On Thu, Oct 03, 2019 at 05:25:16PM -0700, James Bottomley wrote:
> On Thu, 2019-10-03 at 21:51 +0300, Jarkko Sakkinen wrote:
> > Switch from GFP_HIGHUSER to GFP_KERNEL. On 32-bit platforms kmap()
> > space
> > could be unnecessarily wasted because of using GFP_HIGHUSER by taking
> > a
> > page of from the highmem.
> >
> > Suggested-by: James Bottomley <j...@linux.ibm.com>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
> > ---
> > drivers/char/tpm/tpm.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> > index a4f74dd02a35..d20745965350 100644
> > --- a/drivers/char/tpm/tpm.h
> > +++ b/drivers/char/tpm/tpm.h
> > @@ -297,7 +297,7 @@ static inline void tpm_buf_reset(struct tpm_buf
> > *buf, u16 tag, u32 ordinal)
> >
> > static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32
> > ordinal)
> > {
> > - buf->data_page = alloc_page(GFP_HIGHUSER);
> > + buf->data_page = alloc_page(GFP_KERNEL);
> > if (!buf->data_page)
> > return -ENOMEM;
>
> The kmap/kunmap needs removing as well, and now the data_page field
> isn't necessary, so it can go. I think the result should be something
> like the below (uncompiled and untested).
>
> James
>
> ---
>
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index a7fea3e0ca86..b4f1cbf344b6 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -284,7 +284,6 @@ enum tpm_buf_flags {
> };
>
> struct tpm_buf {
> - struct page *data_page;
> unsigned int flags;
> u8 *data;
> };
> @@ -300,20 +299,18 @@ static inline void tpm_buf_reset(struct tpm_buf *buf,
> u16 tag, u32 ordinal)
>
> static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
> {
> - buf->data_page = alloc_page(GFP_HIGHUSER);
> - if (!buf->data_page)
> + buf->data = (u8 *)__get_free_page(GFP_KERNEL);
> + if (!buf->data)
> return -ENOMEM;
>
> buf->flags = 0;
> - buf->data = kmap(buf->data_page);
> tpm_buf_reset(buf, tag, ordinal);
> return 0;
> }
>
> static inline void tpm_buf_destroy(struct tpm_buf *buf)
> {
> - kunmap(buf->data_page);
> - __free_page(buf->data_page);
> + free_page(buf->data);
> }
>
> static inline u32 tpm_buf_length(struct tpm_buf *buf)
>
>
Care to make this a proper patch? Much better idea to do it this
way, agreed.
/Jarkko
