name = (char *)pname;
> + pp->name = (char *)memcpy(pp + 1, pname, name_len + 1);
> pp->length = sz;
> - pp->value = (__be32 *)p;
> + pp->value = (__be32 *)memcpy((void *)pp +
> + ALIGN(sizeof(struct property) +
> + name_len + 1, 4), p, sz);
> *prev_pp = pp;
> prev_pp = &pp->next;
> }
> @@ -564,6 +569,20 @@ void __init early_init_fdt_scan_reserved_mem(void)
> fdt_init_reserved_mem();
> }
>
> +void __init free_early_init_fdt_scan_reserved_mem(void)
> +{
> + unsigned long start, end, size;
> + if (!initial_boot_params)
> + return;
> +
> + size = fdt_totalsize(initial_boot_params);
> + memblock_free(__pa(initial_boot_params), size);
> + start = round_down((unsigned long)initial_boot_params, PAGE_SIZE);
> + end = round_up((unsigned long)initial_boot_params + size, PAGE_SIZE);
> + free_reserved_area((void *)start, (void *)end, 0, "fdt");
> + initial_boot_params = 0;
> +}
> +
> /**
> * of_scan_flat_dt - scan flattened tree blob and call callback on each.
> * @it: callback function
> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
> index 0ff360d..21d51ce 100644
> --- a/include/linux/of_fdt.h
> +++ b/include/linux/of_fdt.h
> @@ -62,6 +62,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
> extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
> int depth, void *data);
> extern void early_init_fdt_scan_reserved_mem(void);
> +extern void free_early_init_fdt_scan_reserved_mem(void);
> extern void early_init_dt_add_memory_arch(u64 base, u64 size);
> extern int early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
> bool no_map);
> @@ -89,6 +90,7 @@ extern u64 fdt_translate_address(const void *blob, int node_offset);
> extern void of_fdt_limit_memory(int limit);
> #else /* CONFIG_OF_FLATTREE */
> static inline void early_init_fdt_scan_reserved_mem(void) {}
> +static inline void free_early_init_fdt_scan_reserved_mem(void) {}
> static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }
> static inline void unflatten_device_tree(void) {}
> static inline void unflatten_and_copy_device_tree(void) {}
> --
> 2.1.0
> --
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