[PATCH v3 05/11] arm64/efi: adapt to relaxed FDT placement requirements
Ard Biesheuvel
ard.biesheuvel at linaro.org
Mon Apr 13 09:25:55 PDT 2015
On 13 April 2015 at 18:20, Mark Rutland <mark.rutland at arm.com> wrote:
> On Fri, Apr 10, 2015 at 02:53:49PM +0100, Ard Biesheuvel wrote:
>> With the relaxed FDT placement requirements in place, we can change
>> the allocation strategy used by the stub to put the FDT image higher
>> up in memory. At the same time, reduce the minimal alignment to 8 bytes,
>> and impose a 2 MB size limit, as per the new requirements.
>>
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
>> ---
>> arch/arm64/include/asm/efi.h | 8 +++-----
>> drivers/firmware/efi/libstub/arm-stub.c | 5 ++---
>> drivers/firmware/efi/libstub/efistub.h | 1 -
>> drivers/firmware/efi/libstub/fdt.c | 23 +++++++++++++----------
>> 4 files changed, 18 insertions(+), 19 deletions(-)
>>
>> diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
>> index ef572206f1c3..bd513dd663b9 100644
>> --- a/arch/arm64/include/asm/efi.h
>> +++ b/arch/arm64/include/asm/efi.h
>> @@ -39,12 +39,10 @@ extern void efi_init(void);
>> /* arch specific definitions used by the stub code */
>>
>> /*
>> - * AArch64 requires the DTB to be 8-byte aligned in the first 512MiB from
>> - * start of kernel and may not cross a 2MiB boundary. We set alignment to
>> - * 2MiB so we know it won't cross a 2MiB boundary.
>> + * AArch64 requires the DTB to be 8-byte aligned and not exceed 2MiB in size.
>> */
>> -#define EFI_FDT_ALIGN SZ_2M /* used by allocate_new_fdt_and_exit_boot() */
>> -#define MAX_FDT_OFFSET SZ_512M
>> +#define EFI_FDT_ALIGN 8
>> +#define EFI_FDT_MAX_SIZE SZ_2M
>
> Is there any way we can organise things so we can share the kernel's
> MAX_FDT_SIZE definition, so as to keep the stub and kernel in sync?
>
I'll put MAX_FDT_SIZE in asm/page.h (unless you can propose a better place)
That way, both fixmap.h and efi.h can refer to it.
> Otherwise, the patch looks good to me.
>
> Mark.
>
>>
>> #define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__)
>>
>> diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
>> index dcae482a9a17..f54c76a4fd32 100644
>> --- a/drivers/firmware/efi/libstub/arm-stub.c
>> +++ b/drivers/firmware/efi/libstub/arm-stub.c
>> @@ -269,9 +269,8 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
>>
>> new_fdt_addr = fdt_addr;
>> status = allocate_new_fdt_and_exit_boot(sys_table, handle,
>> - &new_fdt_addr, dram_base + MAX_FDT_OFFSET,
>> - initrd_addr, initrd_size, cmdline_ptr,
>> - fdt_addr, fdt_size);
>> + &new_fdt_addr, initrd_addr, initrd_size,
>> + cmdline_ptr, fdt_addr, fdt_size);
>>
>> /*
>> * If all went well, we need to return the FDT address to the
>> diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
>> index 47437b16b186..c8e096094ea9 100644
>> --- a/drivers/firmware/efi/libstub/efistub.h
>> +++ b/drivers/firmware/efi/libstub/efistub.h
>> @@ -35,7 +35,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
>> efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
>> void *handle,
>> unsigned long *new_fdt_addr,
>> - unsigned long max_addr,
>> u64 initrd_addr, u64 initrd_size,
>> char *cmdline_ptr,
>> unsigned long fdt_addr,
>> diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
>> index 91da56c4fd54..ace5ed70a88e 100644
>> --- a/drivers/firmware/efi/libstub/fdt.c
>> +++ b/drivers/firmware/efi/libstub/fdt.c
>> @@ -165,10 +165,6 @@ fdt_set_fail:
>> return EFI_LOAD_ERROR;
>> }
>>
>> -#ifndef EFI_FDT_ALIGN
>> -#define EFI_FDT_ALIGN EFI_PAGE_SIZE
>> -#endif
>> -
>> /*
>> * Allocate memory for a new FDT, then add EFI, commandline, and
>> * initrd related fields to the FDT. This routine increases the
>> @@ -186,7 +182,6 @@ fdt_set_fail:
>> efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
>> void *handle,
>> unsigned long *new_fdt_addr,
>> - unsigned long max_addr,
>> u64 initrd_addr, u64 initrd_size,
>> char *cmdline_ptr,
>> unsigned long fdt_addr,
>> @@ -197,6 +192,7 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
>> unsigned long mmap_key;
>> efi_memory_desc_t *memory_map, *runtime_map;
>> unsigned long new_fdt_size;
>> + void *fdt_alloc;
>> efi_status_t status;
>> int runtime_entry_count = 0;
>>
>> @@ -221,14 +217,21 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
>> * will allocate a bigger buffer if this ends up being too
>> * small, so a rough guess is OK here.
>> */
>> - new_fdt_size = fdt_size + EFI_PAGE_SIZE;
>> + new_fdt_size = fdt_size + EFI_PAGE_SIZE + EFI_FDT_ALIGN;
>> while (1) {
>> - status = efi_high_alloc(sys_table, new_fdt_size, EFI_FDT_ALIGN,
>> - new_fdt_addr, max_addr);
>> + if (new_fdt_size > EFI_FDT_MAX_SIZE) {
>> + pr_efi_err(sys_table, "FDT size exceeds EFI_FDT_MAX_SIZE.\n");
>> + goto fail;
>> + }
>> + status = sys_table->boottime->allocate_pool(EFI_LOADER_DATA,
>> + new_fdt_size,
>> + &fdt_alloc);
>> if (status != EFI_SUCCESS) {
>> pr_efi_err(sys_table, "Unable to allocate memory for new device tree.\n");
>> goto fail;
>> }
>> + *new_fdt_addr = round_up((unsigned long)fdt_alloc,
>> + EFI_FDT_ALIGN);
>>
>> /*
>> * Now that we have done our final memory allocation (and free)
>> @@ -258,7 +261,7 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
>> * to get new one that reflects the free/alloc we do
>> * on the device tree buffer.
>> */
>> - efi_free(sys_table, new_fdt_size, *new_fdt_addr);
>> + sys_table->boottime->free_pool(&fdt_alloc);
>> sys_table->boottime->free_pool(memory_map);
>> new_fdt_size += EFI_PAGE_SIZE;
>> } else {
>> @@ -316,7 +319,7 @@ fail_free_mmap:
>> sys_table->boottime->free_pool(memory_map);
>>
>> fail_free_new_fdt:
>> - efi_free(sys_table, new_fdt_size, *new_fdt_addr);
>> + sys_table->boottime->free_pool(&fdt_alloc);
>>
>> fail:
>> sys_table->boottime->free_pool(runtime_map);
>> --
>> 1.8.3.2
>>
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