[PATCH] enic: switch from 'pci_' to 'dma_' API

From: Christophe JAILLET
Date: Sun Sep 06 2020 - 08:47:50 EST

The wrappers in include/linux/pci-dma-compat.h should go away.

The patch has been generated with the coccinelle script below and has been
hand modified to replace GFP_ with a correct flag.
It has been compile tested.

When memory is allocated in 'vnic_dev_classifier()', 'vnic_dev_fw_info()',
'vnic_dev_notify_set()' and 'vnic_dev_stats_dump()' (vnic_dev.c) GFP_ATOMIC
must be used because its callers take a spinlock before calling these
functions.

When memory is allocated in '__enic_set_rsskey()' and 'enic_set_rsscpu()'
GFP_ATOMIC must be used because they can be called with a spinlock.
The call chain is:
enic_reset <-- takes 'enic->enic_api_lock'
--> enic_set_rss_nic_cfg
--> enic_set_rsskey
--> __enic_set_rsskey <-- uses dma_alloc_coherent
--> enic_set_rsscpu <-- uses dma_alloc_coherent

When memory is allocated in 'vnic_dev_init_prov2()' GFP_ATOMIC must be used
because a spinlock is hidden in the ENIC_DEVCMD_PROXY_BY_INDEX macro, when
this function is called in 'enic_set_port_profile()'.

When memory is allocated in 'vnic_dev_alloc_desc_ring()' GFP_KERNEL can be
used because it is only called from 5 functions ('vnic_dev_init_devcmd2()',
'vnic_cq_alloc()', 'vnic_rq_alloc()', 'vnic_wq_alloc()' and
'enic_wq_devcmd2_alloc()'.

'vnic_dev_init_devcmd2()': already uses GFP_KERNEL and no lock is taken
in the between.
'enic_wq_devcmd2_alloc()': is called from ' vnic_dev_init_devcmd2()'
which already uses GFP_KERNEL and no lock is taken in the between.
'vnic_cq_alloc()', 'vnic_rq_alloc()', 'vnic_wq_alloc()': are called
from 'enic_alloc_vnic_resources()'
'enic_alloc_vnic_resources()' has only 2 call chains:

1) enic_probe
--> enic_dev_init
--> enic_alloc_vnic_resources
'enic_probe()' is a probe function and no lock is taken in the between

2) enic_set_ringparam
--> enic_alloc_vnic_resources
'enic_set_ringparam()' is a .set_ringparam function (see struct
ethtool_ops). It seems to only take a mutex and no spinlock.


So all paths are safe to use GFP_KERNEL.


@@
@@
- PCI_DMA_BIDIRECTIONAL
+ DMA_BIDIRECTIONAL

@@
@@
- PCI_DMA_TODEVICE
+ DMA_TO_DEVICE

@@
@@
- PCI_DMA_FROMDEVICE
+ DMA_FROM_DEVICE

@@
@@
- PCI_DMA_NONE
+ DMA_NONE

@@
expression e1, e2, e3;
@@
- pci_alloc_consistent(e1, e2, e3)
+ dma_alloc_coherent(&e1->dev, e2, e3, GFP_)

@@
expression e1, e2, e3;
@@
- pci_zalloc_consistent(e1, e2, e3)
+ dma_alloc_coherent(&e1->dev, e2, e3, GFP_)

@@
expression e1, e2, e3, e4;
@@
- pci_free_consistent(e1, e2, e3, e4)
+ dma_free_coherent(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
- pci_map_single(e1, e2, e3, e4)
+ dma_map_single(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
- pci_unmap_single(e1, e2, e3, e4)
+ dma_unmap_single(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4, e5;
@@
- pci_map_page(e1, e2, e3, e4, e5)
+ dma_map_page(&e1->dev, e2, e3, e4, e5)

@@
expression e1, e2, e3, e4;
@@
- pci_unmap_page(e1, e2, e3, e4)
+ dma_unmap_page(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
- pci_map_sg(e1, e2, e3, e4)
+ dma_map_sg(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
- pci_unmap_sg(e1, e2, e3, e4)
+ dma_unmap_sg(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
- pci_dma_sync_single_for_cpu(e1, e2, e3, e4)
+ dma_sync_single_for_cpu(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
- pci_dma_sync_single_for_device(e1, e2, e3, e4)
+ dma_sync_single_for_device(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
- pci_dma_sync_sg_for_cpu(e1, e2, e3, e4)
+ dma_sync_sg_for_cpu(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
- pci_dma_sync_sg_for_device(e1, e2, e3, e4)
+ dma_sync_sg_for_device(&e1->dev, e2, e3, e4)

@@
expression e1, e2;
@@
- pci_dma_mapping_error(e1, e2)
+ dma_mapping_error(&e1->dev, e2)

@@
expression e1, e2;
@@
- pci_set_dma_mask(e1, e2)
+ dma_set_mask(&e1->dev, e2)

@@
expression e1, e2;
@@
- pci_set_consistent_dma_mask(e1, e2)
+ dma_set_coherent_mask(&e1->dev, e2)

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
If needed, see post from Christoph Hellwig on the kernel-janitors ML:
https://marc.info/?l=kernel-janitors&m=158745678307186&w=4


This patch and its explanation is a bit tricky, so review carefully !
Tricky means error prone, so maybe it would be safer to keep GFP_ATOMIC in
'vnic_dev_alloc_desc_ring()'
---
drivers/net/ethernet/cisco/enic/enic_main.c | 76 +++++++++++----------
drivers/net/ethernet/cisco/enic/vnic_dev.c | 66 +++++++++---------
2 files changed, 72 insertions(+), 70 deletions(-)

diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index 552d89fdf54a..bcf3c0adedb0 100644
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -326,11 +326,11 @@ static void enic_free_wq_buf(struct vnic_wq *wq, struct vnic_wq_buf *buf)
struct enic *enic = vnic_dev_priv(wq->vdev);

if (buf->sop)
- pci_unmap_single(enic->pdev, buf->dma_addr,
- buf->len, PCI_DMA_TODEVICE);
+ dma_unmap_single(&enic->pdev->dev, buf->dma_addr, buf->len,
+ DMA_TO_DEVICE);
else
- pci_unmap_page(enic->pdev, buf->dma_addr,
- buf->len, PCI_DMA_TODEVICE);
+ dma_unmap_page(&enic->pdev->dev, buf->dma_addr, buf->len,
+ DMA_TO_DEVICE);

if (buf->os_buf)
dev_kfree_skb_any(buf->os_buf);
@@ -574,8 +574,8 @@ static int enic_queue_wq_skb_vlan(struct enic *enic, struct vnic_wq *wq,
dma_addr_t dma_addr;
int err = 0;

- dma_addr = pci_map_single(enic->pdev, skb->data, head_len,
- PCI_DMA_TODEVICE);
+ dma_addr = dma_map_single(&enic->pdev->dev, skb->data, head_len,
+ DMA_TO_DEVICE);
if (unlikely(enic_dma_map_check(enic, dma_addr)))
return -ENOMEM;

@@ -605,8 +605,8 @@ static int enic_queue_wq_skb_csum_l4(struct enic *enic, struct vnic_wq *wq,
dma_addr_t dma_addr;
int err = 0;

- dma_addr = pci_map_single(enic->pdev, skb->data, head_len,
- PCI_DMA_TODEVICE);
+ dma_addr = dma_map_single(&enic->pdev->dev, skb->data, head_len,
+ DMA_TO_DEVICE);
if (unlikely(enic_dma_map_check(enic, dma_addr)))
return -ENOMEM;

@@ -693,8 +693,9 @@ static int enic_queue_wq_skb_tso(struct enic *enic, struct vnic_wq *wq,
*/
while (frag_len_left) {
len = min(frag_len_left, (unsigned int)WQ_ENET_MAX_DESC_LEN);
- dma_addr = pci_map_single(enic->pdev, skb->data + offset, len,
- PCI_DMA_TODEVICE);
+ dma_addr = dma_map_single(&enic->pdev->dev,
+ skb->data + offset, len,
+ DMA_TO_DEVICE);
if (unlikely(enic_dma_map_check(enic, dma_addr)))
return -ENOMEM;
enic_queue_wq_desc_tso(wq, skb, dma_addr, len, mss, hdr_len,
@@ -752,8 +753,8 @@ static inline int enic_queue_wq_skb_encap(struct enic *enic, struct vnic_wq *wq,
dma_addr_t dma_addr;
int err = 0;

- dma_addr = pci_map_single(enic->pdev, skb->data, head_len,
- PCI_DMA_TODEVICE);
+ dma_addr = dma_map_single(&enic->pdev->dev, skb->data, head_len,
+ DMA_TO_DEVICE);
if (unlikely(enic_dma_map_check(enic, dma_addr)))
return -ENOMEM;

@@ -1222,8 +1223,8 @@ static void enic_free_rq_buf(struct vnic_rq *rq, struct vnic_rq_buf *buf)
if (!buf->os_buf)
return;

- pci_unmap_single(enic->pdev, buf->dma_addr,
- buf->len, PCI_DMA_FROMDEVICE);
+ dma_unmap_single(&enic->pdev->dev, buf->dma_addr, buf->len,
+ DMA_FROM_DEVICE);
dev_kfree_skb_any(buf->os_buf);
buf->os_buf = NULL;
}
@@ -1248,8 +1249,8 @@ static int enic_rq_alloc_buf(struct vnic_rq *rq)
if (!skb)
return -ENOMEM;

- dma_addr = pci_map_single(enic->pdev, skb->data, len,
- PCI_DMA_FROMDEVICE);
+ dma_addr = dma_map_single(&enic->pdev->dev, skb->data, len,
+ DMA_FROM_DEVICE);
if (unlikely(enic_dma_map_check(enic, dma_addr))) {
dev_kfree_skb(skb);
return -ENOMEM;
@@ -1281,8 +1282,8 @@ static bool enic_rxcopybreak(struct net_device *netdev, struct sk_buff **skb,
new_skb = netdev_alloc_skb_ip_align(netdev, len);
if (!new_skb)
return false;
- pci_dma_sync_single_for_cpu(enic->pdev, buf->dma_addr, len,
- DMA_FROM_DEVICE);
+ dma_sync_single_for_cpu(&enic->pdev->dev, buf->dma_addr, len,
+ DMA_FROM_DEVICE);
memcpy(new_skb->data, (*skb)->data, len);
*skb = new_skb;

@@ -1331,8 +1332,8 @@ static void enic_rq_indicate_buf(struct vnic_rq *rq,
enic->rq_truncated_pkts++;
}

- pci_unmap_single(enic->pdev, buf->dma_addr, buf->len,
- PCI_DMA_FROMDEVICE);
+ dma_unmap_single(&enic->pdev->dev, buf->dma_addr, buf->len,
+ DMA_FROM_DEVICE);
dev_kfree_skb_any(skb);
buf->os_buf = NULL;

@@ -1346,8 +1347,8 @@ static void enic_rq_indicate_buf(struct vnic_rq *rq,

if (!enic_rxcopybreak(netdev, &skb, buf, bytes_written)) {
buf->os_buf = NULL;
- pci_unmap_single(enic->pdev, buf->dma_addr, buf->len,
- PCI_DMA_FROMDEVICE);
+ dma_unmap_single(&enic->pdev->dev, buf->dma_addr,
+ buf->len, DMA_FROM_DEVICE);
}
prefetch(skb->data - NET_IP_ALIGN);

@@ -1420,8 +1421,8 @@ static void enic_rq_indicate_buf(struct vnic_rq *rq,
/* Buffer overflow
*/

- pci_unmap_single(enic->pdev, buf->dma_addr, buf->len,
- PCI_DMA_FROMDEVICE);
+ dma_unmap_single(&enic->pdev->dev, buf->dma_addr, buf->len,
+ DMA_FROM_DEVICE);
dev_kfree_skb_any(skb);
buf->os_buf = NULL;
}
@@ -2178,9 +2179,9 @@ int __enic_set_rsskey(struct enic *enic)
dma_addr_t rss_key_buf_pa;
int i, kidx, bidx, err;

- rss_key_buf_va = pci_zalloc_consistent(enic->pdev,
- sizeof(union vnic_rss_key),
- &rss_key_buf_pa);
+ rss_key_buf_va = dma_alloc_coherent(&enic->pdev->dev,
+ sizeof(union vnic_rss_key),
+ &rss_key_buf_pa, GFP_ATOMIC);
if (!rss_key_buf_va)
return -ENOMEM;

@@ -2195,8 +2196,8 @@ int __enic_set_rsskey(struct enic *enic)
sizeof(union vnic_rss_key));
spin_unlock_bh(&enic->devcmd_lock);

- pci_free_consistent(enic->pdev, sizeof(union vnic_rss_key),
- rss_key_buf_va, rss_key_buf_pa);
+ dma_free_coherent(&enic->pdev->dev, sizeof(union vnic_rss_key),
+ rss_key_buf_va, rss_key_buf_pa);

return err;
}
@@ -2215,8 +2216,9 @@ static int enic_set_rsscpu(struct enic *enic, u8 rss_hash_bits)
unsigned int i;
int err;

- rss_cpu_buf_va = pci_alloc_consistent(enic->pdev,
- sizeof(union vnic_rss_cpu), &rss_cpu_buf_pa);
+ rss_cpu_buf_va = dma_alloc_coherent(&enic->pdev->dev,
+ sizeof(union vnic_rss_cpu),
+ &rss_cpu_buf_pa, GFP_ATOMIC);
if (!rss_cpu_buf_va)
return -ENOMEM;

@@ -2229,8 +2231,8 @@ static int enic_set_rsscpu(struct enic *enic, u8 rss_hash_bits)
sizeof(union vnic_rss_cpu));
spin_unlock_bh(&enic->devcmd_lock);

- pci_free_consistent(enic->pdev, sizeof(union vnic_rss_cpu),
- rss_cpu_buf_va, rss_cpu_buf_pa);
+ dma_free_coherent(&enic->pdev->dev, sizeof(union vnic_rss_cpu),
+ rss_cpu_buf_va, rss_cpu_buf_pa);

return err;
}
@@ -2699,21 +2701,21 @@ static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
* fail to 32-bit.
*/

- err = pci_set_dma_mask(pdev, DMA_BIT_MASK(47));
+ err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(47));
if (err) {
- err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+ err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
if (err) {
dev_err(dev, "No usable DMA configuration, aborting\n");
goto err_out_release_regions;
}
- err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
+ err = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
if (err) {
dev_err(dev, "Unable to obtain %u-bit DMA "
"for consistent allocations, aborting\n", 32);
goto err_out_release_regions;
}
} else {
- err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(47));
+ err = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(47));
if (err) {
dev_err(dev, "Unable to obtain %u-bit DMA "
"for consistent allocations, aborting\n", 47);
diff --git a/drivers/net/ethernet/cisco/enic/vnic_dev.c b/drivers/net/ethernet/cisco/enic/vnic_dev.c
index 901e44b0b795..45015931b335 100644
--- a/drivers/net/ethernet/cisco/enic/vnic_dev.c
+++ b/drivers/net/ethernet/cisco/enic/vnic_dev.c
@@ -193,9 +193,10 @@ int vnic_dev_alloc_desc_ring(struct vnic_dev *vdev, struct vnic_dev_ring *ring,
{
vnic_dev_desc_ring_size(ring, desc_count, desc_size);

- ring->descs_unaligned = pci_alloc_consistent(vdev->pdev,
- ring->size_unaligned,
- &ring->base_addr_unaligned);
+ ring->descs_unaligned = dma_alloc_coherent(&vdev->pdev->dev,
+ ring->size_unaligned,
+ &ring->base_addr_unaligned,
+ GFP_KERNEL);

if (!ring->descs_unaligned) {
vdev_err(vdev, "Failed to allocate ring (size=%d), aborting\n",
@@ -218,10 +219,9 @@ int vnic_dev_alloc_desc_ring(struct vnic_dev *vdev, struct vnic_dev_ring *ring,
void vnic_dev_free_desc_ring(struct vnic_dev *vdev, struct vnic_dev_ring *ring)
{
if (ring->descs) {
- pci_free_consistent(vdev->pdev,
- ring->size_unaligned,
- ring->descs_unaligned,
- ring->base_addr_unaligned);
+ dma_free_coherent(&vdev->pdev->dev, ring->size_unaligned,
+ ring->descs_unaligned,
+ ring->base_addr_unaligned);
ring->descs = NULL;
}
}
@@ -551,9 +551,9 @@ int vnic_dev_fw_info(struct vnic_dev *vdev,
int err = 0;

if (!vdev->fw_info) {
- vdev->fw_info = pci_zalloc_consistent(vdev->pdev,
- sizeof(struct vnic_devcmd_fw_info),
- &vdev->fw_info_pa);
+ vdev->fw_info = dma_alloc_coherent(&vdev->pdev->dev,
+ sizeof(struct vnic_devcmd_fw_info),
+ &vdev->fw_info_pa, GFP_ATOMIC);
if (!vdev->fw_info)
return -ENOMEM;

@@ -603,8 +603,9 @@ int vnic_dev_stats_dump(struct vnic_dev *vdev, struct vnic_stats **stats)
int wait = 1000;

if (!vdev->stats) {
- vdev->stats = pci_alloc_consistent(vdev->pdev,
- sizeof(struct vnic_stats), &vdev->stats_pa);
+ vdev->stats = dma_alloc_coherent(&vdev->pdev->dev,
+ sizeof(struct vnic_stats),
+ &vdev->stats_pa, GFP_ATOMIC);
if (!vdev->stats)
return -ENOMEM;
}
@@ -852,9 +853,9 @@ int vnic_dev_notify_set(struct vnic_dev *vdev, u16 intr)
return -EINVAL;
}

- notify_addr = pci_alloc_consistent(vdev->pdev,
- sizeof(struct vnic_devcmd_notify),
- &notify_pa);
+ notify_addr = dma_alloc_coherent(&vdev->pdev->dev,
+ sizeof(struct vnic_devcmd_notify),
+ &notify_pa, GFP_ATOMIC);
if (!notify_addr)
return -ENOMEM;

@@ -882,10 +883,9 @@ static int vnic_dev_notify_unsetcmd(struct vnic_dev *vdev)
int vnic_dev_notify_unset(struct vnic_dev *vdev)
{
if (vdev->notify) {
- pci_free_consistent(vdev->pdev,
- sizeof(struct vnic_devcmd_notify),
- vdev->notify,
- vdev->notify_pa);
+ dma_free_coherent(&vdev->pdev->dev,
+ sizeof(struct vnic_devcmd_notify),
+ vdev->notify, vdev->notify_pa);
}

return vnic_dev_notify_unsetcmd(vdev);
@@ -1046,18 +1046,17 @@ void vnic_dev_unregister(struct vnic_dev *vdev)
{
if (vdev) {
if (vdev->notify)
- pci_free_consistent(vdev->pdev,
- sizeof(struct vnic_devcmd_notify),
- vdev->notify,
- vdev->notify_pa);
+ dma_free_coherent(&vdev->pdev->dev,
+ sizeof(struct vnic_devcmd_notify),
+ vdev->notify, vdev->notify_pa);
if (vdev->stats)
- pci_free_consistent(vdev->pdev,
- sizeof(struct vnic_stats),
- vdev->stats, vdev->stats_pa);
+ dma_free_coherent(&vdev->pdev->dev,
+ sizeof(struct vnic_stats),
+ vdev->stats, vdev->stats_pa);
if (vdev->fw_info)
- pci_free_consistent(vdev->pdev,
- sizeof(struct vnic_devcmd_fw_info),
- vdev->fw_info, vdev->fw_info_pa);
+ dma_free_coherent(&vdev->pdev->dev,
+ sizeof(struct vnic_devcmd_fw_info),
+ vdev->fw_info, vdev->fw_info_pa);
if (vdev->devcmd2)
vnic_dev_deinit_devcmd2(vdev);

@@ -1127,7 +1126,7 @@ int vnic_dev_init_prov2(struct vnic_dev *vdev, u8 *buf, u32 len)
void *prov_buf;
int ret;

- prov_buf = pci_alloc_consistent(vdev->pdev, len, &prov_pa);
+ prov_buf = dma_alloc_coherent(&vdev->pdev->dev, len, &prov_pa, GFP_ATOMIC);
if (!prov_buf)
return -ENOMEM;

@@ -1137,7 +1136,7 @@ int vnic_dev_init_prov2(struct vnic_dev *vdev, u8 *buf, u32 len)

ret = vnic_dev_cmd(vdev, CMD_INIT_PROV_INFO2, &a0, &a1, wait);

- pci_free_consistent(vdev->pdev, len, prov_buf, prov_pa);
+ dma_free_coherent(&vdev->pdev->dev, len, prov_buf, prov_pa);

return ret;
}
@@ -1217,7 +1216,8 @@ int vnic_dev_classifier(struct vnic_dev *vdev, u8 cmd, u16 *entry,
tlv_size = sizeof(struct filter) +
sizeof(struct filter_action) +
2 * sizeof(struct filter_tlv);
- tlv_va = pci_alloc_consistent(vdev->pdev, tlv_size, &tlv_pa);
+ tlv_va = dma_alloc_coherent(&vdev->pdev->dev, tlv_size,
+ &tlv_pa, GFP_ATOMIC);
if (!tlv_va)
return -ENOMEM;
tlv = tlv_va;
@@ -1240,7 +1240,7 @@ int vnic_dev_classifier(struct vnic_dev *vdev, u8 cmd, u16 *entry,

ret = vnic_dev_cmd(vdev, CMD_ADD_FILTER, &a0, &a1, wait);
*entry = (u16)a0;
- pci_free_consistent(vdev->pdev, tlv_size, tlv_va, tlv_pa);
+ dma_free_coherent(&vdev->pdev->dev, tlv_size, tlv_va, tlv_pa);
} else if (cmd == CLSF_DEL) {
a0 = *entry;
ret = vnic_dev_cmd(vdev, CMD_DEL_FILTER, &a0, &a1, wait);
--
2.25.1