mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-04 18:19:28 +09:00
2fe2434392
The driver supports a "direct" mode of operation, where the SMP req frame is directly copied into the command payload (and vice-versa for the SMP resp). To get at the SMP req frame data in the scatterlist the driver uses phys_to_virt() on the DMA mapped memory dma_addr_t . This is broken, and subsequently crashes as follows when an IOMMU is enabled: Unable to handle kernel paging request at virtual address ffff0000fcebfb00 ... pc : pm80xx_chip_smp_req+0x2d0/0x3d0 lr : pm80xx_chip_smp_req+0xac/0x3d0 pm80xx_chip_smp_req+0x2d0/0x3d0 pm8001_task_exec.constprop.0+0x368/0x520 pm8001_queue_command+0x1c/0x30 smp_execute_task_sg+0xdc/0x204 sas_discover_expander.part.0+0xac/0x6cc sas_discover_root_expander+0x8c/0x150 sas_discover_domain+0x3ac/0x6a0 process_one_work+0x1d0/0x354 worker_thread+0x13c/0x470 kthread+0x17c/0x190 ret_from_fork+0x10/0x20 Code: 371806e1 910006d6 6b16033f 54000249 (38766b05) ---[ end trace b91d59aaee98ea2d ]--- note: kworker/u192:0[7] exited with preempt_count 1 Instead use kmap_atomic(). -- Difference to v1: - use kmap_atomic() in both locations Difference to v2: - add whitespace around arithmetic (Damien) Link: https://lore.kernel.org/r/1639390248-213603-1-git-send-email-john.garry@huawei.com Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.