From: Stefano Stabellini <sstabellini@kernel.org> To: konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, jgross@suse.com Cc: xen-devel@lists.xenproject.org, Julien.Grall@arm.com, sstabellini@kernel.org Subject: [PATCH v2] xen/swiotlb: don't initialize swiotlb twice on arm64 Date: Tue, 28 May 2019 15:48:22 -0700 (PDT) [thread overview] Message-ID: <alpine.DEB.2.21.1905281546410.16734@sstabellini-ThinkPad-T480s> (raw) From: Stefano Stabellini <stefanos@xilinx.com> On arm64 swiotlb is often (not always) already initialized by mem_init. We don't want to initialize it twice, which would trigger a second memory allocation. Moreover, the second memory pool is typically made of high pages and ends up replacing the original memory pool of low pages. As a side effect of this change, it is possible to have low pages in swiotlb-xen on arm64. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> --- Changes in v2: - improve commit message - don't add nested ifs diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 877baf2..8a3cdd1 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -211,6 +211,15 @@ int __ref xen_swiotlb_init(int verbose, bool early) retry: bytes = xen_set_nslabs(xen_io_tlb_nslabs); order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT); + + /* + * IO TLB memory already allocated. Just use it. + */ + if (io_tlb_start != 0) { + xen_io_tlb_start = phys_to_virt(io_tlb_start); + goto end; + } + /* * Get IO TLB memory from any location. */ @@ -240,7 +249,6 @@ int __ref xen_swiotlb_init(int verbose, bool early) m_ret = XEN_SWIOTLB_ENOMEM; goto error; } - xen_io_tlb_end = xen_io_tlb_start + bytes; /* * And replace that memory with pages under 4GB. */ @@ -267,6 +275,8 @@ int __ref xen_swiotlb_init(int verbose, bool early) } else rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs); +end: + xen_io_tlb_end = xen_io_tlb_start + bytes; if (!rc) swiotlb_set_max_segment(PAGE_SIZE); -- 2.7.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
WARNING: multiple messages have this Message-ID (diff)
From: Stefano Stabellini <sstabellini@kernel.org> To: konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, jgross@suse.com Cc: xen-devel@lists.xenproject.org, Julien.Grall@arm.com, sstabellini@kernel.org Subject: [Xen-devel] [PATCH v2] xen/swiotlb: don't initialize swiotlb twice on arm64 Date: Tue, 28 May 2019 15:48:22 -0700 (PDT) [thread overview] Message-ID: <alpine.DEB.2.21.1905281546410.16734@sstabellini-ThinkPad-T480s> (raw) Message-ID: <20190528224822.rM7eZfwZSXO7-sGa7maCfLg7H_mMkrbh2myHfBF2QxU@z> (raw) From: Stefano Stabellini <stefanos@xilinx.com> On arm64 swiotlb is often (not always) already initialized by mem_init. We don't want to initialize it twice, which would trigger a second memory allocation. Moreover, the second memory pool is typically made of high pages and ends up replacing the original memory pool of low pages. As a side effect of this change, it is possible to have low pages in swiotlb-xen on arm64. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> --- Changes in v2: - improve commit message - don't add nested ifs diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 877baf2..8a3cdd1 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -211,6 +211,15 @@ int __ref xen_swiotlb_init(int verbose, bool early) retry: bytes = xen_set_nslabs(xen_io_tlb_nslabs); order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT); + + /* + * IO TLB memory already allocated. Just use it. + */ + if (io_tlb_start != 0) { + xen_io_tlb_start = phys_to_virt(io_tlb_start); + goto end; + } + /* * Get IO TLB memory from any location. */ @@ -240,7 +249,6 @@ int __ref xen_swiotlb_init(int verbose, bool early) m_ret = XEN_SWIOTLB_ENOMEM; goto error; } - xen_io_tlb_end = xen_io_tlb_start + bytes; /* * And replace that memory with pages under 4GB. */ @@ -267,6 +275,8 @@ int __ref xen_swiotlb_init(int verbose, bool early) } else rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs); +end: + xen_io_tlb_end = xen_io_tlb_start + bytes; if (!rc) swiotlb_set_max_segment(PAGE_SIZE); -- 2.7.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
next reply other threads:[~2019-05-28 22:48 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-28 22:48 Stefano Stabellini [this message] 2019-05-28 22:48 ` [Xen-devel] [PATCH v2] xen/swiotlb: don't initialize swiotlb twice on arm64 Stefano Stabellini 2019-05-28 23:50 ` Boris Ostrovsky 2019-05-28 23:50 ` [Xen-devel] " Boris Ostrovsky 2019-06-03 18:25 ` Stefano Stabellini 2019-06-03 18:25 ` [Xen-devel] " Stefano Stabellini 2019-06-03 23:16 ` Boris Ostrovsky 2019-06-03 23:16 ` [Xen-devel] " Boris Ostrovsky 2019-06-04 16:51 ` Stefano Stabellini 2019-06-04 19:41 ` Boris Ostrovsky 2019-06-05 14:13 ` Konrad Rzeszutek Wilk 2019-06-05 14:24 ` Juergen Gross 2019-06-13 14:23 ` Konrad Rzeszutek Wilk 2019-06-13 15:04 ` Juergen Gross 2019-06-13 21:00 ` Konrad Rzeszutek Wilk 2019-06-17 8:21 ` Christoph Hellwig
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