[SPARC64]: First cut at SUN4V PCI IOMMU handling.

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 550 insertions, 31 deletions

diff --git a/arch/sparc64/kernel/pci_iommu.c b/arch/sparc64/kernel/pci_iommu.c
index 8e52232f6f31..c9320eac45d3 100644
--- a/arch/sparc64/kernel/pci_iommu.c
+++ b/arch/sparc64/kernel/pci_iommu.c
@@ -562,9 +562,9 @@ static int pci_4u_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int n
         /* Fast path single entry scatterlists. */
         if (nelems == 1) {
                 sglist->dma_address =
-                        pci_map_single(pdev,
-                                       (page_address(sglist->page) + sglist->offset),
-                                       sglist->length, direction);
+                        pci_4u_map_single(pdev,
+                                          (page_address(sglist->page) + sglist->offset),
+                                          sglist->length, direction);
                 if (unlikely(sglist->dma_address == PCI_DMA_ERROR_CODE))
                         return 0;
                 sglist->dma_length = sglist->length;
diff --git a/arch/sparc64/kernel/pci_sun4v.c b/arch/sparc64/kernel/pci_sun4v.c
index abd9bfb245cb..3f0e3c09f4d3 100644
--- a/arch/sparc64/kernel/pci_sun4v.c
+++ b/arch/sparc64/kernel/pci_sun4v.c
@@ -9,6 +9,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
+#include <linux/percpu.h>
 
 #include <asm/pbm.h>
 #include <asm/iommu.h>
@@ -23,39 +24,481 @@
 
 #include "pci_sun4v.h"
 
+#define PGLIST_NENTS    2048
+
+struct sun4v_pglist {
+        u64     pglist[PGLIST_NENTS];
+};
+
+static DEFINE_PER_CPU(struct sun4v_pglist, iommu_pglists);
+
+static long pci_arena_alloc(struct pci_iommu_arena *arena, unsigned long npages)
+{
+        unsigned long n, i, start, end, limit;
+        int pass;
+
+        limit = arena->limit;
+        start = arena->hint;
+        pass = 0;
+
+again:
+        n = find_next_zero_bit(arena->map, limit, start);
+        end = n + npages;
+        if (unlikely(end >= limit)) {
+                if (likely(pass < 1)) {
+                        limit = start;
+                        start = 0;
+                        pass++;
+                        goto again;
+                } else {
+                        /* Scanned the whole thing, give up. */
+                        return -1;
+                }
+        }
+
+        for (i = n; i < end; i++) {
+                if (test_bit(i, arena->map)) {
+                        start = i + 1;
+                        goto again;
+                }
+        }
+
+        for (i = n; i < end; i++)
+                __set_bit(i, arena->map);
+
+        arena->hint = end;
+
+        return n;
+}
+
+static void pci_arena_free(struct pci_iommu_arena *arena, unsigned long base, unsigned long npages)
+{
+        unsigned long i;
+
+        for (i = base; i < (base + npages); i++)
+                __clear_bit(i, arena->map);
+}
+
 static void *pci_4v_alloc_consistent(struct pci_dev *pdev, size_t size, dma_addr_t *dma_addrp)
 {
-        return NULL;
+        struct pcidev_cookie *pcp;
+        struct pci_iommu *iommu;
+        unsigned long devhandle, flags, order, first_page, npages, n;
+        void *ret;
+        long entry;
+        u64 *pglist;
+        int cpu;
+
+        size = IO_PAGE_ALIGN(size);
+        order = get_order(size);
+        if (order >= MAX_ORDER)
+                return NULL;
+
+        npages = size >> IO_PAGE_SHIFT;
+        if (npages > PGLIST_NENTS)
+                return NULL;
+
+        first_page = __get_free_pages(GFP_ATOMIC, order);
+        if (first_page == 0UL)
+                return NULL;
+        memset((char *)first_page, 0, PAGE_SIZE << order);
+
+        pcp = pdev->sysdata;
+        devhandle = pcp->pbm->devhandle;
+        iommu = pcp->pbm->iommu;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        entry = pci_arena_alloc(&iommu->arena, npages);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        if (unlikely(entry < 0L)) {
+                free_pages(first_page, order);
+                return NULL;
+        }
+
+        *dma_addrp = (iommu->page_table_map_base +
+                      (entry << IO_PAGE_SHIFT));
+        ret = (void *) first_page;
+        first_page = __pa(first_page);
+
+        cpu = get_cpu();
+
+        pglist = &__get_cpu_var(iommu_pglists).pglist[0];
+        for (n = 0; n < npages; n++)
+                pglist[n] = first_page + (n * PAGE_SIZE);
+
+        do {
+                unsigned long num;
+
+                num = pci_sun4v_iommu_map(devhandle, HV_PCI_TSBID(0, entry),
+                                          npages,
+                                          (HV_PCI_MAP_ATTR_READ |
+                                           HV_PCI_MAP_ATTR_WRITE),
+                                          __pa(pglist));
+                entry += num;
+                npages -= num;
+                pglist += num;
+        } while (npages != 0);
+
+        put_cpu();
+
+        return ret;
 }
 
 static void pci_4v_free_consistent(struct pci_dev *pdev, size_t size, void *cpu, dma_addr_t dvma)
 {
+        struct pcidev_cookie *pcp;
+        struct pci_iommu *iommu;
+        unsigned long flags, order, npages, entry, devhandle;
+
+        npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
+        pcp = pdev->sysdata;
+        iommu = pcp->pbm->iommu;
+        devhandle = pcp->pbm->devhandle;
+        entry = ((dvma - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        pci_arena_free(&iommu->arena, entry, npages);
+
+        do {
+                unsigned long num;
+
+                num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry),
+                                            npages);
+                entry += num;
+                npages -= num;
+        } while (npages != 0);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        order = get_order(size);
+        if (order < 10)
+                free_pages((unsigned long)cpu, order);
 }
 
 static dma_addr_t pci_4v_map_single(struct pci_dev *pdev, void *ptr, size_t sz, int direction)
 {
-        return 0;
+        struct pcidev_cookie *pcp;
+        struct pci_iommu *iommu;
+        unsigned long flags, npages, oaddr;
+        unsigned long i, base_paddr, devhandle;
+        u32 bus_addr, ret;
+        unsigned long prot;
+        long entry;
+        u64 *pglist;
+        int cpu;
+
+        pcp = pdev->sysdata;
+        iommu = pcp->pbm->iommu;
+        devhandle = pcp->pbm->devhandle;
+
+        if (unlikely(direction == PCI_DMA_NONE))
+                goto bad;
+
+        oaddr = (unsigned long)ptr;
+        npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
+        npages >>= IO_PAGE_SHIFT;
+        if (unlikely(npages > PGLIST_NENTS))
+                goto bad;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        entry = pci_arena_alloc(&iommu->arena, npages);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        if (unlikely(entry < 0L))
+                goto bad;
+
+        bus_addr = (iommu->page_table_map_base +
+                    (entry << IO_PAGE_SHIFT));
+        ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
+        base_paddr = __pa(oaddr & IO_PAGE_MASK);
+        prot = HV_PCI_MAP_ATTR_READ;
+        if (direction != PCI_DMA_TODEVICE)
+                prot |= HV_PCI_MAP_ATTR_WRITE;
+
+        cpu = get_cpu();
+
+        pglist = &__get_cpu_var(iommu_pglists).pglist[0];
+        for (i = 0; i < npages; i++, base_paddr += IO_PAGE_SIZE)
+                pglist[i] = base_paddr;
+
+        do {
+                unsigned long num;
+
+                num = pci_sun4v_iommu_map(devhandle, HV_PCI_TSBID(0, entry),
+                                          npages, prot,
+                                          __pa(pglist));
+                entry += num;
+                npages -= num;
+                pglist += num;
+        } while (npages != 0);
+
+        put_cpu();
+
+        return ret;
+
+bad:
+        if (printk_ratelimit())
+                WARN_ON(1);
+        return PCI_DMA_ERROR_CODE;
 }
 
 static void pci_4v_unmap_single(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int direction)
 {
+        struct pcidev_cookie *pcp;
+        struct pci_iommu *iommu;
+        unsigned long flags, npages, devhandle;
+        long entry;
+
+        if (unlikely(direction == PCI_DMA_NONE)) {
+                if (printk_ratelimit())
+                        WARN_ON(1);
+                return;
+        }
+
+        pcp = pdev->sysdata;
+        iommu = pcp->pbm->iommu;
+        devhandle = pcp->pbm->devhandle;
+
+        npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
+        npages >>= IO_PAGE_SHIFT;
+        bus_addr &= IO_PAGE_MASK;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        entry = (bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
+        pci_arena_free(&iommu->arena, entry, npages);
+
+        do {
+                unsigned long num;
+
+                num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry),
+                                            npages);
+                entry += num;
+                npages -= num;
+        } while (npages != 0);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+#define SG_ENT_PHYS_ADDRESS(SG) \
+        (__pa(page_address((SG)->page)) + (SG)->offset)
+
+static inline void fill_sg(long entry, unsigned long devhandle,
+                           struct scatterlist *sg,
+                           int nused, int nelems, unsigned long prot)
+{
+        struct scatterlist *dma_sg = sg;
+        struct scatterlist *sg_end = sg + nelems;
+        int i, cpu, pglist_ent;
+        u64 *pglist;
+
+        cpu = get_cpu();
+        pglist = &__get_cpu_var(iommu_pglists).pglist[0];
+        pglist_ent = 0;
+        for (i = 0; i < nused; i++) {
+                unsigned long pteval = ~0UL;
+                u32 dma_npages;
+
+                dma_npages = ((dma_sg->dma_address & (IO_PAGE_SIZE - 1UL)) +
+                              dma_sg->dma_length +
+                              ((IO_PAGE_SIZE - 1UL))) >> IO_PAGE_SHIFT;
+                do {
+                        unsigned long offset;
+                        signed int len;
+
+                        /* If we are here, we know we have at least one
+                         * more page to map.  So walk forward until we
+                         * hit a page crossing, and begin creating new
+                         * mappings from that spot.
+                         */
+                        for (;;) {
+                                unsigned long tmp;
+
+                                tmp = SG_ENT_PHYS_ADDRESS(sg);
+                                len = sg->length;
+                                if (((tmp ^ pteval) >> IO_PAGE_SHIFT) != 0UL) {
+                                        pteval = tmp & IO_PAGE_MASK;
+                                        offset = tmp & (IO_PAGE_SIZE - 1UL);
+                                        break;
+                                }
+                                if (((tmp ^ (tmp + len - 1UL)) >> IO_PAGE_SHIFT) != 0UL) {
+                                        pteval = (tmp + IO_PAGE_SIZE) & IO_PAGE_MASK;
+                                        offset = 0UL;
+                                        len -= (IO_PAGE_SIZE - (tmp & (IO_PAGE_SIZE - 1UL)));
+                                        break;
+                                }
+                                sg++;
+                        }
+
+                        pteval = (pteval & IOPTE_PAGE);
+                        while (len > 0) {
+                                pglist[pglist_ent++] = pteval;
+                                pteval += IO_PAGE_SIZE;
+                                len -= (IO_PAGE_SIZE - offset);
+                                offset = 0;
+                                dma_npages--;
+                        }
+
+                        pteval = (pteval & IOPTE_PAGE) + len;
+                        sg++;
+
+                        /* Skip over any tail mappings we've fully mapped,
+                         * adjusting pteval along the way.  Stop when we
+                         * detect a page crossing event.
+                         */
+                        while (sg < sg_end &&
+                               (pteval << (64 - IO_PAGE_SHIFT)) != 0UL &&
+                               (pteval == SG_ENT_PHYS_ADDRESS(sg)) &&
+                               ((pteval ^
+                                 (SG_ENT_PHYS_ADDRESS(sg) + sg->length - 1UL)) >> IO_PAGE_SHIFT) == 0UL) {
+                                pteval += sg->length;
+                                sg++;
+                        }
+                        if ((pteval << (64 - IO_PAGE_SHIFT)) == 0UL)
+                                pteval = ~0UL;
+                } while (dma_npages != 0);
+                dma_sg++;
+        }
+
+        BUG_ON(pglist_ent == 0);
+
+        do {
+                unsigned long num;
+
+                num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry),
+                                            pglist_ent);
+                entry += num;
+                pglist_ent -= num;
+        } while (pglist_ent != 0);
+
+        put_cpu();
 }
 
 static int pci_4v_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int direction)
 {
-        return nelems;
+        struct pcidev_cookie *pcp;
+        struct pci_iommu *iommu;
+        unsigned long flags, npages, prot, devhandle;
+        u32 dma_base;
+        struct scatterlist *sgtmp;
+        long entry;
+        int used;
+
+        /* Fast path single entry scatterlists. */
+        if (nelems == 1) {
+                sglist->dma_address =
+                        pci_4v_map_single(pdev,
+                                          (page_address(sglist->page) + sglist->offset),
+                                          sglist->length, direction);
+                if (unlikely(sglist->dma_address == PCI_DMA_ERROR_CODE))
+                        return 0;
+                sglist->dma_length = sglist->length;
+                return 1;
+        }
+
+        pcp = pdev->sysdata;
+        iommu = pcp->pbm->iommu;
+        devhandle = pcp->pbm->devhandle;
+        
+        if (unlikely(direction == PCI_DMA_NONE))
+                goto bad;
+
+        /* Step 1: Prepare scatter list. */
+        npages = prepare_sg(sglist, nelems);
+        if (unlikely(npages > PGLIST_NENTS))
+                goto bad;
+
+        /* Step 2: Allocate a cluster and context, if necessary. */
+        spin_lock_irqsave(&iommu->lock, flags);
+        entry = pci_arena_alloc(&iommu->arena, npages);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        if (unlikely(entry < 0L))
+                goto bad;
+
+        dma_base = iommu->page_table_map_base +
+                (entry << IO_PAGE_SHIFT);
+
+        /* Step 3: Normalize DMA addresses. */
+        used = nelems;
+
+        sgtmp = sglist;
+        while (used && sgtmp->dma_length) {
+                sgtmp->dma_address += dma_base;
+                sgtmp++;
+                used--;
+        }
+        used = nelems - used;
+
+        /* Step 4: Create the mappings. */
+        prot = HV_PCI_MAP_ATTR_READ;
+        if (direction != PCI_DMA_TODEVICE)
+                prot |= HV_PCI_MAP_ATTR_WRITE;
+
+        fill_sg(entry, devhandle, sglist, used, nelems, prot);
+
+        return used;
+
+bad:
+        if (printk_ratelimit())
+                WARN_ON(1);
+        return 0;
 }
 
 static void pci_4v_unmap_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int direction)
 {
+        struct pcidev_cookie *pcp;
+        struct pci_iommu *iommu;
+        unsigned long flags, i, npages, devhandle;
+        long entry;
+        u32 bus_addr;
+
+        if (unlikely(direction == PCI_DMA_NONE)) {
+                if (printk_ratelimit())
+                        WARN_ON(1);
+        }
+
+        pcp = pdev->sysdata;
+        iommu = pcp->pbm->iommu;
+        devhandle = pcp->pbm->devhandle;
+        
+        bus_addr = sglist->dma_address & IO_PAGE_MASK;
+
+        for (i = 1; i < nelems; i++)
+                if (sglist[i].dma_length == 0)
+                        break;
+        i--;
+        npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) -
+                  bus_addr) >> IO_PAGE_SHIFT;
+
+        entry = ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        pci_arena_free(&iommu->arena, entry, npages);
+
+        do {
+                unsigned long num;
+
+                num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry),
+                                            npages);
+                entry += num;
+                npages -= num;
+        } while (npages != 0);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
 static void pci_4v_dma_sync_single_for_cpu(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int direction)
 {
+        /* Nothing to do... */
 }
 
 static void pci_4v_dma_sync_sg_for_cpu(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int direction)
 {
+        /* Nothing to do... */
 }
 
 struct pci_iommu_ops pci_sun4v_iommu_ops = {
@@ -264,9 +707,83 @@ static void pbm_register_toplevel_resources(struct pci_controller_info *p,
                                     &pbm->mem_space);
 }
 
+static void probe_existing_entries(struct pci_pbm_info *pbm,
+                                   struct pci_iommu *iommu)
+{
+        struct pci_iommu_arena *arena = &iommu->arena;
+        unsigned long i, devhandle;
+
+        devhandle = pbm->devhandle;
+        for (i = 0; i < arena->limit; i++) {
+                unsigned long ret, io_attrs, ra;
+
+                ret = pci_sun4v_iommu_getmap(devhandle,
+                                             HV_PCI_TSBID(0, i),
+                                             &io_attrs, &ra);
+                if (ret == HV_EOK)
+                        __set_bit(i, arena->map);
+        }
+}
+
 static void pci_sun4v_iommu_init(struct pci_pbm_info *pbm)
 {
-        /* XXX Implement me! XXX */
+        struct pci_iommu *iommu = pbm->iommu;
+        unsigned long num_tsb_entries, sz;
+        u32 vdma[2], dma_mask, dma_offset;
+        int err, tsbsize;
+
+        err = prom_getproperty(pbm->prom_node, "virtual-dma",
+                               (char *)&vdma[0], sizeof(vdma));
+        if (err == 0 || err == -1) {
+                /* No property, use default values. */
+                vdma[0] = 0x80000000;
+                vdma[1] = 0x80000000;
+        }
+
+        dma_mask = vdma[0];
+        switch (vdma[1]) {
+                case 0x20000000:
+                        dma_mask |= 0x1fffffff;
+                        tsbsize = 64;
+                        break;
+
+                case 0x40000000:
+                        dma_mask |= 0x3fffffff;
+                        tsbsize = 128;
+                        break;
+
+                case 0x80000000:
+                        dma_mask |= 0x7fffffff;
+                        tsbsize = 128;
+                        break;
+
+                default:
+                        prom_printf("PCI-SUN4V: strange virtual-dma size.\n");
+                        prom_halt();
+        };
+
+        num_tsb_entries = tsbsize / sizeof(iopte_t);
+
+        dma_offset = vdma[0];
+
+        /* Setup initial software IOMMU state. */
+        spin_lock_init(&iommu->lock);
+        iommu->ctx_lowest_free = 1;
+        iommu->page_table_map_base = dma_offset;
+        iommu->dma_addr_mask = dma_mask;
+
+        /* Allocate and initialize the free area map.  */
+        sz = num_tsb_entries / 8;
+        sz = (sz + 7UL) & ~7UL;
+        iommu->arena.map = kmalloc(sz, GFP_KERNEL);
+        if (!iommu->arena.map) {
+                prom_printf("PCI_IOMMU: Error, kmalloc(arena.map) failed.\n");
+                prom_halt();
+        }
+        memset(iommu->arena.map, 0, sz);
+        iommu->arena.limit = num_tsb_entries;
+
+        probe_existing_entries(pbm, iommu);
 }
 
 static void pci_sun4v_pbm_init(struct pci_controller_info *p, int prom_node)
diff --git a/arch/sparc64/kernel/pci_sun4v.h b/arch/sparc64/kernel/pci_sun4v.h
index 5c7ed2ca1505..00322ed0cf8a 100644
--- a/arch/sparc64/kernel/pci_sun4v.h
+++ b/arch/sparc64/kernel/pci_sun4v.h
@@ -16,6 +16,10 @@ extern unsigned long pci_sun4v_iommu_map(unsigned long devhandle,
 extern unsigned long pci_sun4v_iommu_demap(unsigned long devhandle,
                                            unsigned long tsbid,
                                            unsigned long num_ttes);
+extern unsigned long pci_sun4v_iommu_getmap(unsigned long devhandle,
+                                            unsigned long tsbid,
+                                            unsigned long *io_attributes,
+                                            unsigned long *real_address);
 extern unsigned long pci_sun4v_config_get(unsigned long devhandle,
                                           unsigned long pci_device,
                                           unsigned long config_offset,
diff --git a/arch/sparc64/kernel/pci_sun4v_asm.S b/arch/sparc64/kernel/pci_sun4v_asm.S
index 2f1147146abe..4a12341dd5d3 100644
--- a/arch/sparc64/kernel/pci_sun4v_asm.S
+++ b/arch/sparc64/kernel/pci_sun4v_asm.S
@@ -12,9 +12,7 @@
          */
         .globl  pci_sun4v_devino_to_sysino
 pci_sun4v_devino_to_sysino:
-        mov     %o1, %o2
-        mov     %o0, %o1
-        mov     HV_FAST_INTR_DEVINO2SYSINO, %o0
+        mov     HV_FAST_INTR_DEVINO2SYSINO, %o5
         ta      HV_FAST_TRAP
         retl
          mov    %o1, %o0
@@ -29,12 +27,7 @@ pci_sun4v_devino_to_sysino:
          */
         .globl  pci_sun4v_iommu_map
 pci_sun4v_iommu_map:
-        mov     %o4, %o5
-        mov     %o3, %o4
-        mov     %o2, %o3
-        mov     %o1, %o2
-        mov     %o0, %o1
-        mov     HV_FAST_PCI_IOMMU_MAP, %o0
+        mov     HV_FAST_PCI_IOMMU_MAP, %o5
         ta      HV_FAST_TRAP
         retl
          mov    %o1, %o0
@@ -47,15 +40,29 @@ pci_sun4v_iommu_map:
          */
         .globl  pci_sun4v_iommu_demap
 pci_sun4v_iommu_demap:
-        mov     %o2, %o3
-        mov     %o1, %o2
-        mov     %o0, %o1
-        mov     HV_FAST_PCI_IOMMU_DEMAP, %o0
+        mov     HV_FAST_PCI_IOMMU_DEMAP, %o5
         ta      HV_FAST_TRAP
         retl
          mov    %o1, %o0
 
         /* %o0: devhandle
+         * %o1: tsbid
+         * %o2: &io_attributes
+         * %o3: &real_address
+         *
+         * returns %o0: status
+         */
+        .globl  pci_sun4v_iommu_getmap
+pci_sun4v_iommu_getmap:
+        mov     %o2, %o4
+        mov     HV_FAST_PCI_IOMMU_GETMAP, %o5
+        ta      HV_FAST_TRAP
+        stx     %o1, [%o4]
+        stx     %o2, [%o3]
+        retl
+         mov    %o0, %o0
+
+        /* %o0: devhandle
          * %o1: pci_device
          * %o2: pci_config_offset
          * %o3: size
@@ -67,11 +74,7 @@ pci_sun4v_iommu_demap:
          */
         .globl  pci_sun4v_config_get
 pci_sun4v_config_get:
-        mov     %o3, %o4
-        mov     %o2, %o3
-        mov     %o1, %o2
-        mov     %o0, %o1
-        mov     HV_FAST_PCI_CONFIG_GET, %o0
+        mov     HV_FAST_PCI_CONFIG_GET, %o5
         ta      HV_FAST_TRAP
         brnz,a,pn %o1, 1f
          mov    -1, %o2
@@ -91,14 +94,9 @@ pci_sun4v_config_get:
          */
         .globl  pci_sun4v_config_put
 pci_sun4v_config_put:
-        mov     %o3, %o4
-        mov     %o2, %o3
-        mov     %o1, %o2
-        mov     %o0, %o1
-        mov     HV_FAST_PCI_CONFIG_PUT, %o0
+        mov     HV_FAST_PCI_CONFIG_PUT, %o5
         ta      HV_FAST_TRAP
         brnz,a,pn %o1, 1f
          mov    -1, %o1
 1:      retl
          mov    %o1, %o0
-