From: Mathias Nyman mathias.nyman@linux.intel.com
commit b106776080a1cf953a1b2fd50cb2a995db4732be upstream.
Up to 64 bytes of data can be read from NVM in one go. Read address must be dword aligned. Data is read into a local buffer.
If caller asks to read data starting at an unaligned address then full dword is anyway read from NVM into a local buffer. Data is then copied from the local buffer starting at the unaligned offset to the caller buffer.
In cases where asked data length + unaligned offset is over 64 bytes we need to make sure we don't read past the 64 bytes in the local buffer when copying to caller buffer, and make sure that we don't skip copying unaligned offset bytes from local buffer anymore after the first round of 64 byte NVM data read.
Fixes: 3e13676862f9 ("thunderbolt: Add support for DMA configuration based mailbox") Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/thunderbolt/dma_port.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
--- a/drivers/thunderbolt/dma_port.c +++ b/drivers/thunderbolt/dma_port.c @@ -366,15 +366,15 @@ int dma_port_flash_read(struct tb_dma_po void *buf, size_t size) { unsigned int retries = DMA_PORT_RETRIES; - unsigned int offset; - - offset = address & 3; - address = address & ~3;
do { - u32 nbytes = min_t(u32, size, MAIL_DATA_DWORDS * 4); + unsigned int offset; + size_t nbytes; int ret;
+ offset = address & 3; + nbytes = min_t(size_t, size + offset, MAIL_DATA_DWORDS * 4); + ret = dma_port_flash_read_block(dma, address, dma->buf, ALIGN(nbytes, 4)); if (ret) { @@ -386,6 +386,7 @@ int dma_port_flash_read(struct tb_dma_po return ret; }
+ nbytes -= offset; memcpy(buf, dma->buf + offset, nbytes);
size -= nbytes;