stmicro uses PCI devres in the wrong way. Resources requested
through pcim_* functions don't need to be cleaned up manually in the
remove() callback or in the error unwind path of a probe() function.
Moreover, there is an unnecessary loop which only requests and ioremaps
BAR 0, but iterates over all BARs nevertheless.
Furthermore, pcim_iomap_regions() and pcim_iomap_table() have been
deprecated by the PCI subsystem in commit e354bb84a4c1 ("PCI: Deprecate
pcim_iomap_table(), pcim_iomap_regions_request_all()").
Replace these functions with pcim_iomap_region().
Remove the unnecessary manual pcim_* cleanup calls.
Remove the unnecessary loop over all BARs.
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
---
.../ethernet/stmicro/stmmac/dwmac-loongson.c | 25 +++++--------------
.../net/ethernet/stmicro/stmmac/stmmac_pci.c | 18 +++++--------
2 files changed, 12 insertions(+), 31 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
index 9e40c28d453a..5d42a9fad672 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
@@ -50,7 +50,7 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
struct plat_stmmacenet_data *plat;
struct stmmac_resources res;
struct device_node *np;
- int ret, i, phy_mode;
+ int ret, phy_mode;
np = dev_of_node(&pdev->dev);
@@ -88,14 +88,11 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
goto err_put_node;
}
- /* Get the base address of device */
- for (i = 0; i < PCI_STD_NUM_BARS; i++) {
- if (pci_resource_len(pdev, i) == 0)
- continue;
- ret = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));
- if (ret)
- goto err_disable_device;
- break;
+ memset(&res, 0, sizeof(res));
+ res.addr = pcim_iomap_region(pdev, 0, pci_name(pdev));
+ if (IS_ERR(res.addr)) {
+ ret = PTR_ERR(res.addr);
+ goto err_disable_device;
}
plat->bus_id = of_alias_get_id(np, "ethernet");
@@ -116,8 +113,6 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
loongson_default_data(plat);
pci_enable_msi(pdev);
- memset(&res, 0, sizeof(res));
- res.addr = pcim_iomap_table(pdev)[0];
res.irq = of_irq_get_byname(np, "macirq");
if (res.irq < 0) {
@@ -158,18 +153,10 @@ static void loongson_dwmac_remove(struct pci_dev *pdev)
{
struct net_device *ndev = dev_get_drvdata(&pdev->dev);
struct stmmac_priv *priv = netdev_priv(ndev);
- int i;
of_node_put(priv->plat->mdio_node);
stmmac_dvr_remove(&pdev->dev);
- for (i = 0; i < PCI_STD_NUM_BARS; i++) {
- if (pci_resource_len(pdev, i) == 0)
- continue;
- pcim_iounmap_regions(pdev, BIT(i));
- break;
- }
-
pci_disable_msi(pdev);
pci_disable_device(pdev);
}
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 352b01678c22..f89a8a54c4e8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
@@ -188,11 +188,11 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
return ret;
}
- /* Get the base address of device */
+ /* Request the base address BAR of device */
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
if (pci_resource_len(pdev, i) == 0)
continue;
- ret = pcim_iomap_regions(pdev, BIT(i), pci_name(pdev));
+ ret = pcim_request_region(pdev, i, pci_name(pdev));
if (ret)
return ret;
break;
@@ -205,7 +205,10 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
return ret;
memset(&res, 0, sizeof(res));
- res.addr = pcim_iomap_table(pdev)[i];
+ /* Get the base address of device */
+ res.addr = pcim_iomap(pdev, i, 0);
+ if (!res.addr)
+ return -ENOMEM;
res.wol_irq = pdev->irq;
res.irq = pdev->irq;
@@ -231,16 +234,7 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
*/
static void stmmac_pci_remove(struct pci_dev *pdev)
{
- int i;
-
stmmac_dvr_remove(&pdev->dev);
-
- for (i = 0; i < PCI_STD_NUM_BARS; i++) {
- if (pci_resource_len(pdev, i) == 0)
- continue;
- pcim_iounmap_regions(pdev, BIT(i));
- break;
- }
}
static int __maybe_unused stmmac_pci_suspend(struct device *dev)
--
2.46.0On Mon, Aug 19, 2024 at 06:51:47PM +0200, Philipp Stanner wrote:
> stmicro uses PCI devres in the wrong way. Resources requested
> through pcim_* functions don't need to be cleaned up manually in the
> remove() callback or in the error unwind path of a probe() function.
>
> Moreover, there is an unnecessary loop which only requests and ioremaps
> BAR 0, but iterates over all BARs nevertheless.
>
> Furthermore, pcim_iomap_regions() and pcim_iomap_table() have been
> deprecated by the PCI subsystem in commit e354bb84a4c1 ("PCI: Deprecate
> pcim_iomap_table(), pcim_iomap_regions_request_all()").
>
> Replace these functions with pcim_iomap_region().
>
> Remove the unnecessary manual pcim_* cleanup calls.
>
> Remove the unnecessary loop over all BARs.
...
loongson_dwmac_probe()
> + memset(&res, 0, sizeof(res));
> + res.addr = pcim_iomap_region(pdev, 0, pci_name(pdev));
> + if (IS_ERR(res.addr)) {
> + ret = PTR_ERR(res.addr);
> + goto err_disable_device;
It seems your series reveals issues in the error paths of .probe():s
in many drivers...
If we use pcim variant to enable device, why do we need to explicitly
disable it?
> }
...
loongson_dwmac_remove()
> pci_disable_msi(pdev);
> pci_disable_device(pdev);
Not sure why we need these either...
--
With Best Regards,
Andy Shevchenko
On Mon, 2024-08-19 at 21:28 +0300, Andy Shevchenko wrote:
> On Mon, Aug 19, 2024 at 06:51:47PM +0200, Philipp Stanner wrote:
> > stmicro uses PCI devres in the wrong way. Resources requested
> > through pcim_* functions don't need to be cleaned up manually in
> > the
> > remove() callback or in the error unwind path of a probe()
> > function.
> >
> > Moreover, there is an unnecessary loop which only requests and
> > ioremaps
> > BAR 0, but iterates over all BARs nevertheless.
> >
> > Furthermore, pcim_iomap_regions() and pcim_iomap_table() have been
> > deprecated by the PCI subsystem in commit e354bb84a4c1 ("PCI:
> > Deprecate
> > pcim_iomap_table(), pcim_iomap_regions_request_all()").
> >
> > Replace these functions with pcim_iomap_region().
> >
> > Remove the unnecessary manual pcim_* cleanup calls.
> >
> > Remove the unnecessary loop over all BARs.
>
> ...
>
> loongson_dwmac_probe()
>
> > + memset(&res, 0, sizeof(res));
> > + res.addr = pcim_iomap_region(pdev, 0, pci_name(pdev));
> > + if (IS_ERR(res.addr)) {
> > + ret = PTR_ERR(res.addr);
> > + goto err_disable_device;
>
> It seems your series reveals issues in the error paths of .probe():s
> in many drivers...
>
> If we use pcim variant to enable device, why do we need to explicitly
> disable it?
No.
>
> > }
>
> ...
>
> loongson_dwmac_remove()
>
> > pci_disable_msi(pdev);
> > pci_disable_device(pdev);
>
> Not sure why we need these either...
It's complicated.
The code uses pciM_enable_device(), but here in remove
pci_disable_device().
pcim_enable_device() sets up a disable callback which only calls
pci_disable_device() if pcim_pin_device() has not been called.
This code doesn't seem to call pcim_pin_device(), so I think
pci_disable_device() could be removed.
I definitely would not feel confident touching pci_disable_msi(),
though. The AFAIK biggest problem remaining in PCI devres is that the
MSI code base implicitly calls into devres, see here [1]
P.
[1] https://lore.kernel.org/all/ee44ea7ac760e73edad3f20b30b4d2fff66c1a85.camel@redhat.com/
On Tue, Aug 20, 2024 at 09:52:40AM +0200, Philipp Stanner wrote:
> On Mon, 2024-08-19 at 21:28 +0300, Andy Shevchenko wrote:
> > On Mon, Aug 19, 2024 at 06:51:47PM +0200, Philipp Stanner wrote:
...
> > loongson_dwmac_probe()
> >
> > > + memset(&res, 0, sizeof(res));
> > > + res.addr = pcim_iomap_region(pdev, 0, pci_name(pdev));
> > > + if (IS_ERR(res.addr)) {
> > > + ret = PTR_ERR(res.addr);
> > > + goto err_disable_device;
> >
> > It seems your series reveals issues in the error paths of .probe():s
> > in many drivers...
> >
> > If we use pcim variant to enable device, why do we need to explicitly
> > disable it?
>
> No.
Can you elaborate? No issues being revealed, or no need to disable it
explicitly, or...?
> > > }
...
> > loongson_dwmac_remove()
> >
> > > pci_disable_msi(pdev);
> > > pci_disable_device(pdev);
> >
> > Not sure why we need these either...
>
> It's complicated.
>
> The code uses pciM_enable_device(), but here in remove
> pci_disable_device().
>
> pcim_enable_device() sets up a disable callback which only calls
> pci_disable_device() if pcim_pin_device() has not been called.
>
> This code doesn't seem to call pcim_pin_device(), so I think
> pci_disable_device() could be removed.
>
>
> I definitely would not feel confident touching pci_disable_msi(),
> though. The AFAIK biggest problem remaining in PCI devres is that the
> MSI code base implicitly calls into devres, see here [1]
But isn't it a busyness of PCI core to call pci_disable_msi() at the right
moment? Okay, I admit that there might be devices that require a special
workflow WRT MSI, is this the case here?
> [1] https://lore.kernel.org/all/ee44ea7ac760e73edad3f20b30b4d2fff66c1a85.camel@redhat.com/
--
With Best Regards,
Andy Shevchenko
On Tue, 2024-08-20 at 13:37 +0300, Andy Shevchenko wrote:
> On Tue, Aug 20, 2024 at 09:52:40AM +0200, Philipp Stanner wrote:
> > On Mon, 2024-08-19 at 21:28 +0300, Andy Shevchenko wrote:
> > > On Mon, Aug 19, 2024 at 06:51:47PM +0200, Philipp Stanner wrote:
>
> ...
>
> > > loongson_dwmac_probe()
> > >
> > > > + memset(&res, 0, sizeof(res));
> > > > + res.addr = pcim_iomap_region(pdev, 0, pci_name(pdev));
> > > > + if (IS_ERR(res.addr)) {
> > > > + ret = PTR_ERR(res.addr);
> > > > + goto err_disable_device;
> > >
> > > It seems your series reveals issues in the error paths of
> > > .probe():s
> > > in many drivers...
> > >
> > > If we use pcim variant to enable device, why do we need to
> > > explicitly
> > > disable it?
> >
> > No.
>
> Can you elaborate? No issues being revealed, or no need to disable it
> explicitly, or...?
Oh, my bad, I overlooked your "why" in that question.
We do not explicitly have to disable it. It's wrong / unnecessary, as
many of the other calls you criticized in this series.
pcim_enable_device() (in pci/devres.c) calls devm_add_action(...,
pcim_disable_device, ...), which will disable the device on driver
detach.
So the call of pci_disable_device() above is redundant. We could remove
it.
>
> > > > }
>
> ...
>
> > > loongson_dwmac_remove()
> > >
> > > > pci_disable_msi(pdev);
> > > > pci_disable_device(pdev);
> > >
> > > Not sure why we need these either...
> >
> > It's complicated.
> >
> > The code uses pciM_enable_device(), but here in remove
> > pci_disable_device().
> >
> > pcim_enable_device() sets up a disable callback which only calls
> > pci_disable_device() if pcim_pin_device() has not been called.
> >
> > This code doesn't seem to call pcim_pin_device(), so I think
> > pci_disable_device() could be removed.
> >
> >
> > I definitely would not feel confident touching pci_disable_msi(),
> > though. The AFAIK biggest problem remaining in PCI devres is that
> > the
> > MSI code base implicitly calls into devres, see here [1]
>
> But isn't it a busyness of PCI core to call pci_disable_msi() at the
> right
> moment? Okay, I admit that there might be devices that require a
> special
> workflow WRT MSI, is this the case here?
I don't know enough about how MSI is intended to be used.
From what I've seen in the code base, pcim_setup_msi_release() does
register a devres callback that will indeed call pci_disable_msi()
after some intermediate calls.
But in my honest opinion, that code is _very_ broken. I was thinking
about how we might clean it up, but couldn't come up with an idea yet.
Only after the code in pci/msi/ has been cleanly separated from
implicit devres I myself would start touching function calls related to
MSI.
That being said, I suspect that one can remove pci_disable_msi() in the
line above. But the risk-benefit-ratio doesn't pay off for me.
P.
>
> > [1]
> > https://lore.kernel.org/all/ee44ea7ac760e73edad3f20b30b4d2fff66c1a85.camel@redhat.com/
>
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