MIPS: use generic dma noncoherent ops for simple noncoherent platforms
Convert everything not overriding dma-coherence.h to the generic
noncoherent ops. The new dma-noncoherent.c file duplicates a lot of
the code in dma-default.c, but that file will be gone by the end of
this series.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Patchwork: https://patchwork.linux-mips.org/patch/19544/
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-mips@linux-mips.org
diff --git a/arch/mips/mm/dma-noncoherent.c b/arch/mips/mm/dma-noncoherent.c
new file mode 100644
index 0000000..25edf6d
--- /dev/null
+++ b/arch/mips/mm/dma-noncoherent.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2000 Ani Joshi <ajoshi@unixbox.com>
+ * Copyright (C) 2000, 2001, 06 Ralf Baechle <ralf@linux-mips.org>
+ * swiped from i386, and cloned for MIPS by Geert, polished by Ralf.
+ */
+#include <linux/dma-direct.h>
+#include <linux/dma-noncoherent.h>
+#include <linux/dma-contiguous.h>
+#include <linux/highmem.h>
+
+#include <asm/cache.h>
+#include <asm/cpu-type.h>
+#include <asm/dma-coherence.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_DMA_PERDEV_COHERENT
+static inline int dev_is_coherent(struct device *dev)
+{
+ return dev->archdata.dma_coherent;
+}
+#else
+static inline int dev_is_coherent(struct device *dev)
+{
+ switch (coherentio) {
+ default:
+ case IO_COHERENCE_DEFAULT:
+ return hw_coherentio;
+ case IO_COHERENCE_ENABLED:
+ return 1;
+ case IO_COHERENCE_DISABLED:
+ return 0;
+ }
+}
+#endif /* CONFIG_DMA_PERDEV_COHERENT */
+
+/*
+ * The affected CPUs below in 'cpu_needs_post_dma_flush()' can speculatively
+ * fill random cachelines with stale data at any time, requiring an extra
+ * flush post-DMA.
+ *
+ * Warning on the terminology - Linux calls an uncached area coherent; MIPS
+ * terminology calls memory areas with hardware maintained coherency coherent.
+ *
+ * Note that the R14000 and R16000 should also be checked for in this condition.
+ * However this function is only called on non-I/O-coherent systems and only the
+ * R10000 and R12000 are used in such systems, the SGI IP28 Indigo² rsp.
+ * SGI IP32 aka O2.
+ */
+static inline bool cpu_needs_post_dma_flush(struct device *dev)
+{
+ if (dev_is_coherent(dev))
+ return false;
+
+ switch (boot_cpu_type()) {
+ case CPU_R10000:
+ case CPU_R12000:
+ case CPU_BMIPS5000:
+ return true;
+ default:
+ /*
+ * Presence of MAARs suggests that the CPU supports
+ * speculatively prefetching data, and therefore requires
+ * the post-DMA flush/invalidate.
+ */
+ return cpu_has_maar;
+ }
+}
+
+void *arch_dma_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+ void *ret;
+
+ ret = dma_direct_alloc(dev, size, dma_handle, gfp, attrs);
+ if (!ret)
+ return NULL;
+
+ if (!dev_is_coherent(dev) && !(attrs & DMA_ATTR_NON_CONSISTENT)) {
+ dma_cache_wback_inv((unsigned long) ret, size);
+ ret = UNCAC_ADDR(ret);
+ }
+
+ return ret;
+}
+
+void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t dma_addr, unsigned long attrs)
+{
+ if (!(attrs & DMA_ATTR_NON_CONSISTENT) && !dev_is_coherent(dev))
+ cpu_addr = (void *)CAC_ADDR((unsigned long)cpu_addr);
+ dma_direct_free(dev, size, cpu_addr, dma_addr, attrs);
+}
+
+int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ unsigned long attrs)
+{
+ unsigned long user_count = vma_pages(vma);
+ unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ unsigned long addr = (unsigned long)cpu_addr;
+ unsigned long off = vma->vm_pgoff;
+ unsigned long pfn;
+ int ret = -ENXIO;
+
+ if (!dev_is_coherent(dev))
+ addr = CAC_ADDR(addr);
+
+ pfn = page_to_pfn(virt_to_page((void *)addr));
+
+ if (attrs & DMA_ATTR_WRITE_COMBINE)
+ vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+ else
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+ if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
+ return ret;
+
+ if (off < count && user_count <= (count - off)) {
+ ret = remap_pfn_range(vma, vma->vm_start,
+ pfn + off,
+ user_count << PAGE_SHIFT,
+ vma->vm_page_prot);
+ }
+
+ return ret;
+}
+
+static inline void dma_sync_virt(void *addr, size_t size,
+ enum dma_data_direction dir)
+{
+ switch (dir) {
+ case DMA_TO_DEVICE:
+ dma_cache_wback((unsigned long)addr, size);
+ break;
+
+ case DMA_FROM_DEVICE:
+ dma_cache_inv((unsigned long)addr, size);
+ break;
+
+ case DMA_BIDIRECTIONAL:
+ dma_cache_wback_inv((unsigned long)addr, size);
+ break;
+
+ default:
+ BUG();
+ }
+}
+
+/*
+ * A single sg entry may refer to multiple physically contiguous pages. But
+ * we still need to process highmem pages individually. If highmem is not
+ * configured then the bulk of this loop gets optimized out.
+ */
+static inline void dma_sync_phys(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
+{
+ struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
+ unsigned long offset = paddr & ~PAGE_MASK;
+ size_t left = size;
+
+ do {
+ size_t len = left;
+
+ if (PageHighMem(page)) {
+ void *addr;
+
+ if (offset + len > PAGE_SIZE) {
+ if (offset >= PAGE_SIZE) {
+ page += offset >> PAGE_SHIFT;
+ offset &= ~PAGE_MASK;
+ }
+ len = PAGE_SIZE - offset;
+ }
+
+ addr = kmap_atomic(page);
+ dma_sync_virt(addr + offset, len, dir);
+ kunmap_atomic(addr);
+ } else
+ dma_sync_virt(page_address(page) + offset, size, dir);
+ offset = 0;
+ page++;
+ left -= len;
+ } while (left);
+}
+
+void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
+ size_t size, enum dma_data_direction dir)
+{
+ if (!dev_is_coherent(dev))
+ dma_sync_phys(paddr, size, dir);
+}
+
+void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
+ size_t size, enum dma_data_direction dir)
+{
+ if (cpu_needs_post_dma_flush(dev))
+ dma_sync_phys(paddr, size, dir);
+}
+
+void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+ enum dma_data_direction direction)
+{
+ BUG_ON(direction == DMA_NONE);
+
+ if (!dev_is_coherent(dev))
+ dma_sync_virt(vaddr, size, direction);
+}