| Message ID | 1391591446-17843-2-git-send-email-l.majewski@samsung.com |
|---|---|
| State | Accepted |
| Delegated to: | Marek Vasut |
| Headers | show |
On Wednesday, February 05, 2014 at 10:10:41 AM, Lukasz Majewski wrote: > Calls to malloc() have been replaced by memalign. It now provides proper > buffer alignment. > > Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> > Cc: Marek Vasut <marex@denx.de> > > --- > Changes for v2: > - Remove Change-Id. > --- > drivers/usb/gadget/f_mass_storage.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/gadget/f_mass_storage.c > b/drivers/usb/gadget/f_mass_storage.c index b1fe8bd..f896169 100644 > --- a/drivers/usb/gadget/f_mass_storage.c > +++ b/drivers/usb/gadget/f_mass_storage.c > @@ -2515,7 +2515,7 @@ static struct fsg_common *fsg_common_init(struct > fsg_common *common, buffhds_first_it: > bh->inreq_busy = 0; > bh->outreq_busy = 0; > - bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL); > + bh->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, FSG_BUFLEN); > if (unlikely(!bh->buf)) { > rc = -ENOMEM; > goto error_release; > @@ -2622,7 +2622,7 @@ usb_copy_descriptors(struct usb_descriptor_header > **src) bytes += (*tmp)->bLength; > bytes += (n_desc + 1) * sizeof(*tmp); > > - mem = kmalloc(bytes, GFP_KERNEL); > + mem = memalign(CONFIG_SYS_CACHELINE_SIZE, bytes); I wonder, does this align the begining of the buffer as well or only the size? Can we rely on the fact the begining is also cacheline-aligned ? > if (!mem) > return NULL; Best regards, Marek Vasut
Hi Marek, > On Wednesday, February 05, 2014 at 10:10:41 AM, Lukasz Majewski wrote: > > Calls to malloc() have been replaced by memalign. It now provides > > proper buffer alignment. > > > > Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> > > Cc: Marek Vasut <marex@denx.de> > > > > --- > > Changes for v2: > > - Remove Change-Id. > > --- > > drivers/usb/gadget/f_mass_storage.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/usb/gadget/f_mass_storage.c > > b/drivers/usb/gadget/f_mass_storage.c index b1fe8bd..f896169 100644 > > --- a/drivers/usb/gadget/f_mass_storage.c > > +++ b/drivers/usb/gadget/f_mass_storage.c > > @@ -2515,7 +2515,7 @@ static struct fsg_common > > *fsg_common_init(struct fsg_common *common, buffhds_first_it: > > bh->inreq_busy = 0; > > bh->outreq_busy = 0; > > - bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL); > > + bh->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, > > FSG_BUFLEN); if (unlikely(!bh->buf)) { > > rc = -ENOMEM; > > goto error_release; > > @@ -2622,7 +2622,7 @@ usb_copy_descriptors(struct > > usb_descriptor_header **src) bytes += (*tmp)->bLength; > > bytes += (n_desc + 1) * sizeof(*tmp); > > > > - mem = kmalloc(bytes, GFP_KERNEL); > > + mem = memalign(CONFIG_SYS_CACHELINE_SIZE, bytes); > > I wonder, does this align the begining of the buffer as well or only > the size? Can we rely on the fact the begining is also > cacheline-aligned ? In this case, the memalign assures, that beginning of the buffer is aligned to a cache line. It is the programmer's responsibility to either have "bytes" aligned to cache line size or use a wrapper like DEFINE_CACHE_ALIGN_BUFFER(). > > > if (!mem) > > return NULL; > > Best regards, > Marek Vasut
On Thursday, February 06, 2014 at 07:33:07 AM, Lukasz Majewski wrote: > Hi Marek, > > > On Wednesday, February 05, 2014 at 10:10:41 AM, Lukasz Majewski wrote: > > > Calls to malloc() have been replaced by memalign. It now provides > > > proper buffer alignment. > > > > > > Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> > > > Cc: Marek Vasut <marex@denx.de> > > > > > > --- > > > Changes for v2: > > > - Remove Change-Id. > > > --- > > > > > > drivers/usb/gadget/f_mass_storage.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/usb/gadget/f_mass_storage.c > > > b/drivers/usb/gadget/f_mass_storage.c index b1fe8bd..f896169 100644 > > > --- a/drivers/usb/gadget/f_mass_storage.c > > > +++ b/drivers/usb/gadget/f_mass_storage.c > > > @@ -2515,7 +2515,7 @@ static struct fsg_common > > > > > > *fsg_common_init(struct fsg_common *common, buffhds_first_it: > > > bh->inreq_busy = 0; > > > bh->outreq_busy = 0; > > > > > > - bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL); > > > + bh->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, > > > FSG_BUFLEN); if (unlikely(!bh->buf)) { > > > > > > rc = -ENOMEM; > > > goto error_release; > > > > > > @@ -2622,7 +2622,7 @@ usb_copy_descriptors(struct > > > usb_descriptor_header **src) bytes += (*tmp)->bLength; > > > > > > bytes += (n_desc + 1) * sizeof(*tmp); > > > > > > - mem = kmalloc(bytes, GFP_KERNEL); > > > + mem = memalign(CONFIG_SYS_CACHELINE_SIZE, bytes); > > > > I wonder, does this align the begining of the buffer as well or only > > the size? Can we rely on the fact the begining is also > > cacheline-aligned ? > > In this case, the memalign assures, that beginning of the buffer is > aligned to a cache line. How so ? :) [...] Best regards, Marek Vasut
Hi Marek, > On Thursday, February 06, 2014 at 07:33:07 AM, Lukasz Majewski wrote: > > Hi Marek, > > > > > On Wednesday, February 05, 2014 at 10:10:41 AM, Lukasz Majewski > > > wrote: > > > > Calls to malloc() have been replaced by memalign. It now > > > > provides proper buffer alignment. > > > > > > > > Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> > > > > Cc: Marek Vasut <marex@denx.de> > > > > > > > > --- > > > > Changes for v2: > > > > - Remove Change-Id. > > > > --- > > > > > > > > drivers/usb/gadget/f_mass_storage.c | 4 ++-- > > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/usb/gadget/f_mass_storage.c > > > > b/drivers/usb/gadget/f_mass_storage.c index b1fe8bd..f896169 > > > > 100644 --- a/drivers/usb/gadget/f_mass_storage.c > > > > +++ b/drivers/usb/gadget/f_mass_storage.c > > > > @@ -2515,7 +2515,7 @@ static struct fsg_common > > > > > > > > *fsg_common_init(struct fsg_common *common, buffhds_first_it: > > > > bh->inreq_busy = 0; > > > > bh->outreq_busy = 0; > > > > > > > > - bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL); > > > > + bh->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, > > > > FSG_BUFLEN); if (unlikely(!bh->buf)) { > > > > > > > > rc = -ENOMEM; > > > > goto error_release; > > > > > > > > @@ -2622,7 +2622,7 @@ usb_copy_descriptors(struct > > > > usb_descriptor_header **src) bytes += (*tmp)->bLength; > > > > > > > > bytes += (n_desc + 1) * sizeof(*tmp); > > > > > > > > - mem = kmalloc(bytes, GFP_KERNEL); > > > > + mem = memalign(CONFIG_SYS_CACHELINE_SIZE, bytes); > > > > > > I wonder, does this align the begining of the buffer as well or > > > only the size? Can we rely on the fact the begining is also > > > cacheline-aligned ? > > > > In this case, the memalign assures, that beginning of the buffer is > > aligned to a cache line. > > How so ? :) I'm just following what is written at ./include/malloc.h :-) memalign(size_t alignment, size_t n); Return a pointer to a newly allocated chunk of n bytes, aligned in accord with the alignment argument, which must be a power of two. Usage of memalign seemed to fix the wrong cache alignment buffer allocation issue in a code which I know. > [...] > > Best regards, > Marek Vasut
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c index b1fe8bd..f896169 100644 --- a/drivers/usb/gadget/f_mass_storage.c +++ b/drivers/usb/gadget/f_mass_storage.c @@ -2515,7 +2515,7 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common, buffhds_first_it: bh->inreq_busy = 0; bh->outreq_busy = 0; - bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL); + bh->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, FSG_BUFLEN); if (unlikely(!bh->buf)) { rc = -ENOMEM; goto error_release; @@ -2622,7 +2622,7 @@ usb_copy_descriptors(struct usb_descriptor_header **src) bytes += (*tmp)->bLength; bytes += (n_desc + 1) * sizeof(*tmp); - mem = kmalloc(bytes, GFP_KERNEL); + mem = memalign(CONFIG_SYS_CACHELINE_SIZE, bytes); if (!mem) return NULL;
Calls to malloc() have been replaced by memalign. It now provides proper buffer alignment. Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> Cc: Marek Vasut <marex@denx.de> --- Changes for v2: - Remove Change-Id. --- drivers/usb/gadget/f_mass_storage.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)