diff options
Diffstat (limited to 'drivers/gpu/drm/drm_panic_qr.rs')
| -rw-r--r-- | drivers/gpu/drm/drm_panic_qr.rs | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs index 09a9b452e8b7..ac27e86c601c 100644 --- a/drivers/gpu/drm/drm_panic_qr.rs +++ b/drivers/gpu/drm/drm_panic_qr.rs @@ -381,6 +381,26 @@ struct DecFifo { len: usize, } +// On arm32 architecture, dividing an `u64` by a constant will generate a call +// to `__aeabi_uldivmod` which is not present in the kernel. +// So use the multiply by inverse method for this architecture. +fn div10(val: u64) -> u64 { + if cfg!(target_arch = "arm") { + let val_h = val >> 32; + let val_l = val & 0xFFFFFFFF; + let b_h: u64 = 0x66666666; + let b_l: u64 = 0x66666667; + + let tmp1 = val_h * b_l + ((val_l * b_l) >> 32); + let tmp2 = val_l * b_h + (tmp1 & 0xffffffff); + let tmp3 = val_h * b_h + (tmp1 >> 32) + (tmp2 >> 32); + + tmp3 >> 2 + } else { + val / 10 + } +} + impl DecFifo { fn push(&mut self, data: u64, len: usize) { let mut chunk = data; @@ -389,7 +409,7 @@ impl DecFifo { } for i in 0..len { self.decimals[i] = (chunk % 10) as u8; - chunk /= 10; + chunk = div10(chunk); } self.len += len; } @@ -948,7 +968,7 @@ pub unsafe extern "C" fn drm_panic_qr_generate( // nul-terminated string. let url_cstr: &CStr = unsafe { CStr::from_char_ptr(url) }; let segments = &[ - &Segment::Binary(url_cstr.as_bytes()), + &Segment::Binary(url_cstr.to_bytes()), &Segment::Numeric(&data_slice[0..data_len]), ]; match EncodedMsg::new(segments, tmp_slice) { |