Re: [linux-next/mainline][bisected 3acac06][ppc] Oops when unloading mpt3sas driver

Christoph Hellwig
2020-01-16T17:44:54Z

Hi Abdul,

I think the problem is that mpt3sas has some convoluted logic to do
some DMA allocations with a 32-bit coherent mask, and then switches
to a 63 or 64 bit mask, which is not supported by the DMA API.

Can you try the patch below?

---
From 0738b1704ed528497b41b0408325f6828a8e51f6 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Thu, 16 Jan 2020 18:31:38 +0100
Subject: mpt3sas: don't change the dma coherent mask after allocations

The DMA layer does not allow changing the DMA coherent mask after
there are outstanding allocations. Stop doing that and always
use a 32-bit coherent DMA mask in mpt3sas.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/scsi/mpt3sas/mpt3sas_base.c | 67 ++++++++---------------------
drivers/scsi/mpt3sas/mpt3sas_base.h | 2 -
2 files changed, 19 insertions(+), 50 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index fea3cb6a090b..3b51bed05008 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -2706,58 +2706,38 @@ _base_build_sg_ieee(struct MPT3SAS_ADAPTER *ioc, void *psge,
static int
_base_config_dma_addressing(struct MPT3SAS_ADAPTER *ioc, struct pci_dev *pdev)
{
- u64 required_mask, coherent_mask;
struct sysinfo s;
- /* Set 63 bit DMA mask for all SAS3 and SAS35 controllers */
- int dma_mask = (ioc->hba_mpi_version_belonged > MPI2_VERSION) ? 63 : 64;
-
- if (ioc->is_mcpu_endpoint)
- goto try_32bit;
+ int dma_mask;

- required_mask = dma_get_required_mask(&pdev->dev);
- if (sizeof(dma_addr_t) == 4 || required_mask == 32)
- goto try_32bit;
-
- if (ioc->dma_mask)
- coherent_mask = DMA_BIT_MASK(dma_mask);
+ if (ioc->is_mcpu_endpoint ||
+ sizeof(dma_addr_t) == 4 ||
+ dma_get_required_mask(&pdev->dev) <= 32)
+ dma_mask = 32;
+ /* Set 63 bit DMA mask for all SAS3 and SAS35 controllers */
+ else if (ioc->hba_mpi_version_belonged > MPI2_VERSION)
+ dma_mask = 63;
else
- coherent_mask = DMA_BIT_MASK(32);
+ dma_mask = 64;

if (dma_set_mask(&pdev->dev, DMA_BIT_MASK(dma_mask)) ||
- dma_set_coherent_mask(&pdev->dev, coherent_mask))
- goto try_32bit;
-
- ioc->base_add_sg_single = &_base_add_sg_single_64;
- ioc->sge_size = sizeof(Mpi2SGESimple64_t);
- ioc->dma_mask = dma_mask;
- goto out;
-
- try_32bit:
- if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)))
+ dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32)))
return -ENODEV;

- ioc->base_add_sg_single = &_base_add_sg_single_32;
- ioc->sge_size = sizeof(Mpi2SGESimple32_t);
- ioc->dma_mask = 32;
- out:
+ if (dma_mask > 32) {
+ ioc->base_add_sg_single = &_base_add_sg_single_64;
+ ioc->sge_size = sizeof(Mpi2SGESimple64_t);
+ } else {
+ ioc->base_add_sg_single = &_base_add_sg_single_32;
+ ioc->sge_size = sizeof(Mpi2SGESimple32_t);
+ }
+
si_meminfo(&s);
ioc_info(ioc, "%d BIT PCI BUS DMA ADDRESSING SUPPORTED, total mem (%ld kB)\n",
- ioc->dma_mask, convert_to_kb(s.totalram));
+ dma_mask, convert_to_kb(s.totalram));

return 0;
}

-static int
-_base_change_consistent_dma_mask(struct MPT3SAS_ADAPTER *ioc,
- struct pci_dev *pdev)
-{
- if (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(ioc->dma_mask))) {
- if (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)))
- return -ENODEV;
- }
- return 0;
-}
-
/**
* _base_check_enable_msix - checks MSIX capabable.
* @ioc: per adapter object
@@ -5030,14 +5010,6 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
total_sz += sz;
} while (ioc->rdpq_array_enable && (++i < ioc->reply_queue_count));

- if (ioc->dma_mask > 32) {
- if (_base_change_consistent_dma_mask(ioc, ioc->pdev) != 0) {
- ioc_warn(ioc, "no suitable consistent DMA mask for %s\n",
- pci_name(ioc->pdev));
- goto out;
- }
- }
-
ioc->scsiio_depth = ioc->hba_queue_depth -
ioc->hi_priority_depth - ioc->internal_depth;

@@ -6965,7 +6937,6 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
ioc->smp_affinity_enable = smp_affinity_enable;

ioc->rdpq_array_enable_assigned = 0;
- ioc->dma_mask = 0;
if (ioc->is_aero_ioc)
ioc->base_readl = &_base_readl_aero;
else
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index faca0a5e71f8..e57cade1155c 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -1011,7 +1011,6 @@ typedef void (*MPT3SAS_FLUSH_RUNNING_CMDS)(struct MPT3SAS_ADAPTER *ioc);
* @ir_firmware: IR firmware present
* @bars: bitmask of BAR's that must be configured
* @mask_interrupts: ignore interrupt
- * @dma_mask: used to set the consistent dma mask
* @pci_access_mutex: Mutex to synchronize ioctl, sysfs show path and
* pci resource handling
* @fault_reset_work_q_name: fw fault work queue
@@ -1185,7 +1184,6 @@ struct MPT3SAS_ADAPTER {
u8 ir_firmware;
int bars;
u8 mask_interrupts;
- int dma_mask;

/* fw fault handler */
char fault_reset_work_q_name[20];
--
2.24.1