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-rw-r--r--arch/m68k/sun3x/dvma.c201
1 files changed, 201 insertions, 0 deletions
diff --git a/arch/m68k/sun3x/dvma.c b/arch/m68k/sun3x/dvma.c
new file mode 100644
index 0000000000..a6034ba058
--- /dev/null
+++ b/arch/m68k/sun3x/dvma.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Virtual DMA allocation
+ *
+ * (C) 1999 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
+ *
+ * 11/26/2000 -- disabled the existing code because it didn't work for
+ * me in 2.4. Replaced with a significantly more primitive version
+ * similar to the sun3 code. the old functionality was probably more
+ * desirable, but.... -- Sam Creasey (sammy@oh.verio.com)
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/mm.h>
+#include <linux/memblock.h>
+#include <linux/vmalloc.h>
+
+#include <asm/sun3x.h>
+#include <asm/dvma.h>
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/tlbflush.h>
+
+/* IOMMU support */
+
+#define IOMMU_ADDR_MASK 0x03ffe000
+#define IOMMU_CACHE_INHIBIT 0x00000040
+#define IOMMU_FULL_BLOCK 0x00000020
+#define IOMMU_MODIFIED 0x00000010
+#define IOMMU_USED 0x00000008
+#define IOMMU_WRITE_PROTECT 0x00000004
+#define IOMMU_DT_MASK 0x00000003
+#define IOMMU_DT_INVALID 0x00000000
+#define IOMMU_DT_VALID 0x00000001
+#define IOMMU_DT_BAD 0x00000002
+
+
+static volatile unsigned long *iommu_pte = (unsigned long *)SUN3X_IOMMU;
+
+
+#define dvma_entry_paddr(index) (iommu_pte[index] & IOMMU_ADDR_MASK)
+#define dvma_entry_vaddr(index,paddr) ((index << DVMA_PAGE_SHIFT) | \
+ (paddr & (DVMA_PAGE_SIZE-1)))
+#if 0
+#define dvma_entry_set(index,addr) (iommu_pte[index] = \
+ (addr & IOMMU_ADDR_MASK) | \
+ IOMMU_DT_VALID | IOMMU_CACHE_INHIBIT)
+#else
+#define dvma_entry_set(index,addr) (iommu_pte[index] = \
+ (addr & IOMMU_ADDR_MASK) | \
+ IOMMU_DT_VALID)
+#endif
+#define dvma_entry_clr(index) (iommu_pte[index] = IOMMU_DT_INVALID)
+#define dvma_entry_hash(addr) ((addr >> DVMA_PAGE_SHIFT) ^ \
+ ((addr & 0x03c00000) >> \
+ (DVMA_PAGE_SHIFT+4)))
+
+#ifdef DEBUG
+/* code to print out a dvma mapping for debugging purposes */
+void dvma_print (unsigned long dvma_addr)
+{
+
+ unsigned long index;
+
+ index = dvma_addr >> DVMA_PAGE_SHIFT;
+
+ pr_info("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr,
+ dvma_entry_paddr(index));
+}
+#endif
+
+
+/* create a virtual mapping for a page assigned within the IOMMU
+ so that the cpu can reach it easily */
+inline int dvma_map_cpu(unsigned long kaddr,
+ unsigned long vaddr, int len)
+{
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ unsigned long end;
+ int ret = 0;
+
+ kaddr &= PAGE_MASK;
+ vaddr &= PAGE_MASK;
+
+ end = PAGE_ALIGN(vaddr + len);
+
+ pr_debug("dvma: mapping kern %08lx to virt %08lx\n", kaddr, vaddr);
+ pgd = pgd_offset_k(vaddr);
+ p4d = p4d_offset(pgd, vaddr);
+ pud = pud_offset(p4d, vaddr);
+
+ do {
+ pmd_t *pmd;
+ unsigned long end2;
+
+ if((pmd = pmd_alloc(&init_mm, pud, vaddr)) == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK))
+ end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK;
+ else
+ end2 = end;
+
+ do {
+ pte_t *pte;
+ unsigned long end3;
+
+ if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if((end2 & PMD_MASK) > (vaddr & PMD_MASK))
+ end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK;
+ else
+ end3 = end2;
+
+ do {
+ pr_debug("mapping %08lx phys to %08lx\n",
+ __pa(kaddr), vaddr);
+ set_pte(pte, pfn_pte(virt_to_pfn((void *)kaddr),
+ PAGE_KERNEL));
+ pte++;
+ kaddr += PAGE_SIZE;
+ vaddr += PAGE_SIZE;
+ } while(vaddr < end3);
+
+ } while(vaddr < end2);
+
+ } while(vaddr < end);
+
+ flush_tlb_all();
+
+ out:
+ return ret;
+}
+
+
+inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
+ int len)
+{
+ unsigned long end, index;
+
+ index = baddr >> DVMA_PAGE_SHIFT;
+ end = ((baddr+len) >> DVMA_PAGE_SHIFT);
+
+ if(len & ~DVMA_PAGE_MASK)
+ end++;
+
+ for(; index < end ; index++) {
+// if(dvma_entry_use(index))
+// BUG();
+// pr_info("mapping pa %lx to ba %lx\n", __pa(kaddr),
+// index << DVMA_PAGE_SHIFT);
+
+ dvma_entry_set(index, __pa(kaddr));
+
+ iommu_pte[index] |= IOMMU_FULL_BLOCK;
+// dvma_entry_inc(index);
+
+ kaddr += DVMA_PAGE_SIZE;
+ }
+
+#ifdef DEBUG
+ for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++)
+ dvma_print(index << DVMA_PAGE_SHIFT);
+#endif
+ return 0;
+
+}
+
+void dvma_unmap_iommu(unsigned long baddr, int len)
+{
+
+ int index, end;
+
+
+ index = baddr >> DVMA_PAGE_SHIFT;
+ end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT);
+
+ for(; index < end ; index++) {
+ pr_debug("freeing bus mapping %08x\n",
+ index << DVMA_PAGE_SHIFT);
+#if 0
+ if(!dvma_entry_use(index))
+ pr_info("dvma_unmap freeing unused entry %04x\n",
+ index);
+ else
+ dvma_entry_dec(index);
+#endif
+ dvma_entry_clr(index);
+ }
+
+}