8f7e001e03
This fixes two issues: I truncated the warning's hart ID when porting to the 64-bit hart ID code, and the original code's warning handling could fire on an uninitialized hart ID. The biggest change here is that riscv_cbom_block_size is no longer initialized, as IMO the default isn't sane: there's nothing in the ISA that mandates any specific cache block size, so falling back to one will just silently produce the wrong answer on some systems. This also changes the probing order so the cache block size is known before enabling Zicbom support. CC: stable@vger.kernel.org CC: Andrew Jones <ajones@ventanamicro.com> CC: Heiko Stuebner <heiko@sntech.de> CC: Atish Patra <atishp@rivosinc.com> Fixes:3aefb2ee5b("riscv: implement Zicbom-based CMO instructions + the t-head variant") Fixes:1631ba1259("riscv: Add support for non-coherent devices using zicbom extension") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> [Conor: fixed the redefinition errors] Tested-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220912224800.998121-1-mail@conchuod.ie Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
120 lines
2.8 KiB
C
120 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* RISC-V specific functions to support DMA for non-coherent devices
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*
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* Copyright (c) 2021 Western Digital Corporation or its affiliates.
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*/
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#include <linux/dma-direct.h>
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#include <linux/dma-map-ops.h>
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#include <linux/mm.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <asm/cacheflush.h>
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unsigned int riscv_cbom_block_size;
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static bool noncoherent_supported;
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void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
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enum dma_data_direction dir)
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{
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void *vaddr = phys_to_virt(paddr);
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switch (dir) {
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case DMA_TO_DEVICE:
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ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size);
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break;
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case DMA_FROM_DEVICE:
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ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size);
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break;
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case DMA_BIDIRECTIONAL:
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ALT_CMO_OP(flush, vaddr, size, riscv_cbom_block_size);
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break;
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default:
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break;
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}
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}
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void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
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enum dma_data_direction dir)
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{
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void *vaddr = phys_to_virt(paddr);
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switch (dir) {
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case DMA_TO_DEVICE:
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break;
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case DMA_FROM_DEVICE:
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case DMA_BIDIRECTIONAL:
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ALT_CMO_OP(flush, vaddr, size, riscv_cbom_block_size);
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break;
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default:
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break;
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}
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}
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void arch_dma_prep_coherent(struct page *page, size_t size)
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{
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void *flush_addr = page_address(page);
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ALT_CMO_OP(flush, flush_addr, size, riscv_cbom_block_size);
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}
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void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
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const struct iommu_ops *iommu, bool coherent)
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{
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WARN_TAINT(!coherent && riscv_cbom_block_size > ARCH_DMA_MINALIGN,
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TAINT_CPU_OUT_OF_SPEC,
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"%s %s: ARCH_DMA_MINALIGN smaller than riscv,cbom-block-size (%d < %d)",
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dev_driver_string(dev), dev_name(dev),
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ARCH_DMA_MINALIGN, riscv_cbom_block_size);
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WARN_TAINT(!coherent && !noncoherent_supported, TAINT_CPU_OUT_OF_SPEC,
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"%s %s: device non-coherent but no non-coherent operations supported",
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dev_driver_string(dev), dev_name(dev));
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dev->dma_coherent = coherent;
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}
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#ifdef CONFIG_RISCV_ISA_ZICBOM
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void riscv_init_cbom_blocksize(void)
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{
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struct device_node *node;
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unsigned long cbom_hartid;
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u32 val, probed_block_size;
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int ret;
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probed_block_size = 0;
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for_each_of_cpu_node(node) {
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unsigned long hartid;
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ret = riscv_of_processor_hartid(node, &hartid);
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if (ret)
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continue;
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/* set block-size for cbom extension if available */
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ret = of_property_read_u32(node, "riscv,cbom-block-size", &val);
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if (ret)
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continue;
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if (!probed_block_size) {
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probed_block_size = val;
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cbom_hartid = hartid;
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} else {
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if (probed_block_size != val)
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pr_warn("cbom-block-size mismatched between harts %lu and %lu\n",
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cbom_hartid, hartid);
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}
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}
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if (probed_block_size)
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riscv_cbom_block_size = probed_block_size;
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}
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#endif
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void riscv_noncoherent_supported(void)
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{
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WARN(!riscv_cbom_block_size,
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"Non-coherent DMA support enabled without a block size\n");
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noncoherent_supported = true;
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}
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