On 11/2/23 07:25, Lukas Wunner wrote:
Jonathan notes that cxl_cdat_get_length() and cxl_cdat_read_table() allocate 32 dwords for the DOE response even though it may be smaller. In the case of cxl_cdat_get_length(), only the second dword of the response is of interest (it contains the length). So reduce the allocation to 2 dwords and let DOE discard the remainder. In the case of cxl_cdat_read_table(), a correctly sized allocation for the full CDAT already exists. Let DOE write each table entry directly into that allocation. There's a snag in that the table entry is preceded by a Table Access Response Header (1 dword). Save the last dword of the previous table entry, let DOE overwrite it with the header of the next entry and restore it afterwards. The resulting CDAT is preceded by 4 unavoidable useless bytes. Increase the allocation size accordingly and skip these bytes when exposing CDAT in sysfs. The buffer overflow check in cxl_cdat_read_table() becomes unnecessary because the remaining bytes in the allocation are tracked in "length", which is passed to DOE and limits how many bytes it writes to the allocation. Additionally, cxl_cdat_read_table() bails out if the DOE response is truncated due to insufficient space. Tested-by: Ira Weiny <ira.weiny@xxxxxxxxx> Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> --- Changes v2 -> v3: * Newly added patch in v3 on popular request (Jonathan) drivers/cxl/core/pci.c | 34 ++++++++++++++++++----------------
Almost no change from this patchset applied cleanly to drivers/cxl/core/pci.c, what is the patchset based on? Thanks,
-- Alexey
