diff options
Diffstat (limited to 'drivers/gpu/drm/drm_panic_qr.rs')
| -rw-r--r-- | drivers/gpu/drm/drm_panic_qr.rs | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs index 18492daae4b3..50c286c5cee8 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; } @@ -404,7 +424,7 @@ impl DecFifo { let mut out = 0; let mut exp = 1; for i in 0..poplen { - out += self.decimals[self.len + i] as u16 * exp; + out += u16::from(self.decimals[self.len + i]) * exp; exp *= 10; } Some((out, NUM_CHARS_BITS[poplen])) @@ -425,7 +445,7 @@ impl Iterator for SegmentIterator<'_> { match self.segment { Segment::Binary(data) => { if self.offset < data.len() { - let byte = data[self.offset] as u16; + let byte = u16::from(data[self.offset]); self.offset += 1; Some((byte, 8)) } else { |