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Message-ID: <496565EC904933469F292DDA3F1663E602F47B2BF1@dlee06.ent.ti.com>
Date: Mon, 11 Oct 2010 10:33:42 -0500
From: "Guzman Lugo, Fernando" <fernando.lugo@...com>
To: Felipe Contreras <felipe.contreras@...il.com>
CC: "Hiroshi.DOYU@...ia.com" <Hiroshi.DOYU@...ia.com>,
"david.cohen@...ia.com" <david.cohen@...ia.com>,
"felipe.contreras@...ia.com" <felipe.contreras@...ia.com>,
"ameya.palande@...ia.com" <ameya.palande@...ia.com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"andy.shevchenko@...il.com" <andy.shevchenko@...il.com>,
"linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>
Subject: RE: [PATCHv2 2/3] iovmm: add superpages support to fixed da address
> -----Original Message-----
> From: Felipe Contreras [mailto:felipe.contreras@...il.com]
> Sent: Sunday, October 10, 2010 10:22 AM
> To: Guzman Lugo, Fernando
> Cc: Hiroshi.DOYU@...ia.com; david.cohen@...ia.com;
> felipe.contreras@...ia.com; ameya.palande@...ia.com;
> linux-kernel@...r.kernel.org; andy.shevchenko@...il.com;
> linux-omap@...r.kernel.org
> Subject: Re: [PATCHv2 2/3] iovmm: add superpages support to
> fixed da address
>
> On Tue, Oct 5, 2010 at 12:02 AM, Fernando Guzman Lugo
> <x0095840@...com> wrote:
> > This patch adds superpages support to fixed ad address inside
> > iommu_kmap function.
> >
> > Signed-off-by: Fernando Guzman Lugo <x0095840@...com>
> > ---
> > arch/arm/plat-omap/iovmm.c | 61
> > ++++++++++++++++++++++++++-----------------
> > 1 files changed, 37 insertions(+), 24 deletions(-)
> >
> > diff --git a/arch/arm/plat-omap/iovmm.c
> b/arch/arm/plat-omap/iovmm.c
> > index 34f0012..8006a19 100644
> > --- a/arch/arm/plat-omap/iovmm.c
> > +++ b/arch/arm/plat-omap/iovmm.c
> > @@ -87,27 +87,37 @@ static size_t sgtable_len(const struct sg_table
> > *sgt)
> > }
> > #define sgtable_ok(x) (!!sgtable_len(x))
> >
> > +
> > +static unsigned max_alignment(u32 addr) {
> > + int i;
> > + unsigned pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, };
> > + for (i = 0; i < ARRAY_SIZE(pagesize) && addr &
> (pagesize[i] -
> > +1); i++)
> > + ;
> > + return (i < ARRAY_SIZE(pagesize)) ? pagesize[i] : 0; }
> > +
> > +
>
> I don't think those extra spaces make sense.
Ok, it will be fixed.
>
> > /*
> > * calculate the optimal number sg elements from total
> bytes based on
> > * iommu superpages
> > */
> > -static unsigned int sgtable_nents(size_t bytes)
> > +static unsigned int sgtable_nents(size_t bytes, u32 da, u32 pa)
> > {
> > - int i;
> > - unsigned int nr_entries;
> > - const unsigned long pagesize[] = { SZ_16M, SZ_1M, SZ_64K,
> > SZ_4K, };
> > + unsigned int nr_entries = 0, ent_sz;
>
> How about s/unsigned int/unsigned/?
It is exactly the same, but not problem for me.
>
> >
> > if (!IS_ALIGNED(bytes, PAGE_SIZE)) {
> > pr_err("%s: wrong size %08x\n", __func__, bytes);
> > return 0;
> > }
> >
> > - nr_entries = 0;
> > - for (i = 0; i < ARRAY_SIZE(pagesize); i++) {
> > - if (bytes >= pagesize[i]) {
> > - nr_entries += (bytes / pagesize[i]);
> > - bytes %= pagesize[i];
> > - }
> > + while (bytes) {
> > + ent_sz = max_alignment(da | pa);
> > + ent_sz = min(ent_sz, (unsigned)iopgsz_max(bytes));
> > + nr_entries++;
> > + da += ent_sz;
> > + pa += ent_sz;
> > + bytes -= ent_sz;
> > }
> > BUG_ON(bytes);
> >
> > @@ -115,7 +125,8 @@ static unsigned int sgtable_nents(size_t bytes)
> > }
> >
> > /* allocate and initialize sg_table header(a kind of
> 'superblock') */
> > -static struct sg_table *sgtable_alloc(const size_t bytes,
> u32 flags)
> > +static struct sg_table *sgtable_alloc(const size_t bytes,
> u32 flags,
> > + u32 da, u32
> > +pa)
> > {
> > unsigned int nr_entries;
> > int err;
> > @@ -127,9 +138,8 @@ static struct sg_table
> *sgtable_alloc(const size_t
> > bytes, u32 flags)
> > if (!IS_ALIGNED(bytes, PAGE_SIZE))
> > return ERR_PTR(-EINVAL);
> >
> > - /* FIXME: IOVMF_DA_FIXED should support 'superpages' */
> > - if ((flags & IOVMF_LINEAR) && (flags & IOVMF_DA_ANON)) {
> > - nr_entries = sgtable_nents(bytes);
> > + if (flags & IOVMF_LINEAR) {
> > + nr_entries = sgtable_nents(bytes, da, pa);
> > if (!nr_entries)
> > return ERR_PTR(-EINVAL);
> > } else
> > @@ -409,7 +419,8 @@ static inline void sgtable_drain_vmalloc(struct
> > sg_table *sgt)
> > BUG_ON(!sgt);
> > }
> >
> > -static void sgtable_fill_kmalloc(struct sg_table *sgt, u32
> pa, size_t
> > len)
> > +static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, u32
> > +da,
> > +
> size_t
> > +len)
> > {
> > unsigned int i;
> > struct scatterlist *sg;
> > @@ -420,7 +431,8 @@ static void sgtable_fill_kmalloc(struct
> sg_table
> > *sgt, u32 pa, size_t len)
> > for_each_sg(sgt->sgl, sg, sgt->nents, i) {
> > size_t bytes;
> >
> > - bytes = iopgsz_max(len);
> > + bytes = max_alignment(da | pa);
> > + bytes = min(bytes, (size_t)iopgsz_max(len));
>
> Why the size_t casting?
To void this warning:
arch/arm/plat-omap/iovmm.c:440: warning: comparison of distinct pointer types lacks a cast
I will update with minor changes and resend.
Thanks and regards,
Fernando.
>
> Otherwise:
> Signed-off-by: Felipe Contreras <felipe.contreras@...il.com>
>
> --
> Felipe Contreras
> --
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