From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3s9XTd4LsVzDqTs for ; Fri, 12 Aug 2016 14:48:53 +1000 (AEST) Date: Fri, 12 Aug 2016 14:02:24 +1000 From: David Gibson To: Alexey Kardashevskiy Cc: linuxppc-dev@lists.ozlabs.org, Alex Williamson , Paul Mackerras Subject: Re: [PATCH kernel 09/15] powerpc/mmu: Add real mode support for IOMMU preregistered memory Message-ID: <20160812040224.GL16493@voom.fritz.box> References: <1470213656-1042-1-git-send-email-aik@ozlabs.ru> <1470213656-1042-10-git-send-email-aik@ozlabs.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="RNGrj7vazCqBHNw7" In-Reply-To: <1470213656-1042-10-git-send-email-aik@ozlabs.ru> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --RNGrj7vazCqBHNw7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 03, 2016 at 06:40:50PM +1000, Alexey Kardashevskiy wrote: > This makes mm_iommu_lookup() able to work in realmode by replacing > list_for_each_entry_rcu() (which can do debug stuff which can fail in > real mode) with list_for_each_entry_lockless(). >=20 > This adds realmode version of mm_iommu_ua_to_hpa() which adds > explicit vmalloc'd-to-linear address conversion. > Unlike mm_iommu_ua_to_hpa(), mm_iommu_ua_to_hpa_rm() can fail. >=20 > This changes mm_iommu_preregistered() to receive @mm as in real mode > @current does not always have a correct pointer. >=20 > This adds realmode version of mm_iommu_lookup() which receives @mm > (for the same reason as for mm_iommu_preregistered()) and uses > lockless version of list_for_each_entry_rcu(). >=20 > Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson > --- > arch/powerpc/include/asm/mmu_context.h | 4 ++++ > arch/powerpc/mm/mmu_context_iommu.c | 39 ++++++++++++++++++++++++++++= ++++++ > 2 files changed, 43 insertions(+) >=20 > diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/includ= e/asm/mmu_context.h > index a4c4ed5..939030c 100644 > --- a/arch/powerpc/include/asm/mmu_context.h > +++ b/arch/powerpc/include/asm/mmu_context.h > @@ -27,10 +27,14 @@ extern long mm_iommu_put(struct mm_struct *mm, > extern void mm_iommu_init(struct mm_struct *mm); > extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_stru= ct *mm, > unsigned long ua, unsigned long size); > +extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm( > + struct mm_struct *mm, unsigned long ua, unsigned long size); > extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct= *mm, > unsigned long ua, unsigned long entries); > extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, > unsigned long ua, unsigned long *hpa); > +extern long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem, > + unsigned long ua, unsigned long *hpa); > extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem); > extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem); > #endif > diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_co= ntext_iommu.c > index 10f01fe..36a906c 100644 > --- a/arch/powerpc/mm/mmu_context_iommu.c > +++ b/arch/powerpc/mm/mmu_context_iommu.c > @@ -242,6 +242,25 @@ struct mm_iommu_table_group_mem_t *mm_iommu_lookup(s= truct mm_struct *mm, > } > EXPORT_SYMBOL_GPL(mm_iommu_lookup); > =20 > +struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(struct mm_struct *= mm, > + unsigned long ua, unsigned long size) > +{ > + struct mm_iommu_table_group_mem_t *mem, *ret =3D NULL; > + > + list_for_each_entry_lockless(mem, &mm->context.iommu_group_mem_list, > + next) { > + if ((mem->ua <=3D ua) && > + (ua + size <=3D mem->ua + > + (mem->entries << PAGE_SHIFT))) { > + ret =3D mem; > + break; > + } > + } > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(mm_iommu_lookup_rm); > + > struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm, > unsigned long ua, unsigned long entries) > { > @@ -273,6 +292,26 @@ long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_= mem_t *mem, > } > EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa); > =20 > +long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem, > + unsigned long ua, unsigned long *hpa) > +{ > + const long entry =3D (ua - mem->ua) >> PAGE_SHIFT; > + void *va =3D &mem->hpas[entry]; > + unsigned long *ra; > + > + if (entry >=3D mem->entries) > + return -EFAULT; > + > + ra =3D (void *) vmalloc_to_phys(va); > + if (!ra) > + return -EFAULT; > + > + *hpa =3D *ra | (ua & ~PAGE_MASK); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa_rm); > + > long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem) > { > if (atomic64_inc_not_zero(&mem->mapped)) --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. 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