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: <c6b051fd9ae34d42f2f4dd2ffb2c5dc968e22837.1690871004.git.petr.tesarik.ext@huawei.com>
Date:   Tue,  1 Aug 2023 08:24:00 +0200
From:   Petr Tesarik <petrtesarik@...weicloud.com>
To:     Stefano Stabellini <sstabellini@...nel.org>,
        Russell King <linux@...linux.org.uk>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        "H. Peter Anvin" <hpa@...or.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Juergen Gross <jgross@...e.com>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>,
        Christoph Hellwig <hch@....de>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Robin Murphy <robin.murphy@....com>,
        Christoph Lameter <cl@...ux.com>,
        Pekka Enberg <penberg@...nel.org>,
        David Rientjes <rientjes@...gle.com>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        Roman Gushchin <roman.gushchin@...ux.dev>,
        Hyeonggon Yoo <42.hyeyoo@...il.com>,
        Petr Tesarik <petr.tesarik.ext@...wei.com>,
        Jonathan Corbet <corbet@....net>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Hans de Goede <hdegoede@...hat.com>,
        James Seo <james@...iv.tech>,
        James Clark <james.clark@....com>,
        Kees Cook <keescook@...omium.org>,
        xen-devel@...ts.xenproject.org (moderated list:XEN HYPERVISOR ARM),
        linux-arm-kernel@...ts.infradead.org (moderated list:ARM PORT),
        linux-kernel@...r.kernel.org (open list),
        linux-mips@...r.kernel.org (open list:MIPS),
        iommu@...ts.linux.dev (open list:XEN SWIOTLB SUBSYSTEM),
        linux-mm@...ck.org (open list:SLAB ALLOCATOR)
Cc:     Roberto Sassu <roberto.sassu@...weicloud.com>, petr@...arici.cz
Subject: [PATCH v7 5/9] swiotlb: add a flag whether SWIOTLB is allowed to grow

From: Petr Tesarik <petr.tesarik.ext@...wei.com>

Add a config option (CONFIG_SWIOTLB_DYNAMIC) to enable or disable dynamic
allocation of additional bounce buffers.

If this option is set, mark the default SWIOTLB as able to grow and
restricted DMA pools as unable.

However, if the address of the default memory pool is explicitly queried,
make the default SWIOTLB also unable to grow. This is currently used to set
up PCI BAR movable regions on some Octeon MIPS boards which may not be able
to use a SWIOTLB pool elsewhere in physical memory. See octeon_pci_setup()
for more details.

If a remap function is specified, it must be also called on any dynamically
allocated pools, but there are some issues:

- The remap function may block, so it should not be called from an atomic
  context.
- There is no corresponding unremap() function if the memory pool is
  freed.
- The only in-tree implementation (xen_swiotlb_fixup) requires that the
  number of slots in the memory pool is a multiple of SWIOTLB_SEGSIZE.

Keep it simple for now and disable growing the SWIOTLB if a remap function
was specified.

Signed-off-by: Petr Tesarik <petr.tesarik.ext@...wei.com>
---
 include/linux/swiotlb.h |  4 ++++
 kernel/dma/Kconfig      | 13 +++++++++++++
 kernel/dma/swiotlb.c    | 13 +++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 247f0ab8795a..57be2a0a9fbf 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -100,6 +100,7 @@ struct io_tlb_pool {
  * @debugfs:	The dentry to debugfs.
  * @force_bounce: %true if swiotlb bouncing is forced
  * @for_alloc:  %true if the pool is used for memory allocation
+ * @can_grow:	%true if more pools can be allocated dynamically.
  * @total_used:	The total number of slots in the pool that are currently used
  *		across all areas. Used only for calculating used_hiwater in
  *		debugfs.
@@ -112,6 +113,9 @@ struct io_tlb_mem {
 	struct dentry *debugfs;
 	bool force_bounce;
 	bool for_alloc;
+#ifdef CONFIG_SWIOTLB_DYNAMIC
+	bool can_grow;
+#endif
 #ifdef CONFIG_DEBUG_FS
 	atomic_long_t total_used;
 	atomic_long_t used_hiwater;
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 562463fe30ea..4c1e9a3c0ab6 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -90,6 +90,19 @@ config SWIOTLB
 	bool
 	select NEED_DMA_MAP_STATE
 
+config SWIOTLB_DYNAMIC
+	bool "Dynamic allocation of DMA bounce buffers"
+	default n
+	depends on SWIOTLB
+	help
+	  This enables dynamic resizing of the software IO TLB. The kernel
+	  starts with one memory pool at boot and it will allocate additional
+	  pools as needed. To reduce run-time kernel memory requirements, you
+	  may have to specify a smaller size of the initial pool using
+	  "swiotlb=" on the kernel command line.
+
+	  If unsure, say N.
+
 config DMA_BOUNCE_UNALIGNED_KMALLOC
 	bool
 	depends on SWIOTLB
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 6fc2606e014b..767c8fb36a6b 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -330,6 +330,11 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
 	io_tlb_default_mem.force_bounce =
 		swiotlb_force_bounce || (flags & SWIOTLB_FORCE);
 
+#ifdef CONFIG_SWIOTLB_DYNAMIC
+	if (!remap)
+		io_tlb_default_mem.can_grow = true;
+#endif
+
 	if (!default_nareas)
 		swiotlb_adjust_nareas(num_possible_cpus());
 
@@ -400,6 +405,11 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask,
 
 	io_tlb_default_mem.force_bounce = swiotlb_force_bounce;
 
+#ifdef CONFIG_SWIOTLB_DYNAMIC
+	if (!remap)
+		io_tlb_default_mem.can_grow = true;
+#endif
+
 	if (!default_nareas)
 		swiotlb_adjust_nareas(num_possible_cpus());
 
@@ -1073,6 +1083,9 @@ bool is_swiotlb_active(struct device *dev)
  */
 phys_addr_t default_swiotlb_base(void)
 {
+#ifdef CONFIG_SWIOTLB_DYNAMIC
+	io_tlb_default_mem.can_grow = false;
+#endif
 	return io_tlb_default_mem.defpool.start;
 }
 
-- 
2.25.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ