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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /arch/arc/mm/dma.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'arch/arc/mm/dma.c')
-rw-r--r--arch/arc/mm/dma.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
new file mode 100644
index 000000000..9b9adb02b
--- /dev/null
+++ b/arch/arc/mm/dma.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#include <linux/dma-map-ops.h>
+#include <asm/cache.h>
+#include <asm/cacheflush.h>
+
+/*
+ * ARCH specific callbacks for generic noncoherent DMA ops
+ * - hardware IOC not available (or "dma-coherent" not set for device in DT)
+ * - But still handle both coherent and non-coherent requests from caller
+ *
+ * For DMA coherent hardware (IOC) generic code suffices
+ */
+
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+ /*
+ * Evict any existing L1 and/or L2 lines for the backing page
+ * in case it was used earlier as a normal "cached" page.
+ * Yeah this bit us - STAR 9000898266
+ *
+ * Although core does call flush_cache_vmap(), it gets kvaddr hence
+ * can't be used to efficiently flush L1 and/or L2 which need paddr
+ * Currently flush_cache_vmap nukes the L1 cache completely which
+ * will be optimized as a separate commit
+ */
+ dma_cache_wback_inv(page_to_phys(page), size);
+}
+
+/*
+ * Cache operations depending on function and direction argument, inspired by
+ * https://lore.kernel.org/lkml/20180518175004.GF17671@n2100.armlinux.org.uk
+ * "dma_sync_*_for_cpu and direction=TO_DEVICE (was Re: [PATCH 02/20]
+ * dma-mapping: provide a generic dma-noncoherent implementation)"
+ *
+ * | map == for_device | unmap == for_cpu
+ * |----------------------------------------------------------------
+ * TO_DEV | writeback writeback | none none
+ * FROM_DEV | invalidate invalidate | invalidate* invalidate*
+ * BIDIR | writeback+inv writeback+inv | invalidate invalidate
+ *
+ * [*] needed for CPU speculative prefetches
+ *
+ * NOTE: we don't check the validity of direction argument as it is done in
+ * upper layer functions (in include/linux/dma-mapping.h)
+ */
+
+void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
+{
+ switch (dir) {
+ case DMA_TO_DEVICE:
+ dma_cache_wback(paddr, size);
+ break;
+
+ case DMA_FROM_DEVICE:
+ dma_cache_inv(paddr, size);
+ break;
+
+ case DMA_BIDIRECTIONAL:
+ dma_cache_wback_inv(paddr, size);
+ break;
+
+ default:
+ break;
+ }
+}
+
+void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
+{
+ switch (dir) {
+ case DMA_TO_DEVICE:
+ break;
+
+ /* FROM_DEVICE invalidate needed if speculative CPU prefetch only */
+ case DMA_FROM_DEVICE:
+ case DMA_BIDIRECTIONAL:
+ dma_cache_inv(paddr, size);
+ break;
+
+ default:
+ break;
+ }
+}
+
+/*
+ * Plug in direct dma map ops.
+ */
+void arch_setup_dma_ops(struct device *dev, bool coherent)
+{
+ /*
+ * IOC hardware snoops all DMA traffic keeping the caches consistent
+ * with memory - eliding need for any explicit cache maintenance of
+ * DMA buffers.
+ */
+ if (is_isa_arcv2() && ioc_enable && coherent)
+ dev_set_dma_coherent(dev);
+
+ dev_info(dev, "use %scoherent DMA ops\n",
+ dev_dma_coherent(dev) ? "" : "non");
+}