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authorDapeng Mi <dapeng1.mi@linux.intel.com>2026-09-17 09:52:33 +0800
committerIngo Molnar <mingo@kernel.org>2026-09-22 11:37:46 +0200
commit0102c8c7fdfc4bd700971daff2b94470f4eafae4 (patch)
tree531306c2299f9a269f0a986e29f17ba972180104 /arch/arc/mm/dma.c
downloadlinux-stable-0102c8c7fdfc4bd700971daff2b94470f4eafae4.tar.gz
linux-stable-0102c8c7fdfc4bd700971daff2b94470f4eafae4.zip
perf/x86/intel: Rename DMR offcore_rsp attribute to offmodule_rspgrafted
DMR introduces Offmodule Response events in place of the legacy Offcore Response events, but it still exposes the inherited offcore_rsp PMU attribute for programming the corresponding MSR data. Rename the DMR PMU attribute to offmodule_rsp so the sysfs interface matches the underlying event name and avoids user & tooling confusion. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://patch.msgid.link/20260917015234.981153-12-dapeng1.mi@linux.intel.com
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");
+}