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Diffstat (limited to 'arch/powerpc/platforms/cell/spufs/fault.c')
-rw-r--r--arch/powerpc/platforms/cell/spufs/fault.c211
1 files changed, 211 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/fault.c b/arch/powerpc/platforms/cell/spufs/fault.c
new file mode 100644
index 00000000000..0f75c07e29d
--- /dev/null
+++ b/arch/powerpc/platforms/cell/spufs/fault.c
@@ -0,0 +1,211 @@
+/*
+ * Low-level SPU handling
+ *
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
+ *
+ * Author: Arnd Bergmann <arndb@de.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+
+#include <asm/spu.h>
+#include <asm/spu_csa.h>
+
+#include "spufs.h"
+
+/*
+ * This ought to be kept in sync with the powerpc specific do_page_fault
+ * function. Currently, there are a few corner cases that we haven't had
+ * to handle fortunately.
+ */
+static int spu_handle_mm_fault(struct mm_struct *mm, unsigned long ea, unsigned long dsisr)
+{
+ struct vm_area_struct *vma;
+ unsigned long is_write;
+ int ret;
+
+#if 0
+ if (!IS_VALID_EA(ea)) {
+ return -EFAULT;
+ }
+#endif /* XXX */
+ if (mm == NULL) {
+ return -EFAULT;
+ }
+ if (mm->pgd == NULL) {
+ return -EFAULT;
+ }
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, ea);
+ if (!vma)
+ goto bad_area;
+ if (vma->vm_start <= ea)
+ goto good_area;
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ goto bad_area;
+ if (expand_stack(vma, ea))
+ goto bad_area;
+good_area:
+ is_write = dsisr & MFC_DSISR_ACCESS_PUT;
+ if (is_write) {
+ if (!(vma->vm_flags & VM_WRITE))
+ goto bad_area;
+ } else {
+ if (dsisr & MFC_DSISR_ACCESS_DENIED)
+ goto bad_area;
+ if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+ goto bad_area;
+ }
+ ret = 0;
+ switch (handle_mm_fault(mm, vma, ea, is_write)) {
+ case VM_FAULT_MINOR:
+ current->min_flt++;
+ break;
+ case VM_FAULT_MAJOR:
+ current->maj_flt++;
+ break;
+ case VM_FAULT_SIGBUS:
+ ret = -EFAULT;
+ goto bad_area;
+ case VM_FAULT_OOM:
+ ret = -ENOMEM;
+ goto bad_area;
+ default:
+ BUG();
+ }
+ up_read(&mm->mmap_sem);
+ return ret;
+
+bad_area:
+ up_read(&mm->mmap_sem);
+ return -EFAULT;
+}
+
+static void spufs_handle_dma_error(struct spu_context *ctx,
+ unsigned long ea, int type)
+{
+ if (ctx->flags & SPU_CREATE_EVENTS_ENABLED) {
+ ctx->event_return |= type;
+ wake_up_all(&ctx->stop_wq);
+ } else {
+ siginfo_t info;
+ memset(&info, 0, sizeof(info));
+
+ switch (type) {
+ case SPE_EVENT_INVALID_DMA:
+ info.si_signo = SIGBUS;
+ info.si_code = BUS_OBJERR;
+ break;
+ case SPE_EVENT_SPE_DATA_STORAGE:
+ info.si_signo = SIGBUS;
+ info.si_addr = (void __user *)ea;
+ info.si_code = BUS_ADRERR;
+ break;
+ case SPE_EVENT_DMA_ALIGNMENT:
+ info.si_signo = SIGBUS;
+ /* DAR isn't set for an alignment fault :( */
+ info.si_code = BUS_ADRALN;
+ break;
+ case SPE_EVENT_SPE_ERROR:
+ info.si_signo = SIGILL;
+ info.si_addr = (void __user *)(unsigned long)
+ ctx->ops->npc_read(ctx) - 4;
+ info.si_code = ILL_ILLOPC;
+ break;
+ }
+ if (info.si_signo)
+ force_sig_info(info.si_signo, &info, current);
+ }
+}
+
+void spufs_dma_callback(struct spu *spu, int type)
+{
+ spufs_handle_dma_error(spu->ctx, spu->dar, type);
+}
+EXPORT_SYMBOL_GPL(spufs_dma_callback);
+
+/*
+ * bottom half handler for page faults, we can't do this from
+ * interrupt context, since we might need to sleep.
+ * we also need to give up the mutex so we can get scheduled
+ * out while waiting for the backing store.
+ *
+ * TODO: try calling hash_page from the interrupt handler first
+ * in order to speed up the easy case.
+ */
+int spufs_handle_class1(struct spu_context *ctx)
+{
+ u64 ea, dsisr, access;
+ unsigned long flags;
+ int ret;
+
+ /*
+ * dar and dsisr get passed from the registers
+ * to the spu_context, to this function, but not
+ * back to the spu if it gets scheduled again.
+ *
+ * if we don't handle the fault for a saved context
+ * in time, we can still expect to get the same fault
+ * the immediately after the context restore.
+ */
+ if (ctx->state == SPU_STATE_RUNNABLE) {
+ ea = ctx->spu->dar;
+ dsisr = ctx->spu->dsisr;
+ ctx->spu->dar= ctx->spu->dsisr = 0;
+ } else {
+ ea = ctx->csa.priv1.mfc_dar_RW;
+ dsisr = ctx->csa.priv1.mfc_dsisr_RW;
+ ctx->csa.priv1.mfc_dar_RW = 0;
+ ctx->csa.priv1.mfc_dsisr_RW = 0;
+ }
+
+ if (!(dsisr & (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED)))
+ return 0;
+
+ pr_debug("ctx %p: ea %016lx, dsisr %016lx state %d\n", ctx, ea,
+ dsisr, ctx->state);
+
+ /* we must not hold the lock when entering spu_handle_mm_fault */
+ spu_release(ctx);
+
+ access = (_PAGE_PRESENT | _PAGE_USER);
+ access |= (dsisr & MFC_DSISR_ACCESS_PUT) ? _PAGE_RW : 0UL;
+ local_irq_save(flags);
+ ret = hash_page(ea, access, 0x300);
+ local_irq_restore(flags);
+
+ /* hashing failed, so try the actual fault handler */
+ if (ret)
+ ret = spu_handle_mm_fault(current->mm, ea, dsisr);
+
+ spu_acquire(ctx);
+ /*
+ * If we handled the fault successfully and are in runnable
+ * state, restart the DMA.
+ * In case of unhandled error report the problem to user space.
+ */
+ if (!ret) {
+ if (ctx->spu)
+ ctx->ops->restart_dma(ctx);
+ } else
+ spufs_handle_dma_error(ctx, ea, SPE_EVENT_SPE_DATA_STORAGE);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(spufs_handle_class1);