diff options
Diffstat (limited to 'drivers/gpu/drm/drm_panic_qr.rs')
| -rw-r--r-- | drivers/gpu/drm/drm_panic_qr.rs | 104 |
1 files changed, 65 insertions, 39 deletions
diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs index f2a99681b998..dd55b1cb764d 100644 --- a/drivers/gpu/drm/drm_panic_qr.rs +++ b/drivers/gpu/drm/drm_panic_qr.rs @@ -5,7 +5,7 @@ //! It is called from a panic handler, so it should't allocate memory and //! does all the work on the stack or on the provided buffers. For //! simplification, it only supports low error correction, and applies the -//! first mask (checkerboard). It will draw the smallest QRcode that can +//! first mask (checkerboard). It will draw the smallest QR code that can //! contain the string passed as parameter. To get the most compact //! QR code, the start of the URL is encoded as binary, and the //! compressed kmsg is encoded as numeric. @@ -315,7 +315,7 @@ impl Segment<'_> { } } - // Returns the size of the length field in bits, depending on QR Version. + /// Returns the size of the length field in bits, depending on QR Version. fn length_bits_count(&self, version: Version) -> usize { let Version(v) = version; match self { @@ -331,7 +331,7 @@ impl Segment<'_> { } } - // Number of characters in the segment. + /// Number of characters in the segment. fn character_count(&self) -> usize { match self { Segment::Binary(data) => data.len(), @@ -366,8 +366,48 @@ impl Segment<'_> { SegmentIterator { segment: self, offset: 0, - carry: 0, - carry_len: 0, + decfifo: Default::default(), + } + } +} + +/// Max fifo size is 17 (max push) + 2 (max remaining) +const MAX_FIFO_SIZE: usize = 19; + +/// A simple Decimal digit FIFO +#[derive(Default)] +struct DecFifo { + decimals: [u8; MAX_FIFO_SIZE], + len: usize, +} + +impl DecFifo { + fn push(&mut self, data: u64, len: usize) { + let mut chunk = data; + for i in (0..self.len).rev() { + self.decimals[i + len] = self.decimals[i]; + } + for i in 0..len { + self.decimals[i] = (chunk % 10) as u8; + chunk /= 10; + } + self.len += len; + } + + /// Pop 3 decimal digits from the FIFO + fn pop3(&mut self) -> Option<(u16, usize)> { + if self.len == 0 { + None + } else { + let poplen = 3.min(self.len); + self.len -= poplen; + let mut out = 0; + let mut exp = 1; + for i in 0..poplen { + out += self.decimals[self.len + i] as u16 * exp; + exp *= 10; + } + Some((out, NUM_CHARS_BITS[poplen])) } } } @@ -375,8 +415,7 @@ impl Segment<'_> { struct SegmentIterator<'a> { segment: &'a Segment<'a>, offset: usize, - carry: u64, - carry_len: usize, + decfifo: DecFifo, } impl Iterator for SegmentIterator<'_> { @@ -394,31 +433,17 @@ impl Iterator for SegmentIterator<'_> { } } Segment::Numeric(data) => { - if self.carry_len < 3 && self.offset < data.len() { - // If there are less than 3 decimal digits in the carry, - // take the next 7 bytes of input, and add them to the carry. + if self.decfifo.len < 3 && self.offset < data.len() { + // If there are less than 3 decimal digits in the fifo, + // take the next 7 bytes of input, and push them to the fifo. let mut buf = [0u8; 8]; let len = 7.min(data.len() - self.offset); buf[..len].copy_from_slice(&data[self.offset..self.offset + len]); let chunk = u64::from_le_bytes(buf); - let pow = u64::pow(10, BYTES_TO_DIGITS[len] as u32); - self.carry = chunk + self.carry * pow; + self.decfifo.push(chunk, BYTES_TO_DIGITS[len]); self.offset += len; - self.carry_len += BYTES_TO_DIGITS[len]; - } - match self.carry_len { - 0 => None, - len => { - // take the next 3 decimal digits of the carry - // and return 10bits of numeric data. - let out_len = 3.min(len); - self.carry_len -= out_len; - let pow = u64::pow(10, self.carry_len as u32); - let out = (self.carry / pow) as u16; - self.carry = self.carry % pow; - Some((out, NUM_CHARS_BITS[out_len])) - } } + self.decfifo.pop3() } } } @@ -569,8 +594,8 @@ struct EncodedMsgIterator<'a> { impl Iterator for EncodedMsgIterator<'_> { type Item = u8; - // Send the bytes in interleaved mode, first byte of first block of group1, - // then first byte of second block of group1, ... + /// Send the bytes in interleaved mode, first byte of first block of group1, + /// then first byte of second block of group1, ... fn next(&mut self) -> Option<Self::Item> { let em = self.em; let blocks = em.g1_blocks + em.g2_blocks; @@ -638,7 +663,7 @@ impl QrImage<'_> { self.data.fill(0); } - // Set pixel to light color. + /// Set pixel to light color. fn set(&mut self, x: u8, y: u8) { let off = y as usize * self.stride as usize + x as usize / 8; let mut v = self.data[off]; @@ -646,13 +671,13 @@ impl QrImage<'_> { self.data[off] = v; } - // Invert a module color. + /// Invert a module color. fn xor(&mut self, x: u8, y: u8) { let off = y as usize * self.stride as usize + x as usize / 8; self.data[off] ^= 0x80 >> (x % 8); } - // Draw a light square at (x, y) top left corner. + /// Draw a light square at (x, y) top left corner. fn draw_square(&mut self, x: u8, y: u8, size: u8) { for k in 0..size { self.set(x + k, y); @@ -784,7 +809,7 @@ impl QrImage<'_> { vinfo != 0 && ((x >= pos && x < pos + 3 && y < 6) || (y >= pos && y < pos + 3 && x < 6)) } - // Returns true if the module is reserved (Not usable for data and EC). + /// Returns true if the module is reserved (Not usable for data and EC). fn is_reserved(&self, x: u8, y: u8) -> bool { self.is_alignment(x, y) || self.is_finder(x, y) @@ -793,13 +818,14 @@ impl QrImage<'_> { || self.is_version_info(x, y) } - // Last module to draw, at bottom left corner. + /// Last module to draw, at bottom left corner. fn is_last(&self, x: u8, y: u8) -> bool { x == 0 && y == self.width - 1 } - // Move to the next module according to QR code order. - // From bottom right corner, to bottom left corner. + /// Move to the next module according to QR code order. + /// + /// From bottom right corner, to bottom left corner. fn next(&self, x: u8, y: u8) -> (u8, u8) { let x_adj = if x <= 6 { x + 1 } else { x }; let column_type = (self.width - x_adj) % 4; @@ -812,7 +838,7 @@ impl QrImage<'_> { } } - // Find next module that can hold data. + /// Find next module that can hold data. fn next_available(&self, x: u8, y: u8) -> (u8, u8) { let (mut x, mut y) = self.next(x, y); while self.is_reserved(x, y) && !self.is_last(x, y) { @@ -841,7 +867,7 @@ impl QrImage<'_> { } } - // Apply checkerboard mask to all non-reserved modules. + /// Apply checkerboard mask to all non-reserved modules. fn apply_mask(&mut self) { for x in 0..self.width { for y in 0..self.width { @@ -852,7 +878,7 @@ impl QrImage<'_> { } } - // Draw the QR code with the provided data iterator. + /// Draw the QR code with the provided data iterator. fn draw_all(&mut self, data: impl Iterator<Item = u8>) { // First clear the table, as it may have already some data. self.clear(); @@ -876,7 +902,7 @@ impl QrImage<'_> { /// will be encoded as binary segment, otherwise it will be encoded /// efficiently as a numeric segment, and appended to the URL. /// * `data_len`: Length of the data, that needs to be encoded, must be less -/// than data_size. +/// than `data_size`. /// * `data_size`: Size of data buffer, it should be at least 4071 bytes to hold /// a V40 QR code. It will then be overwritten with the QR code image. /// * `tmp`: A temporary buffer that the QR code encoder will use, to write the |