1 files changed, 475 insertions, 0 deletions

diff --git a/arch/sparc/mm/iommu.c b/arch/sparc/mm/iommu.c
new file mode 100644
index 00000000000..489bf68d5f0
--- /dev/null
+++ b/arch/sparc/mm/iommu.c
@@ -0,0 +1,475 @@
+/*
+ * 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/config.h>
+#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 <asm/scatterlist.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/sbus.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>
+
+/*
+ * 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, 265KB */
+#define IOMMU_ORDER	6				/* 4096 * (1<<6) */
+
+/* srmmu.c */
+extern int viking_mxcc_present;
+BTFIXUPDEF_CALL(void, flush_page_for_dma, unsigned long)
+#define flush_page_for_dma(page) BTFIXUP_CALL(flush_page_for_dma)(page)
+extern int flush_page_for_dma_global;
+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)
+
+void __init
+iommu_init(int iommund, struct sbus_bus *sbus)
+{
+	unsigned int impl, vers;
+	unsigned long tmp;
+	struct iommu_struct *iommu;
+	struct linux_prom_registers iommu_promregs[PROMREG_MAX];
+	struct resource r;
+	unsigned long *bitmap;
+
+	iommu = kmalloc(sizeof(struct iommu_struct), GFP_ATOMIC);
+	if (!iommu) {
+		prom_printf("Unable to allocate iommu structure\n");
+		prom_halt();
+	}
+	iommu->regs = NULL;
+	if (prom_getproperty(iommund, "reg", (void *) iommu_promregs,
+			 sizeof(iommu_promregs)) != -1) {
+		memset(&r, 0, sizeof(r));
+		r.flags = iommu_promregs[0].which_io;
+		r.start = iommu_promregs[0].phys_addr;
+		iommu->regs = (struct iommu_regs *)
+			sbus_ioremap(&r, 0, PAGE_SIZE * 3, "iommu_regs");
+	}
+	if (!iommu->regs) {
+		prom_printf("Cannot map IOMMU registers\n");
+		prom_halt();
+	}
+	impl = (iommu->regs->control & IOMMU_CTRL_IMPL) >> 28;
+	vers = (iommu->regs->control & IOMMU_CTRL_VERS) >> 24;
+	tmp = iommu->regs->control;
+	tmp &= ~(IOMMU_CTRL_RNGE);
+	tmp |= (IOMMU_RNGE_256MB | IOMMU_CTRL_ENAB);
+	iommu->regs->control = tmp;
+	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%08x]\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();
+	iommu->regs->base = __pa((unsigned long) iommu->page_table) >> 4;
+	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("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);
+
+	sbus->iommu = iommu;
+}
+
+/* This begs to be btfixup-ed by srmmu. */
+/* 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 & PAGE_MASK;
+	end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
+	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 page *page, int npages, struct sbus_bus *sbus)
+{
+	struct iommu_struct *iommu = sbus->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(char *vaddr, unsigned int len,
+    struct sbus_bus *sbus)
+{
+	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(page, npages, sbus);
+	return busa + off;
+}
+
+static __u32 iommu_get_scsi_one_noflush(char *vaddr, unsigned long len, struct sbus_bus *sbus)
+{
+	return iommu_get_scsi_one(vaddr, len, sbus);
+}
+
+static __u32 iommu_get_scsi_one_gflush(char *vaddr, unsigned long len, struct sbus_bus *sbus)
+{
+	flush_page_for_dma(0);
+	return iommu_get_scsi_one(vaddr, len, sbus);
+}
+
+static __u32 iommu_get_scsi_one_pflush(char *vaddr, unsigned long len, struct sbus_bus *sbus)
+{
+	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(vaddr, len, sbus);
+}
+
+static void iommu_get_scsi_sgl_noflush(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
+{
+	int n;
+
+	while (sz != 0) {
+		--sz;
+		n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
+		sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
+		sg->dvma_length = (__u32) sg->length;
+		sg++;
+	}
+}
+
+static void iommu_get_scsi_sgl_gflush(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
+{
+	int n;
+
+	flush_page_for_dma(0);
+	while (sz != 0) {
+		--sz;
+		n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
+		sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
+		sg->dvma_length = (__u32) sg->length;
+		sg++;
+	}
+}
+
+static void iommu_get_scsi_sgl_pflush(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
+{
+	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)) != 0) {
+			for (i = 0; i < n; i++) {
+				if (page != oldpage) {	/* Already flushed? */
+					flush_page_for_dma(page);
+					oldpage = page;
+				}
+				page += PAGE_SIZE;
+			}
+		}
+
+		sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
+		sg->dvma_length = (__u32) sg->length;
+		sg++;
+	}
+}
+
+static void iommu_release_one(u32 busa, int npages, struct sbus_bus *sbus)
+{
+	struct iommu_struct *iommu = sbus->iommu;
+	int ioptex;
+	int i;
+
+	if (busa < iommu->start)
+		BUG();
+	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(__u32 vaddr, unsigned long len, struct sbus_bus *sbus)
+{
+	unsigned long off;
+	int npages;
+
+	off = vaddr & ~PAGE_MASK;
+	npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
+	iommu_release_one(vaddr & PAGE_MASK, npages, sbus);
+}
+
+static void iommu_release_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
+{
+	int n;
+
+	while(sz != 0) {
+		--sz;
+
+		n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
+		iommu_release_one(sg->dvma_address & PAGE_MASK, n, sbus);
+		sg->dvma_address = 0x21212121;
+		sg++;
+	}
+}
+
+#ifdef CONFIG_SBUS
+static int iommu_map_dma_area(dma_addr_t *pba, unsigned long va,
+    unsigned long addr, int len)
+{
+	unsigned long page, end;
+	struct iommu_struct *iommu = sbus_root->iommu;
+	iopte_t *iopte = iommu->page_table;
+	iopte_t *first;
+	int ioptex;
+
+	if ((va & ~PAGE_MASK) != 0) BUG();
+	if ((addr & ~PAGE_MASK) != 0) BUG();
+	if ((len & ~PAGE_MASK) != 0) BUG();
+
+	/* 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(unsigned long busa, int len)
+{
+	struct iommu_struct *iommu = sbus_root->iommu;
+	iopte_t *iopte = iommu->page_table;
+	unsigned long end;
+	int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
+
+	if ((busa & ~PAGE_MASK) != 0) BUG();
+	if ((len & ~PAGE_MASK) != 0) BUG();
+
+	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);
+}
+
+static struct page *iommu_translate_dvma(unsigned long busa)
+{
+	struct iommu_struct *iommu = sbus_root->iommu;
+	iopte_t *iopte = iommu->page_table;
+
+	iopte += ((busa - iommu->start) >> PAGE_SHIFT);
+	return pfn_to_page((iopte_val(*iopte) & IOPTE_PAGE) >> (PAGE_SHIFT-4));
+}
+#endif
+
+static char *iommu_lockarea(char *vaddr, unsigned long len)
+{
+	return vaddr;
+}
+
+static void iommu_unlockarea(char *vaddr, unsigned long len)
+{
+}
+
+void __init ld_mmu_iommu(void)
+{
+	viking_flush = (BTFIXUPVAL_CALL(flush_page_for_dma) == (unsigned long)viking_flush_page);
+	BTFIXUPSET_CALL(mmu_lockarea, iommu_lockarea, BTFIXUPCALL_RETO0);
+	BTFIXUPSET_CALL(mmu_unlockarea, iommu_unlockarea, BTFIXUPCALL_NOP);
+
+	if (!BTFIXUPVAL_CALL(flush_page_for_dma)) {
+		/* IO coherent chip */
+		BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_noflush, BTFIXUPCALL_RETO0);
+		BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_noflush, BTFIXUPCALL_NORM);
+	} else if (flush_page_for_dma_global) {
+		/* flush_page_for_dma flushes everything, no matter of what page is it */
+		BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_gflush, BTFIXUPCALL_NORM);
+		BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_gflush, BTFIXUPCALL_NORM);
+	} else {
+		BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_pflush, BTFIXUPCALL_NORM);
+		BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_pflush, BTFIXUPCALL_NORM);
+	}
+	BTFIXUPSET_CALL(mmu_release_scsi_one, iommu_release_scsi_one, BTFIXUPCALL_NORM);
+	BTFIXUPSET_CALL(mmu_release_scsi_sgl, iommu_release_scsi_sgl, BTFIXUPCALL_NORM);
+
+#ifdef CONFIG_SBUS
+	BTFIXUPSET_CALL(mmu_map_dma_area, iommu_map_dma_area, BTFIXUPCALL_NORM);
+	BTFIXUPSET_CALL(mmu_unmap_dma_area, iommu_unmap_dma_area, BTFIXUPCALL_NORM);
+	BTFIXUPSET_CALL(mmu_translate_dvma, iommu_translate_dvma, BTFIXUPCALL_NORM);
+#endif
+
+	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;
+	}
+}