| Message ID | 1425380630-3684-6-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 11 March 2015 at 13:09, Mark Rutland <mark.rutland@arm.com> wrote: > On Tue, Mar 03, 2015 at 11:03:50AM +0000, 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 a >> power of 2 upper bound of the size: this way, we are still guaranteed >> not to cross a 2 MB boundary, but will potentially waste less memory >> doing so. >> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> --- >> arch/arm64/include/asm/efi.h | 9 ++++----- >> drivers/firmware/efi/libstub/arm-stub.c | 2 +- >> drivers/firmware/efi/libstub/fdt.c | 7 ++----- >> 3 files changed, 7 insertions(+), 11 deletions(-) >> >> diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h >> index ef572206f1c3..68f7bb2ddad7 100644 >> --- a/arch/arm64/include/asm/efi.h >> +++ b/arch/arm64/include/asm/efi.h >> @@ -39,12 +39,11 @@ 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 cross a 2MiB boundary. >> + * So align to a power of 2 upper bound of the FDT 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(x) roundup_pow_of_two(x) >> +#define MAX_FDT_OFFSET ULONG_MAX >> >> #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..c58c21c22dbe 100644 >> --- a/drivers/firmware/efi/libstub/arm-stub.c >> +++ b/drivers/firmware/efi/libstub/arm-stub.c >> @@ -269,7 +269,7 @@ 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, >> + &new_fdt_addr, MAX_FDT_OFFSET, > > Do we still need the max_addr parameter and MAX_FDT_OFFSET, or can we > just have allocate_new_fdt_and_exit_boot assume it can allocate anywhere > in the physical address space (or ULONG_MAX if we want to allocate below > 4GB whenever we get 32-bit EFI stub support). > Yes, I could probably drop the parameter and hardcode ULONG_MAX in there. (32-bit EFI stub support is still on our todo list, but nobody is actually working on it atm)
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index ef572206f1c3..68f7bb2ddad7 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -39,12 +39,11 @@ 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 cross a 2MiB boundary. + * So align to a power of 2 upper bound of the FDT 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(x) roundup_pow_of_two(x) +#define MAX_FDT_OFFSET ULONG_MAX #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..c58c21c22dbe 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -269,7 +269,7 @@ 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, + &new_fdt_addr, MAX_FDT_OFFSET, initrd_addr, initrd_size, cmdline_ptr, fdt_addr, fdt_size); diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index 91da56c4fd54..1a44d410a63b 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 @@ -223,7 +219,8 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, */ new_fdt_size = fdt_size + EFI_PAGE_SIZE; while (1) { - status = efi_high_alloc(sys_table, new_fdt_size, EFI_FDT_ALIGN, + status = efi_high_alloc(sys_table, new_fdt_size, + EFI_FDT_ALIGN(new_fdt_size), new_fdt_addr, max_addr); if (status != EFI_SUCCESS) { pr_efi_err(sys_table, "Unable to allocate memory for new device tree.\n");
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 a power of 2 upper bound of the size: this way, we are still guaranteed not to cross a 2 MB boundary, but will potentially waste less memory doing so. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/include/asm/efi.h | 9 ++++----- drivers/firmware/efi/libstub/arm-stub.c | 2 +- drivers/firmware/efi/libstub/fdt.c | 7 ++----- 3 files changed, 7 insertions(+), 11 deletions(-)