v4.19.13 snapshot.
diff --git a/arch/sparc/mm/io-unit.c b/arch/sparc/mm/io-unit.c
new file mode 100644
index 0000000..c8cb27d
--- /dev/null
+++ b/arch/sparc/mm/io-unit.c
@@ -0,0 +1,263 @@
+// 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/highmem.h> /* pte_offset_map => kmap_atomic */
+#include <linux/bitops.h>
+#include <linux/scatterlist.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <asm/pgalloc.h>
+#include <asm/pgtable.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 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);
+}
+
+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 __u32 iounit_get_scsi_one(struct device *dev, char *vaddr, unsigned long len)
+{
+ struct iounit_struct *iounit = dev->archdata.iommu;
+ unsigned long ret, flags;
+
+ spin_lock_irqsave(&iounit->lock, flags);
+ ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
+ spin_unlock_irqrestore(&iounit->lock, flags);
+ return ret;
+}
+
+static void iounit_get_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
+{
+ struct iounit_struct *iounit = dev->archdata.iommu;
+ unsigned long flags;
+
+ /* FIXME: Cache some resolved pages - often several sg entries are to the same page */
+ spin_lock_irqsave(&iounit->lock, flags);
+ while (sz != 0) {
+ --sz;
+ sg->dma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length);
+ sg->dma_length = sg->length;
+ sg = sg_next(sg);
+ }
+ spin_unlock_irqrestore(&iounit->lock, flags);
+}
+
+static void iounit_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
+{
+ 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_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
+{
+ struct iounit_struct *iounit = dev->archdata.iommu;
+ unsigned long flags;
+ unsigned long vaddr, len;
+
+ spin_lock_irqsave(&iounit->lock, flags);
+ while (sz != 0) {
+ --sz;
+ 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);
+ sg = sg_next(sg);
+ }
+ spin_unlock_irqrestore(&iounit->lock, flags);
+}
+
+#ifdef CONFIG_SBUS
+static int iounit_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va, unsigned long addr, int len)
+{
+ struct iounit_struct *iounit = dev->archdata.iommu;
+ unsigned long page, end;
+ pgprot_t dvma_prot;
+ iopte_t __iomem *iopte;
+
+ *pba = addr;
+
+ dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
+ end = PAGE_ALIGN((addr + len));
+ while(addr < end) {
+ page = va;
+ {
+ pgd_t *pgdp;
+ pmd_t *pmdp;
+ pte_t *ptep;
+ long i;
+
+ pgdp = pgd_offset(&init_mm, addr);
+ pmdp = pmd_offset(pgdp, addr);
+ ptep = pte_offset_map(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 0;
+}
+
+static void iounit_unmap_dma_area(struct device *dev, unsigned long addr, int len)
+{
+ /* XXX Somebody please fill this in */
+}
+#endif
+
+static const struct sparc32_dma_ops iounit_dma_ops = {
+ .get_scsi_one = iounit_get_scsi_one,
+ .get_scsi_sgl = iounit_get_scsi_sgl,
+ .release_scsi_one = iounit_release_scsi_one,
+ .release_scsi_sgl = iounit_release_scsi_sgl,
+#ifdef CONFIG_SBUS
+ .map_dma_area = iounit_map_dma_area,
+ .unmap_dma_area = iounit_unmap_dma_area,
+#endif
+};
+
+void __init ld_mmu_iounit(void)
+{
+ sparc32_dma_ops = &iounit_dma_ops;
+}