Merge master.kernel.org:/home/rmk/linux-2.6-arm
[safe/jmp/linux-2.6] / arch / powerpc / platforms / cell / spufs / file.c
index 80911a3..884e8bc 100644 (file)
 #include <linux/poll.h>
 #include <linux/ptrace.h>
 #include <linux/seq_file.h>
-#include <linux/marker.h>
 
 #include <asm/io.h>
+#include <asm/time.h>
 #include <asm/spu.h>
 #include <asm/spu_info.h>
 #include <asm/uaccess.h>
 
 #include "spufs.h"
+#include "sputrace.h"
 
 #define SPUFS_MMAP_4K (PAGE_SIZE == 0x1000)
 
@@ -146,7 +147,7 @@ static int __fops ## _open(struct inode *inode, struct file *file)  \
        __simple_attr_check_format(__fmt, 0ull);                        \
        return spufs_attr_open(inode, file, __get, __set, __fmt);       \
 }                                                                      \
-static struct file_operations __fops = {                               \
+static const struct file_operations __fops = {                         \
        .owner   = THIS_MODULE,                                         \
        .open    = __fops ## _open,                                     \
        .release = spufs_attr_release,                                  \
@@ -237,11 +238,13 @@ spufs_mem_write(struct file *file, const char __user *buffer,
        return size;
 }
 
-static unsigned long spufs_mem_mmap_nopfn(struct vm_area_struct *vma,
-                                         unsigned long address)
+static int
+spufs_mem_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
        struct spu_context *ctx = vma->vm_file->private_data;
-       unsigned long pfn, offset, addr0 = address;
+       unsigned long address = (unsigned long)vmf->virtual_address;
+       unsigned long pfn, offset;
+
 #ifdef CONFIG_SPU_FS_64K_LS
        struct spu_state *csa = &ctx->csa;
        int psize;
@@ -259,35 +262,56 @@ static unsigned long spufs_mem_mmap_nopfn(struct vm_area_struct *vma,
        }
 #endif /* CONFIG_SPU_FS_64K_LS */
 
-       offset = (address - vma->vm_start) + (vma->vm_pgoff << PAGE_SHIFT);
+       offset = vmf->pgoff << PAGE_SHIFT;
        if (offset >= LS_SIZE)
-               return NOPFN_SIGBUS;
+               return VM_FAULT_SIGBUS;
 
-       pr_debug("spufs_mem_mmap_nopfn address=0x%lx -> 0x%lx, offset=0x%lx\n",
-                addr0, address, offset);
+       pr_debug("spufs_mem_mmap_fault address=0x%lx, offset=0x%lx\n",
+                       address, offset);
 
        if (spu_acquire(ctx))
-               return NOPFN_REFAULT;
+               return VM_FAULT_NOPAGE;
 
        if (ctx->state == SPU_STATE_SAVED) {
-               vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                                       & ~_PAGE_NO_CACHE);
+               vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
                pfn = vmalloc_to_pfn(ctx->csa.lscsa->ls + offset);
        } else {
-               vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                            | _PAGE_NO_CACHE);
+               vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot);
                pfn = (ctx->spu->local_store_phys + offset) >> PAGE_SHIFT;
        }
        vm_insert_pfn(vma, address, pfn);
 
        spu_release(ctx);
 
-       return NOPFN_REFAULT;
+       return VM_FAULT_NOPAGE;
 }
 
+static int spufs_mem_mmap_access(struct vm_area_struct *vma,
+                               unsigned long address,
+                               void *buf, int len, int write)
+{
+       struct spu_context *ctx = vma->vm_file->private_data;
+       unsigned long offset = address - vma->vm_start;
+       char *local_store;
+
+       if (write && !(vma->vm_flags & VM_WRITE))
+               return -EACCES;
+       if (spu_acquire(ctx))
+               return -EINTR;
+       if ((offset + len) > vma->vm_end)
+               len = vma->vm_end - offset;
+       local_store = ctx->ops->get_ls(ctx);
+       if (write)
+               memcpy_toio(local_store + offset, buf, len);
+       else
+               memcpy_fromio(buf, local_store + offset, len);
+       spu_release(ctx);
+       return len;
+}
 
-static struct vm_operations_struct spufs_mem_mmap_vmops = {
-       .nopfn = spufs_mem_mmap_nopfn,
+static const struct vm_operations_struct spufs_mem_mmap_vmops = {
+       .fault = spufs_mem_mmap_fault,
+       .access = spufs_mem_mmap_access,
 };
 
 static int spufs_mem_mmap(struct file *file, struct vm_area_struct *vma)
@@ -312,8 +336,7 @@ static int spufs_mem_mmap(struct file *file, struct vm_area_struct *vma)
                return -EINVAL;
 
        vma->vm_flags |= VM_IO | VM_PFNMAP;
-       vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                    | _PAGE_NO_CACHE);
+       vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot);
 
        vma->vm_ops = &spufs_mem_mmap_vmops;
        return 0;
@@ -350,20 +373,22 @@ static const struct file_operations spufs_mem_fops = {
 #endif
 };
 
-static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
-                                   unsigned long address,
+static int spufs_ps_fault(struct vm_area_struct *vma,
+                                   struct vm_fault *vmf,
                                    unsigned long ps_offs,
                                    unsigned long ps_size)
 {
        struct spu_context *ctx = vma->vm_file->private_data;
-       unsigned long area, offset = address - vma->vm_start;
+       unsigned long area, offset = vmf->pgoff << PAGE_SHIFT;
        int ret = 0;
 
-       spu_context_nospu_trace(spufs_ps_nopfn__enter, ctx);
+       spu_context_nospu_trace(spufs_ps_fault__enter, ctx);
 
-       offset += vma->vm_pgoff << PAGE_SHIFT;
        if (offset >= ps_size)
-               return NOPFN_SIGBUS;
+               return VM_FAULT_SIGBUS;
+
+       if (fatal_signal_pending(current))
+               return VM_FAULT_SIGBUS;
 
        /*
         * Because we release the mmap_sem, the context may be destroyed while
@@ -377,7 +402,7 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
         * pages to hand out to the user, but we don't want to wait
         * with the mmap_sem held.
         * It is possible to drop the mmap_sem here, but then we need
-        * to return NOPFN_REFAULT because the mappings may have
+        * to return VM_FAULT_NOPAGE because the mappings may have
         * hanged.
         */
        if (spu_acquire(ctx))
@@ -385,14 +410,15 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
 
        if (ctx->state == SPU_STATE_SAVED) {
                up_read(&current->mm->mmap_sem);
-               spu_context_nospu_trace(spufs_ps_nopfn__sleep, ctx);
+               spu_context_nospu_trace(spufs_ps_fault__sleep, ctx);
                ret = spufs_wait(ctx->run_wq, ctx->state == SPU_STATE_RUNNABLE);
-               spu_context_trace(spufs_ps_nopfn__wake, ctx, ctx->spu);
+               spu_context_trace(spufs_ps_fault__wake, ctx, ctx->spu);
                down_read(&current->mm->mmap_sem);
        } else {
                area = ctx->spu->problem_phys + ps_offs;
-               vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT);
-               spu_context_trace(spufs_ps_nopfn__insert, ctx, ctx->spu);
+               vm_insert_pfn(vma, (unsigned long)vmf->virtual_address,
+                                       (area + offset) >> PAGE_SHIFT);
+               spu_context_trace(spufs_ps_fault__insert, ctx, ctx->spu);
        }
 
        if (!ret)
@@ -400,18 +426,18 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
 
 refault:
        put_spu_context(ctx);
-       return NOPFN_REFAULT;
+       return VM_FAULT_NOPAGE;
 }
 
 #if SPUFS_MMAP_4K
-static unsigned long spufs_cntl_mmap_nopfn(struct vm_area_struct *vma,
-                                          unsigned long address)
+static int spufs_cntl_mmap_fault(struct vm_area_struct *vma,
+                                          struct vm_fault *vmf)
 {
-       return spufs_ps_nopfn(vma, address, 0x4000, 0x1000);
+       return spufs_ps_fault(vma, vmf, 0x4000, SPUFS_CNTL_MAP_SIZE);
 }
 
-static struct vm_operations_struct spufs_cntl_mmap_vmops = {
-       .nopfn = spufs_cntl_mmap_nopfn,
+static const struct vm_operations_struct spufs_cntl_mmap_vmops = {
+       .fault = spufs_cntl_mmap_fault,
 };
 
 /*
@@ -423,8 +449,7 @@ static int spufs_cntl_mmap(struct file *file, struct vm_area_struct *vma)
                return -EINVAL;
 
        vma->vm_flags |= VM_IO | VM_PFNMAP;
-       vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                    | _PAGE_NO_CACHE | _PAGE_GUARDED);
+       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
        vma->vm_ops = &spufs_cntl_mmap_vmops;
        return 0;
@@ -522,6 +547,11 @@ spufs_regs_read(struct file *file, char __user *buffer,
        int ret;
        struct spu_context *ctx = file->private_data;
 
+       /* pre-check for file position: if we'd return EOF, there's no point
+        * causing a deschedule */
+       if (*pos >= sizeof(ctx->csa.lscsa->gprs))
+               return 0;
+
        ret = spu_acquire_saved(ctx);
        if (ret)
                return ret;
@@ -538,16 +568,17 @@ spufs_regs_write(struct file *file, const char __user *buffer,
        struct spu_lscsa *lscsa = ctx->csa.lscsa;
        int ret;
 
-       size = min_t(ssize_t, sizeof lscsa->gprs - *pos, size);
-       if (size <= 0)
+       if (*pos >= sizeof(lscsa->gprs))
                return -EFBIG;
+
+       size = min_t(ssize_t, sizeof(lscsa->gprs) - *pos, size);
        *pos += size;
 
        ret = spu_acquire_saved(ctx);
        if (ret)
                return ret;
 
-       ret = copy_from_user(lscsa->gprs + *pos - size,
+       ret = copy_from_user((char *)lscsa->gprs + *pos - size,
                             buffer, size) ? -EFAULT : size;
 
        spu_release_saved(ctx);
@@ -593,10 +624,11 @@ spufs_fpcr_write(struct file *file, const char __user * buffer,
        struct spu_lscsa *lscsa = ctx->csa.lscsa;
        int ret;
 
-       size = min_t(ssize_t, sizeof(lscsa->fpcr) - *pos, size);
-       if (size <= 0)
+       if (*pos >= sizeof(lscsa->fpcr))
                return -EFBIG;
 
+       size = min_t(ssize_t, sizeof(lscsa->fpcr) - *pos, size);
+
        ret = spu_acquire_saved(ctx);
        if (ret)
                return ret;
@@ -1096,23 +1128,23 @@ static ssize_t spufs_signal1_write(struct file *file, const char __user *buf,
        return 4;
 }
 
-static unsigned long spufs_signal1_mmap_nopfn(struct vm_area_struct *vma,
-                                             unsigned long address)
+static int
+spufs_signal1_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-#if PAGE_SIZE == 0x1000
-       return spufs_ps_nopfn(vma, address, 0x14000, 0x1000);
-#elif PAGE_SIZE == 0x10000
+#if SPUFS_SIGNAL_MAP_SIZE == 0x1000
+       return spufs_ps_fault(vma, vmf, 0x14000, SPUFS_SIGNAL_MAP_SIZE);
+#elif SPUFS_SIGNAL_MAP_SIZE == 0x10000
        /* For 64k pages, both signal1 and signal2 can be used to mmap the whole
         * signal 1 and 2 area
         */
-       return spufs_ps_nopfn(vma, address, 0x10000, 0x10000);
+       return spufs_ps_fault(vma, vmf, 0x10000, SPUFS_SIGNAL_MAP_SIZE);
 #else
 #error unsupported page size
 #endif
 }
 
-static struct vm_operations_struct spufs_signal1_mmap_vmops = {
-       .nopfn = spufs_signal1_mmap_nopfn,
+static const struct vm_operations_struct spufs_signal1_mmap_vmops = {
+       .fault = spufs_signal1_mmap_fault,
 };
 
 static int spufs_signal1_mmap(struct file *file, struct vm_area_struct *vma)
@@ -1121,8 +1153,7 @@ static int spufs_signal1_mmap(struct file *file, struct vm_area_struct *vma)
                return -EINVAL;
 
        vma->vm_flags |= VM_IO | VM_PFNMAP;
-       vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                    | _PAGE_NO_CACHE | _PAGE_GUARDED);
+       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
        vma->vm_ops = &spufs_signal1_mmap_vmops;
        return 0;
@@ -1233,23 +1264,23 @@ static ssize_t spufs_signal2_write(struct file *file, const char __user *buf,
 }
 
 #if SPUFS_MMAP_4K
-static unsigned long spufs_signal2_mmap_nopfn(struct vm_area_struct *vma,
-                                             unsigned long address)
+static int
+spufs_signal2_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-#if PAGE_SIZE == 0x1000
-       return spufs_ps_nopfn(vma, address, 0x1c000, 0x1000);
-#elif PAGE_SIZE == 0x10000
+#if SPUFS_SIGNAL_MAP_SIZE == 0x1000
+       return spufs_ps_fault(vma, vmf, 0x1c000, SPUFS_SIGNAL_MAP_SIZE);
+#elif SPUFS_SIGNAL_MAP_SIZE == 0x10000
        /* For 64k pages, both signal1 and signal2 can be used to mmap the whole
         * signal 1 and 2 area
         */
-       return spufs_ps_nopfn(vma, address, 0x10000, 0x10000);
+       return spufs_ps_fault(vma, vmf, 0x10000, SPUFS_SIGNAL_MAP_SIZE);
 #else
 #error unsupported page size
 #endif
 }
 
-static struct vm_operations_struct spufs_signal2_mmap_vmops = {
-       .nopfn = spufs_signal2_mmap_nopfn,
+static const struct vm_operations_struct spufs_signal2_mmap_vmops = {
+       .fault = spufs_signal2_mmap_fault,
 };
 
 static int spufs_signal2_mmap(struct file *file, struct vm_area_struct *vma)
@@ -1258,8 +1289,7 @@ static int spufs_signal2_mmap(struct file *file, struct vm_area_struct *vma)
                return -EINVAL;
 
        vma->vm_flags |= VM_IO | VM_PFNMAP;
-       vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                    | _PAGE_NO_CACHE | _PAGE_GUARDED);
+       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
        vma->vm_ops = &spufs_signal2_mmap_vmops;
        return 0;
@@ -1361,14 +1391,14 @@ DEFINE_SPUFS_ATTRIBUTE(spufs_signal2_type, spufs_signal2_type_get,
                       spufs_signal2_type_set, "%llu\n", SPU_ATTR_ACQUIRE);
 
 #if SPUFS_MMAP_4K
-static unsigned long spufs_mss_mmap_nopfn(struct vm_area_struct *vma,
-                                         unsigned long address)
+static int
+spufs_mss_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-       return spufs_ps_nopfn(vma, address, 0x0000, 0x1000);
+       return spufs_ps_fault(vma, vmf, 0x0000, SPUFS_MSS_MAP_SIZE);
 }
 
-static struct vm_operations_struct spufs_mss_mmap_vmops = {
-       .nopfn = spufs_mss_mmap_nopfn,
+static const struct vm_operations_struct spufs_mss_mmap_vmops = {
+       .fault = spufs_mss_mmap_fault,
 };
 
 /*
@@ -1380,8 +1410,7 @@ static int spufs_mss_mmap(struct file *file, struct vm_area_struct *vma)
                return -EINVAL;
 
        vma->vm_flags |= VM_IO | VM_PFNMAP;
-       vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                    | _PAGE_NO_CACHE | _PAGE_GUARDED);
+       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
        vma->vm_ops = &spufs_mss_mmap_vmops;
        return 0;
@@ -1423,14 +1452,14 @@ static const struct file_operations spufs_mss_fops = {
        .mmap    = spufs_mss_mmap,
 };
 
-static unsigned long spufs_psmap_mmap_nopfn(struct vm_area_struct *vma,
-                                           unsigned long address)
+static int
+spufs_psmap_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-       return spufs_ps_nopfn(vma, address, 0x0000, 0x20000);
+       return spufs_ps_fault(vma, vmf, 0x0000, SPUFS_PS_MAP_SIZE);
 }
 
-static struct vm_operations_struct spufs_psmap_mmap_vmops = {
-       .nopfn = spufs_psmap_mmap_nopfn,
+static const struct vm_operations_struct spufs_psmap_mmap_vmops = {
+       .fault = spufs_psmap_mmap_fault,
 };
 
 /*
@@ -1442,8 +1471,7 @@ static int spufs_psmap_mmap(struct file *file, struct vm_area_struct *vma)
                return -EINVAL;
 
        vma->vm_flags |= VM_IO | VM_PFNMAP;
-       vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                    | _PAGE_NO_CACHE | _PAGE_GUARDED);
+       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
        vma->vm_ops = &spufs_psmap_mmap_vmops;
        return 0;
@@ -1483,14 +1511,14 @@ static const struct file_operations spufs_psmap_fops = {
 
 
 #if SPUFS_MMAP_4K
-static unsigned long spufs_mfc_mmap_nopfn(struct vm_area_struct *vma,
-                                         unsigned long address)
+static int
+spufs_mfc_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-       return spufs_ps_nopfn(vma, address, 0x3000, 0x1000);
+       return spufs_ps_fault(vma, vmf, 0x3000, SPUFS_MFC_MAP_SIZE);
 }
 
-static struct vm_operations_struct spufs_mfc_mmap_vmops = {
-       .nopfn = spufs_mfc_mmap_nopfn,
+static const struct vm_operations_struct spufs_mfc_mmap_vmops = {
+       .fault = spufs_mfc_mmap_fault,
 };
 
 /*
@@ -1502,8 +1530,7 @@ static int spufs_mfc_mmap(struct file *file, struct vm_area_struct *vma)
                return -EINVAL;
 
        vma->vm_flags |= VM_IO | VM_PFNMAP;
-       vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
-                                    | _PAGE_NO_CACHE | _PAGE_GUARDED);
+       vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
        vma->vm_ops = &spufs_mfc_mmap_vmops;
        return 0;
@@ -1629,7 +1656,7 @@ out:
 
 static int spufs_check_valid_dma(struct mfc_dma_command *cmd)
 {
-       pr_debug("queueing DMA %x %lx %x %x %x\n", cmd->lsa,
+       pr_debug("queueing DMA %x %llx %x %x %x\n", cmd->lsa,
                 cmd->ea, cmd->size, cmd->tag, cmd->cmd);
 
        switch (cmd->cmd) {
@@ -1646,7 +1673,7 @@ static int spufs_check_valid_dma(struct mfc_dma_command *cmd)
        }
 
        if ((cmd->lsa & 0xf) != (cmd->ea &0xf)) {
-               pr_debug("invalid DMA alignment, ea %lx lsa %x\n",
+               pr_debug("invalid DMA alignment, ea %llx lsa %x\n",
                                cmd->ea, cmd->lsa);
                return -EIO;
        }
@@ -2400,38 +2427,49 @@ static inline int spufs_switch_log_avail(struct spu_context *ctx)
 static int spufs_switch_log_open(struct inode *inode, struct file *file)
 {
        struct spu_context *ctx = SPUFS_I(inode)->i_ctx;
+       int rc;
+
+       rc = spu_acquire(ctx);
+       if (rc)
+               return rc;
 
-       /*
-        * We (ab-)use the mapping_lock here because it serves the similar
-        * purpose for synchronizing open/close elsewhere.  Maybe it should
-        * be renamed eventually.
-        */
-       mutex_lock(&ctx->mapping_lock);
        if (ctx->switch_log) {
-               spin_lock(&ctx->switch_log->lock);
-               ctx->switch_log->head = 0;
-               ctx->switch_log->tail = 0;
-               spin_unlock(&ctx->switch_log->lock);
-       } else {
-               /*
-                * We allocate the switch log data structures on first open.
-                * They will never be free because we assume a context will
-                * be traced until it goes away.
-                */
-               ctx->switch_log = kzalloc(sizeof(struct switch_log) +
-                       SWITCH_LOG_BUFSIZE * sizeof(struct switch_log_entry),
-                       GFP_KERNEL);
-               if (!ctx->switch_log)
-                       goto out;
-               spin_lock_init(&ctx->switch_log->lock);
-               init_waitqueue_head(&ctx->switch_log->wait);
+               rc = -EBUSY;
+               goto out;
        }
-       mutex_unlock(&ctx->mapping_lock);
+
+       ctx->switch_log = kmalloc(sizeof(struct switch_log) +
+               SWITCH_LOG_BUFSIZE * sizeof(struct switch_log_entry),
+               GFP_KERNEL);
+
+       if (!ctx->switch_log) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       ctx->switch_log->head = ctx->switch_log->tail = 0;
+       init_waitqueue_head(&ctx->switch_log->wait);
+       rc = 0;
+
+out:
+       spu_release(ctx);
+       return rc;
+}
+
+static int spufs_switch_log_release(struct inode *inode, struct file *file)
+{
+       struct spu_context *ctx = SPUFS_I(inode)->i_ctx;
+       int rc;
+
+       rc = spu_acquire(ctx);
+       if (rc)
+               return rc;
+
+       kfree(ctx->switch_log);
+       ctx->switch_log = NULL;
+       spu_release(ctx);
 
        return 0;
- out:
-       mutex_unlock(&ctx->mapping_lock);
-       return -ENOMEM;
 }
 
 static int switch_log_sprint(struct spu_context *ctx, char *tbuf, int n)
@@ -2459,42 +2497,54 @@ static ssize_t spufs_switch_log_read(struct file *file, char __user *buf,
        if (!buf || len < 0)
                return -EINVAL;
 
+       error = spu_acquire(ctx);
+       if (error)
+               return error;
+
        while (cnt < len) {
                char tbuf[128];
                int width;
 
-               if (file->f_flags & O_NONBLOCK) {
-                       if (spufs_switch_log_used(ctx) <= 0)
-                               return cnt ? cnt : -EAGAIN;
-               } else {
-                       /* Wait for data in buffer */
-                       error = wait_event_interruptible(ctx->switch_log->wait,
-                                       spufs_switch_log_used(ctx) > 0);
-                       if (error)
+               if (spufs_switch_log_used(ctx) == 0) {
+                       if (cnt > 0) {
+                               /* If there's data ready to go, we can
+                                * just return straight away */
                                break;
-               }
 
-               spin_lock(&ctx->switch_log->lock);
-               if (ctx->switch_log->head == ctx->switch_log->tail) {
-                       /* multiple readers race? */
-                       spin_unlock(&ctx->switch_log->lock);
-                       continue;
+                       } else if (file->f_flags & O_NONBLOCK) {
+                               error = -EAGAIN;
+                               break;
+
+                       } else {
+                               /* spufs_wait will drop the mutex and
+                                * re-acquire, but since we're in read(), the
+                                * file cannot be _released (and so
+                                * ctx->switch_log is stable).
+                                */
+                               error = spufs_wait(ctx->switch_log->wait,
+                                               spufs_switch_log_used(ctx) > 0);
+
+                               /* On error, spufs_wait returns without the
+                                * state mutex held */
+                               if (error)
+                                       return error;
+
+                               /* We may have had entries read from underneath
+                                * us while we dropped the mutex in spufs_wait,
+                                * so re-check */
+                               if (spufs_switch_log_used(ctx) == 0)
+                                       continue;
+                       }
                }
 
                width = switch_log_sprint(ctx, tbuf, sizeof(tbuf));
-               if (width < len) {
+               if (width < len)
                        ctx->switch_log->tail =
                                (ctx->switch_log->tail + 1) %
                                 SWITCH_LOG_BUFSIZE;
-               }
-
-               spin_unlock(&ctx->switch_log->lock);
-
-               /*
-                * If the record is greater than space available return
-                * partial buffer (so far)
-                */
-               if (width >= len)
+               else
+                       /* If the record is greater than space available return
+                        * partial buffer (so far) */
                        break;
 
                error = copy_to_user(buf + cnt, tbuf, width);
@@ -2503,6 +2553,8 @@ static ssize_t spufs_switch_log_read(struct file *file, char __user *buf,
                cnt += width;
        }
 
+       spu_release(ctx);
+
        return cnt == 0 ? error : cnt;
 }
 
@@ -2511,29 +2563,41 @@ static unsigned int spufs_switch_log_poll(struct file *file, poll_table *wait)
        struct inode *inode = file->f_path.dentry->d_inode;
        struct spu_context *ctx = SPUFS_I(inode)->i_ctx;
        unsigned int mask = 0;
+       int rc;
 
        poll_wait(file, &ctx->switch_log->wait, wait);
 
+       rc = spu_acquire(ctx);
+       if (rc)
+               return rc;
+
        if (spufs_switch_log_used(ctx) > 0)
                mask |= POLLIN;
 
+       spu_release(ctx);
+
        return mask;
 }
 
 static const struct file_operations spufs_switch_log_fops = {
-       .owner  = THIS_MODULE,
-       .open   = spufs_switch_log_open,
-       .read   = spufs_switch_log_read,
-       .poll   = spufs_switch_log_poll,
+       .owner          = THIS_MODULE,
+       .open           = spufs_switch_log_open,
+       .read           = spufs_switch_log_read,
+       .poll           = spufs_switch_log_poll,
+       .release        = spufs_switch_log_release,
 };
 
+/**
+ * Log a context switch event to a switch log reader.
+ *
+ * Must be called with ctx->state_mutex held.
+ */
 void spu_switch_log_notify(struct spu *spu, struct spu_context *ctx,
                u32 type, u32 val)
 {
        if (!ctx->switch_log)
                return;
 
-       spin_lock(&ctx->switch_log->lock);
        if (spufs_switch_log_avail(ctx) > 1) {
                struct switch_log_entry *p;
 
@@ -2547,27 +2611,78 @@ void spu_switch_log_notify(struct spu *spu, struct spu_context *ctx,
                ctx->switch_log->head =
                        (ctx->switch_log->head + 1) % SWITCH_LOG_BUFSIZE;
        }
-       spin_unlock(&ctx->switch_log->lock);
 
        wake_up(&ctx->switch_log->wait);
 }
 
-struct tree_descr spufs_dir_contents[] = {
+static int spufs_show_ctx(struct seq_file *s, void *private)
+{
+       struct spu_context *ctx = s->private;
+       u64 mfc_control_RW;
+
+       mutex_lock(&ctx->state_mutex);
+       if (ctx->spu) {
+               struct spu *spu = ctx->spu;
+               struct spu_priv2 __iomem *priv2 = spu->priv2;
+
+               spin_lock_irq(&spu->register_lock);
+               mfc_control_RW = in_be64(&priv2->mfc_control_RW);
+               spin_unlock_irq(&spu->register_lock);
+       } else {
+               struct spu_state *csa = &ctx->csa;
+
+               mfc_control_RW = csa->priv2.mfc_control_RW;
+       }
+
+       seq_printf(s, "%c flgs(%lx) sflgs(%lx) pri(%d) ts(%d) spu(%02d)"
+               " %c %llx %llx %llx %llx %x %x\n",
+               ctx->state == SPU_STATE_SAVED ? 'S' : 'R',
+               ctx->flags,
+               ctx->sched_flags,
+               ctx->prio,
+               ctx->time_slice,
+               ctx->spu ? ctx->spu->number : -1,
+               !list_empty(&ctx->rq) ? 'q' : ' ',
+               ctx->csa.class_0_pending,
+               ctx->csa.class_0_dar,
+               ctx->csa.class_1_dsisr,
+               mfc_control_RW,
+               ctx->ops->runcntl_read(ctx),
+               ctx->ops->status_read(ctx));
+
+       mutex_unlock(&ctx->state_mutex);
+
+       return 0;
+}
+
+static int spufs_ctx_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, spufs_show_ctx, SPUFS_I(inode)->i_ctx);
+}
+
+static const struct file_operations spufs_ctx_fops = {
+       .open           = spufs_ctx_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+const struct spufs_tree_descr spufs_dir_contents[] = {
        { "capabilities", &spufs_caps_fops, 0444, },
-       { "mem",  &spufs_mem_fops,  0666, },
-       { "regs", &spufs_regs_fops,  0666, },
+       { "mem",  &spufs_mem_fops,  0666, LS_SIZE, },
+       { "regs", &spufs_regs_fops,  0666, sizeof(struct spu_reg128[128]), },
        { "mbox", &spufs_mbox_fops, 0444, },
        { "ibox", &spufs_ibox_fops, 0444, },
        { "wbox", &spufs_wbox_fops, 0222, },
-       { "mbox_stat", &spufs_mbox_stat_fops, 0444, },
-       { "ibox_stat", &spufs_ibox_stat_fops, 0444, },
-       { "wbox_stat", &spufs_wbox_stat_fops, 0444, },
+       { "mbox_stat", &spufs_mbox_stat_fops, 0444, sizeof(u32), },
+       { "ibox_stat", &spufs_ibox_stat_fops, 0444, sizeof(u32), },
+       { "wbox_stat", &spufs_wbox_stat_fops, 0444, sizeof(u32), },
        { "signal1", &spufs_signal1_fops, 0666, },
        { "signal2", &spufs_signal2_fops, 0666, },
        { "signal1_type", &spufs_signal1_type, 0666, },
        { "signal2_type", &spufs_signal2_type, 0666, },
        { "cntl", &spufs_cntl_fops,  0666, },
-       { "fpcr", &spufs_fpcr_fops, 0666, },
+       { "fpcr", &spufs_fpcr_fops, 0666, sizeof(struct spu_reg128), },
        { "lslr", &spufs_lslr_ops, 0444, },
        { "mfc", &spufs_mfc_fops, 0666, },
        { "mss", &spufs_mss_fops, 0666, },
@@ -2577,29 +2692,31 @@ struct tree_descr spufs_dir_contents[] = {
        { "decr_status", &spufs_decr_status_ops, 0666, },
        { "event_mask", &spufs_event_mask_ops, 0666, },
        { "event_status", &spufs_event_status_ops, 0444, },
-       { "psmap", &spufs_psmap_fops, 0666, },
+       { "psmap", &spufs_psmap_fops, 0666, SPUFS_PS_MAP_SIZE, },
        { "phys-id", &spufs_id_ops, 0666, },
        { "object-id", &spufs_object_id_ops, 0666, },
-       { "mbox_info", &spufs_mbox_info_fops, 0444, },
-       { "ibox_info", &spufs_ibox_info_fops, 0444, },
-       { "wbox_info", &spufs_wbox_info_fops, 0444, },
-       { "dma_info", &spufs_dma_info_fops, 0444, },
-       { "proxydma_info", &spufs_proxydma_info_fops, 0444, },
+       { "mbox_info", &spufs_mbox_info_fops, 0444, sizeof(u32), },
+       { "ibox_info", &spufs_ibox_info_fops, 0444, sizeof(u32), },
+       { "wbox_info", &spufs_wbox_info_fops, 0444, sizeof(u32), },
+       { "dma_info", &spufs_dma_info_fops, 0444,
+               sizeof(struct spu_dma_info), },
+       { "proxydma_info", &spufs_proxydma_info_fops, 0444,
+               sizeof(struct spu_proxydma_info)},
        { "tid", &spufs_tid_fops, 0444, },
        { "stat", &spufs_stat_fops, 0444, },
        { "switch_log", &spufs_switch_log_fops, 0444 },
        {},
 };
 
-struct tree_descr spufs_dir_nosched_contents[] = {
+const struct spufs_tree_descr spufs_dir_nosched_contents[] = {
        { "capabilities", &spufs_caps_fops, 0444, },
-       { "mem",  &spufs_mem_fops,  0666, },
+       { "mem",  &spufs_mem_fops,  0666, LS_SIZE, },
        { "mbox", &spufs_mbox_fops, 0444, },
        { "ibox", &spufs_ibox_fops, 0444, },
        { "wbox", &spufs_wbox_fops, 0222, },
-       { "mbox_stat", &spufs_mbox_stat_fops, 0444, },
-       { "ibox_stat", &spufs_ibox_stat_fops, 0444, },
-       { "wbox_stat", &spufs_wbox_stat_fops, 0444, },
+       { "mbox_stat", &spufs_mbox_stat_fops, 0444, sizeof(u32), },
+       { "ibox_stat", &spufs_ibox_stat_fops, 0444, sizeof(u32), },
+       { "wbox_stat", &spufs_wbox_stat_fops, 0444, sizeof(u32), },
        { "signal1", &spufs_signal1_nosched_fops, 0222, },
        { "signal2", &spufs_signal2_nosched_fops, 0222, },
        { "signal1_type", &spufs_signal1_type, 0666, },
@@ -2608,7 +2725,7 @@ struct tree_descr spufs_dir_nosched_contents[] = {
        { "mfc", &spufs_mfc_fops, 0666, },
        { "cntl", &spufs_cntl_fops,  0666, },
        { "npc", &spufs_npc_ops, 0666, },
-       { "psmap", &spufs_psmap_fops, 0666, },
+       { "psmap", &spufs_psmap_fops, 0666, SPUFS_PS_MAP_SIZE, },
        { "phys-id", &spufs_id_ops, 0666, },
        { "object-id", &spufs_object_id_ops, 0666, },
        { "tid", &spufs_tid_fops, 0444, },
@@ -2616,7 +2733,12 @@ struct tree_descr spufs_dir_nosched_contents[] = {
        {},
 };
 
-struct spufs_coredump_reader spufs_coredump_read[] = {
+const struct spufs_tree_descr spufs_dir_debug_contents[] = {
+       { ".ctx", &spufs_ctx_fops, 0444, },
+       {},
+};
+
+const struct spufs_coredump_reader spufs_coredump_read[] = {
        { "regs", __spufs_regs_read, NULL, sizeof(struct spu_reg128[128])},
        { "fpcr", __spufs_fpcr_read, NULL, sizeof(struct spu_reg128) },
        { "lslr", NULL, spufs_lslr_get, 19 },