1 files changed, 454 insertions, 0 deletions

diff --git a/arch/sparc/mm/iommu.c b/arch/sparc/mm/iommu.c
new file mode 100644
index 000000000..9e3f6933c
--- /dev/null
+++ b/arch/sparc/mm/iommu.c
@@ -0,0 +1,454 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * iommu.c:  IOMMU specific routines for memory management.
+ *
+ * Copyright (C) 1995 David S. Miller  (davem@caip.rutgers.edu)
+ * Copyright (C) 1995,2002 Pete Zaitcev     (zaitcev@yahoo.com)
+ * Copyright (C) 1996 Eddie C. Dost    (ecd@skynet.be)
+ * Copyright (C) 1997,1998 Jakub Jelinek    (jj@sunsite.mff.cuni.cz)
+ */
+ 
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/dma-map-ops.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <asm/io.h>
+#include <asm/mxcc.h>
+#include <asm/mbus.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/bitext.h>
+#include <asm/iommu.h>
+#include <asm/dma.h>
+
+#include "mm_32.h"
+
+/*
+ * This can be sized dynamically, but we will do this
+ * only when we have a guidance about actual I/O pressures.
+ */
+#define IOMMU_RNGE	IOMMU_RNGE_256MB
+#define IOMMU_START	0xF0000000
+#define IOMMU_WINSIZE	(256*1024*1024U)
+#define IOMMU_NPTES	(IOMMU_WINSIZE/PAGE_SIZE)	/* 64K PTEs, 256KB */
+#define IOMMU_ORDER	6				/* 4096 * (1<<6) */
+
+static int viking_flush;
+/* viking.S */
+extern void viking_flush_page(unsigned long page);
+extern void viking_mxcc_flush_page(unsigned long page);
+
+/*
+ * Values precomputed according to CPU type.
+ */
+static unsigned int ioperm_noc;		/* Consistent mapping iopte flags */
+static pgprot_t dvma_prot;		/* Consistent mapping pte flags */
+
+#define IOPERM        (IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID)
+#define MKIOPTE(pfn, perm) (((((pfn)<<8) & IOPTE_PAGE) | (perm)) & ~IOPTE_WAZ)
+
+static const struct dma_map_ops sbus_iommu_dma_gflush_ops;
+static const struct dma_map_ops sbus_iommu_dma_pflush_ops;
+
+static void __init sbus_iommu_init(struct platform_device *op)
+{
+	struct iommu_struct *iommu;
+	unsigned int impl, vers;
+	unsigned long *bitmap;
+	unsigned long control;
+	unsigned long base;
+	unsigned long tmp;
+
+	iommu = kmalloc(sizeof(struct iommu_struct), GFP_KERNEL);
+	if (!iommu) {
+		prom_printf("Unable to allocate iommu structure\n");
+		prom_halt();
+	}
+
+	iommu->regs = of_ioremap(&op->resource[0], 0, PAGE_SIZE * 3,
+				 "iommu_regs");
+	if (!iommu->regs) {
+		prom_printf("Cannot map IOMMU registers\n");
+		prom_halt();
+	}
+
+	control = sbus_readl(&iommu->regs->control);
+	impl = (control & IOMMU_CTRL_IMPL) >> 28;
+	vers = (control & IOMMU_CTRL_VERS) >> 24;
+	control &= ~(IOMMU_CTRL_RNGE);
+	control |= (IOMMU_RNGE_256MB | IOMMU_CTRL_ENAB);
+	sbus_writel(control, &iommu->regs->control);
+
+	iommu_invalidate(iommu->regs);
+	iommu->start = IOMMU_START;
+	iommu->end = 0xffffffff;
+
+	/* Allocate IOMMU page table */
+	/* Stupid alignment constraints give me a headache. 
+	   We need 256K or 512K or 1M or 2M area aligned to
+           its size and current gfp will fortunately give
+           it to us. */
+        tmp = __get_free_pages(GFP_KERNEL, IOMMU_ORDER);
+	if (!tmp) {
+		prom_printf("Unable to allocate iommu table [0x%lx]\n",
+			    IOMMU_NPTES * sizeof(iopte_t));
+		prom_halt();
+	}
+	iommu->page_table = (iopte_t *)tmp;
+
+	/* Initialize new table. */
+	memset(iommu->page_table, 0, IOMMU_NPTES*sizeof(iopte_t));
+	flush_cache_all();
+	flush_tlb_all();
+
+	base = __pa((unsigned long)iommu->page_table) >> 4;
+	sbus_writel(base, &iommu->regs->base);
+	iommu_invalidate(iommu->regs);
+
+	bitmap = kmalloc(IOMMU_NPTES>>3, GFP_KERNEL);
+	if (!bitmap) {
+		prom_printf("Unable to allocate iommu bitmap [%d]\n",
+			    (int)(IOMMU_NPTES>>3));
+		prom_halt();
+	}
+	bit_map_init(&iommu->usemap, bitmap, IOMMU_NPTES);
+	/* To be coherent on HyperSparc, the page color of DVMA
+	 * and physical addresses must match.
+	 */
+	if (srmmu_modtype == HyperSparc)
+		iommu->usemap.num_colors = vac_cache_size >> PAGE_SHIFT;
+	else
+		iommu->usemap.num_colors = 1;
+
+	printk(KERN_INFO "IOMMU: impl %d vers %d table 0x%p[%d B] map [%d b]\n",
+	       impl, vers, iommu->page_table,
+	       (int)(IOMMU_NPTES*sizeof(iopte_t)), (int)IOMMU_NPTES);
+
+	op->dev.archdata.iommu = iommu;
+
+	if (flush_page_for_dma_global)
+		op->dev.dma_ops = &sbus_iommu_dma_gflush_ops;
+	 else
+		op->dev.dma_ops = &sbus_iommu_dma_pflush_ops;
+}
+
+static int __init iommu_init(void)
+{
+	struct device_node *dp;
+
+	for_each_node_by_name(dp, "iommu") {
+		struct platform_device *op = of_find_device_by_node(dp);
+
+		sbus_iommu_init(op);
+		of_propagate_archdata(op);
+	}
+
+	return 0;
+}
+
+subsys_initcall(iommu_init);
+
+/* Flush the iotlb entries to ram. */
+/* This could be better if we didn't have to flush whole pages. */
+static void iommu_flush_iotlb(iopte_t *iopte, unsigned int niopte)
+{
+	unsigned long start;
+	unsigned long end;
+
+	start = (unsigned long)iopte;
+	end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
+	start &= PAGE_MASK;
+	if (viking_mxcc_present) {
+		while(start < end) {
+			viking_mxcc_flush_page(start);
+			start += PAGE_SIZE;
+		}
+	} else if (viking_flush) {
+		while(start < end) {
+			viking_flush_page(start);
+			start += PAGE_SIZE;
+		}
+	} else {
+		while(start < end) {
+			__flush_page_to_ram(start);
+			start += PAGE_SIZE;
+		}
+	}
+}
+
+static dma_addr_t __sbus_iommu_map_page(struct device *dev, struct page *page,
+		unsigned long offset, size_t len, bool per_page_flush)
+{
+	struct iommu_struct *iommu = dev->archdata.iommu;
+	phys_addr_t paddr = page_to_phys(page) + offset;
+	unsigned long off = paddr & ~PAGE_MASK;
+	unsigned long npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	unsigned long pfn = __phys_to_pfn(paddr);
+	unsigned int busa, busa0;
+	iopte_t *iopte, *iopte0;
+	int ioptex, i;
+
+	/* XXX So what is maxphys for us and how do drivers know it? */
+	if (!len || len > 256 * 1024)
+		return DMA_MAPPING_ERROR;
+
+	/*
+	 * We expect unmapped highmem pages to be not in the cache.
+	 * XXX Is this a good assumption?
+	 * XXX What if someone else unmaps it here and races us?
+	 */
+	if (per_page_flush && !PageHighMem(page)) {
+		unsigned long vaddr, p;
+
+		vaddr = (unsigned long)page_address(page) + offset;
+		for (p = vaddr & PAGE_MASK; p < vaddr + len; p += PAGE_SIZE)
+			flush_page_for_dma(p);
+	}
+
+	/* page color = pfn of page */
+	ioptex = bit_map_string_get(&iommu->usemap, npages, pfn);
+	if (ioptex < 0)
+		panic("iommu out");
+	busa0 = iommu->start + (ioptex << PAGE_SHIFT);
+	iopte0 = &iommu->page_table[ioptex];
+
+	busa = busa0;
+	iopte = iopte0;
+	for (i = 0; i < npages; i++) {
+		iopte_val(*iopte) = MKIOPTE(pfn, IOPERM);
+		iommu_invalidate_page(iommu->regs, busa);
+		busa += PAGE_SIZE;
+		iopte++;
+		pfn++;
+	}
+
+	iommu_flush_iotlb(iopte0, npages);
+	return busa0 + off;
+}
+
+static dma_addr_t sbus_iommu_map_page_gflush(struct device *dev,
+		struct page *page, unsigned long offset, size_t len,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	flush_page_for_dma(0);
+	return __sbus_iommu_map_page(dev, page, offset, len, false);
+}
+
+static dma_addr_t sbus_iommu_map_page_pflush(struct device *dev,
+		struct page *page, unsigned long offset, size_t len,
+		enum dma_data_direction dir, unsigned long attrs)
+{
+	return __sbus_iommu_map_page(dev, page, offset, len, true);
+}
+
+static int __sbus_iommu_map_sg(struct device *dev, struct scatterlist *sgl,
+		int nents, enum dma_data_direction dir, unsigned long attrs,
+		bool per_page_flush)
+{
+	struct scatterlist *sg;
+	int j;
+
+	for_each_sg(sgl, sg, nents, j) {
+		sg->dma_address =__sbus_iommu_map_page(dev, sg_page(sg),
+				sg->offset, sg->length, per_page_flush);
+		if (sg->dma_address == DMA_MAPPING_ERROR)
+			return -EIO;
+		sg->dma_length = sg->length;
+	}
+
+	return nents;
+}
+
+static int sbus_iommu_map_sg_gflush(struct device *dev, struct scatterlist *sgl,
+		int nents, enum dma_data_direction dir, unsigned long attrs)
+{
+	flush_page_for_dma(0);
+	return __sbus_iommu_map_sg(dev, sgl, nents, dir, attrs, false);
+}
+
+static int sbus_iommu_map_sg_pflush(struct device *dev, struct scatterlist *sgl,
+		int nents, enum dma_data_direction dir, unsigned long attrs)
+{
+	return __sbus_iommu_map_sg(dev, sgl, nents, dir, attrs, true);
+}
+
+static void sbus_iommu_unmap_page(struct device *dev, dma_addr_t dma_addr,
+		size_t len, enum dma_data_direction dir, unsigned long attrs)
+{
+	struct iommu_struct *iommu = dev->archdata.iommu;
+	unsigned int busa = dma_addr & PAGE_MASK;
+	unsigned long off = dma_addr & ~PAGE_MASK;
+	unsigned int npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
+	unsigned int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
+	unsigned int i;
+
+	BUG_ON(busa < iommu->start);
+	for (i = 0; i < npages; i++) {
+		iopte_val(iommu->page_table[ioptex + i]) = 0;
+		iommu_invalidate_page(iommu->regs, busa);
+		busa += PAGE_SIZE;
+	}
+	bit_map_clear(&iommu->usemap, ioptex, npages);
+}
+
+static void sbus_iommu_unmap_sg(struct device *dev, struct scatterlist *sgl,
+		int nents, enum dma_data_direction dir, unsigned long attrs)
+{
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sg(sgl, sg, nents, i) {
+		sbus_iommu_unmap_page(dev, sg->dma_address, sg->length, dir,
+				attrs);
+		sg->dma_address = 0x21212121;
+	}
+}
+
+#ifdef CONFIG_SBUS
+static void *sbus_iommu_alloc(struct device *dev, size_t len,
+		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+	struct iommu_struct *iommu = dev->archdata.iommu;
+	unsigned long va, addr, page, end, ret;
+	iopte_t *iopte = iommu->page_table;
+	iopte_t *first;
+	int ioptex;
+
+	/* 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 == 0)
+		return NULL;
+
+	addr = ret = sparc_dma_alloc_resource(dev, len);
+	if (!addr)
+		goto out_free_pages;
+
+	BUG_ON((va & ~PAGE_MASK) != 0);
+	BUG_ON((addr & ~PAGE_MASK) != 0);
+	BUG_ON((len & ~PAGE_MASK) != 0);
+
+	/* page color = physical address */
+	ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT,
+		addr >> PAGE_SHIFT);
+	if (ioptex < 0)
+		panic("iommu out");
+
+	iopte += ioptex;
+	first = iopte;
+	end = addr + len;
+	while(addr < end) {
+		page = va;
+		{
+			pmd_t *pmdp;
+			pte_t *ptep;
+
+			if (viking_mxcc_present)
+				viking_mxcc_flush_page(page);
+			else if (viking_flush)
+				viking_flush_page(page);
+			else
+				__flush_page_to_ram(page);
+
+			pmdp = pmd_off_k(addr);
+			ptep = pte_offset_map(pmdp, addr);
+
+			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
+		}
+		iopte_val(*iopte++) =
+		    MKIOPTE(page_to_pfn(virt_to_page(page)), ioperm_noc);
+		addr += PAGE_SIZE;
+		va += PAGE_SIZE;
+	}
+	/* P3: why do we need this?
+	 *
+	 * DAVEM: Because there are several aspects, none of which
+	 *        are handled by a single interface.  Some cpus are
+	 *        completely not I/O DMA coherent, and some have
+	 *        virtually indexed caches.  The driver DMA flushing
+	 *        methods handle the former case, but here during
+	 *        IOMMU page table modifications, and usage of non-cacheable
+	 *        cpu mappings of pages potentially in the cpu caches, we have
+	 *        to handle the latter case as well.
+	 */
+	flush_cache_all();
+	iommu_flush_iotlb(first, len >> PAGE_SHIFT);
+	flush_tlb_all();
+	iommu_invalidate(iommu->regs);
+
+	*dma_handle = iommu->start + (ioptex << PAGE_SHIFT);
+	return (void *)ret;
+
+out_free_pages:
+	free_pages(va, get_order(len));
+	return NULL;
+}
+
+static void sbus_iommu_free(struct device *dev, size_t len, void *cpu_addr,
+			       dma_addr_t busa, unsigned long attrs)
+{
+	struct iommu_struct *iommu = dev->archdata.iommu;
+	iopte_t *iopte = iommu->page_table;
+	struct page *page = virt_to_page(cpu_addr);
+	int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
+	unsigned long end;
+
+	if (!sparc_dma_free_resource(cpu_addr, len))
+		return;
+
+	BUG_ON((busa & ~PAGE_MASK) != 0);
+	BUG_ON((len & ~PAGE_MASK) != 0);
+
+	iopte += ioptex;
+	end = busa + len;
+	while (busa < end) {
+		iopte_val(*iopte++) = 0;
+		busa += PAGE_SIZE;
+	}
+	flush_tlb_all();
+	iommu_invalidate(iommu->regs);
+	bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);
+
+	__free_pages(page, get_order(len));
+}
+#endif
+
+static const struct dma_map_ops sbus_iommu_dma_gflush_ops = {
+#ifdef CONFIG_SBUS
+	.alloc			= sbus_iommu_alloc,
+	.free			= sbus_iommu_free,
+#endif
+	.map_page		= sbus_iommu_map_page_gflush,
+	.unmap_page		= sbus_iommu_unmap_page,
+	.map_sg			= sbus_iommu_map_sg_gflush,
+	.unmap_sg		= sbus_iommu_unmap_sg,
+};
+
+static const struct dma_map_ops sbus_iommu_dma_pflush_ops = {
+#ifdef CONFIG_SBUS
+	.alloc			= sbus_iommu_alloc,
+	.free			= sbus_iommu_free,
+#endif
+	.map_page		= sbus_iommu_map_page_pflush,
+	.unmap_page		= sbus_iommu_unmap_page,
+	.map_sg			= sbus_iommu_map_sg_pflush,
+	.unmap_sg		= sbus_iommu_unmap_sg,
+};
+
+void __init ld_mmu_iommu(void)
+{
+	if (viking_mxcc_present || srmmu_modtype == HyperSparc) {
+		dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
+		ioperm_noc = IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID;
+	} else {
+		dvma_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV);
+		ioperm_noc = IOPTE_WRITE | IOPTE_VALID;
+	}
+}