2017-12-30 15:42:45

by Himanshu Jha

Subject: [PATCH] USB: host: Use zeroing memory allocator rather than allocator/memset

Use dma_zalloc_coherent for allocating zeroed
memory and remove unnecessary memset function.

Done using Coccinelle.
Generated-by: scripts/coccinelle/api/alloc/kzalloc-simple.cocci
0-day tested with no failures.

Suggested-by: Luis R. Rodriguez <[email protected]>
Signed-off-by: Himanshu Jha <[email protected]>
---
drivers/usb/host/uhci-hcd.c | 7 +++----
drivers/usb/host/xhci-mem.c | 7 ++-----
2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index f5c9021..ac53398 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -600,15 +600,14 @@ static int uhci_start(struct usb_hcd *hcd)
uhci->dentry = dentry;
#endif

- uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
- UHCI_NUMFRAMES * sizeof(*uhci->frame),
- &uhci->frame_dma_handle, GFP_KERNEL);
+ uhci->frame = dma_zalloc_coherent(uhci_dev(uhci),
+ UHCI_NUMFRAMES * sizeof(*uhci->frame),
+ &uhci->frame_dma_handle, GFP_KERNEL);
if (!uhci->frame) {
dev_err(uhci_dev(uhci),
"unable to allocate consistent memory for frame list\n");
goto err_alloc_frame;
}
- memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));

uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
GFP_KERNEL);
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 554a8a5..332420d 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1782,14 +1782,11 @@ int xhci_alloc_erst(struct xhci_hcd *xhci,
struct xhci_erst_entry *entry;

size = sizeof(struct xhci_erst_entry) * evt_ring->num_segs;
- erst->entries = dma_alloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
- size,
- &erst->erst_dma_addr,
- flags);
+ erst->entries = dma_zalloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
+ size, &erst->erst_dma_addr, flags);
if (!erst->entries)
return -ENOMEM;

- memset(erst->entries, 0, size);
erst->num_entries = evt_ring->num_segs;

seg = evt_ring->first_seg;
--
2.7.4

2017-12-30 16:41:21

by Alan Stern

Subject: Re: [PATCH] USB: host: Use zeroing memory allocator rather than allocator/memset

On Sat, 30 Dec 2017, Himanshu Jha wrote:

> Use dma_zalloc_coherent for allocating zeroed
> memory and remove unnecessary memset function.
>
> Done using Coccinelle.
> Generated-by: scripts/coccinelle/api/alloc/kzalloc-simple.cocci
> 0-day tested with no failures.
>
> Suggested-by: Luis R. Rodriguez <[email protected]>
> Signed-off-by: Himanshu Jha <[email protected]>
> ---
> drivers/usb/host/uhci-hcd.c | 7 +++----
> drivers/usb/host/xhci-mem.c | 7 ++-----
> 2 files changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
> index f5c9021..ac53398 100644
> --- a/drivers/usb/host/uhci-hcd.c
> +++ b/drivers/usb/host/uhci-hcd.c
> @@ -600,15 +600,14 @@ static int uhci_start(struct usb_hcd *hcd)
> uhci->dentry = dentry;
> #endif
>
> - uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
> - UHCI_NUMFRAMES * sizeof(*uhci->frame),
> - &uhci->frame_dma_handle, GFP_KERNEL);
> + uhci->frame = dma_zalloc_coherent(uhci_dev(uhci),
> + UHCI_NUMFRAMES * sizeof(*uhci->frame),
> + &uhci->frame_dma_handle, GFP_KERNEL);

Please don't change the existing whitespace scheme when you make
changes like this one.

Alan Stern

> if (!uhci->frame) {
> dev_err(uhci_dev(uhci),
> "unable to allocate consistent memory for frame list\n");
> goto err_alloc_frame;
> }
> - memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));
>
> uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
> GFP_KERNEL);
> diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
> index 554a8a5..332420d 100644
> --- a/drivers/usb/host/xhci-mem.c
> +++ b/drivers/usb/host/xhci-mem.c
> @@ -1782,14 +1782,11 @@ int xhci_alloc_erst(struct xhci_hcd *xhci,
> struct xhci_erst_entry *entry;
>
> size = sizeof(struct xhci_erst_entry) * evt_ring->num_segs;
> - erst->entries = dma_alloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
> - size,
> - &erst->erst_dma_addr,
> - flags);
> + erst->entries = dma_zalloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
> + size, &erst->erst_dma_addr, flags);
> if (!erst->entries)
> return -ENOMEM;
>
> - memset(erst->entries, 0, size);
> erst->num_entries = evt_ring->num_segs;
>
> seg = evt_ring->first_seg;
>

2017-12-30 18:26:10

by Himanshu Jha

Subject: Re: [PATCH] USB: host: Use zeroing memory allocator rather than allocator/memset

On Sat, Dec 30, 2017 at 11:41:19AM -0500, Alan Stern wrote:
> On Sat, 30 Dec 2017, Himanshu Jha wrote:
>
> > Use dma_zalloc_coherent for allocating zeroed
> > memory and remove unnecessary memset function.
> >
> > Done using Coccinelle.
> > Generated-by: scripts/coccinelle/api/alloc/kzalloc-simple.cocci
> > 0-day tested with no failures.
> >
> > Suggested-by: Luis R. Rodriguez <[email protected]>
> > Signed-off-by: Himanshu Jha <[email protected]>
> > ---
> > drivers/usb/host/uhci-hcd.c | 7 +++----
> > drivers/usb/host/xhci-mem.c | 7 ++-----
> > 2 files changed, 5 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
> > index f5c9021..ac53398 100644
> > --- a/drivers/usb/host/uhci-hcd.c
> > +++ b/drivers/usb/host/uhci-hcd.c
> > @@ -600,15 +600,14 @@ static int uhci_start(struct usb_hcd *hcd)
> > uhci->dentry = dentry;
> > #endif
> >
> > - uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
> > - UHCI_NUMFRAMES * sizeof(*uhci->frame),
> > - &uhci->frame_dma_handle, GFP_KERNEL);
> > + uhci->frame = dma_zalloc_coherent(uhci_dev(uhci),
> > + UHCI_NUMFRAMES * sizeof(*uhci->frame),
> > + &uhci->frame_dma_handle, GFP_KERNEL);
>
> Please don't change the existing whitespace scheme when you make
> changes like this one.

Thanks for the feedback!
Do I need to send v2 for this ?

Thanks
Himanshu Jha

2017-12-30 19:27:02

by Alan Stern

Subject: Re: [PATCH] USB: host: Use zeroing memory allocator rather than allocator/memset

On Sat, 30 Dec 2017, Himanshu Jha wrote:

> On Sat, Dec 30, 2017 at 11:41:19AM -0500, Alan Stern wrote:
> > On Sat, 30 Dec 2017, Himanshu Jha wrote:
> >
> > > Use dma_zalloc_coherent for allocating zeroed
> > > memory and remove unnecessary memset function.
> > >
> > > Done using Coccinelle.
> > > Generated-by: scripts/coccinelle/api/alloc/kzalloc-simple.cocci
> > > 0-day tested with no failures.
> > >
> > > Suggested-by: Luis R. Rodriguez <[email protected]>
> > > Signed-off-by: Himanshu Jha <[email protected]>
> > > ---
> > > drivers/usb/host/uhci-hcd.c | 7 +++----
> > > drivers/usb/host/xhci-mem.c | 7 ++-----
> > > 2 files changed, 5 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
> > > index f5c9021..ac53398 100644
> > > --- a/drivers/usb/host/uhci-hcd.c
> > > +++ b/drivers/usb/host/uhci-hcd.c
> > > @@ -600,15 +600,14 @@ static int uhci_start(struct usb_hcd *hcd)
> > > uhci->dentry = dentry;
> > > #endif
> > >
> > > - uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
> > > - UHCI_NUMFRAMES * sizeof(*uhci->frame),
> > > - &uhci->frame_dma_handle, GFP_KERNEL);
> > > + uhci->frame = dma_zalloc_coherent(uhci_dev(uhci),
> > > + UHCI_NUMFRAMES * sizeof(*uhci->frame),
> > > + &uhci->frame_dma_handle, GFP_KERNEL);
> >
> > Please don't change the existing whitespace scheme when you make
> > changes like this one.
>
> Thanks for the feedback!
> Do I need to send v2 for this ?

Okay, yes, go ahead.

Alan Stern