Merge tag 'riscv-for-linus-5.20-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Palmer Dabbelt:
 "There's still a handful of new features in here, but there are a lot
  of fixes/cleanups as well:

   - Support for the Zicbom extension for explicit cache-block
     management, along with the necessary bits to make the non-standard
     cache management ops on the Allwinner D1 function

   - Support for the Zihintpause extension, which codifies a go-slow
     instruction used for cpu_relax()

   - Support for the Sstc extension for supervisor-mode timer/counter
     management

   - Many device tree fixes and cleanups, including a large set for the
     Canaan device trees

   - A handful of fixes and cleanups for the PMU driver"

* tag 'riscv-for-linus-5.20-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (43 commits)
  dt-bindings: gpio: sifive: add gpio-line-names
  wireguard: selftests: set CONFIG_NONPORTABLE on riscv32
  RISC-V: KVM: Support sstc extension
  RISC-V: Improve SBI definitions
  RISC-V: Move counter info definition to sbi header file
  RISC-V: Fix SBI PMU calls for RV32
  RISC-V: Update user page mapping only once during start
  RISC-V: Fix counter restart during overflow for RV32
  RISC-V: Prefer sstc extension if available
  RISC-V: Enable sstc extension parsing from DT
  RISC-V: Add SSTC extension CSR details
  riscv:uprobe fix SR_SPIE set/clear handling
  dt-bindings: riscv: fix SiFive l2-cache's cache-sets
  riscv: ensure cpu_ops_sbi is declared
  RISC-V: cpu_ops_spinwait.c should include head.h
  RISC-V: Declare cpu_ops_spinwait in <asm/cpu_ops.h>
  riscv: dts: starfive: correct number of external interrupts
  riscv: dts: sifive unmatched: Add PWM controlled LEDs
  riscv/purgatory: Omit use of bin2c
  riscv/purgatory: hard-code obj-y in Makefile
  ...

1 files changed, 116 insertions, 0 deletions

diff --git a/arch/riscv/mm/dma-noncoherent.c b/arch/riscv/mm/dma-noncoherent.c
new file mode 100644
index 000000000000..cd2225304c82
--- /dev/null
+++ b/arch/riscv/mm/dma-noncoherent.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RISC-V specific functions to support DMA for non-coherent devices
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/dma-direct.h>
+#include <linux/dma-map-ops.h>
+#include <linux/mm.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <asm/cacheflush.h>
+
+static unsigned int riscv_cbom_block_size = L1_CACHE_BYTES;
+static bool noncoherent_supported;
+
+void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
+			      enum dma_data_direction dir)
+{
+	void *vaddr = phys_to_virt(paddr);
+
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size);
+		break;
+	case DMA_FROM_DEVICE:
+		ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size);
+		break;
+	case DMA_BIDIRECTIONAL:
+		ALT_CMO_OP(flush, vaddr, size, riscv_cbom_block_size);
+		break;
+	default:
+		break;
+	}
+}
+
+void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
+			   enum dma_data_direction dir)
+{
+	void *vaddr = phys_to_virt(paddr);
+
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		break;
+	case DMA_FROM_DEVICE:
+	case DMA_BIDIRECTIONAL:
+		ALT_CMO_OP(flush, vaddr, size, riscv_cbom_block_size);
+		break;
+	default:
+		break;
+	}
+}
+
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+	void *flush_addr = page_address(page);
+
+	ALT_CMO_OP(flush, flush_addr, size, riscv_cbom_block_size);
+}
+
+void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+		const struct iommu_ops *iommu, bool coherent)
+{
+	WARN_TAINT(!coherent && riscv_cbom_block_size > ARCH_DMA_MINALIGN,
+		   TAINT_CPU_OUT_OF_SPEC,
+		   "%s %s: ARCH_DMA_MINALIGN smaller than riscv,cbom-block-size (%d < %d)",
+		   dev_driver_string(dev), dev_name(dev),
+		   ARCH_DMA_MINALIGN, riscv_cbom_block_size);
+
+	WARN_TAINT(!coherent && !noncoherent_supported, TAINT_CPU_OUT_OF_SPEC,
+		   "%s %s: device non-coherent but no non-coherent operations supported",
+		   dev_driver_string(dev), dev_name(dev));
+
+	dev->dma_coherent = coherent;
+}
+
+#ifdef CONFIG_RISCV_ISA_ZICBOM
+void riscv_init_cbom_blocksize(void)
+{
+	struct device_node *node;
+	int ret;
+	u32 val;
+
+	for_each_of_cpu_node(node) {
+		unsigned long hartid;
+		int cbom_hartid;
+
+		ret = riscv_of_processor_hartid(node, &hartid);
+		if (ret)
+			continue;
+
+		if (hartid < 0)
+			continue;
+
+		/* set block-size for cbom extension if available */
+		ret = of_property_read_u32(node, "riscv,cbom-block-size", &val);
+		if (ret)
+			continue;
+
+		if (!riscv_cbom_block_size) {
+			riscv_cbom_block_size = val;
+			cbom_hartid = hartid;
+		} else {
+			if (riscv_cbom_block_size != val)
+				pr_warn("cbom-block-size mismatched between harts %d and %lu\n",
+					cbom_hartid, hartid);
+		}
+	}
+}
+#endif
+
+void riscv_noncoherent_supported(void)
+{
+	noncoherent_supported = true;
+}