IB/ipath: Improved support for PowerPC
authorBryan O'Sullivan <bos@pathscale.com>
Thu, 28 Sep 2006 16:00:13 +0000 (09:00 -0700)
committerRoland Dreier <rolandd@cisco.com>
Thu, 28 Sep 2006 18:16:53 +0000 (11:16 -0700)
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
drivers/infiniband/hw/ipath/ipath_driver.c
drivers/infiniband/hw/ipath/ipath_file_ops.c
drivers/infiniband/hw/ipath/ipath_iba6120.c
drivers/infiniband/hw/ipath/ipath_init_chip.c
drivers/infiniband/hw/ipath/ipath_intr.c
drivers/infiniband/hw/ipath/ipath_kernel.h
drivers/infiniband/hw/ipath/ipath_user_pages.c
drivers/infiniband/hw/ipath/ipath_wc_ppc64.c

index 4678160..68fc9b5 100644 (file)
@@ -755,8 +755,8 @@ static void get_rhf_errstring(u32 err, char *msg, size_t len)
 static inline void *ipath_get_egrbuf(struct ipath_devdata *dd, u32 bufnum,
                                     int err)
 {
-       return dd->ipath_port0_skbs ?
-               (void *)dd->ipath_port0_skbs[bufnum]->data : NULL;
+       return dd->ipath_port0_skbinfo ?
+               (void *) dd->ipath_port0_skbinfo[bufnum].skb->data : NULL;
 }
 
 /**
@@ -778,31 +778,34 @@ struct sk_buff *ipath_alloc_skb(struct ipath_devdata *dd,
         */
 
        /*
-        * We need 4 extra bytes for unaligned transfer copying
+        * We need 2 extra bytes for ipath_ether data sent in the
+        * key header.  In order to keep everything dword aligned,
+        * we'll reserve 4 bytes.
         */
+       len = dd->ipath_ibmaxlen + 4;
+
        if (dd->ipath_flags & IPATH_4BYTE_TID) {
-               /* we need a 4KB multiple alignment, and there is no way
+               /* We need a 2KB multiple alignment, and there is no way
                 * to do it except to allocate extra and then skb_reserve
                 * enough to bring it up to the right alignment.
                 */
-               len = dd->ipath_ibmaxlen + 4 + (1 << 11) - 1;
+               len += 2047;
        }
-       else
-               len = dd->ipath_ibmaxlen + 4;
+
        skb = __dev_alloc_skb(len, gfp_mask);
        if (!skb) {
                ipath_dev_err(dd, "Failed to allocate skbuff, length %u\n",
                              len);
                goto bail;
        }
+
+       skb_reserve(skb, 4);
+
        if (dd->ipath_flags & IPATH_4BYTE_TID) {
-               u32 una = ((1 << 11) - 1) & (unsigned long)(skb->data + 4);
+               u32 una = (unsigned long)skb->data & 2047;
                if (una)
-                       skb_reserve(skb, 4 + (1 << 11) - una);
-               else
-                       skb_reserve(skb, 4);
-       } else
-               skb_reserve(skb, 4);
+                       skb_reserve(skb, 2048 - una);
+       }
 
 bail:
        return skb;
@@ -1345,8 +1348,9 @@ int ipath_create_rcvhdrq(struct ipath_devdata *dd,
                ipath_cdbg(VERBOSE, "reuse port %d rcvhdrq @%p %llx phys; "
                           "hdrtailaddr@%p %llx physical\n",
                           pd->port_port, pd->port_rcvhdrq,
-                          pd->port_rcvhdrq_phys, pd->port_rcvhdrtail_kvaddr,
-                          (unsigned long long)pd->port_rcvhdrqtailaddr_phys);
+                          (unsigned long long) pd->port_rcvhdrq_phys,
+                          pd->port_rcvhdrtail_kvaddr, (unsigned long long)
+                          pd->port_rcvhdrqtailaddr_phys);
 
        /* clear for security and sanity on each use */
        memset(pd->port_rcvhdrq, 0, pd->port_rcvhdrq_size);
@@ -1827,17 +1831,22 @@ void ipath_free_pddata(struct ipath_devdata *dd, struct ipath_portdata *pd)
                kfree(pd->port_rcvegrbuf_phys);
                pd->port_rcvegrbuf_phys = NULL;
                pd->port_rcvegrbuf_chunks = 0;
-       } else if (pd->port_port == 0 && dd->ipath_port0_skbs) {
+       } else if (pd->port_port == 0 && dd->ipath_port0_skbinfo) {
                unsigned e;
-               struct sk_buff **skbs = dd->ipath_port0_skbs;
+               struct ipath_skbinfo *skbinfo = dd->ipath_port0_skbinfo;
 
-               dd->ipath_port0_skbs = NULL;
-               ipath_cdbg(VERBOSE, "free closed port %d ipath_port0_skbs "
-                          "@ %p\n", pd->port_port, skbs);
+               dd->ipath_port0_skbinfo = NULL;
+               ipath_cdbg(VERBOSE, "free closed port %d "
+                          "ipath_port0_skbinfo @ %p\n", pd->port_port,
+                          skbinfo);
                for (e = 0; e < dd->ipath_rcvegrcnt; e++)
-                       if (skbs[e])
-                               dev_kfree_skb(skbs[e]);
-               vfree(skbs);
+               if (skbinfo[e].skb) {
+                       pci_unmap_single(dd->pcidev, skbinfo[e].phys,
+                                        dd->ipath_ibmaxlen,
+                                        PCI_DMA_FROMDEVICE);
+                       dev_kfree_skb(skbinfo[e].skb);
+               }
+               vfree(skbinfo);
        }
        kfree(pd->port_tid_pg_list);
        vfree(pd->subport_uregbase);
@@ -1934,7 +1943,7 @@ static void cleanup_device(struct ipath_devdata *dd)
 
        if (dd->ipath_pioavailregs_dma) {
                dma_free_coherent(&dd->pcidev->dev, PAGE_SIZE,
-                                 dd->ipath_pioavailregs_dma,
+                                 (void *) dd->ipath_pioavailregs_dma,
                                  dd->ipath_pioavailregs_phys);
                dd->ipath_pioavailregs_dma = NULL;
        }
@@ -1947,6 +1956,7 @@ static void cleanup_device(struct ipath_devdata *dd)
 
        if (dd->ipath_pageshadow) {
                struct page **tmpp = dd->ipath_pageshadow;
+               dma_addr_t *tmpd = dd->ipath_physshadow;
                int i, cnt = 0;
 
                ipath_cdbg(VERBOSE, "Unlocking any expTID pages still "
@@ -1957,6 +1967,8 @@ static void cleanup_device(struct ipath_devdata *dd)
                        for (i = port_tidbase; i < maxtid; i++) {
                                if (!tmpp[i])
                                        continue;
+                               pci_unmap_page(dd->pcidev, tmpd[i],
+                                              PAGE_SIZE, PCI_DMA_FROMDEVICE);
                                ipath_release_user_pages(&tmpp[i], 1);
                                tmpp[i] = NULL;
                                cnt++;
index d4fc411..64221b9 100644 (file)
@@ -364,11 +364,14 @@ static int ipath_tid_update(struct ipath_portdata *pd, struct file *fp,
                           "vaddr %lx\n", i, tid + tidoff, vaddr);
                /* we "know" system pages and TID pages are same size */
                dd->ipath_pageshadow[porttid + tid] = pagep[i];
+               dd->ipath_physshadow[porttid + tid] = ipath_map_page(
+                       dd->pcidev, pagep[i], 0, PAGE_SIZE,
+                       PCI_DMA_FROMDEVICE);
                /*
                 * don't need atomic or it's overhead
                 */
                __set_bit(tid, tidmap);
-               physaddr = page_to_phys(pagep[i]);
+               physaddr = dd->ipath_physshadow[porttid + tid];
                ipath_stats.sps_pagelocks++;
                ipath_cdbg(VERBOSE,
                           "TID %u, vaddr %lx, physaddr %llx pgp %p\n",
@@ -402,6 +405,9 @@ static int ipath_tid_update(struct ipath_portdata *pd, struct file *fp,
                                           tid);
                                dd->ipath_f_put_tid(dd, &tidbase[tid], 1,
                                                    dd->ipath_tidinvalid);
+                               pci_unmap_page(dd->pcidev,
+                                       dd->ipath_physshadow[porttid + tid],
+                                       PAGE_SIZE, PCI_DMA_FROMDEVICE);
                                dd->ipath_pageshadow[porttid + tid] = NULL;
                                ipath_stats.sps_pageunlocks++;
                        }
@@ -515,6 +521,9 @@ static int ipath_tid_free(struct ipath_portdata *pd, unsigned subport,
                                   pd->port_pid, tid);
                        dd->ipath_f_put_tid(dd, &tidbase[tid], 1,
                                            dd->ipath_tidinvalid);
+                       pci_unmap_page(dd->pcidev,
+                               dd->ipath_physshadow[porttid + tid],
+                               PAGE_SIZE, PCI_DMA_FROMDEVICE);
                        ipath_release_user_pages(
                                &dd->ipath_pageshadow[porttid + tid], 1);
                        dd->ipath_pageshadow[porttid + tid] = NULL;
@@ -711,7 +720,7 @@ static int ipath_manage_rcvq(struct ipath_portdata *pd, unsigned subport,
                 * updated and correct itself, even in the face of software
                 * bugs.
                 */
-               *pd->port_rcvhdrtail_kvaddr = 0;
+               *(volatile u64 *)pd->port_rcvhdrtail_kvaddr = 0;
                set_bit(INFINIPATH_R_PORTENABLE_SHIFT + pd->port_port,
                        &dd->ipath_rcvctrl);
        } else
@@ -923,11 +932,11 @@ bail:
 
 /* common code for the mappings on dma_alloc_coherent mem */
 static int ipath_mmap_mem(struct vm_area_struct *vma,
-                            struct ipath_portdata *pd, unsigned len,
-                            int write_ok, dma_addr_t addr, char *what)
+       struct ipath_portdata *pd, unsigned len, int write_ok,
+       void *kvaddr, char *what)
 {
        struct ipath_devdata *dd = pd->port_dd;
-       unsigned pfn = (unsigned long)addr >> PAGE_SHIFT;
+       unsigned long pfn;
        int ret;
 
        if ((vma->vm_end - vma->vm_start) > len) {
@@ -950,17 +959,17 @@ static int ipath_mmap_mem(struct vm_area_struct *vma,
                vma->vm_flags &= ~VM_MAYWRITE;
        }
 
+       pfn = virt_to_phys(kvaddr) >> PAGE_SHIFT;
        ret = remap_pfn_range(vma, vma->vm_start, pfn,
                              len, vma->vm_page_prot);
        if (ret)
-               dev_info(&dd->pcidev->dev,
-                        "%s port%u mmap of %lx, %x bytes r%c failed: %d\n",
-                        what, pd->port_port, (unsigned long)addr, len,
-                        write_ok?'w':'o', ret);
+               dev_info(&dd->pcidev->dev, "%s port%u mmap of %lx, %x "
+                        "bytes r%c failed: %d\n", what, pd->port_port,
+                        pfn, len, write_ok?'w':'o', ret);
        else
-               ipath_cdbg(VERBOSE, "%s port%u mmaped %lx, %x bytes r%c\n",
-                       what, pd->port_port, (unsigned long)addr, len,
-                        write_ok?'w':'o');
+               ipath_cdbg(VERBOSE, "%s port%u mmaped %lx, %x bytes "
+                          "r%c\n", what, pd->port_port, pfn, len,
+                          write_ok?'w':'o');
 bail:
        return ret;
 }
@@ -1049,7 +1058,7 @@ static int mmap_rcvegrbufs(struct vm_area_struct *vma,
        struct ipath_devdata *dd = pd->port_dd;
        unsigned long start, size;
        size_t total_size, i;
-       dma_addr_t *phys;
+       unsigned long pfn;
        int ret;
 
        size = pd->port_rcvegrbuf_size;
@@ -1073,11 +1082,11 @@ static int mmap_rcvegrbufs(struct vm_area_struct *vma,
        vma->vm_flags &= ~VM_MAYWRITE;
 
        start = vma->vm_start;
-       phys = pd->port_rcvegrbuf_phys;
 
        for (i = 0; i < pd->port_rcvegrbuf_chunks; i++, start += size) {
-               ret = remap_pfn_range(vma, start, phys[i] >> PAGE_SHIFT,
-                                     size, vma->vm_page_prot);
+               pfn = virt_to_phys(pd->port_rcvegrbuf[i]) >> PAGE_SHIFT;
+               ret = remap_pfn_range(vma, start, pfn, size,
+                                     vma->vm_page_prot);
                if (ret < 0)
                        goto bail;
        }
@@ -1290,7 +1299,7 @@ static int ipath_mmap(struct file *fp, struct vm_area_struct *vma)
        else if (pgaddr == dd->ipath_pioavailregs_phys)
                /* in-memory copy of pioavail registers */
                ret = ipath_mmap_mem(vma, pd, PAGE_SIZE, 0,
-                                    dd->ipath_pioavailregs_phys,
+                                    (void *) dd->ipath_pioavailregs_dma,
                                     "pioavail registers");
        else if (subport_fp(fp))
                /* Subports don't mmap the physical receive buffers */
@@ -1304,12 +1313,12 @@ static int ipath_mmap(struct file *fp, struct vm_area_struct *vma)
                 * from an i/o perspective.
                 */
                ret = ipath_mmap_mem(vma, pd, pd->port_rcvhdrq_size, 1,
-                                    pd->port_rcvhdrq_phys,
+                                    pd->port_rcvhdrq,
                                     "rcvhdrq");
        else if (pgaddr == (u64) pd->port_rcvhdrqtailaddr_phys)
                /* in-memory copy of rcvhdrq tail register */
                ret = ipath_mmap_mem(vma, pd, PAGE_SIZE, 0,
-                                    pd->port_rcvhdrqtailaddr_phys,
+                                    pd->port_rcvhdrtail_kvaddr,
                                     "rcvhdrq tail");
        else
                ret = -EINVAL;
@@ -1802,7 +1811,7 @@ static int ipath_do_user_init(struct file *fp,
         * We explictly set the in-memory copy to 0 beforehand, so we don't
         * have to wait to be sure the DMA update has happened.
         */
-       *pd->port_rcvhdrtail_kvaddr = 0ULL;
+       *(volatile u64 *)pd->port_rcvhdrtail_kvaddr = 0ULL;
        set_bit(INFINIPATH_R_PORTENABLE_SHIFT + pd->port_port,
                &dd->ipath_rcvctrl);
        ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
@@ -1832,6 +1841,8 @@ static void unlock_expected_tids(struct ipath_portdata *pd)
                if (!dd->ipath_pageshadow[i])
                        continue;
 
+               pci_unmap_page(dd->pcidev, dd->ipath_physshadow[i],
+                       PAGE_SIZE, PCI_DMA_FROMDEVICE);
                ipath_release_user_pages_on_close(&dd->ipath_pageshadow[i],
                                                  1);
                dd->ipath_pageshadow[i] = NULL;
@@ -1936,14 +1947,14 @@ static int ipath_close(struct inode *in, struct file *fp)
                i = dd->ipath_pbufsport * (port - 1);
                ipath_disarm_piobufs(dd, i, dd->ipath_pbufsport);
 
+               dd->ipath_f_clear_tids(dd, pd->port_port);
+
                if (dd->ipath_pageshadow)
                        unlock_expected_tids(pd);
                ipath_stats.sps_ports--;
                ipath_cdbg(PROC, "%s[%u] closed port %u:%u\n",
                           pd->port_comm, pd->port_pid,
                           dd->ipath_unit, port);
-
-               dd->ipath_f_clear_tids(dd, pd->port_port);
        }
 
        pd->port_pid = 0;
index ac5cbe2..08a44dd 100644 (file)
@@ -1113,7 +1113,7 @@ static void ipath_pe_put_tid_2(struct ipath_devdata *dd, u64 __iomem *tidptr,
        if (pa != dd->ipath_tidinvalid) {
                if (pa & ((1U << 11) - 1)) {
                        dev_info(&dd->pcidev->dev, "BUG: physaddr %lx "
-                                "not 4KB aligned!\n", pa);
+                                "not 2KB aligned!\n", pa);
                        return;
                }
                pa >>= 11;
index 44669dc..d819cca 100644 (file)
@@ -88,13 +88,13 @@ MODULE_PARM_DESC(kpiobufs, "Set number of PIO buffers for driver");
 static int create_port0_egr(struct ipath_devdata *dd)
 {
        unsigned e, egrcnt;
-       struct sk_buff **skbs;
+       struct ipath_skbinfo *skbinfo;
        int ret;
 
        egrcnt = dd->ipath_rcvegrcnt;
 
-       skbs = vmalloc(sizeof(*dd->ipath_port0_skbs) * egrcnt);
-       if (skbs == NULL) {
+       skbinfo = vmalloc(sizeof(*dd->ipath_port0_skbinfo) * egrcnt);
+       if (skbinfo == NULL) {
                ipath_dev_err(dd, "allocation error for eager TID "
                              "skb array\n");
                ret = -ENOMEM;
@@ -109,13 +109,13 @@ static int create_port0_egr(struct ipath_devdata *dd)
                 * 4 bytes so that the data buffer stays word aligned.
                 * See ipath_kreceive() for more details.
                 */
-               skbs[e] = ipath_alloc_skb(dd, GFP_KERNEL);
-               if (!skbs[e]) {
+               skbinfo[e].skb = ipath_alloc_skb(dd, GFP_KERNEL);
+               if (!skbinfo[e].skb) {
                        ipath_dev_err(dd, "SKB allocation error for "
                                      "eager TID %u\n", e);
                        while (e != 0)
-                               dev_kfree_skb(skbs[--e]);
-                       vfree(skbs);
+                               dev_kfree_skb(skbinfo[--e].skb);
+                       vfree(skbinfo);
                        ret = -ENOMEM;
                        goto bail;
                }
@@ -124,14 +124,17 @@ static int create_port0_egr(struct ipath_devdata *dd)
         * After loop above, so we can test non-NULL to see if ready
         * to use at receive, etc.
         */
-       dd->ipath_port0_skbs = skbs;
+       dd->ipath_port0_skbinfo = skbinfo;
 
        for (e = 0; e < egrcnt; e++) {
-               unsigned long phys =
-                       virt_to_phys(dd->ipath_port0_skbs[e]->data);
+               dd->ipath_port0_skbinfo[e].phys =
+                 ipath_map_single(dd->pcidev,
+                                  dd->ipath_port0_skbinfo[e].skb->data,
+                                  dd->ipath_ibmaxlen, PCI_DMA_FROMDEVICE);
                dd->ipath_f_put_tid(dd, e + (u64 __iomem *)
                                    ((char __iomem *) dd->ipath_kregbase +
-                                    dd->ipath_rcvegrbase), 0, phys);
+                                    dd->ipath_rcvegrbase), 0,
+                                   dd->ipath_port0_skbinfo[e].phys);
        }
 
        ret = 0;
@@ -432,16 +435,33 @@ done:
  */
 static void init_shadow_tids(struct ipath_devdata *dd)
 {
-       dd->ipath_pageshadow = (struct page **)
-               vmalloc(dd->ipath_cfgports * dd->ipath_rcvtidcnt *
+       struct page **pages;
+       dma_addr_t *addrs;
+
+       pages = vmalloc(dd->ipath_cfgports * dd->ipath_rcvtidcnt *
                        sizeof(struct page *));
-       if (!dd->ipath_pageshadow)
+       if (!pages) {
                ipath_dev_err(dd, "failed to allocate shadow page * "
                              "array, no expected sends!\n");
-       else
-               memset(dd->ipath_pageshadow, 0,
-                      dd->ipath_cfgports * dd->ipath_rcvtidcnt *
-                      sizeof(struct page *));
+               dd->ipath_pageshadow = NULL;
+               return;
+       }
+
+       addrs = vmalloc(dd->ipath_cfgports * dd->ipath_rcvtidcnt *
+                       sizeof(dma_addr_t));
+       if (!addrs) {
+               ipath_dev_err(dd, "failed to allocate shadow dma handle "
+                             "array, no expected sends!\n");
+               vfree(dd->ipath_pageshadow);
+               dd->ipath_pageshadow = NULL;
+               return;
+       }
+
+       memset(pages, 0, dd->ipath_cfgports * dd->ipath_rcvtidcnt *
+              sizeof(struct page *));
+
+       dd->ipath_pageshadow = pages;
+       dd->ipath_physshadow = addrs;
 }
 
 static void enable_chip(struct ipath_devdata *dd,
index 54b3dbc..f4d8aaf 100644 (file)
@@ -605,7 +605,7 @@ static int handle_errors(struct ipath_devdata *dd, ipath_err_t errs)
                                 * don't report same point multiple times,
                                 * except kernel
                                 */
-                               tl = (u32) * pd->port_rcvhdrtail_kvaddr;
+                               tl = *(u64 *) pd->port_rcvhdrtail_kvaddr;
                                if (tl == dd->ipath_lastrcvhdrqtails[i])
                                        continue;
                                hd = ipath_read_ureg32(dd, ur_rcvhdrhead,
index 96e2bd8..2a0e9a4 100644 (file)
@@ -39,6 +39,8 @@
  */
 
 #include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/dma-mapping.h>
 #include <asm/io.h>
 
 #include "ipath_common.h"
@@ -62,7 +64,7 @@ struct ipath_portdata {
        /* rcvhdrq base, needs mmap before useful */
        void *port_rcvhdrq;
        /* kernel virtual address where hdrqtail is updated */
-       volatile __le64 *port_rcvhdrtail_kvaddr;
+       void *port_rcvhdrtail_kvaddr;
        /*
         * temp buffer for expected send setup, allocated at open, instead
         * of each setup call
@@ -146,6 +148,11 @@ struct _ipath_layer {
        void *l_arg;
 };
 
+struct ipath_skbinfo {
+       struct sk_buff *skb;
+       dma_addr_t phys;
+};
+
 struct ipath_devdata {
        struct list_head ipath_list;
 
@@ -168,7 +175,7 @@ struct ipath_devdata {
        /* ipath_cfgports pointers */
        struct ipath_portdata **ipath_pd;
        /* sk_buffs used by port 0 eager receive queue */
-       struct sk_buff **ipath_port0_skbs;
+       struct ipath_skbinfo *ipath_port0_skbinfo;
        /* kvirt address of 1st 2k pio buffer */
        void __iomem *ipath_pio2kbase;
        /* kvirt address of 1st 4k pio buffer */
@@ -335,6 +342,8 @@ struct ipath_devdata {
        u64 *ipath_tidsimshadow;
        /* shadow copy of struct page *'s for exp tid pages */
        struct page **ipath_pageshadow;
+       /* shadow copy of dma handles for exp tid pages */
+       dma_addr_t *ipath_physshadow;
        /* lock to workaround chip bug 9437 */
        spinlock_t ipath_tid_lock;
 
@@ -865,6 +874,13 @@ int ipathfs_add_device(struct ipath_devdata *);
 int ipathfs_remove_device(struct ipath_devdata *);
 
 /*
+ * dma_addr wrappers - all 0's invalid for hw
+ */
+dma_addr_t ipath_map_page(struct pci_dev *, struct page *, unsigned long,
+                         size_t, int);
+dma_addr_t ipath_map_single(struct pci_dev *, void *, size_t, int);
+
+/*
  * Flush write combining store buffers (if present) and perform a write
  * barrier.
  */
index e32fca9..413754b 100644 (file)
@@ -90,6 +90,62 @@ bail:
 }
 
 /**
+ * ipath_map_page - a safety wrapper around pci_map_page()
+ *
+ * A dma_addr of all 0's is interpreted by the chip as "disabled".
+ * Unfortunately, it can also be a valid dma_addr returned on some
+ * architectures.
+ *
+ * The powerpc iommu assigns dma_addrs in ascending order, so we don't
+ * have to bother with retries or mapping a dummy page to insure we
+ * don't just get the same mapping again.
+ *
+ * I'm sure we won't be so lucky with other iommu's, so FIXME.
+ */
+dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page,
+       unsigned long offset, size_t size, int direction)
+{
+       dma_addr_t phys;
+
+       phys = pci_map_page(hwdev, page, offset, size, direction);
+
+       if (phys == 0) {
+               pci_unmap_page(hwdev, phys, size, direction);
+               phys = pci_map_page(hwdev, page, offset, size, direction);
+               /*
+                * FIXME: If we get 0 again, we should keep this page,
+                * map another, then free the 0 page.
+                */
+       }
+
+       return phys;
+}
+
+/**
+ * ipath_map_single - a safety wrapper around pci_map_single()
+ *
+ * Same idea as ipath_map_page().
+ */
+dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size,
+       int direction)
+{
+       dma_addr_t phys;
+
+       phys = pci_map_single(hwdev, ptr, size, direction);
+
+       if (phys == 0) {
+               pci_unmap_single(hwdev, phys, size, direction);
+               phys = pci_map_single(hwdev, ptr, size, direction);
+               /*
+                * FIXME: If we get 0 again, we should keep this page,
+                * map another, then free the 0 page.
+                */
+       }
+
+       return phys;
+}
+
+/**
  * ipath_get_user_pages - lock user pages into memory
  * @start_page: the start page
  * @num_pages: the number of pages
index 036fde6..0095bb7 100644 (file)
 #include "ipath_kernel.h"
 
 /**
- * ipath_unordered_wc - indicate whether write combining is ordered
+ * ipath_enable_wc - enable write combining for MMIO writes to the device
+ * @dd: infinipath device
  *
- * PowerPC systems (at least those in the 970 processor family)
- * write partially filled store buffers in address order, but will write
- * completely filled store buffers in "random" order, and therefore must
- * have serialization for correctness with current InfiniPath chips.
+ * Nothing to do on PowerPC, so just return without error.
+ */
+int ipath_enable_wc(struct ipath_devdata *dd)
+{
+       return 0;
+}
+
+/**
+ * ipath_unordered_wc - indicate whether write combining is unordered
  *
+ * Because our performance depends on our ability to do write
+ * combining mmio writes in the most efficient way, we need to
+ * know if we are on a processor that may reorder stores when
+ * write combining.
  */
 int ipath_unordered_wc(void)
 {