2024-06-05 08:22:29

by Philipp Stanner

[permalink] [raw]
Subject: [PATCH v7 01/13] PCI: Add and use devres helper for bit masks

The current derves implementation uses manual shift operations to check
whether a bit in a mask is set. The code can be made more readable by
writing a small helper function for that.

Implement mask_contains_bar() and use it where applicable.

Signed-off-by: Philipp Stanner <[email protected]>
---
drivers/pci/devres.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index 2c562b9eaf80..f13edd4a3873 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -161,6 +161,10 @@ int pcim_set_mwi(struct pci_dev *dev)
}
EXPORT_SYMBOL(pcim_set_mwi);

+static inline bool mask_contains_bar(int mask, int bar)
+{
+ return mask & BIT(bar);
+}

static void pcim_release(struct device *gendev, void *res)
{
@@ -169,7 +173,7 @@ static void pcim_release(struct device *gendev, void *res)
int i;

for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
- if (this->region_mask & (1 << i))
+ if (mask_contains_bar(this->region_mask, i))
pci_release_region(dev, i);

if (this->mwi)
@@ -363,7 +367,7 @@ int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
unsigned long len;

- if (!(mask & (1 << i)))
+ if (!mask_contains_bar(mask, i))
continue;

rc = -EINVAL;
@@ -386,7 +390,7 @@ int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
pci_release_region(pdev, i);
err_inval:
while (--i >= 0) {
- if (!(mask & (1 << i)))
+ if (!mask_contains_bar(mask, i))
continue;
pcim_iounmap(pdev, iomap[i]);
pci_release_region(pdev, i);
@@ -438,7 +442,7 @@ void pcim_iounmap_regions(struct pci_dev *pdev, int mask)
return;

for (i = 0; i < PCIM_IOMAP_MAX; i++) {
- if (!(mask & (1 << i)))
+ if (!mask_contains_bar(mask, i))
continue;

pcim_iounmap(pdev, iomap[i]);
--
2.45.0



2024-06-13 19:23:14

by Ilpo Järvinen

[permalink] [raw]
Subject: Re: [PATCH v7 01/13] PCI: Add and use devres helper for bit masks

On Wed, 5 Jun 2024, Philipp Stanner wrote:

> The current derves implementation uses manual shift operations to check
> whether a bit in a mask is set. The code can be made more readable by
> writing a small helper function for that.
>
> Implement mask_contains_bar() and use it where applicable.
>
> Signed-off-by: Philipp Stanner <[email protected]>
> ---
> drivers/pci/devres.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
> index 2c562b9eaf80..f13edd4a3873 100644
> --- a/drivers/pci/devres.c
> +++ b/drivers/pci/devres.c
> @@ -161,6 +161,10 @@ int pcim_set_mwi(struct pci_dev *dev)
> }
> EXPORT_SYMBOL(pcim_set_mwi);
>
> +static inline bool mask_contains_bar(int mask, int bar)

Why these are signed? Using & for signed values is an indication that the
types should have been unsigned. The typing change has ripple effects to
caller-side typing.

> +{
> + return mask & BIT(bar);
> +}

--
i.

>
> static void pcim_release(struct device *gendev, void *res)
> {
> @@ -169,7 +173,7 @@ static void pcim_release(struct device *gendev, void *res)
> int i;
>
> for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
> - if (this->region_mask & (1 << i))
> + if (mask_contains_bar(this->region_mask, i))
> pci_release_region(dev, i);
>
> if (this->mwi)
> @@ -363,7 +367,7 @@ int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
> for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> unsigned long len;
>
> - if (!(mask & (1 << i)))
> + if (!mask_contains_bar(mask, i))
> continue;
>
> rc = -EINVAL;
> @@ -386,7 +390,7 @@ int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
> pci_release_region(pdev, i);
> err_inval:
> while (--i >= 0) {
> - if (!(mask & (1 << i)))
> + if (!mask_contains_bar(mask, i))
> continue;
> pcim_iounmap(pdev, iomap[i]);
> pci_release_region(pdev, i);
> @@ -438,7 +442,7 @@ void pcim_iounmap_regions(struct pci_dev *pdev, int mask)
> return;
>
> for (i = 0; i < PCIM_IOMAP_MAX; i++) {
> - if (!(mask & (1 << i)))
> + if (!mask_contains_bar(mask, i))
> continue;
>
> pcim_iounmap(pdev, iomap[i]);
>