v4.19.13 snapshot.
diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c
new file mode 100644
index 0000000..6799c93
--- /dev/null
+++ b/arch/sparc/kernel/ioport.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ioport.c:  Simple io mapping allocator.
+ *
+ * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 1995 Miguel de Icaza (miguel@nuclecu.unam.mx)
+ *
+ * 1996: sparc_free_io, 1999: ioremap()/iounmap() by Pete Zaitcev.
+ *
+ * 2000/01/29
+ * <rth> zait: as long as pci_alloc_consistent produces something addressable, 
+ *	things are ok.
+ * <zaitcev> rth: no, it is relevant, because get_free_pages returns you a
+ *	pointer into the big page mapping
+ * <rth> zait: so what?
+ * <rth> zait: remap_it_my_way(virt_to_phys(get_free_page()))
+ * <zaitcev> Hmm
+ * <zaitcev> Suppose I did this remap_it_my_way(virt_to_phys(get_free_page())).
+ *	So far so good.
+ * <zaitcev> Now, driver calls pci_free_consistent(with result of
+ *	remap_it_my_way()).
+ * <zaitcev> How do you find the address to pass to free_pages()?
+ * <rth> zait: walk the page tables?  It's only two or three level after all.
+ * <rth> zait: you have to walk them anyway to remove the mapping.
+ * <zaitcev> Hmm
+ * <zaitcev> Sounds reasonable
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/pci.h>		/* struct pci_dev */
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-noncoherent.h>
+#include <linux/of_device.h>
+
+#include <asm/io.h>
+#include <asm/vaddrs.h>
+#include <asm/oplib.h>
+#include <asm/prom.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/dma.h>
+#include <asm/iommu.h>
+#include <asm/io-unit.h>
+#include <asm/leon.h>
+
+const struct sparc32_dma_ops *sparc32_dma_ops;
+
+/* This function must make sure that caches and memory are coherent after DMA
+ * On LEON systems without cache snooping it flushes the entire D-CACHE.
+ */
+static inline void dma_make_coherent(unsigned long pa, unsigned long len)
+{
+	if (sparc_cpu_model == sparc_leon) {
+		if (!sparc_leon3_snooping_enabled())
+			leon_flush_dcache_all();
+	}
+}
+
+static void __iomem *_sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz);
+static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys,
+    unsigned long size, char *name);
+static void _sparc_free_io(struct resource *res);
+
+static void register_proc_sparc_ioport(void);
+
+/* This points to the next to use virtual memory for DVMA mappings */
+static struct resource _sparc_dvma = {
+	.name = "sparc_dvma", .start = DVMA_VADDR, .end = DVMA_END - 1
+};
+/* This points to the start of I/O mappings, cluable from outside. */
+/*ext*/ struct resource sparc_iomap = {
+	.name = "sparc_iomap", .start = IOBASE_VADDR, .end = IOBASE_END - 1
+};
+
+/*
+ * Our mini-allocator...
+ * Boy this is gross! We need it because we must map I/O for
+ * timers and interrupt controller before the kmalloc is available.
+ */
+
+#define XNMLN  15
+#define XNRES  10	/* SS-10 uses 8 */
+
+struct xresource {
+	struct resource xres;	/* Must be first */
+	int xflag;		/* 1 == used */
+	char xname[XNMLN+1];
+};
+
+static struct xresource xresv[XNRES];
+
+static struct xresource *xres_alloc(void) {
+	struct xresource *xrp;
+	int n;
+
+	xrp = xresv;
+	for (n = 0; n < XNRES; n++) {
+		if (xrp->xflag == 0) {
+			xrp->xflag = 1;
+			return xrp;
+		}
+		xrp++;
+	}
+	return NULL;
+}
+
+static void xres_free(struct xresource *xrp) {
+	xrp->xflag = 0;
+}
+
+/*
+ * These are typically used in PCI drivers
+ * which are trying to be cross-platform.
+ *
+ * Bus type is always zero on IIep.
+ */
+void __iomem *ioremap(phys_addr_t offset, size_t size)
+{
+	char name[14];
+
+	sprintf(name, "phys_%08x", (u32)offset);
+	return _sparc_alloc_io(0, (unsigned long)offset, size, name);
+}
+EXPORT_SYMBOL(ioremap);
+
+/*
+ * Complementary to ioremap().
+ */
+void iounmap(volatile void __iomem *virtual)
+{
+	unsigned long vaddr = (unsigned long) virtual & PAGE_MASK;
+	struct resource *res;
+
+	/*
+	 * XXX Too slow. Can have 8192 DVMA pages on sun4m in the worst case.
+	 * This probably warrants some sort of hashing.
+	*/
+	if ((res = lookup_resource(&sparc_iomap, vaddr)) == NULL) {
+		printk("free_io/iounmap: cannot free %lx\n", vaddr);
+		return;
+	}
+	_sparc_free_io(res);
+
+	if ((char *)res >= (char*)xresv && (char *)res < (char *)&xresv[XNRES]) {
+		xres_free((struct xresource *)res);
+	} else {
+		kfree(res);
+	}
+}
+EXPORT_SYMBOL(iounmap);
+
+void __iomem *of_ioremap(struct resource *res, unsigned long offset,
+			 unsigned long size, char *name)
+{
+	return _sparc_alloc_io(res->flags & 0xF,
+			       res->start + offset,
+			       size, name);
+}
+EXPORT_SYMBOL(of_ioremap);
+
+void of_iounmap(struct resource *res, void __iomem *base, unsigned long size)
+{
+	iounmap(base);
+}
+EXPORT_SYMBOL(of_iounmap);
+
+/*
+ * Meat of mapping
+ */
+static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys,
+    unsigned long size, char *name)
+{
+	static int printed_full;
+	struct xresource *xres;
+	struct resource *res;
+	char *tack;
+	int tlen;
+	void __iomem *va;	/* P3 diag */
+
+	if (name == NULL) name = "???";
+
+	if ((xres = xres_alloc()) != NULL) {
+		tack = xres->xname;
+		res = &xres->xres;
+	} else {
+		if (!printed_full) {
+			printk("ioremap: done with statics, switching to malloc\n");
+			printed_full = 1;
+		}
+		tlen = strlen(name);
+		tack = kmalloc(sizeof (struct resource) + tlen + 1, GFP_KERNEL);
+		if (tack == NULL) return NULL;
+		memset(tack, 0, sizeof(struct resource));
+		res = (struct resource *) tack;
+		tack += sizeof (struct resource);
+	}
+
+	strlcpy(tack, name, XNMLN+1);
+	res->name = tack;
+
+	va = _sparc_ioremap(res, busno, phys, size);
+	/* printk("ioremap(0x%x:%08lx[0x%lx])=%p\n", busno, phys, size, va); */ /* P3 diag */
+	return va;
+}
+
+/*
+ */
+static void __iomem *
+_sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz)
+{
+	unsigned long offset = ((unsigned long) pa) & (~PAGE_MASK);
+
+	if (allocate_resource(&sparc_iomap, res,
+	    (offset + sz + PAGE_SIZE-1) & PAGE_MASK,
+	    sparc_iomap.start, sparc_iomap.end, PAGE_SIZE, NULL, NULL) != 0) {
+		/* Usually we cannot see printks in this case. */
+		prom_printf("alloc_io_res(%s): cannot occupy\n",
+		    (res->name != NULL)? res->name: "???");
+		prom_halt();
+	}
+
+	pa &= PAGE_MASK;
+	srmmu_mapiorange(bus, pa, res->start, resource_size(res));
+
+	return (void __iomem *)(unsigned long)(res->start + offset);
+}
+
+/*
+ * Complementary to _sparc_ioremap().
+ */
+static void _sparc_free_io(struct resource *res)
+{
+	unsigned long plen;
+
+	plen = resource_size(res);
+	BUG_ON((plen & (PAGE_SIZE-1)) != 0);
+	srmmu_unmapiorange(res->start, plen);
+	release_resource(res);
+}
+
+#ifdef CONFIG_SBUS
+
+void sbus_set_sbus64(struct device *dev, int x)
+{
+	printk("sbus_set_sbus64: unsupported\n");
+}
+EXPORT_SYMBOL(sbus_set_sbus64);
+
+/*
+ * Allocate a chunk of memory suitable for DMA.
+ * Typically devices use them for control blocks.
+ * CPU may access them without any explicit flushing.
+ */
+static void *sbus_alloc_coherent(struct device *dev, size_t len,
+				 dma_addr_t *dma_addrp, gfp_t gfp,
+				 unsigned long attrs)
+{
+	struct platform_device *op = to_platform_device(dev);
+	unsigned long len_total = PAGE_ALIGN(len);
+	unsigned long va;
+	struct resource *res;
+	int order;
+
+	/* XXX why are some lengths signed, others unsigned? */
+	if (len <= 0) {
+		return NULL;
+	}
+	/* XXX So what is maxphys for us and how do drivers know it? */
+	if (len > 256*1024) {			/* __get_free_pages() limit */
+		return NULL;
+	}
+
+	order = get_order(len_total);
+	va = __get_free_pages(gfp, order);
+	if (va == 0)
+		goto err_nopages;
+
+	if ((res = kzalloc(sizeof(struct resource), GFP_KERNEL)) == NULL)
+		goto err_nomem;
+
+	if (allocate_resource(&_sparc_dvma, res, len_total,
+	    _sparc_dvma.start, _sparc_dvma.end, PAGE_SIZE, NULL, NULL) != 0) {
+		printk("sbus_alloc_consistent: cannot occupy 0x%lx", len_total);
+		goto err_nova;
+	}
+
+	// XXX The sbus_map_dma_area does this for us below, see comments.
+	// srmmu_mapiorange(0, virt_to_phys(va), res->start, len_total);
+	/*
+	 * XXX That's where sdev would be used. Currently we load
+	 * all iommu tables with the same translations.
+	 */
+	if (sbus_map_dma_area(dev, dma_addrp, va, res->start, len_total) != 0)
+		goto err_noiommu;
+
+	res->name = op->dev.of_node->name;
+
+	return (void *)(unsigned long)res->start;
+
+err_noiommu:
+	release_resource(res);
+err_nova:
+	kfree(res);
+err_nomem:
+	free_pages(va, order);
+err_nopages:
+	return NULL;
+}
+
+static void sbus_free_coherent(struct device *dev, size_t n, void *p,
+			       dma_addr_t ba, unsigned long attrs)
+{
+	struct resource *res;
+	struct page *pgv;
+
+	if ((res = lookup_resource(&_sparc_dvma,
+	    (unsigned long)p)) == NULL) {
+		printk("sbus_free_consistent: cannot free %p\n", p);
+		return;
+	}
+
+	if (((unsigned long)p & (PAGE_SIZE-1)) != 0) {
+		printk("sbus_free_consistent: unaligned va %p\n", p);
+		return;
+	}
+
+	n = PAGE_ALIGN(n);
+	if (resource_size(res) != n) {
+		printk("sbus_free_consistent: region 0x%lx asked 0x%zx\n",
+		    (long)resource_size(res), n);
+		return;
+	}
+
+	release_resource(res);
+	kfree(res);
+
+	pgv = virt_to_page(p);
+	sbus_unmap_dma_area(dev, ba, n);
+
+	__free_pages(pgv, get_order(n));
+}
+
+/*
+ * Map a chunk of memory so that devices can see it.
+ * CPU view of this memory may be inconsistent with
+ * a device view and explicit flushing is necessary.
+ */
+static dma_addr_t sbus_map_page(struct device *dev, struct page *page,
+				unsigned long offset, size_t len,
+				enum dma_data_direction dir,
+				unsigned long attrs)
+{
+	void *va = page_address(page) + offset;
+
+	/* XXX why are some lengths signed, others unsigned? */
+	if (len <= 0) {
+		return 0;
+	}
+	/* XXX So what is maxphys for us and how do drivers know it? */
+	if (len > 256*1024) {			/* __get_free_pages() limit */
+		return 0;
+	}
+	return mmu_get_scsi_one(dev, va, len);
+}
+
+static void sbus_unmap_page(struct device *dev, dma_addr_t ba, size_t n,
+			    enum dma_data_direction dir, unsigned long attrs)
+{
+	mmu_release_scsi_one(dev, ba, n);
+}
+
+static int sbus_map_sg(struct device *dev, struct scatterlist *sg, int n,
+		       enum dma_data_direction dir, unsigned long attrs)
+{
+	mmu_get_scsi_sgl(dev, sg, n);
+	return n;
+}
+
+static void sbus_unmap_sg(struct device *dev, struct scatterlist *sg, int n,
+			  enum dma_data_direction dir, unsigned long attrs)
+{
+	mmu_release_scsi_sgl(dev, sg, n);
+}
+
+static void sbus_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+				 int n,	enum dma_data_direction dir)
+{
+	BUG();
+}
+
+static void sbus_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+				    int n, enum dma_data_direction dir)
+{
+	BUG();
+}
+
+static int sbus_dma_supported(struct device *dev, u64 mask)
+{
+	return 0;
+}
+
+static const struct dma_map_ops sbus_dma_ops = {
+	.alloc			= sbus_alloc_coherent,
+	.free			= sbus_free_coherent,
+	.map_page		= sbus_map_page,
+	.unmap_page		= sbus_unmap_page,
+	.map_sg			= sbus_map_sg,
+	.unmap_sg		= sbus_unmap_sg,
+	.sync_sg_for_cpu	= sbus_sync_sg_for_cpu,
+	.sync_sg_for_device	= sbus_sync_sg_for_device,
+	.dma_supported		= sbus_dma_supported,
+};
+
+static int __init sparc_register_ioport(void)
+{
+	register_proc_sparc_ioport();
+
+	return 0;
+}
+
+arch_initcall(sparc_register_ioport);
+
+#endif /* CONFIG_SBUS */
+
+
+/* Allocate and map kernel buffer using consistent mode DMA for a device.
+ * hwdev should be valid struct pci_dev pointer for PCI devices.
+ */
+void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		gfp_t gfp, unsigned long attrs)
+{
+	unsigned long len_total = PAGE_ALIGN(size);
+	void *va;
+	struct resource *res;
+	int order;
+
+	if (size == 0) {
+		return NULL;
+	}
+	if (size > 256*1024) {			/* __get_free_pages() limit */
+		return NULL;
+	}
+
+	order = get_order(len_total);
+	va = (void *) __get_free_pages(gfp, order);
+	if (va == NULL) {
+		printk("%s: no %ld pages\n", __func__, len_total>>PAGE_SHIFT);
+		goto err_nopages;
+	}
+
+	if ((res = kzalloc(sizeof(struct resource), GFP_KERNEL)) == NULL) {
+		printk("%s: no core\n", __func__);
+		goto err_nomem;
+	}
+
+	if (allocate_resource(&_sparc_dvma, res, len_total,
+	    _sparc_dvma.start, _sparc_dvma.end, PAGE_SIZE, NULL, NULL) != 0) {
+		printk("%s: cannot occupy 0x%lx", __func__, len_total);
+		goto err_nova;
+	}
+	srmmu_mapiorange(0, virt_to_phys(va), res->start, len_total);
+
+	*dma_handle = virt_to_phys(va);
+	return (void *) res->start;
+
+err_nova:
+	kfree(res);
+err_nomem:
+	free_pages((unsigned long)va, order);
+err_nopages:
+	return NULL;
+}
+
+/* Free and unmap a consistent DMA buffer.
+ * cpu_addr is what was returned arch_dma_alloc, size must be the same as what
+ * was passed into arch_dma_alloc, and likewise dma_addr must be the same as
+ * what *dma_ndler was set to.
+ *
+ * References to the memory and mappings associated with cpu_addr/dma_addr
+ * past this call are illegal.
+ */
+void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
+		dma_addr_t dma_addr, unsigned long attrs)
+{
+	struct resource *res;
+
+	if ((res = lookup_resource(&_sparc_dvma,
+	    (unsigned long)cpu_addr)) == NULL) {
+		printk("%s: cannot free %p\n", __func__, cpu_addr);
+		return;
+	}
+
+	if (((unsigned long)cpu_addr & (PAGE_SIZE-1)) != 0) {
+		printk("%s: unaligned va %p\n", __func__, cpu_addr);
+		return;
+	}
+
+	size = PAGE_ALIGN(size);
+	if (resource_size(res) != size) {
+		printk("%s: region 0x%lx asked 0x%zx\n", __func__,
+		    (long)resource_size(res), size);
+		return;
+	}
+
+	dma_make_coherent(dma_addr, size);
+	srmmu_unmapiorange((unsigned long)cpu_addr, size);
+
+	release_resource(res);
+	kfree(res);
+	free_pages((unsigned long)phys_to_virt(dma_addr), get_order(size));
+}
+
+/* IIep is write-through, not flushing on cpu to device transfer. */
+
+void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
+		size_t size, enum dma_data_direction dir)
+{
+	if (dir != PCI_DMA_TODEVICE)
+		dma_make_coherent(paddr, PAGE_ALIGN(size));
+}
+
+const struct dma_map_ops *dma_ops = &sbus_dma_ops;
+EXPORT_SYMBOL(dma_ops);
+
+#ifdef CONFIG_PROC_FS
+
+static int sparc_io_proc_show(struct seq_file *m, void *v)
+{
+	struct resource *root = m->private, *r;
+	const char *nm;
+
+	for (r = root->child; r != NULL; r = r->sibling) {
+		if ((nm = r->name) == NULL) nm = "???";
+		seq_printf(m, "%016llx-%016llx: %s\n",
+				(unsigned long long)r->start,
+				(unsigned long long)r->end, nm);
+	}
+
+	return 0;
+}
+#endif /* CONFIG_PROC_FS */
+
+static void register_proc_sparc_ioport(void)
+{
+#ifdef CONFIG_PROC_FS
+	proc_create_single_data("io_map", 0, NULL, sparc_io_proc_show,
+			&sparc_iomap);
+	proc_create_single_data("dvma_map", 0, NULL, sparc_io_proc_show,
+			&_sparc_dvma);
+#endif
+}