Merge tag 'for-5.16/parisc-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc updates from Helge Deller:
 "Lots of new features and fixes:

   - Added TOC (table of content) support, which is a debugging feature
     which is either initiated by pressing the TOC button or via command
     in the BMC. If pressed the Linux built-in KDB/KGDB will be called
     (Sven Schnelle)

   - Fix CONFIG_PREEMPT (Sven)

   - Fix unwinder on 64-bit kernels (Sven)

   - Various kgdb fixes (Sven)

   - Added KFENCE support (me)

   - Switch to ARCH_STACKWALK implementation (me)

   - Fix ptrace check on syscall return (me)

   - Fix kernel crash with fixmaps on PA1.x machines (me)

   - Move thread_info into task struct, aka CONFIG_THREAD_INFO_IN_TASK
     (me)

   - Updated defconfigs

   - Smaller cleanups, including Makefile cleanups (Masahiro Yamada),
     use kthread_run() macro (Cai Huoqing), use swap() macro (Yihao
     Han)"

* tag 'for-5.16/parisc-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: (36 commits)
  parisc: Fix set_fixmap() on PA1.x CPUs
  parisc: Use swap() to swap values in setup_bootmem()
  parisc: Update defconfigs
  parisc: decompressor: clean up Makefile
  parisc: decompressor: remove repeated depenency of misc.o
  parisc: Remove unused constants from asm-offsets.c
  parisc/ftrace: use static key to enable/disable function graph tracer
  parisc/ftrace: set function trace function
  parisc: Make use of the helper macro kthread_run()
  parisc: mark xchg functions notrace
  parisc: enhance warning regarding usage of O_NONBLOCK
  parisc: Drop ifdef __KERNEL__ from non-uapi kernel headers
  parisc: Use PRIV_USER and PRIV_KERNEL in ptrace.h
  parisc: Use PRIV_USER in syscall.S
  parisc/kgdb: add kgdb_roundup() to make kgdb work with idle polling
  parisc: Move thread_info into task struct
  parisc: add support for TOC (transfer of control)
  parisc/firmware: add functions to retrieve TOC data
  parisc: add PIM TOC data structures
  parisc: move virt_map macro to assembly.h
  ...

1 files changed, 44 insertions, 0 deletions

diff --git a/arch/parisc/include/asm/kfence.h b/arch/parisc/include/asm/kfence.h
new file mode 100644
index 000000000000..6259e5ac1fea
--- /dev/null
+++ b/arch/parisc/include/asm/kfence.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * PA-RISC KFENCE support.
+ *
+ * Copyright (C) 2021, Helge Deller <deller@gmx.de>
+ */
+
+#ifndef _ASM_PARISC_KFENCE_H
+#define _ASM_PARISC_KFENCE_H
+
+#include <linux/kfence.h>
+
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+
+static inline bool arch_kfence_init_pool(void)
+{
+	return true;
+}
+
+/* Protect the given page and flush TLB. */
+static inline bool kfence_protect_page(unsigned long addr, bool protect)
+{
+	pte_t *pte = virt_to_kpte(addr);
+
+	if (WARN_ON(!pte))
+		return false;
+
+	/*
+	 * We need to avoid IPIs, as we may get KFENCE allocations or faults
+	 * with interrupts disabled.
+	 */
+
+	if (protect)
+		set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
+	else
+		set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
+
+	flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+
+	return true;
+}
+
+#endif /* _ASM_PARISC_KFENCE_H */