From mboxrd@z Thu Jan 1 00:00:00 1970 From: Khalid Aziz Subject: [RFC PATCH v8 04/14] swiotlb: Map the buffer if it was unmapped by XPFO Date: Wed, 13 Feb 2019 17:01:27 -0700 Message-Id: In-Reply-To: References: In-Reply-To: References: To: juergh@gmail.com, tycho@tycho.ws, jsteckli@amazon.de, ak@linux.intel.com, torvalds@linux-foundation.org, liran.alon@oracle.com, keescook@google.com, akpm@linux-foundation.org, mhocko@suse.com, catalin.marinas@arm.com, will.deacon@arm.com, jmorris@namei.org, konrad.wilk@oracle.com Cc: Juerg Haefliger , deepa.srinivasan@oracle.com, chris.hyser@oracle.com, tyhicks@canonical.com, dwmw@amazon.co.uk, andrew.cooper3@citrix.com, jcm@redhat.com, boris.ostrovsky@oracle.com, kanth.ghatraju@oracle.com, oao.m.martins@oracle.com, jmattson@google.com, pradeep.vincent@oracle.com, john.haxby@oracle.com, tglx@linutronix.de, kirill.shutemov@linux.intel.com, hch@lst.de, steven.sistare@oracle.com, labbott@redhat.com, luto@kernel.org, dave.hansen@intel.com, peterz@infradead.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Tycho Andersen List-ID: From: Juerg Haefliger v6: * guard against lookup_xpfo() returning NULL CC: Konrad Rzeszutek Wilk Signed-off-by: Juerg Haefliger Signed-off-by: Tycho Andersen Reviewed-by: Khalid Aziz Reviewed-by: Konrad Rzeszutek Wilk --- include/linux/xpfo.h | 4 ++++ kernel/dma/swiotlb.c | 3 ++- mm/xpfo.c | 15 +++++++++++++++ 3 files changed, 21 insertions(+), 1 deletion(-) diff --git a/include/linux/xpfo.h b/include/linux/xpfo.h index b15234745fb4..cba37ffb09b1 100644 --- a/include/linux/xpfo.h +++ b/include/linux/xpfo.h @@ -36,6 +36,8 @@ void xpfo_kunmap(void *kaddr, struct page *page); void xpfo_alloc_pages(struct page *page, int order, gfp_t gfp); void xpfo_free_pages(struct page *page, int order); +bool xpfo_page_is_unmapped(struct page *page); + #else /* !CONFIG_XPFO */ static inline void xpfo_kmap(void *kaddr, struct page *page) { } @@ -43,6 +45,8 @@ static inline void xpfo_kunmap(void *kaddr, struct page *page) { } static inline void xpfo_alloc_pages(struct page *page, int order, gfp_t gfp) { } static inline void xpfo_free_pages(struct page *page, int order) { } +static inline bool xpfo_page_is_unmapped(struct page *page) { return false; } + #endif /* CONFIG_XPFO */ #endif /* _LINUX_XPFO_H */ diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 045930e32c0e..820a54b57491 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -396,8 +396,9 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, { unsigned long pfn = PFN_DOWN(orig_addr); unsigned char *vaddr = phys_to_virt(tlb_addr); + struct page *page = pfn_to_page(pfn); - if (PageHighMem(pfn_to_page(pfn))) { + if (PageHighMem(page) || xpfo_page_is_unmapped(page)) { /* The buffer does not have a mapping. Map it in and copy */ unsigned int offset = orig_addr & ~PAGE_MASK; char *buffer; diff --git a/mm/xpfo.c b/mm/xpfo.c index 24b33d3c20cb..67884736bebe 100644 --- a/mm/xpfo.c +++ b/mm/xpfo.c @@ -221,3 +221,18 @@ void xpfo_kunmap(void *kaddr, struct page *page) spin_unlock(&xpfo->maplock); } EXPORT_SYMBOL(xpfo_kunmap); + +bool xpfo_page_is_unmapped(struct page *page) +{ + struct xpfo *xpfo; + + if (!static_branch_unlikely(&xpfo_inited)) + return false; + + xpfo = lookup_xpfo(page); + if (unlikely(!xpfo) && !xpfo->inited) + return false; + + return test_bit(XPFO_PAGE_UNMAPPED, &xpfo->flags); +} +EXPORT_SYMBOL(xpfo_page_is_unmapped); -- 2.17.1