1 files changed, 148 insertions, 0 deletions
diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c
new file mode 100644
index 000000000..8acd00178
--- /dev/null
+++ b/arch/powerpc/mm/copro_fault.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * CoProcessor (SPU/AFU) mm fault handler
+ *
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2007
+ *
+ * Author: Arnd Bergmann <arndb@de.ibm.com>
+ * Author: Jeremy Kerr <jk@ozlabs.org>
+ */
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <asm/reg.h>
+#include <asm/copro.h>
+#include <asm/spu.h>
+#include <misc/cxl-base.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.
+ */
+int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
+		unsigned long dsisr, vm_fault_t *flt)
+{
+	struct vm_area_struct *vma;
+	unsigned long is_write;
+	int ret;
+
+	if (mm == NULL)
+		return -EFAULT;
+
+	if (mm->pgd == NULL)
+		return -EFAULT;
+
+	mmap_read_lock(mm);
+	ret = -EFAULT;
+	vma = find_vma(mm, ea);
+	if (!vma)
+		goto out_unlock;
+
+	if (ea < vma->vm_start) {
+		if (!(vma->vm_flags & VM_GROWSDOWN))
+			goto out_unlock;
+		if (expand_stack(vma, ea))
+			goto out_unlock;
+	}
+
+	is_write = dsisr & DSISR_ISSTORE;
+	if (is_write) {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto out_unlock;
+	} else {
+		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+			goto out_unlock;
+		/*
+		 * PROT_NONE is covered by the VMA check above.
+		 * and hash should get a NOHPTE fault instead of
+		 * a PROTFAULT in case fixup is needed for things
+		 * like autonuma.
+		 */
+		if (!radix_enabled())
+			WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
+	}
+
+	ret = 0;
+	*flt = handle_mm_fault(vma, ea, is_write ? FAULT_FLAG_WRITE : 0, NULL);
+	if (unlikely(*flt & VM_FAULT_ERROR)) {
+		if (*flt & VM_FAULT_OOM) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		} else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
+			ret = -EFAULT;
+			goto out_unlock;
+		}
+		BUG();
+	}
+
+out_unlock:
+	mmap_read_unlock(mm);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
+
+int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
+{
+	u64 vsid, vsidkey;
+	int psize, ssize;
+
+	switch (get_region_id(ea)) {
+	case USER_REGION_ID:
+		pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
+		if (mm == NULL)
+			return 1;
+		psize = get_slice_psize(mm, ea);
+		ssize = user_segment_size(ea);
+		vsid = get_user_vsid(&mm->context, ea, ssize);
+		vsidkey = SLB_VSID_USER;
+		break;
+	case VMALLOC_REGION_ID:
+		pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
+		psize = mmu_vmalloc_psize;
+		ssize = mmu_kernel_ssize;
+		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
+		vsidkey = SLB_VSID_KERNEL;
+		break;
+	case IO_REGION_ID:
+		pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea);
+		psize = mmu_io_psize;
+		ssize = mmu_kernel_ssize;
+		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
+		vsidkey = SLB_VSID_KERNEL;
+		break;
+	case LINEAR_MAP_REGION_ID:
+		pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea);
+		psize = mmu_linear_psize;
+		ssize = mmu_kernel_ssize;
+		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
+		vsidkey = SLB_VSID_KERNEL;
+		break;
+	default:
+		pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
+		return 1;
+	}
+	/* Bad address */
+	if (!vsid)
+		return 1;
+
+	vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
+
+	vsid |= mmu_psize_defs[psize].sllp |
+		((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
+
+	slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
+	slb->vsid = vsid;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(copro_calculate_slb);
+
+void copro_flush_all_slbs(struct mm_struct *mm)
+{
+#ifdef CONFIG_SPU_BASE
+	spu_flush_all_slbs(mm);
+#endif
+	cxl_slbia(mm);
+}
+EXPORT_SYMBOL_GPL(copro_flush_all_slbs);