From: aik@ozlabs.ru
To: unlisted-recipients:; (no To-header on input)
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>,
Paul Mackerras <paulus@samba.org>, Alexander Graf <agraf@suse.de>,
Michael Ellerman <michael@ellerman.id.au>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
kvm-ppc@vger.kernel.org, kvm@vger.kernel.org,
David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 3/4] powerpc: preparing to support real mode optimization
Date: Mon, 11 Feb 2013 23:12:42 +1100 [thread overview]
Message-ID: <5118e069.22ca320a.1f08.ffffe2f0@mx.google.com> (raw)
In-Reply-To: <1360584763-21988-1-git-send-email-a>
From: Alexey Kardashevskiy <aik@ozlabs.ru>
he current VFIO-on-POWER implementation supports only user mode
driven mapping, i.e. QEMU is sending requests to map/unmap pages.
However this approach is really slow in really fast hardware so
it is better to be moved to the real mode.
The patch adds an API to increment/decrement page counter as
get_user_pages API used for user mode mapping does not work
in the real mode.
CONFIG_SPARSEMEM_VMEMMAP and CONFIG_FLATMEN are supported.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: David Gibson <david@gibson.dropbear.id.au>
---
arch/powerpc/include/asm/pgtable-ppc64.h | 3 ++
arch/powerpc/mm/init_64.c | 56 +++++++++++++++++++++++++++++-
2 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index ddcc898..b7a1fb2 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -377,6 +377,9 @@ static inline pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
}
#endif /* !CONFIG_HUGETLB_PAGE */
+struct page *vmemmap_pfn_to_page(unsigned long pfn);
+long vmemmap_get_page(struct page *page);
+long vmemmap_put_page(struct page *page);
pte_t lookup_linux_pte(pgd_t *pgdir, unsigned long hva,
int writing, unsigned long *pte_sizep);
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index 95a4529..068e9e9 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -297,5 +297,59 @@ int __meminit vmemmap_populate(struct page *start_page,
return 0;
}
-#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+struct page *vmemmap_pfn_to_page(unsigned long pfn)
+{
+ struct vmemmap_backing *vmem_back;
+ struct page *page;
+ unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
+ unsigned long pg_va = (unsigned long) pfn_to_page(pfn);
+
+ for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) {
+ if (pg_va < vmem_back->virt_addr)
+ continue;
+
+ /* Check that page struct is not split between real pages */
+ if ((pg_va + sizeof(struct page)) >
+ (vmem_back->virt_addr + page_size))
+ return NULL;
+
+ page = (struct page *) (vmem_back->phys + pg_va -
+ vmem_back->virt_addr);
+ return page;
+ }
+
+ return NULL;
+}
+
+#elif defined(CONFIG_FLATMEM)
+
+struct page *vmemmap_pfn_to_page(unsigned long pfn)
+{
+ struct page *page = pfn_to_page(pfn);
+ return page;
+}
+
+#endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */
+
+#if defined(CONFIG_SPARSEMEM_VMEMMAP) || defined(CONFIG_FLATMEM)
+long vmemmap_get_page(struct page *page)
+{
+ if (PageTail(page))
+ return -EAGAIN;
+
+ get_page(page);
+
+ return 0;
+}
+
+long vmemmap_put_page(struct page *page)
+{
+ if (PageCompound(page))
+ return -EAGAIN;
+
+ put_page(page);
+
+ return 0;
+}
+#endif
--
1.7.10.4
next prev parent reply other threads:[~2013-02-11 12:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1360584763-21988-1-git-send-email-a>
2013-02-11 12:12 ` [PATCH 1/4] powerpc: lookup_linux_pte has been made public aik
2013-02-15 3:13 ` Paul Mackerras
2013-02-11 12:12 ` [PATCH 2/4] powerpc kvm: added multiple TCEs requests support aik
2013-02-15 3:24 ` Paul Mackerras
2013-02-18 8:14 ` Alexey Kardashevskiy
2013-02-11 12:12 ` aik [this message]
2013-02-15 3:37 ` [PATCH 3/4] powerpc: preparing to support real mode optimization Paul Mackerras
2013-02-11 12:12 ` [PATCH 4/4] vfio powerpc: added real mode support aik
2013-02-15 3:54 ` Paul Mackerras
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