Merge tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for the memtest= kernel command-line argument.

 - Support for building the kernel with FORTIFY_SOURCE.

 - Support for generic clockevent broadcasts.

 - Support for the buildtar build target.

 - Some build system cleanups to pass more LLVM-friendly arguments.

 - Support for kprobes.

 - A rearranged kernel memory map, the first part of supporting sv48
   systems.

 - Improvements to kexec, along with support for kdump and crash
   kernels.

 - An alternatives-based errata framework, along with support for
   handling a pair of errata that manifest on some SiFive designs
   (including the HiFive Unmatched).

 - Support for XIP.

 - A device tree for the Microchip PolarFire ICICLE SoC and associated
   dev board.

... along with a bunch of cleanups.  There are already a handful of fixes
on the list so there will likely be a part 2.

* tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (45 commits)
  RISC-V: Always define XIP_FIXUP
  riscv: Remove 32b kernel mapping from page table dump
  riscv: Fix 32b kernel build with CONFIG_DEBUG_VIRTUAL=y
  RISC-V: Fix error code returned by riscv_hartid_to_cpuid()
  RISC-V: Enable Microchip PolarFire ICICLE SoC
  RISC-V: Initial DTS for Microchip ICICLE board
  dt-bindings: riscv: microchip: Add YAML documentation for the PolarFire SoC
  RISC-V: Add Microchip PolarFire SoC kconfig option
  RISC-V: enable XIP
  RISC-V: Add crash kernel support
  RISC-V: Add kdump support
  RISC-V: Improve init_resources()
  RISC-V: Add kexec support
  RISC-V: Add EM_RISCV to kexec UAPI header
  riscv: vdso: fix and clean-up Makefile
  riscv/mm: Use BUG_ON instead of if condition followed by BUG.
  riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobe
  riscv: Set ARCH_HAS_STRICT_MODULE_RWX if MMU
  riscv: module: Create module allocations without exec permissions
  riscv: bpf: Avoid breaking W^X
  ...

4 files changed, 92 insertions, 1 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a1266f33d6e6..5bcc229d31e2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2821,7 +2821,7 @@
 			Note that even when enabled, there are a few cases where
 			the feature is not effective.
 
-	memtest=	[KNL,X86,ARM,PPC] Enable memtest
+	memtest=	[KNL,X86,ARM,PPC,RISCV] Enable memtest
 			Format: <integer>
 			default : 0 <disable>
 			Specifies the number of memtest passes to be
diff --git a/Documentation/devicetree/bindings/riscv/microchip.yaml b/Documentation/devicetree/bindings/riscv/microchip.yaml
new file mode 100644
index 000000000000..3f981e897126
--- /dev/null
+++ b/Documentation/devicetree/bindings/riscv/microchip.yaml
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/riscv/microchip.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip PolarFire SoC-based boards device tree bindings
+
+maintainers:
+  - Cyril Jean <Cyril.Jean@microchip.com>
+  - Lewis Hanly <lewis.hanly@microchip.com>
+
+description:
+  Microchip PolarFire SoC-based boards
+
+properties:
+  $nodename:
+    const: '/'
+  compatible:
+    items:
+      - enum:
+          - microchip,mpfs-icicle-kit
+      - const: microchip,mpfs
+
+additionalProperties: true
+
+...
diff --git a/Documentation/riscv/index.rst b/Documentation/riscv/index.rst
index 6e6e39482502..ea915c196048 100644
--- a/Documentation/riscv/index.rst
+++ b/Documentation/riscv/index.rst
@@ -6,6 +6,7 @@ RISC-V architecture
     :maxdepth: 1
 
     boot-image-header
+    vm-layout
     pmu
     patch-acceptance
 
diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst
new file mode 100644
index 000000000000..329d32098af4
--- /dev/null
+++ b/Documentation/riscv/vm-layout.rst
@@ -0,0 +1,63 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================================
+Virtual Memory Layout on RISC-V Linux
+=====================================
+
+:Author: Alexandre Ghiti <alex@ghiti.fr>
+:Date: 12 February 2021
+
+This document describes the virtual memory layout used by the RISC-V Linux
+Kernel.
+
+RISC-V Linux Kernel 32bit
+=========================
+
+RISC-V Linux Kernel SV32
+------------------------
+
+TODO
+
+RISC-V Linux Kernel 64bit
+=========================
+
+The RISC-V privileged architecture document states that the 64bit addresses
+"must have bits 63–48 all equal to bit 47, or else a page-fault exception will
+occur.": that splits the virtual address space into 2 halves separated by a very
+big hole, the lower half is where the userspace resides, the upper half is where
+the RISC-V Linux Kernel resides.
+
+RISC-V Linux Kernel SV39
+------------------------
+
+::
+
+  ========================================================================================================================
+      Start addr    |   Offset   |     End addr     |  Size   | VM area description
+  ========================================================================================================================
+                    |            |                  |         |
+   0000000000000000 |    0       | 0000003fffffffff |  256 GB | user-space virtual memory, different per mm
+  __________________|____________|__________________|_________|___________________________________________________________
+                    |            |                  |         |
+   0000004000000000 | +256    GB | ffffffbfffffffff | ~16M TB | ... huge, almost 64 bits wide hole of non-canonical
+                    |            |                  |         |     virtual memory addresses up to the -256 GB
+                    |            |                  |         |     starting offset of kernel mappings.
+  __________________|____________|__________________|_________|___________________________________________________________
+                                                              |
+                                                              | Kernel-space virtual memory, shared between all processes:
+  ____________________________________________________________|___________________________________________________________
+                    |            |                  |         |
+   ffffffc000000000 | -256    GB | ffffffc7ffffffff |   32 GB | kasan
+   ffffffcefee00000 | -196    GB | ffffffcefeffffff |    2 MB | fixmap
+   ffffffceff000000 | -196    GB | ffffffceffffffff |   16 MB | PCI io
+   ffffffcf00000000 | -196    GB | ffffffcfffffffff |    4 GB | vmemmap
+   ffffffd000000000 | -192    GB | ffffffdfffffffff |   64 GB | vmalloc/ioremap space
+   ffffffe000000000 | -128    GB | ffffffff7fffffff |  124 GB | direct mapping of all physical memory
+  __________________|____________|__________________|_________|____________________________________________________________
+                                                              |
+                                                              |
+  ____________________________________________________________|____________________________________________________________
+                    |            |                  |         |
+   ffffffff00000000 |   -4    GB | ffffffff7fffffff |    2 GB | modules
+   ffffffff80000000 |   -2    GB | ffffffffffffffff |    2 GB | kernel, BPF
+  __________________|____________|__________________|_________|____________________________________________________________