[PATCH 2/2] cnic,bnx2,bnx2x: use UIO_MEM_DMA_COHERENT

From: Chris Leech
Date: Wed Jan 31 2024 - 14:18:49 EST


Use the UIO_MEM_DMA_COHERENT type to properly handle mmap for
dma_alloc_coherent buffers.

The cnic l2_ring and l2_buf mmaps have caused page refcount issues as
the dma_alloc_coherent no longer provide __GFP_COMP allocation as per
commit "dma-mapping: reject __GFP_COMP in dma_alloc_attrs".

Fix this by having the uio device use dma_mmap_coherent.

The bnx2 and bnx2x status block allocations are also dma_alloc_coherent,
and should use dma_mmap_coherent. They don't allocate multiple pages,
but this interface does not work correctly with an iommu enabled unless
dma_mmap_coherent is used.

Fixes: bb73955c0b1d ("cnic: don't pass bogus GFP_ flags to dma_alloc_coherent")
Signed-off-by: Nilesh Javali <njavali@xxxxxxxxxxx>
Signed-off-by: Chris Leech <cleech@xxxxxxxxxx>
---
drivers/net/ethernet/broadcom/bnx2.c | 1 +
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 2 ++
drivers/net/ethernet/broadcom/cnic.c | 15 ++++++++++++---
drivers/net/ethernet/broadcom/cnic.h | 1 +
drivers/net/ethernet/broadcom/cnic_if.h | 1 +
5 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c
index 0d917a9699c58..b65b8592ad759 100644
--- a/drivers/net/ethernet/broadcom/bnx2.c
+++ b/drivers/net/ethernet/broadcom/bnx2.c
@@ -367,6 +367,7 @@ static void bnx2_setup_cnic_irq_info(struct bnx2 *bp)
cp->irq_arr[0].status_blk = (void *)
((unsigned long) bnapi->status_blk.msi +
(BNX2_SBLK_MSIX_ALIGN_SIZE * sb_id));
+ cp->irq_arr[0].status_blk_map = bp->status_blk_mapping;
cp->irq_arr[0].status_blk_num = sb_id;
cp->num_irq = 1;
}
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
index 0d8e61c63c7c6..678829646cec3 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
@@ -14912,9 +14912,11 @@ void bnx2x_setup_cnic_irq_info(struct bnx2x *bp)
else
cp->irq_arr[0].status_blk = (void *)bp->cnic_sb.e1x_sb;

+ cp->irq_arr[0].status_blk_map = bp->cnic_sb_mapping;
cp->irq_arr[0].status_blk_num = bnx2x_cnic_fw_sb_id(bp);
cp->irq_arr[0].status_blk_num2 = bnx2x_cnic_igu_sb_id(bp);
cp->irq_arr[1].status_blk = bp->def_status_blk;
+ cp->irq_arr[1].status_blk_map = bp->def_status_blk_mapping;
cp->irq_arr[1].status_blk_num = DEF_SB_ID;
cp->irq_arr[1].status_blk_num2 = DEF_SB_IGU_ID;

diff --git a/drivers/net/ethernet/broadcom/cnic.c b/drivers/net/ethernet/broadcom/cnic.c
index 7926aaef8f0c5..cca1e94fc35dc 100644
--- a/drivers/net/ethernet/broadcom/cnic.c
+++ b/drivers/net/ethernet/broadcom/cnic.c
@@ -1107,6 +1107,7 @@ static int cnic_init_uio(struct cnic_dev *dev)
TX_MAX_TSS_RINGS + 1);
uinfo->mem[1].addr = (unsigned long) cp->status_blk.gen &
CNIC_PAGE_MASK;
+ uinfo->mem[1].dma_addr = cp->status_blk_map;
if (cp->ethdev->drv_state & CNIC_DRV_STATE_USING_MSIX)
uinfo->mem[1].size = BNX2_SBLK_MSIX_ALIGN_SIZE * 9;
else
@@ -1118,20 +1119,26 @@ static int cnic_init_uio(struct cnic_dev *dev)

uinfo->mem[1].addr = (unsigned long) cp->bnx2x_def_status_blk &
CNIC_PAGE_MASK;
+ uinfo->mem[1].dma_addr = cp->status_blk_map;
uinfo->mem[1].size = sizeof(*cp->bnx2x_def_status_blk);

uinfo->name = "bnx2x_cnic";
}

- uinfo->mem[1].memtype = UIO_MEM_LOGICAL;
+ uinfo->mem[1].dma_device = &dev->pcidev->dev;
+ uinfo->mem[1].memtype = UIO_MEM_DMA_COHERENT;

uinfo->mem[2].addr = (unsigned long) udev->l2_ring;
+ uinfo->mem[2].dma_addr = udev->l2_ring_map;
uinfo->mem[2].size = udev->l2_ring_size;
- uinfo->mem[2].memtype = UIO_MEM_LOGICAL;
+ uinfo->mem[2].dma_device = &dev->pcidev->dev;
+ uinfo->mem[2].memtype = UIO_MEM_DMA_COHERENT;

uinfo->mem[3].addr = (unsigned long) udev->l2_buf;
+ uinfo->mem[3].dma_addr = udev->l2_buf_map;
uinfo->mem[3].size = udev->l2_buf_size;
- uinfo->mem[3].memtype = UIO_MEM_LOGICAL;
+ uinfo->mem[3].dma_device = &dev->pcidev->dev;
+ uinfo->mem[3].memtype = UIO_MEM_DMA_COHERENT;

uinfo->version = CNIC_MODULE_VERSION;
uinfo->irq = UIO_IRQ_CUSTOM;
@@ -1313,6 +1320,7 @@ static int cnic_alloc_bnx2x_resc(struct cnic_dev *dev)
return 0;

cp->bnx2x_def_status_blk = cp->ethdev->irq_arr[1].status_blk;
+ cp->status_blk_map = cp->ethdev->irq_arr[1].status_blk_map;

cp->l2_rx_ring_size = 15;

@@ -5323,6 +5331,7 @@ static int cnic_start_hw(struct cnic_dev *dev)
pci_dev_get(dev->pcidev);
cp->func = PCI_FUNC(dev->pcidev->devfn);
cp->status_blk.gen = ethdev->irq_arr[0].status_blk;
+ cp->status_blk_map = ethdev->irq_arr[0].status_blk_map;
cp->status_blk_num = ethdev->irq_arr[0].status_blk_num;

err = cp->alloc_resc(dev);
diff --git a/drivers/net/ethernet/broadcom/cnic.h b/drivers/net/ethernet/broadcom/cnic.h
index 4baea81bae7a3..fedc84ada937d 100644
--- a/drivers/net/ethernet/broadcom/cnic.h
+++ b/drivers/net/ethernet/broadcom/cnic.h
@@ -260,6 +260,7 @@ struct cnic_local {
#define SM_RX_ID 0
#define SM_TX_ID 1
} status_blk;
+ dma_addr_t status_blk_map;

struct host_sp_status_block *bnx2x_def_status_blk;

diff --git a/drivers/net/ethernet/broadcom/cnic_if.h b/drivers/net/ethernet/broadcom/cnic_if.h
index 789e5c7e93116..49a11ec80b364 100644
--- a/drivers/net/ethernet/broadcom/cnic_if.h
+++ b/drivers/net/ethernet/broadcom/cnic_if.h
@@ -190,6 +190,7 @@ struct cnic_ops {
struct cnic_irq {
unsigned int vector;
void *status_blk;
+ dma_addr_t status_blk_map;
u32 status_blk_num;
u32 status_blk_num2;
u32 irq_flags;
--
2.43.0