--- /dev/null
+/*
+ * 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/highmem.h> /* pte_offset_map => kmap_atomic */
+#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/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 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;
+}
+
+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 u32 iommu_get_one(struct device *dev, struct page *page, int npages)
+{
+ struct iommu_struct *iommu = dev->archdata.iommu;
+ int ioptex;
+ iopte_t *iopte, *iopte0;
+ unsigned int busa, busa0;
+ int i;
+
+ /* page color = pfn of page */
+ ioptex = bit_map_string_get(&iommu->usemap, npages, page_to_pfn(page));
+ 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(page_to_pfn(page), IOPERM);
+ iommu_invalidate_page(iommu->regs, busa);
+ busa += PAGE_SIZE;
+ iopte++;
+ page++;
+ }
+
+ iommu_flush_iotlb(iopte0, npages);
+
+ return busa0;
+}
+
+static u32 iommu_get_scsi_one(struct device *dev, char *vaddr, unsigned int len)
+{
+ unsigned long off;
+ int npages;
+ struct page *page;
+ u32 busa;
+
+ off = (unsigned long)vaddr & ~PAGE_MASK;
+ npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
+ page = virt_to_page((unsigned long)vaddr & PAGE_MASK);
+ busa = iommu_get_one(dev, page, npages);
+ return busa + off;
+}
+
+static __u32 iommu_get_scsi_one_gflush(struct device *dev, char *vaddr, unsigned long len)
+{
+ flush_page_for_dma(0);
+ return iommu_get_scsi_one(dev, vaddr, len);
+}
+
+static __u32 iommu_get_scsi_one_pflush(struct device *dev, char *vaddr, unsigned long len)
+{
+ unsigned long page = ((unsigned long) vaddr) & PAGE_MASK;
+
+ while(page < ((unsigned long)(vaddr + len))) {
+ flush_page_for_dma(page);
+ page += PAGE_SIZE;
+ }
+ return iommu_get_scsi_one(dev, vaddr, len);
+}
+
+static void iommu_get_scsi_sgl_gflush(struct device *dev, struct scatterlist *sg, int sz)
+{
+ int n;
+
+ flush_page_for_dma(0);
+ while (sz != 0) {
+ --sz;
+ n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
+ sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
+ sg->dma_length = sg->length;
+ sg = sg_next(sg);
+ }
+}
+
+static void iommu_get_scsi_sgl_pflush(struct device *dev, struct scatterlist *sg, int sz)
+{
+ unsigned long page, oldpage = 0;
+ int n, i;
+
+ while(sz != 0) {
+ --sz;
+
+ n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
+
+ /*
+ * 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 ((page = (unsigned long) page_address(sg_page(sg))) != 0) {
+ for (i = 0; i < n; i++) {
+ if (page != oldpage) { /* Already flushed? */
+ flush_page_for_dma(page);
+ oldpage = page;
+ }
+ page += PAGE_SIZE;
+ }
+ }
+
+ sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
+ sg->dma_length = sg->length;
+ sg = sg_next(sg);
+ }
+}
+
+static void iommu_release_one(struct device *dev, u32 busa, int npages)
+{
+ struct iommu_struct *iommu = dev->archdata.iommu;
+ int ioptex;
+ int i;
+
+ BUG_ON(busa < iommu->start);
+ ioptex = (busa - iommu->start) >> PAGE_SHIFT;
+ 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 iommu_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
+{
+ unsigned long off;
+ int npages;
+
+ off = vaddr & ~PAGE_MASK;
+ npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
+ iommu_release_one(dev, vaddr & PAGE_MASK, npages);
+}
+
+static void iommu_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
+{
+ int n;
+
+ while(sz != 0) {
+ --sz;
+
+ n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
+ iommu_release_one(dev, sg->dma_address & PAGE_MASK, n);
+ sg->dma_address = 0x21212121;
+ sg = sg_next(sg);
+ }
+}
+
+#ifdef CONFIG_SBUS
+static int iommu_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va,
+ unsigned long addr, int len)
+{
+ struct iommu_struct *iommu = dev->archdata.iommu;
+ unsigned long page, end;
+ iopte_t *iopte = iommu->page_table;
+ iopte_t *first;
+ int ioptex;
+
+ 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;
+ {
+ pgd_t *pgdp;
+ 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);
+
+ 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));
+ }
+ 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);
+
+ *pba = iommu->start + (ioptex << PAGE_SHIFT);
+ return 0;
+}
+
+static void iommu_unmap_dma_area(struct device *dev, unsigned long busa, int len)
+{
+ struct iommu_struct *iommu = dev->archdata.iommu;
+ iopte_t *iopte = iommu->page_table;
+ unsigned long end;
+ int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
+
+ 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);
+}
+#endif
+
+static const struct sparc32_dma_ops iommu_dma_gflush_ops = {
+ .get_scsi_one = iommu_get_scsi_one_gflush,
+ .get_scsi_sgl = iommu_get_scsi_sgl_gflush,
+ .release_scsi_one = iommu_release_scsi_one,
+ .release_scsi_sgl = iommu_release_scsi_sgl,
+#ifdef CONFIG_SBUS
+ .map_dma_area = iommu_map_dma_area,
+ .unmap_dma_area = iommu_unmap_dma_area,
+#endif
+};
+
+static const struct sparc32_dma_ops iommu_dma_pflush_ops = {
+ .get_scsi_one = iommu_get_scsi_one_pflush,
+ .get_scsi_sgl = iommu_get_scsi_sgl_pflush,
+ .release_scsi_one = iommu_release_scsi_one,
+ .release_scsi_sgl = iommu_release_scsi_sgl,
+#ifdef CONFIG_SBUS
+ .map_dma_area = iommu_map_dma_area,
+ .unmap_dma_area = iommu_unmap_dma_area,
+#endif
+};
+
+void __init ld_mmu_iommu(void)
+{
+ if (flush_page_for_dma_global) {
+ /* flush_page_for_dma flushes everything, no matter of what page is it */
+ sparc32_dma_ops = &iommu_dma_gflush_ops;
+ } else {
+ sparc32_dma_ops = &iommu_dma_pflush_ops;
+ }
+
+ 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;
+ }
+}
Code Review / kvmfornfv.git / blobdiff