2023-02-06 16:10:23

by Andy Shevchenko

Subject: [PATCH v1 2/7] xhci: mem: Use __GFP_ZERO instead of explicit memset() call

Use __GFP_ZERO instead of explicit memset() call in
xhci_alloc_stream_ctx().

Signed-off-by: Andy Shevchenko <[email protected]>
---
drivers/usb/host/xhci-mem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index c385513ad00b..768adcb544a7 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -571,6 +571,8 @@ static struct xhci_stream_ctx *xhci_alloc_stream_ctx(struct xhci_hcd *xhci,
struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
size_t size = size_mul(sizeof(struct xhci_stream_ctx), num_stream_ctxs);

+ mem_flags |= __GFP_ZERO;
+
if (size > MEDIUM_STREAM_ARRAY_SIZE)
return dma_alloc_coherent(dev, size,
dma, mem_flags);
@@ -643,8 +645,6 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
mem_flags);
if (!stream_info->stream_ctx_array)
goto cleanup_ring_array;
- memset(stream_info->stream_ctx_array, 0,
- sizeof(struct xhci_stream_ctx)*num_stream_ctxs);

/* Allocate everything needed to free the stream rings later */
stream_info->free_streams_command =
--
2.39.1

2023-02-07 15:11:06

by Mathias Nyman

Subject: Re: [PATCH v1 2/7] xhci: mem: Use __GFP_ZERO instead of explicit memset() call

On 6.2.2023 18.10, Andy Shevchenko wrote:
> Use __GFP_ZERO instead of explicit memset() call in
> xhci_alloc_stream_ctx().
>
> Signed-off-by: Andy Shevchenko <[email protected]>
> ---
> drivers/usb/host/xhci-mem.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
> index c385513ad00b..768adcb544a7 100644
> --- a/drivers/usb/host/xhci-mem.c
> +++ b/drivers/usb/host/xhci-mem.c
> @@ -571,6 +571,8 @@ static struct xhci_stream_ctx *xhci_alloc_stream_ctx(struct xhci_hcd *xhci,
> struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
> size_t size = size_mul(sizeof(struct xhci_stream_ctx), num_stream_ctxs);
>
> + mem_flags |= __GFP_ZERO;
> +

How about calling dma_pool_zalloc() instead of setting __GFP_ZERO flag?
Memory returned by dma_alloc_coherent() should already be zeroed if I remember correctly

-Mathias

2023-02-07 22:50:01

by Andy Shevchenko

Subject: Re: [PATCH v1 2/7] xhci: mem: Use __GFP_ZERO instead of explicit memset() call

On Tue, Feb 07, 2023 at 05:11:23PM +0200, Mathias Nyman wrote:
> On 6.2.2023 18.10, Andy Shevchenko wrote:
> > Use __GFP_ZERO instead of explicit memset() call in
> > xhci_alloc_stream_ctx().

...

> > + mem_flags |= __GFP_ZERO;
>
> How about calling dma_pool_zalloc() instead of setting __GFP_ZERO flag?
> Memory returned by dma_alloc_coherent() should already be zeroed if I remember correctly

That will work too.

--
With Best Regards,
Andy Shevchenko