On Thu, Apr 14, 2016 at 01:10:35PM +0200, Ard Biesheuvel wrote:
> On 14 April 2016 at 13:02, Steve Capper <steve.capper@xxxxxxx> wrote:
> > On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote:
> >> From: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> >>
> >> There are two problems with the UEFI stub DT memory node removal
> >> routine:
> >> - it deletes nodes as it traverses the tree, which happens to work
> >> but is not supported, as deletion invalidates the node iterator;
> >> - deleting memory nodes entirely may discard annotations in the form
> >> of additional properties on the nodes.
> >>
> >> Since the discovery of DT memory nodes occurs strictly before the
> >> UEFI init sequence, we can simply clear the memblock memory table
> >> before parsing the UEFI memory map. This way, it is no longer
> >> necessary to remove the nodes, so we can remove that logic from the
> >> stub as well.
> >>
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> >> Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
> >> ---
> >> drivers/firmware/efi/arm-init.c | 8 ++++++++
> >> drivers/firmware/efi/libstub/fdt.c | 24 +-----------------------
> >> 2 files changed, 9 insertions(+), 23 deletions(-)
> >>
> >> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
> >> index aa1f743..5d6945b 100644
> >> --- a/drivers/firmware/efi/arm-init.c
> >> +++ b/drivers/firmware/efi/arm-init.c
> >> @@ -143,6 +143,14 @@ static __init void reserve_regions(void)
> >> if (efi_enabled(EFI_DBG))
> >> pr_info("Processing EFI memory map:\n");
> >>
> >> + /*
> >> + * Discard memblocks discovered so far: if there are any at this
> >> + * point, they originate from memory nodes in the DT, and UEFI
> >> + * uses its own memory map instead.
> >> + */
> >> + memblock_dump_all();
> >> + memblock_remove(0, ULLONG_MAX);
> >> +
> >
> > Does this change need to be applied to any other architectures given
> > that deletion code has been removed from libstub below?
> >
>
> The 'generic' libstub code below is only used by ARM, so we're safe
> here in that regard.
Thanks Ard,
In that case, FWIW:
Acked-by: Steve Capper <steve.capper@xxxxxxx>
Cheers,
--
Steve
>
>
> >> for_each_efi_memory_desc(&memmap, md) {
> >> paddr = md->phys_addr;
> >> npages = md->num_pages;
> >> diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
> >> index 6dba78a..e58abfa 100644
> >> --- a/drivers/firmware/efi/libstub/fdt.c
> >> +++ b/drivers/firmware/efi/libstub/fdt.c
> >> @@ -24,7 +24,7 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
> >> unsigned long map_size, unsigned long desc_size,
> >> u32 desc_ver)
> >> {
> >> - int node, prev, num_rsv;
> >> + int node, num_rsv;
> >> int status;
> >> u32 fdt_val32;
> >> u64 fdt_val64;
> >> @@ -54,28 +54,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
> >> goto fdt_set_fail;
> >>
> >> /*
> >> - * Delete any memory nodes present. We must delete nodes which
> >> - * early_init_dt_scan_memory may try to use.
> >> - */
> >> - prev = 0;
> >> - for (;;) {
> >> - const char *type;
> >> - int len;
> >> -
> >> - node = fdt_next_node(fdt, prev, NULL);
> >> - if (node < 0)
> >> - break;
> >> -
> >> - type = fdt_getprop(fdt, node, "device_type", &len);
> >> - if (type && strncmp(type, "memory", len) == 0) {
> >> - fdt_del_node(fdt, node);
> >> - continue;
> >> - }
> >> -
> >> - prev = node;
> >> - }
> >> -
> >> - /*
> >> * Delete all memory reserve map entries. When booting via UEFI,
> >> * kernel will use the UEFI memory map to find reserved regions.
> >> */
> >> --
> >> 1.8.3.1
> >>
> >>
> >> _______________________________________________
> >> linux-arm-kernel mailing list
> >> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >>
>
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