ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/arc/mm/fault.c b/marvell/linux/arch/arc/mm/fault.c
new file mode 100644
index 0000000..fdf09db
--- /dev/null
+++ b/marvell/linux/arch/arc/mm/fault.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Page Fault Handling for ARC (TLB Miss / ProtV)
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#include <linux/signal.h>
+#include <linux/interrupt.h>
+#include <linux/sched/signal.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/uaccess.h>
+#include <linux/kdebug.h>
+#include <linux/perf_event.h>
+#include <linux/mm_types.h>
+#include <asm/pgalloc.h>
+#include <asm/mmu.h>
+
+/*
+ * kernel virtual address is required to implement vmalloc/pkmap/fixmap
+ * Refer to asm/processor.h for System Memory Map
+ *
+ * It simply copies the PMD entry (pointer to 2nd level page table or hugepage)
+ * from swapper pgdir to task pgdir. The 2nd level table/page is thus shared
+ */
+noinline static int handle_kernel_vaddr_fault(unsigned long address)
+{
+ /*
+ * Synchronize this task's top level page-table
+ * with the 'reference' page table.
+ */
+ pgd_t *pgd, *pgd_k;
+ pud_t *pud, *pud_k;
+ pmd_t *pmd, *pmd_k;
+
+ pgd = pgd_offset_fast(current->active_mm, address);
+ pgd_k = pgd_offset_k(address);
+
+ if (!pgd_present(*pgd_k))
+ goto bad_area;
+
+ pud = pud_offset(pgd, address);
+ pud_k = pud_offset(pgd_k, address);
+ if (!pud_present(*pud_k))
+ goto bad_area;
+
+ pmd = pmd_offset(pud, address);
+ pmd_k = pmd_offset(pud_k, address);
+ if (!pmd_present(*pmd_k))
+ goto bad_area;
+
+ set_pmd(pmd, *pmd_k);
+
+ /* XXX: create the TLB entry here */
+ return 0;
+
+bad_area:
+ return 1;
+}
+
+void do_page_fault(unsigned long address, struct pt_regs *regs)
+{
+ struct vm_area_struct *vma = NULL;
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+ int sig, si_code = SEGV_MAPERR;
+ unsigned int write = 0, exec = 0, mask;
+ vm_fault_t fault = VM_FAULT_SIGSEGV; /* handle_mm_fault() output */
+ unsigned int flags; /* handle_mm_fault() input */
+
+ /*
+ * NOTE! We MUST NOT take any locks for this case. We may
+ * be in an interrupt or a critical region, and should
+ * only copy the information from the master page table,
+ * nothing more.
+ */
+ if (address >= VMALLOC_START && !user_mode(regs)) {
+ if (unlikely(handle_kernel_vaddr_fault(address)))
+ goto no_context;
+ else
+ return;
+ }
+
+ /*
+ * If we're in an interrupt or have no user
+ * context, we must not take the fault..
+ */
+ if (faulthandler_disabled() || !mm)
+ goto no_context;
+
+ if (regs->ecr_cause & ECR_C_PROTV_STORE) /* ST/EX */
+ write = 1;
+ else if ((regs->ecr_vec == ECR_V_PROTV) &&
+ (regs->ecr_cause == ECR_C_PROTV_INST_FETCH))
+ exec = 1;
+
+ flags = FAULT_FLAG_DEFAULT;
+ if (user_mode(regs))
+ flags |= FAULT_FLAG_USER;
+ if (write)
+ flags |= FAULT_FLAG_WRITE;
+
+retry:
+ down_read(&mm->mmap_sem);
+
+ vma = find_vma(mm, address);
+ if (!vma)
+ goto bad_area;
+ if (unlikely(address < vma->vm_start)) {
+ if (!(vma->vm_flags & VM_GROWSDOWN) || expand_stack(vma, address))
+ goto bad_area;
+ }
+
+ /*
+ * vm_area is good, now check permissions for this memory access
+ */
+ mask = VM_READ;
+ if (write)
+ mask = VM_WRITE;
+ if (exec)
+ mask = VM_EXEC;
+
+ if (!(vma->vm_flags & mask)) {
+ si_code = SEGV_ACCERR;
+ goto bad_area;
+ }
+
+ fault = handle_mm_fault(vma, address, flags);
+
+ /* Quick path to respond to signals */
+ if (fault_signal_pending(fault, regs)) {
+ if (!user_mode(regs))
+ goto no_context;
+ return;
+ }
+
+ /*
+ * Fault retry nuances, mmap_sem already relinquished by core mm
+ */
+ if (unlikely((fault & VM_FAULT_RETRY) &&
+ (flags & FAULT_FLAG_ALLOW_RETRY))) {
+ flags |= FAULT_FLAG_TRIED;
+ goto retry;
+ }
+
+bad_area:
+ up_read(&mm->mmap_sem);
+
+ /*
+ * Major/minor page fault accounting
+ * (in case of retry we only land here once)
+ */
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+
+ if (likely(!(fault & VM_FAULT_ERROR))) {
+ if (fault & VM_FAULT_MAJOR) {
+ tsk->maj_flt++;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
+ regs, address);
+ } else {
+ tsk->min_flt++;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
+ regs, address);
+ }
+
+ /* Normal return path: fault Handled Gracefully */
+ return;
+ }
+
+ if (!user_mode(regs))
+ goto no_context;
+
+ if (fault & VM_FAULT_OOM) {
+ pagefault_out_of_memory();
+ return;
+ }
+
+ if (fault & VM_FAULT_SIGBUS) {
+ sig = SIGBUS;
+ si_code = BUS_ADRERR;
+ }
+ else {
+ sig = SIGSEGV;
+ }
+
+ tsk->thread.fault_address = address;
+ force_sig_fault(sig, si_code, (void __user *)address);
+ return;
+
+no_context:
+ if (fixup_exception(regs))
+ return;
+
+ die("Oops", regs, address);
+}