From: John Garry john.garry@huawei.com
[ Upstream commit 2fe24343922e0428fb68674a4fae099171141bc7 ]
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@huaw... 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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/pm8001/pm80xx_hwi.c | 38 ++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 17 deletions(-)
diff --git a/drivers/scsi/pm8001/pm80xx_hwi.c b/drivers/scsi/pm8001/pm80xx_hwi.c index a203a4fc2674a..4badd2ad2a460 100644 --- a/drivers/scsi/pm8001/pm80xx_hwi.c +++ b/drivers/scsi/pm8001/pm80xx_hwi.c @@ -2965,7 +2965,6 @@ mpi_smp_completion(struct pm8001_hba_info *pm8001_ha, void *piomb) struct smp_completion_resp *psmpPayload; struct task_status_struct *ts; struct pm8001_device *pm8001_dev; - char *pdma_respaddr = NULL;
psmpPayload = (struct smp_completion_resp *)(piomb + 4); status = le32_to_cpu(psmpPayload->status); @@ -2992,19 +2991,23 @@ mpi_smp_completion(struct pm8001_hba_info *pm8001_ha, void *piomb) if (pm8001_dev) atomic_dec(&pm8001_dev->running_req); if (pm8001_ha->smp_exp_mode == SMP_DIRECT) { + struct scatterlist *sg_resp = &t->smp_task.smp_resp; + u8 *payload; + void *to; + pm8001_dbg(pm8001_ha, IO, "DIRECT RESPONSE Length:%d\n", param); - pdma_respaddr = (char *)(phys_to_virt(cpu_to_le64 - ((u64)sg_dma_address - (&t->smp_task.smp_resp)))); + to = kmap_atomic(sg_page(sg_resp)); + payload = to + sg_resp->offset; for (i = 0; i < param; i++) { - *(pdma_respaddr+i) = psmpPayload->_r_a[i]; + *(payload + i) = psmpPayload->_r_a[i]; pm8001_dbg(pm8001_ha, IO, "SMP Byte%d DMA data 0x%x psmp 0x%x\n", - i, *(pdma_respaddr + i), + i, *(payload + i), psmpPayload->_r_a[i]); } + kunmap_atomic(to); } break; case IO_ABORTED: @@ -4133,14 +4136,14 @@ static int pm80xx_chip_smp_req(struct pm8001_hba_info *pm8001_ha, struct sas_task *task = ccb->task; struct domain_device *dev = task->dev; struct pm8001_device *pm8001_dev = dev->lldd_dev; - struct scatterlist *sg_req, *sg_resp; + struct scatterlist *sg_req, *sg_resp, *smp_req; u32 req_len, resp_len; struct smp_req smp_cmd; u32 opc; struct inbound_queue_table *circularQ; - char *preq_dma_addr = NULL; - __le64 tmp_addr; u32 i, length; + u8 *payload; + u8 *to;
memset(&smp_cmd, 0, sizeof(smp_cmd)); /* @@ -4177,8 +4180,9 @@ static int pm80xx_chip_smp_req(struct pm8001_hba_info *pm8001_ha, pm8001_ha->smp_exp_mode = SMP_INDIRECT;
- tmp_addr = cpu_to_le64((u64)sg_dma_address(&task->smp_task.smp_req)); - preq_dma_addr = (char *)phys_to_virt(tmp_addr); + smp_req = &task->smp_task.smp_req; + to = kmap_atomic(sg_page(smp_req)); + payload = to + smp_req->offset;
/* INDIRECT MODE command settings. Use DMA */ if (pm8001_ha->smp_exp_mode == SMP_INDIRECT) { @@ -4186,7 +4190,7 @@ static int pm80xx_chip_smp_req(struct pm8001_hba_info *pm8001_ha, /* for SPCv indirect mode. Place the top 4 bytes of * SMP Request header here. */ for (i = 0; i < 4; i++) - smp_cmd.smp_req16[i] = *(preq_dma_addr + i); + smp_cmd.smp_req16[i] = *(payload + i); /* exclude top 4 bytes for SMP req header */ smp_cmd.long_smp_req.long_req_addr = cpu_to_le64((u64)sg_dma_address @@ -4217,20 +4221,20 @@ static int pm80xx_chip_smp_req(struct pm8001_hba_info *pm8001_ha, pm8001_dbg(pm8001_ha, IO, "SMP REQUEST DIRECT MODE\n"); for (i = 0; i < length; i++) if (i < 16) { - smp_cmd.smp_req16[i] = *(preq_dma_addr+i); + smp_cmd.smp_req16[i] = *(payload + i); pm8001_dbg(pm8001_ha, IO, "Byte[%d]:%x (DMA data:%x)\n", i, smp_cmd.smp_req16[i], - *(preq_dma_addr)); + *(payload)); } else { - smp_cmd.smp_req[i] = *(preq_dma_addr+i); + smp_cmd.smp_req[i] = *(payload + i); pm8001_dbg(pm8001_ha, IO, "Byte[%d]:%x (DMA data:%x)\n", i, smp_cmd.smp_req[i], - *(preq_dma_addr)); + *(payload)); } } - + kunmap_atomic(to); build_smp_cmd(pm8001_dev->device_id, smp_cmd.tag, &smp_cmd, pm8001_ha->smp_exp_mode, length); rc = pm8001_mpi_build_cmd(pm8001_ha, circularQ, opc, &smp_cmd,