1 files changed, 286 insertions, 0 deletions

diff --git a/arch/sparc/mm/io-unit.c b/arch/sparc/mm/io-unit.c
new file mode 100644
index 0000000000..d8376f61b4
--- /dev/null
+++ b/arch/sparc/mm/io-unit.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * io-unit.c:  IO-UNIT specific routines for memory management.
+ *
+ * Copyright (C) 1997,1998 Jakub Jelinek    (jj@sunsite.mff.cuni.cz)
+ */
+ 
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/bitops.h>
+#include <linux/dma-map-ops.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <asm/io.h>
+#include <asm/io-unit.h>
+#include <asm/mxcc.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/dma.h>
+#include <asm/oplib.h>
+
+#include "mm_32.h"
+
+/* #define IOUNIT_DEBUG */
+#ifdef IOUNIT_DEBUG
+#define IOD(x) printk(x)
+#else
+#define IOD(x) do { } while (0)
+#endif
+
+#define IOPERM        (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID)
+#define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM)
+
+static const struct dma_map_ops iounit_dma_ops;
+
+static void __init iounit_iommu_init(struct platform_device *op)
+{
+	struct iounit_struct *iounit;
+	iopte_t __iomem *xpt;
+	iopte_t __iomem *xptend;
+
+	iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
+	if (!iounit) {
+		prom_printf("SUN4D: Cannot alloc iounit, halting.\n");
+		prom_halt();
+	}
+
+	iounit->limit[0] = IOUNIT_BMAP1_START;
+	iounit->limit[1] = IOUNIT_BMAP2_START;
+	iounit->limit[2] = IOUNIT_BMAPM_START;
+	iounit->limit[3] = IOUNIT_BMAPM_END;
+	iounit->rotor[1] = IOUNIT_BMAP2_START;
+	iounit->rotor[2] = IOUNIT_BMAPM_START;
+
+	xpt = of_ioremap(&op->resource[2], 0, PAGE_SIZE * 16, "XPT");
+	if (!xpt) {
+		prom_printf("SUN4D: Cannot map External Page Table.");
+		prom_halt();
+	}
+	
+	op->dev.archdata.iommu = iounit;
+	iounit->page_table = xpt;
+	spin_lock_init(&iounit->lock);
+
+	xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
+	for (; xpt < xptend; xpt++)
+		sbus_writel(0, xpt);
+
+	op->dev.dma_ops = &iounit_dma_ops;
+}
+
+static int __init iounit_init(void)
+{
+	extern void sun4d_init_sbi_irq(void);
+	struct device_node *dp;
+
+	for_each_node_by_name(dp, "sbi") {
+		struct platform_device *op = of_find_device_by_node(dp);
+
+		iounit_iommu_init(op);
+		of_propagate_archdata(op);
+	}
+
+	sun4d_init_sbi_irq();
+
+	return 0;
+}
+
+subsys_initcall(iounit_init);
+
+/* One has to hold iounit->lock to call this */
+static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size)
+{
+	int i, j, k, npages;
+	unsigned long rotor, scan, limit;
+	iopte_t iopte;
+
+        npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
+
+	/* A tiny bit of magic ingredience :) */
+	switch (npages) {
+	case 1: i = 0x0231; break;
+	case 2: i = 0x0132; break;
+	default: i = 0x0213; break;
+	}
+	
+	IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages));
+	
+next:	j = (i & 15);
+	rotor = iounit->rotor[j - 1];
+	limit = iounit->limit[j];
+	scan = rotor;
+nexti:	scan = find_next_zero_bit(iounit->bmap, limit, scan);
+	if (scan + npages > limit) {
+		if (limit != rotor) {
+			limit = rotor;
+			scan = iounit->limit[j - 1];
+			goto nexti;
+		}
+		i >>= 4;
+		if (!(i & 15))
+			panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size);
+		goto next;
+	}
+	for (k = 1, scan++; k < npages; k++)
+		if (test_bit(scan++, iounit->bmap))
+			goto nexti;
+	iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
+	scan -= npages;
+	iopte = MKIOPTE(__pa(vaddr & PAGE_MASK));
+	vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
+	for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
+		set_bit(scan, iounit->bmap);
+		sbus_writel(iopte_val(iopte), &iounit->page_table[scan]);
+	}
+	IOD(("%08lx\n", vaddr));
+	return vaddr;
+}
+
+static dma_addr_t iounit_map_page(struct device *dev, struct page *page,
+		unsigned long offset, size_t len, enum dma_data_direction dir,
+		unsigned long attrs)
+{
+	void *vaddr = page_address(page) + offset;
+	struct iounit_struct *iounit = dev->archdata.iommu;
+	unsigned long ret, flags;
+	
+	/* XXX So what is maxphys for us and how do drivers know it? */
+	if (!len || len > 256 * 1024)
+		return DMA_MAPPING_ERROR;
+
+	spin_lock_irqsave(&iounit->lock, flags);
+	ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
+	spin_unlock_irqrestore(&iounit->lock, flags);
+	return ret;
+}
+
+static int iounit_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	struct iounit_struct *iounit = dev->archdata.iommu;
+	struct scatterlist *sg;
+	unsigned long flags;
+	int i;
+
+	/* FIXME: Cache some resolved pages - often several sg entries are to the same page */
+	spin_lock_irqsave(&iounit->lock, flags);
+	for_each_sg(sgl, sg, nents, i) {
+		sg->dma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length);
+		sg->dma_length = sg->length;
+	}
+	spin_unlock_irqrestore(&iounit->lock, flags);
+	return nents;
+}
+
+static void iounit_unmap_page(struct device *dev, dma_addr_t vaddr, size_t len,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	struct iounit_struct *iounit = dev->archdata.iommu;
+	unsigned long flags;
+	
+	spin_lock_irqsave(&iounit->lock, flags);
+	len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
+	vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
+	IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
+	for (len += vaddr; vaddr < len; vaddr++)
+		clear_bit(vaddr, iounit->bmap);
+	spin_unlock_irqrestore(&iounit->lock, flags);
+}
+
+static void iounit_unmap_sg(struct device *dev, struct scatterlist *sgl,
+		int nents, enum dma_data_direction dir, unsigned long attrs)
+{
+	struct iounit_struct *iounit = dev->archdata.iommu;
+	unsigned long flags, vaddr, len;
+	struct scatterlist *sg;
+	int i;
+
+	spin_lock_irqsave(&iounit->lock, flags);
+	for_each_sg(sgl, sg, nents, i) {
+		len = ((sg->dma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
+		vaddr = (sg->dma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
+		IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
+		for (len += vaddr; vaddr < len; vaddr++)
+			clear_bit(vaddr, iounit->bmap);
+	}
+	spin_unlock_irqrestore(&iounit->lock, flags);
+}
+
+#ifdef CONFIG_SBUS
+static void *iounit_alloc(struct device *dev, size_t len,
+		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+	struct iounit_struct *iounit = dev->archdata.iommu;
+	unsigned long va, addr, page, end, ret;
+	pgprot_t dvma_prot;
+	iopte_t __iomem *iopte;
+
+	/* XXX So what is maxphys for us and how do drivers know it? */
+	if (!len || len > 256 * 1024)
+		return NULL;
+
+	len = PAGE_ALIGN(len);
+	va = __get_free_pages(gfp | __GFP_ZERO, get_order(len));
+	if (!va)
+		return NULL;
+
+	addr = ret = sparc_dma_alloc_resource(dev, len);
+	if (!addr)
+		goto out_free_pages;
+	*dma_handle = addr;
+
+	dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
+	end = PAGE_ALIGN((addr + len));
+	while(addr < end) {
+		page = va;
+		{
+			pmd_t *pmdp;
+			pte_t *ptep;
+			long i;
+
+			pmdp = pmd_off_k(addr);
+			ptep = pte_offset_kernel(pmdp, addr);
+
+			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
+
+			i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
+
+			iopte = iounit->page_table + i;
+			sbus_writel(iopte_val(MKIOPTE(__pa(page))), iopte);
+		}
+		addr += PAGE_SIZE;
+		va += PAGE_SIZE;
+	}
+	flush_cache_all();
+	flush_tlb_all();
+
+	return (void *)ret;
+
+out_free_pages:
+	free_pages(va, get_order(len));
+	return NULL;
+}
+
+static void iounit_free(struct device *dev, size_t size, void *cpu_addr,
+		dma_addr_t dma_addr, unsigned long attrs)
+{
+	/* XXX Somebody please fill this in */
+}
+#endif
+
+static const struct dma_map_ops iounit_dma_ops = {
+#ifdef CONFIG_SBUS
+	.alloc			= iounit_alloc,
+	.free			= iounit_free,
+#endif
+	.map_page		= iounit_map_page,
+	.unmap_page		= iounit_unmap_page,
+	.map_sg			= iounit_map_sg,
+	.unmap_sg		= iounit_unmap_sg,
+};