From: David Gibson <david@gibson•dropbear.id.au>
To: Alexey Kardashevskiy <aik@ozlabs•ru>
Cc: linuxppc-dev@lists•ozlabs.org,
Alex Williamson <alex.williamson@redhat•com>,
Paul Mackerras <paulus@samba•org>
Subject: Re: [PATCH kernel 09/15] powerpc/mmu: Add real mode support for IOMMU preregistered memory
Date: Fri, 12 Aug 2016 14:02:24 +1000 [thread overview]
Message-ID: <20160812040224.GL16493@voom.fritz.box> (raw)
In-Reply-To: <1470213656-1042-10-git-send-email-aik@ozlabs.ru>
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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().
>
> 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.
>
> This changes mm_iommu_preregistered() to receive @mm as in real mode
> @current does not always have a correct pointer.
>
> 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().
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs•ru>
Reviewed-by: David Gibson <david@gibson•dropbear.id.au>
> ---
> arch/powerpc/include/asm/mmu_context.h | 4 ++++
> arch/powerpc/mm/mmu_context_iommu.c | 39 ++++++++++++++++++++++++++++++++++
> 2 files changed, 43 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/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_struct *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_context_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(struct mm_struct *mm,
> }
> EXPORT_SYMBOL_GPL(mm_iommu_lookup);
>
> +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 = NULL;
> +
> + list_for_each_entry_lockless(mem, &mm->context.iommu_group_mem_list,
> + next) {
> + if ((mem->ua <= ua) &&
> + (ua + size <= mem->ua +
> + (mem->entries << PAGE_SHIFT))) {
> + ret = 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);
>
> +long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
> + unsigned long ua, unsigned long *hpa)
> +{
> + const long entry = (ua - mem->ua) >> PAGE_SHIFT;
> + void *va = &mem->hpas[entry];
> + unsigned long *ra;
> +
> + if (entry >= mem->entries)
> + return -EFAULT;
> +
> + ra = (void *) vmalloc_to_phys(va);
> + if (!ra)
> + return -EFAULT;
> +
> + *hpa = *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))
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2016-08-12 4:48 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-03 8:40 [PATCH kernel 00/15] powerpc/kvm/vfio: Enable in-kernel acceleration Alexey Kardashevskiy
2016-08-03 8:40 ` [PATCH kernel 01/15] Revert "iommu: Add a function to find an iommu group by id" Alexey Kardashevskiy
2016-08-15 4:58 ` Paul Mackerras
2016-08-03 8:40 ` [PATCH kernel 02/15] KVM: PPC: Finish enabling VFIO KVM device on POWER Alexey Kardashevskiy
2016-08-04 5:21 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 03/15] KVM: PPC: Reserve KVM_CAP_SPAPR_TCE_VFIO capability number Alexey Kardashevskiy
2016-08-03 8:40 ` [PATCH kernel 04/15] powerpc/powernv/ioda: Fix TCE invalidate to work in real mode again Alexey Kardashevskiy
2016-08-04 5:23 ` David Gibson
2016-08-09 11:26 ` [kernel, " Michael Ellerman
2016-08-03 8:40 ` [PATCH kernel 05/15] powerpc/iommu: Stop using @current in mm_iommu_xxx Alexey Kardashevskiy
2016-08-03 10:10 ` Nicholas Piggin
2016-08-05 7:00 ` Michael Ellerman
2016-08-09 5:29 ` Alexey Kardashevskiy
2016-08-09 4:43 ` Balbir Singh
2016-08-09 6:04 ` Nicholas Piggin
2016-08-09 6:17 ` Balbir Singh
2016-08-12 2:57 ` David Gibson
2016-08-12 4:56 ` Alexey Kardashevskiy
2016-08-15 10:58 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 06/15] powerpc/mm/iommu: Put pages on process exit Alexey Kardashevskiy
2016-08-03 10:11 ` Nicholas Piggin
2016-08-12 3:13 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 07/15] powerpc/iommu: Cleanup iommu_table disposal Alexey Kardashevskiy
2016-08-12 3:18 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 08/15] powerpc/vfio_spapr_tce: Add reference counting to iommu_table Alexey Kardashevskiy
2016-08-12 3:29 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 09/15] powerpc/mmu: Add real mode support for IOMMU preregistered memory Alexey Kardashevskiy
2016-08-12 4:02 ` David Gibson [this message]
2016-08-03 8:40 ` [PATCH kernel 10/15] KVM: PPC: Use preregistered memory API to access TCE list Alexey Kardashevskiy
2016-08-12 4:17 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 11/15] powerpc/powernv/iommu: Add real mode version of iommu_table_ops::exchange() Alexey Kardashevskiy
2016-08-12 4:29 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 12/15] KVM: PPC: Enable IOMMU_API for KVM_BOOK3S_64 permanently Alexey Kardashevskiy
2016-08-12 4:34 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 13/15] KVM: PPC: Pass kvm* to kvmppc_find_table() Alexey Kardashevskiy
2016-08-12 4:45 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 14/15] vfio/spapr_tce: Export container API for external users Alexey Kardashevskiy
2016-08-08 16:43 ` Alex Williamson
2016-08-09 5:19 ` Alexey Kardashevskiy
2016-08-09 12:16 ` Alex Williamson
2016-08-10 5:37 ` Alexey Kardashevskiy
2016-08-10 16:46 ` Alex Williamson
2016-08-12 5:46 ` David Gibson
2016-08-12 6:12 ` Alexey Kardashevskiy
2016-08-15 11:07 ` David Gibson
2016-08-17 8:31 ` Alexey Kardashevskiy
2016-08-12 15:22 ` Alex Williamson
2016-08-17 3:17 ` David Gibson
2016-08-18 0:22 ` Alexey Kardashevskiy
2016-08-29 6:35 ` Alexey Kardashevskiy
2016-08-29 13:27 ` David Gibson
2016-09-07 9:09 ` Alexey Kardashevskiy
2016-09-21 6:56 ` Alexey Kardashevskiy
2016-09-23 7:12 ` David Gibson
2016-10-17 6:06 ` Alexey Kardashevskiy
2016-10-18 1:42 ` David Gibson
2016-08-15 3:59 ` Paul Mackerras
2016-08-15 15:32 ` Alex Williamson
2016-08-12 5:25 ` David Gibson
2016-08-03 8:40 ` [PATCH kernel 15/15] KVM: PPC: Add in-kernel acceleration for VFIO Alexey Kardashevskiy
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