On Fri, Aug 11, 2017 at 2:10 PM, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 08/11/2017 07:27 PM, Rob Clark wrote:
On Fri, Aug 11, 2017 at 12:58 PM, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 08/10/2017 08:29 PM, Rob Clark wrote:
This avoids printf() spam about file reads (such as loading an image) into unaligned buffers (and the associated memcpy()). And generally seems like a good idea.
Signed-off-by: Rob Clark robdclark@gmail.com
lib/efi_loader/efi_memory.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c index 9e079f1fa3..2ba8d8b42b 100644 --- a/lib/efi_loader/efi_memory.c +++ b/lib/efi_loader/efi_memory.c @@ -43,7 +43,7 @@ void *efi_bounce_buffer; */ struct efi_pool_allocation { u64 num_pages;
char data[];
char data[] __attribute__((aligned(ARCH_DMA_MINALIGN)));};
/* @@ -356,7 +356,8 @@ efi_status_t efi_allocate_pool(int pool_type, unsigned long size, { efi_status_t r; efi_physical_addr_t t;
u64 num_pages = (size + sizeof(u64) + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
u64 num_pages = DIV_ROUND_UP(size + sizeof(struct efi_pool_allocation),EFI_PAGE_SIZE);It seems you missed my mail dated 2017-08-02T01:21Z:
With DIV_ROUND_UP you introduce a 64bit division. Depending on the architecture this is only available via stdlib which is not available in U-Boot.
Please, use
- EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
as in the original line.
I didn't miss it.. but I did disagree with it. It is an unsigned division by a power-of-two. The compiler turns this into a right-shift. So in fact both ways generate the same code, but the DIV_ROUND_UP() is more clear.
BR, -R
I compiled:
int main(int argc, char *argv[]) { long long int a = 16; long long int b = 2; long long int c; c = a / b; return c; }
on a mips system with gcc 6.3
gcc -O0 -nostdlib test.c > test
and got
/tmp/ccenefOj.o: In function `main': test.c:(.text+0x48): undefined reference to `__divdi3' test.c:(.text+0x60): undefined reference to `__divdi3'
Note that EFI_LOADER does not even compile with -O0.. but try: c = a / 2;
my guess is with -O0 gcc is not doing constant propagation.
I did already try this on aarch64 with -O0 (but without the variable in between)
BR, -R