linux-kernel - [PATCH v4 01/14] swiotlb: Remove external access to io_tlb

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210209062131.2300005-2-tientzu@chromium.org>
Date:   Tue,  9 Feb 2021 14:21:18 +0800
From:   Claire Chang <tientzu@...omium.org>
To:     Rob Herring <robh+dt@...nel.org>, mpe@...erman.id.au,
        Joerg Roedel <joro@...tes.org>, Will Deacon <will@...nel.org>,
        Frank Rowand <frowand.list@...il.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
        boris.ostrovsky@...cle.com, jgross@...e.com,
        Christoph Hellwig <hch@....de>,
        Marek Szyprowski <m.szyprowski@...sung.com>
Cc:     benh@...nel.crashing.org, paulus@...ba.org,
        "list@....net:IOMMU DRIVERS" <iommu@...ts.linux-foundation.org>,
        sstabellini@...nel.org, Robin Murphy <robin.murphy@....com>,
        grant.likely@....com, xypron.glpk@....de,
        Thierry Reding <treding@...dia.com>, mingo@...nel.org,
        bauerman@...ux.ibm.com, peterz@...radead.org,
        Greg KH <gregkh@...uxfoundation.org>,
        Saravana Kannan <saravanak@...gle.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        heikki.krogerus@...ux.intel.com,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Randy Dunlap <rdunlap@...radead.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        linux-devicetree <devicetree@...r.kernel.org>,
        lkml <linux-kernel@...r.kernel.org>,
        linuxppc-dev@...ts.ozlabs.org, xen-devel@...ts.xenproject.org,
        Nicolas Boichat <drinkcat@...omium.org>,
        Jim Quinlan <james.quinlan@...adcom.com>,
        Claire Chang <tientzu@...omium.org>
Subject: [PATCH v4 01/14] swiotlb: Remove external access to io_tlb_start

Add a new function, get_swiotlb_start(), and remove external access to
io_tlb_start, so we can entirely hide struct swiotlb inside of swiotlb.c
in the following patches.

Signed-off-by: Claire Chang <tientzu@...omium.org>
---
 arch/powerpc/platforms/pseries/svm.c | 4 ++--
 drivers/xen/swiotlb-xen.c            | 4 ++--
 include/linux/swiotlb.h              | 1 +
 kernel/dma/swiotlb.c                 | 5 +++++
 4 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c
index 7b739cc7a8a9..c10c51d49f3d 100644
--- a/arch/powerpc/platforms/pseries/svm.c
+++ b/arch/powerpc/platforms/pseries/svm.c
@@ -55,8 +55,8 @@ void __init svm_swiotlb_init(void)
 	if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false))
 		return;
 
-	if (io_tlb_start)
-		memblock_free_early(io_tlb_start,
+	if (vstart)
+		memblock_free_early(vstart,
 				    PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
 	panic("SVM: Cannot allocate SWIOTLB buffer");
 }
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 2b385c1b4a99..91f8c68d1a9b 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -192,8 +192,8 @@ int __ref xen_swiotlb_init(int verbose, bool early)
 	/*
 	 * IO TLB memory already allocated. Just use it.
 	 */
-	if (io_tlb_start != 0) {
-		xen_io_tlb_start = phys_to_virt(io_tlb_start);
+	if (is_swiotlb_active()) {
+		xen_io_tlb_start = phys_to_virt(get_swiotlb_start());
 		goto end;
 	}
 
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index d9c9fc9ca5d2..83200f3b042a 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -81,6 +81,7 @@ void __init swiotlb_exit(void);
 unsigned int swiotlb_max_segment(void);
 size_t swiotlb_max_mapping_size(struct device *dev);
 bool is_swiotlb_active(void);
+phys_addr_t get_swiotlb_start(void);
 void __init swiotlb_adjust_size(unsigned long new_size);
 #else
 #define swiotlb_force SWIOTLB_NO_FORCE
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 7c42df6e6100..e180211f6ad9 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -719,6 +719,11 @@ bool is_swiotlb_active(void)
 	return io_tlb_end != 0;
 }
 
+phys_addr_t get_swiotlb_start(void)
+{
+	return io_tlb_start;
+}
+
 #ifdef CONFIG_DEBUG_FS
 
 static int __init swiotlb_create_debugfs(void)
--

This can be dropped if Christoph's swiotlb cleanups are landed.
https://lore.kernel.org/linux-iommu/20210207160934.2955931-1-hch@lst.de/T/#m7124f29b6076d462101fcff6433295157621da09 

2.30.0.478.g8a0d178c01-goog