[SPARC64]: Remove PGLIST_NENTS PCI IOMMU mapping limitation on SUN4V.

Use a batching queue system for IOMMU mapping setup,
with a page sized batch.

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

3 files changed, 171 insertions, 83 deletions

diff --git a/arch/sparc64/kernel/pci_sun4v.c b/arch/sparc64/kernel/pci_sun4v.c
index 902d07c714fb..4e9d3c451af2 100644
--- a/arch/sparc64/kernel/pci_sun4v.c
+++ b/arch/sparc64/kernel/pci_sun4v.c
@@ -26,11 +26,86 @@
 
 #define PGLIST_NENTS    (PAGE_SIZE / sizeof(u64))
 
-struct sun4v_pglist {
-        u64     *pglist;
+struct pci_iommu_batch {
+        struct pci_dev  *pdev;          /* Device mapping is for.       */
+        unsigned long   prot;           /* IOMMU page protections       */
+        unsigned long   entry;          /* Index into IOTSB.            */
+        u64             *pglist;        /* List of physical pages       */
+        unsigned long   npages;         /* Number of pages in list.     */
 };
 
-static DEFINE_PER_CPU(struct sun4v_pglist, iommu_pglists);
+static DEFINE_PER_CPU(struct pci_iommu_batch, pci_iommu_batch);
+
+/* Interrupts must be disabled.  */
+static inline void pci_iommu_batch_start(struct pci_dev *pdev, unsigned long prot, unsigned long entry)
+{
+        struct pci_iommu_batch *p = &__get_cpu_var(pci_iommu_batch);
+
+        p->pdev         = pdev;
+        p->prot         = prot;
+        p->entry        = entry;
+        p->npages       = 0;
+}
+
+/* Interrupts must be disabled.  */
+static long pci_iommu_batch_flush(struct pci_iommu_batch *p)
+{
+        struct pcidev_cookie *pcp = p->pdev->sysdata;
+        unsigned long devhandle = pcp->pbm->devhandle;
+        unsigned long prot = p->prot;
+        unsigned long entry = p->entry;
+        u64 *pglist = p->pglist;
+        unsigned long npages = p->npages;
+
+        do {
+                long num;
+
+                num = pci_sun4v_iommu_map(devhandle, HV_PCI_TSBID(0, entry),
+                                          npages, prot, __pa(pglist));
+                if (unlikely(num < 0)) {
+                        if (printk_ratelimit())
+                                printk("pci_iommu_batch_flush: IOMMU map of "
+                                       "[%08lx:%08lx:%lx:%lx:%lx] failed with "
+                                       "status %ld\n",
+                                       devhandle, HV_PCI_TSBID(0, entry),
+                                       npages, prot, __pa(pglist), num);
+                        return -1;
+                }
+
+                entry += num;
+                npages -= num;
+                pglist += num;
+        } while (npages != 0);
+
+        p->entry = entry;
+        p->npages = 0;
+
+        return 0;
+}
+
+/* Interrupts must be disabled.  */
+static inline long pci_iommu_batch_add(u64 phys_page)
+{
+        struct pci_iommu_batch *p = &__get_cpu_var(pci_iommu_batch);
+
+        BUG_ON(p->npages >= PGLIST_NENTS);
+
+        p->pglist[p->npages++] = phys_page;
+        if (p->npages == PGLIST_NENTS)
+                return pci_iommu_batch_flush(p);
+
+        return 0;
+}
+
+/* Interrupts must be disabled.  */
+static inline long pci_iommu_batch_end(void)
+{
+        struct pci_iommu_batch *p = &__get_cpu_var(pci_iommu_batch);
+
+        BUG_ON(p->npages >= PGLIST_NENTS);
+
+        return pci_iommu_batch_flush(p);
+}
 
 static long pci_arena_alloc(struct pci_iommu_arena *arena, unsigned long npages)
 {
@@ -86,65 +161,64 @@ static void *pci_4v_alloc_consistent(struct pci_dev *pdev, size_t size, dma_addr
         unsigned long flags, order, first_page, npages, n;
         void *ret;
         long entry;
-        u64 *pglist;
-        u32 devhandle;
-        int cpu;
 
         size = IO_PAGE_ALIGN(size);
         order = get_order(size);
-        if (order >= MAX_ORDER)
+        if (unlikely(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)
+        if (unlikely(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;
-        }
+        if (unlikely(entry < 0L))
+                goto arena_alloc_fail;
 
         *dma_addrp = (iommu->page_table_map_base +
                       (entry << IO_PAGE_SHIFT));
         ret = (void *) first_page;
         first_page = __pa(first_page);
 
-        cpu = get_cpu();
+        local_irq_save(flags);
 
-        pglist = __get_cpu_var(iommu_pglists).pglist;
-        for (n = 0; n < npages; n++)
-                pglist[n] = first_page + (n * PAGE_SIZE);
+        pci_iommu_batch_start(pdev,
+                              (HV_PCI_MAP_ATTR_READ |
+                               HV_PCI_MAP_ATTR_WRITE),
+                              entry);
 
-        do {
-                unsigned long num;
+        for (n = 0; n < npages; n++) {
+                long err = pci_iommu_batch_add(first_page + (n * PAGE_SIZE));
+                if (unlikely(err < 0L))
+                        goto iommu_map_fail;
+        }
 
-                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);
+        if (unlikely(pci_iommu_batch_end() < 0L))
+                goto iommu_map_fail;
 
-        put_cpu();
+        local_irq_restore(flags);
 
         return ret;
+
+iommu_map_fail:
+        /* Interrupts are disabled.  */
+        spin_lock(&iommu->lock);
+        pci_arena_free(&iommu->arena, entry, npages);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+arena_alloc_fail:
+        free_pages(first_page, order);
+        return NULL;
 }
 
 static void pci_4v_free_consistent(struct pci_dev *pdev, size_t size, void *cpu, dma_addr_t dvma)
@@ -186,15 +260,12 @@ static dma_addr_t pci_4v_map_single(struct pci_dev *pdev, void *ptr, size_t sz,
         struct pci_iommu *iommu;
         unsigned long flags, npages, oaddr;
         unsigned long i, base_paddr;
-        u32 devhandle, bus_addr, ret;
+        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;
@@ -202,8 +273,6 @@ static dma_addr_t pci_4v_map_single(struct pci_dev *pdev, void *ptr, size_t sz,
         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);
@@ -220,24 +289,19 @@ static dma_addr_t pci_4v_map_single(struct pci_dev *pdev, void *ptr, size_t sz,
         if (direction != PCI_DMA_TODEVICE)
                 prot |= HV_PCI_MAP_ATTR_WRITE;
 
-        cpu = get_cpu();
-
-        pglist = __get_cpu_var(iommu_pglists).pglist;
-        for (i = 0; i < npages; i++, base_paddr += IO_PAGE_SIZE)
-                pglist[i] = base_paddr;
+        local_irq_save(flags);
 
-        do {
-                unsigned long num;
+        pci_iommu_batch_start(pdev, prot, entry);
 
-                num = pci_sun4v_iommu_map(devhandle, HV_PCI_TSBID(0, entry),
-                                          npages, prot,
-                                          __pa(pglist));
-                entry += num;
-                npages -= num;
-                pglist += num;
-        } while (npages != 0);
+        for (i = 0; i < npages; i++, base_paddr += IO_PAGE_SIZE) {
+                long err = pci_iommu_batch_add(base_paddr);
+                if (unlikely(err < 0L))
+                        goto iommu_map_fail;
+        }
+        if (unlikely(pci_iommu_batch_end() < 0L))
+                goto iommu_map_fail;
 
-        put_cpu();
+        local_irq_restore(flags);
 
         return ret;
 
@@ -245,6 +309,14 @@ bad:
         if (printk_ratelimit())
                 WARN_ON(1);
         return PCI_DMA_ERROR_CODE;
+
+iommu_map_fail:
+        /* Interrupts are disabled.  */
+        spin_lock(&iommu->lock);
+        pci_arena_free(&iommu->arena, entry, npages);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        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)
@@ -289,18 +361,19 @@ static void pci_4v_unmap_single(struct pci_dev *pdev, dma_addr_t bus_addr, size_
 #define SG_ENT_PHYS_ADDRESS(SG) \
         (__pa(page_address((SG)->page)) + (SG)->offset)
 
-static inline void fill_sg(long entry, u32 devhandle,
+static inline long fill_sg(long entry, struct pci_dev *pdev,
                            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;
+        unsigned long flags;
+        int i;
+
+        local_irq_save(flags);
+
+        pci_iommu_batch_start(pdev, prot, entry);
 
-        cpu = get_cpu();
-        pglist = __get_cpu_var(iommu_pglists).pglist;
-        pglist_ent = 0;
         for (i = 0; i < nused; i++) {
                 unsigned long pteval = ~0UL;
                 u32 dma_npages;
@@ -338,7 +411,12 @@ static inline void fill_sg(long entry, u32 devhandle,
 
                         pteval = (pteval & IOPTE_PAGE);
                         while (len > 0) {
-                                pglist[pglist_ent++] = pteval;
+                                long err;
+
+                                err = pci_iommu_batch_add(pteval);
+                                if (unlikely(err < 0L))
+                                        goto iommu_map_failed;
+
                                 pteval += IO_PAGE_SIZE;
                                 len -= (IO_PAGE_SIZE - offset);
                                 offset = 0;
@@ -366,18 +444,15 @@ static inline void fill_sg(long entry, u32 devhandle,
                 dma_sg++;
         }
 
-        BUG_ON(pglist_ent == 0);
+        if (unlikely(pci_iommu_batch_end() < 0L))
+                goto iommu_map_failed;
 
-        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);
+        local_irq_restore(flags);
+        return 0;
 
-        put_cpu();
+iommu_map_failed:
+        local_irq_restore(flags);
+        return -1L;
 }
 
 static int pci_4v_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int direction)
@@ -385,9 +460,9 @@ static int pci_4v_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int n
         struct pcidev_cookie *pcp;
         struct pci_iommu *iommu;
         unsigned long flags, npages, prot;
-        u32 devhandle, dma_base;
+        u32 dma_base;
         struct scatterlist *sgtmp;
-        long entry;
+        long entry, err;
         int used;
 
         /* Fast path single entry scatterlists. */
@@ -404,7 +479,6 @@ static int pci_4v_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int n
 
         pcp = pdev->sysdata;
         iommu = pcp->pbm->iommu;
-        devhandle = pcp->pbm->devhandle;
         
         if (unlikely(direction == PCI_DMA_NONE))
                 goto bad;
@@ -441,7 +515,9 @@ static int pci_4v_map_sg(struct pci_dev *pdev, struct scatterlist *sglist, int n
         if (direction != PCI_DMA_TODEVICE)
                 prot |= HV_PCI_MAP_ATTR_WRITE;
 
-        fill_sg(entry, devhandle, sglist, used, nelems, prot);
+        err = fill_sg(entry, pdev, sglist, used, nelems, prot);
+        if (unlikely(err < 0L))
+                goto iommu_map_failed;
 
         return used;
 
@@ -449,6 +525,13 @@ bad:
         if (printk_ratelimit())
                 WARN_ON(1);
         return 0;
+
+iommu_map_failed:
+        spin_lock_irqsave(&iommu->lock, flags);
+        pci_arena_free(&iommu->arena, entry, npages);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        return 0;
 }
 
 static void pci_4v_unmap_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, int direction)
@@ -1011,13 +1094,13 @@ void sun4v_pci_init(int node, char *model_name)
                 }
         }
 
-        for (i = 0; i < NR_CPUS; i++) {
+        for_each_cpu(i) {
                 unsigned long page = get_zeroed_page(GFP_ATOMIC);
 
                 if (!page)
                         goto fatal_memory_error;
 
-                per_cpu(iommu_pglists, i).pglist = (u64 *) page;
+                per_cpu(pci_iommu_batch, i).pglist = (u64 *) page;
         }
 
         p = kmalloc(sizeof(struct pci_controller_info), GFP_ATOMIC);
diff --git a/arch/sparc64/kernel/pci_sun4v.h b/arch/sparc64/kernel/pci_sun4v.h
index 88f199e11a71..884d25f6158d 100644
--- a/arch/sparc64/kernel/pci_sun4v.h
+++ b/arch/sparc64/kernel/pci_sun4v.h
@@ -6,11 +6,11 @@
 #ifndef _PCI_SUN4V_H
 #define _PCI_SUN4V_H
 
-extern unsigned long pci_sun4v_iommu_map(unsigned long devhandle,
-                                         unsigned long tsbid,
-                                         unsigned long num_ttes,
-                                         unsigned long io_attributes,
-                                         unsigned long io_page_list_pa);
+extern long pci_sun4v_iommu_map(unsigned long devhandle,
+                                unsigned long tsbid,
+                                unsigned long num_ttes,
+                                unsigned long io_attributes,
+                                unsigned long io_page_list_pa);
 extern unsigned long pci_sun4v_iommu_demap(unsigned long devhandle,
                                            unsigned long tsbid,
                                            unsigned long num_ttes);
diff --git a/arch/sparc64/kernel/pci_sun4v_asm.S b/arch/sparc64/kernel/pci_sun4v_asm.S
index 424db6526648..6604fdbf746c 100644
--- a/arch/sparc64/kernel/pci_sun4v_asm.S
+++ b/arch/sparc64/kernel/pci_sun4v_asm.S
@@ -11,14 +11,19 @@
          * %o3: io_attributes
          * %o4: io_page_list phys address
          *
-         * returns %o0: num ttes mapped
+         * returns %o0: -status if status was non-zero, else
+         *         %o0: num pages mapped
          */
         .globl  pci_sun4v_iommu_map
 pci_sun4v_iommu_map:
+        mov     %o5, %g1
         mov     HV_FAST_PCI_IOMMU_MAP, %o5
         ta      HV_FAST_TRAP
-        retl
-         mov    %o1, %o0
+        brnz,pn %o0, 1f
+         sub    %g0, %o0, %o0
+        mov     %o1, %o0
+1:      retl
+         nop
 
         /* %o0: devhandle
          * %o1: tsbid