RISC-V patches for v5.2-rc6

This tag contains fixes, defconfig, and DT data changes for the v5.2-rc
 series.  The fixes are relatively straightforward:
 
 - Addition of a TLB fence in the vmalloc_fault path, so the CPU doesn't
   enter an infinite page fault loop;
 - Readdition of the pm_power_off export, so device drivers that
   reassign it can now be built as modules;
 - A udelay() fix for RV32, fixing a miscomputation of the delay time;
 - Removal of deprecated smp_mb__*() barriers.
 
 The tag also adds initial DT data infrastructure for arch/riscv, along
 with initial data for the SiFive FU540-C000 SoC and the corresponding
 HiFive Unleashed board.
 
 We also update the RV64 defconfig to include some core drivers for the
 FU540 in the build.
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Merge tag 'riscv-for-v5.2/fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Paul Walmsley:
 "This contains fixes, defconfig, and DT data changes for the v5.2-rc
  series.

  The fixes are relatively straightforward:

   - Addition of a TLB fence in the vmalloc_fault path, so the CPU
     doesn't enter an infinite page fault loop

   - Readdition of the pm_power_off export, so device drivers that
     reassign it can now be built as modules

   - A udelay() fix for RV32, fixing a miscomputation of the delay time

   - Removal of deprecated smp_mb__*() barriers

  This also adds initial DT data infrastructure for arch/riscv, along
  with initial data for the SiFive FU540-C000 SoC and the corresponding
  HiFive Unleashed board.

  We also update the RV64 defconfig to include some core drivers for the
  FU540 in the build"

* tag 'riscv-for-v5.2/fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: remove unused barrier defines
  riscv: mm: synchronize MMU after pte change
  riscv: dts: add initial board data for the SiFive HiFive Unleashed
  riscv: dts: add initial support for the SiFive FU540-C000 SoC
  dt-bindings: riscv: convert cpu binding to json-schema
  dt-bindings: riscv: sifive: add YAML documentation for the SiFive FU540
  arch: riscv: add support for building DTB files from DT source data
  riscv: Fix udelay in RV32.
  riscv: export pm_power_off again
  RISC-V: defconfig: enable clocks, serial console

Documentation/devicetree/bindings/riscv/cpus.yaml

@@ -0,0 +1,168 @@
+# SPDX-License-Identifier: (GPL-2.0 OR MIT)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/riscv/cpus.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V bindings for 'cpus' DT nodes
+
+maintainers:
+  - Paul Walmsley <paul.walmsley@sifive.com>
+  - Palmer Dabbelt <palmer@sifive.com>
+
+allOf:
+  - $ref: /schemas/cpus.yaml#
+
+properties:
+  $nodename:
+    const: cpus
+    description: Container of cpu nodes
+
+  '#address-cells':
+    const: 1
+    description: |
+      A single unsigned 32-bit integer uniquely identifies each RISC-V
+      hart in a system.  (See the "reg" node under the "cpu" node,
+      below).
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  '^cpu@[0-9a-f]+$':
+    properties:
+      compatible:
+        type: array
+        items:
+          - enum:
+              - sifive,rocket0
+              - sifive,e5
+              - sifive,e51
+              - sifive,u54-mc
+              - sifive,u54
+              - sifive,u5
+          - const: riscv
+        description:
+          Identifies that the hart uses the RISC-V instruction set
+          and identifies the type of the hart.
+
+      mmu-type:
+        allOf:
+          - $ref: "/schemas/types.yaml#/definitions/string"
+          - enum:
+              - riscv,sv32
+              - riscv,sv39
+              - riscv,sv48
+        description:
+          Identifies the MMU address translation mode used on this
+          hart.  These values originate from the RISC-V Privileged
+          Specification document, available from
+          https://riscv.org/specifications/
+
+      riscv,isa:
+        allOf:
+          - $ref: "/schemas/types.yaml#/definitions/string"
+          - enum:
+              - rv64imac
+              - rv64imafdc
+        description:
+          Identifies the specific RISC-V instruction set architecture
+          supported by the hart.  These are documented in the RISC-V
+          User-Level ISA document, available from
+          https://riscv.org/specifications/
+
+      timebase-frequency:
+        type: integer
+        minimum: 1
+        description:
+          Specifies the clock frequency of the system timer in Hz.
+          This value is common to all harts on a single system image.
+
+      interrupt-controller:
+        type: object
+        description: Describes the CPU's local interrupt controller
+
+        properties:
+          '#interrupt-cells':
+            const: 1
+
+          compatible:
+            const: riscv,cpu-intc
+
+          interrupt-controller: true
+
+        required:
+          - '#interrupt-cells'
+          - compatible
+          - interrupt-controller
+
+    required:
+      - riscv,isa
+      - timebase-frequency
+      - interrupt-controller
+
+examples:
+  - |
+    // Example 1: SiFive Freedom U540G Development Kit
+    cpus {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        timebase-frequency = <1000000>;
+        cpu@0 {
+                clock-frequency = <0>;
+                compatible = "sifive,rocket0", "riscv";
+                device_type = "cpu";
+                i-cache-block-size = <64>;
+                i-cache-sets = <128>;
+                i-cache-size = <16384>;
+                reg = <0>;
+                riscv,isa = "rv64imac";
+                cpu_intc0: interrupt-controller {
+                        #interrupt-cells = <1>;
+                        compatible = "riscv,cpu-intc";
+                        interrupt-controller;
+                };
+        };
+        cpu@1 {
+                clock-frequency = <0>;
+                compatible = "sifive,rocket0", "riscv";
+                d-cache-block-size = <64>;
+                d-cache-sets = <64>;
+                d-cache-size = <32768>;
+                d-tlb-sets = <1>;
+                d-tlb-size = <32>;
+                device_type = "cpu";
+                i-cache-block-size = <64>;
+                i-cache-sets = <64>;
+                i-cache-size = <32768>;
+                i-tlb-sets = <1>;
+                i-tlb-size = <32>;
+                mmu-type = "riscv,sv39";
+                reg = <1>;
+                riscv,isa = "rv64imafdc";
+                tlb-split;
+                cpu_intc1: interrupt-controller {
+                        #interrupt-cells = <1>;
+                        compatible = "riscv,cpu-intc";
+                        interrupt-controller;
+                };
+        };
+    };
+
+  - |
+    // Example 2: Spike ISA Simulator with 1 Hart
+    cpus {
+            cpu@0 {
+                    device_type = "cpu";
+                    reg = <0>;
+                    compatible = "riscv";
+                    riscv,isa = "rv64imafdc";
+                    mmu-type = "riscv,sv48";
+                    interrupt-controller {
+                            #interrupt-cells = <1>;
+                            interrupt-controller;
+                            compatible = "riscv,cpu-intc";
+                    };
+            };
+    };
+...

Documentation/devicetree/bindings/riscv/sifive.yaml

@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: (GPL-2.0 OR MIT)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/riscv/sifive.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SiFive SoC-based boards
+
+maintainers:
+  - Paul Walmsley <paul.walmsley@sifive.com>
+  - Palmer Dabbelt <palmer@sifive.com>
+
+description:
+  SiFive SoC-based boards
+
+properties:
+  $nodename:
+    const: '/'
+  compatible:
+    items:
+      - enum:
+          - sifive,freedom-unleashed-a00
+      - const: sifive,fu540-c000
+      - const: sifive,fu540
+...

MAINTAINERS

@@ -14335,6 +14335,15 @@ S:	Supported
 K:	sifive
 N:	sifive
 
+SIFIVE FU540 SYSTEM-ON-CHIP
+M:	Paul Walmsley <paul.walmsley@sifive.com>
+M:	Palmer Dabbelt <palmer@sifive.com>
+L:	linux-riscv@lists.infradead.org
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/pjw/sifive.git
+S:	Supported
+K:	fu540
+N:	fu540
+
 SILEAD TOUCHSCREEN DRIVER
 M:	Hans de Goede <hdegoede@redhat.com>
 L:	linux-input@vger.kernel.org

arch/riscv/boot/dts/Makefile

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+subdir-y += sifive

arch/riscv/boot/dts/sifive/Makefile

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+dtb-y += hifive-unleashed-a00.dtb

arch/riscv/boot/dts/sifive/fu540-c000.dtsi

@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/* Copyright (c) 2018-2019 SiFive, Inc */
+
+/dts-v1/;
+
+#include <dt-bindings/clock/sifive-fu540-prci.h>
+
+/ {
+	#address-cells = <2>;
+	#size-cells = <2>;
+	compatible = "sifive,fu540-c000", "sifive,fu540";
+
+	aliases {
+		serial0 = &uart0;
+		serial1 = &uart1;
+	};
+
+	chosen {
+	};
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		timebase-frequency = <1000000>;
+		cpu0: cpu@0 {
+			compatible = "sifive,e51", "sifive,rocket0", "riscv";
+			device_type = "cpu";
+			i-cache-block-size = <64>;
+			i-cache-sets = <128>;
+			i-cache-size = <16384>;
+			reg = <0>;
+			riscv,isa = "rv64imac";
+			status = "disabled";
+			cpu0_intc: interrupt-controller {
+				#interrupt-cells = <1>;
+				compatible = "riscv,cpu-intc";
+				interrupt-controller;
+			};
+		};
+		cpu1: cpu@1 {
+			compatible = "sifive,u54-mc", "sifive,rocket0", "riscv";
+			d-cache-block-size = <64>;
+			d-cache-sets = <64>;
+			d-cache-size = <32768>;
+			d-tlb-sets = <1>;
+			d-tlb-size = <32>;
+			device_type = "cpu";
+			i-cache-block-size = <64>;
+			i-cache-sets = <64>;
+			i-cache-size = <32768>;
+			i-tlb-sets = <1>;
+			i-tlb-size = <32>;
+			mmu-type = "riscv,sv39";
+			reg = <1>;
+			riscv,isa = "rv64imafdc";
+			tlb-split;
+			cpu1_intc: interrupt-controller {
+				#interrupt-cells = <1>;
+				compatible = "riscv,cpu-intc";
+				interrupt-controller;
+			};
+		};
+		cpu2: cpu@2 {
+			clock-frequency = <0>;
+			compatible = "sifive,u54-mc", "sifive,rocket0", "riscv";
+			d-cache-block-size = <64>;
+			d-cache-sets = <64>;
+			d-cache-size = <32768>;
+			d-tlb-sets = <1>;
+			d-tlb-size = <32>;
+			device_type = "cpu";
+			i-cache-block-size = <64>;
+			i-cache-sets = <64>;
+			i-cache-size = <32768>;
+			i-tlb-sets = <1>;
+			i-tlb-size = <32>;
+			mmu-type = "riscv,sv39";
+			reg = <2>;
+			riscv,isa = "rv64imafdc";
+			tlb-split;
+			cpu2_intc: interrupt-controller {
+				#interrupt-cells = <1>;
+				compatible = "riscv,cpu-intc";
+				interrupt-controller;
+			};
+		};
+		cpu3: cpu@3 {
+			clock-frequency = <0>;
+			compatible = "sifive,u54-mc", "sifive,rocket0", "riscv";
+			d-cache-block-size = <64>;
+			d-cache-sets = <64>;
+			d-cache-size = <32768>;
+			d-tlb-sets = <1>;
+			d-tlb-size = <32>;
+			device_type = "cpu";
+			i-cache-block-size = <64>;
+			i-cache-sets = <64>;
+			i-cache-size = <32768>;
+			i-tlb-sets = <1>;
+			i-tlb-size = <32>;
+			mmu-type = "riscv,sv39";
+			reg = <3>;
+			riscv,isa = "rv64imafdc";
+			tlb-split;
+			cpu3_intc: interrupt-controller {
+				#interrupt-cells = <1>;
+				compatible = "riscv,cpu-intc";
+				interrupt-controller;
+			};
+		};
+		cpu4: cpu@4 {
+			clock-frequency = <0>;
+			compatible = "sifive,u54-mc", "sifive,rocket0", "riscv";
+			d-cache-block-size = <64>;
+			d-cache-sets = <64>;
+			d-cache-size = <32768>;
+			d-tlb-sets = <1>;
+			d-tlb-size = <32>;
+			device_type = "cpu";
+			i-cache-block-size = <64>;
+			i-cache-sets = <64>;
+			i-cache-size = <32768>;
+			i-tlb-sets = <1>;
+			i-tlb-size = <32>;
+			mmu-type = "riscv,sv39";
+			reg = <4>;
+			riscv,isa = "rv64imafdc";
+			tlb-split;
+			cpu4_intc: interrupt-controller {
+				#interrupt-cells = <1>;
+				compatible = "riscv,cpu-intc";
+				interrupt-controller;
+			};
+		};
+	};
+	soc {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		compatible = "sifive,fu540-c000", "sifive,fu540", "simple-bus";
+		ranges;
+		plic0: interrupt-controller@c000000 {
+			#interrupt-cells = <1>;
+			compatible = "sifive,plic-1.0.0";
+			reg = <0x0 0xc000000 0x0 0x4000000>;
+			riscv,ndev = <53>;
+			interrupt-controller;
+			interrupts-extended = <
+				&cpu0_intc 0xffffffff
+				&cpu1_intc 0xffffffff &cpu1_intc 9
+				&cpu2_intc 0xffffffff &cpu2_intc 9
+				&cpu3_intc 0xffffffff &cpu3_intc 9
+				&cpu4_intc 0xffffffff &cpu4_intc 9>;
+		};
+		prci: clock-controller@10000000 {
+			compatible = "sifive,fu540-c000-prci";
+			reg = <0x0 0x10000000 0x0 0x1000>;
+			clocks = <&hfclk>, <&rtcclk>;
+			#clock-cells = <1>;
+		};
+		uart0: serial@10010000 {
+			compatible = "sifive,fu540-c000-uart", "sifive,uart0";
+			reg = <0x0 0x10010000 0x0 0x1000>;
+			interrupt-parent = <&plic0>;
+			interrupts = <4>;
+			clocks = <&prci PRCI_CLK_TLCLK>;
+		};
+		uart1: serial@10011000 {
+			compatible = "sifive,fu540-c000-uart", "sifive,uart0";
+			reg = <0x0 0x10011000 0x0 0x1000>;
+			interrupt-parent = <&plic0>;
+			interrupts = <5>;
+			clocks = <&prci PRCI_CLK_TLCLK>;
+		};
+		i2c0: i2c@10030000 {
+			compatible = "sifive,fu540-c000-i2c", "sifive,i2c0";
+			reg = <0x0 0x10030000 0x0 0x1000>;
+			interrupt-parent = <&plic0>;
+			interrupts = <50>;
+			clocks = <&prci PRCI_CLK_TLCLK>;
+			reg-shift = <2>;
+			reg-io-width = <1>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+		qspi0: spi@10040000 {
+			compatible = "sifive,fu540-c000-spi", "sifive,spi0";
+			reg = <0x0 0x10040000 0x0 0x1000
+			       0x0 0x20000000 0x0 0x10000000>;
+			interrupt-parent = <&plic0>;
+			interrupts = <51>;
+			clocks = <&prci PRCI_CLK_TLCLK>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+		qspi1: spi@10041000 {
+			compatible = "sifive,fu540-c000-spi", "sifive,spi0";
+			reg = <0x0 0x10041000 0x0 0x1000
+			       0x0 0x30000000 0x0 0x10000000>;
+			interrupt-parent = <&plic0>;
+			interrupts = <52>;
+			clocks = <&prci PRCI_CLK_TLCLK>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+		qspi2: spi@10050000 {
+			compatible = "sifive,fu540-c000-spi", "sifive,spi0";
+			reg = <0x0 0x10050000 0x0 0x1000>;
+			interrupt-parent = <&plic0>;
+			interrupts = <6>;
+			clocks = <&prci PRCI_CLK_TLCLK>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+	};
+};

arch/riscv/boot/dts/sifive/hifive-unleashed-a00.dts

@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/* Copyright (c) 2018-2019 SiFive, Inc */
+
+#include "fu540-c000.dtsi"
+
+/* Clock frequency (in Hz) of the PCB crystal for rtcclk */
+#define RTCCLK_FREQ		1000000
+
+/ {
+	#address-cells = <2>;
+	#size-cells = <2>;
+	model = "SiFive HiFive Unleashed A00";
+	compatible = "sifive,hifive-unleashed-a00", "sifive,fu540-c000";
+
+	chosen {
+	};
+
+	cpus {
+		timebase-frequency = <RTCCLK_FREQ>;
+	};
+
+	memory@80000000 {
+		device_type = "memory";
+		reg = <0x0 0x80000000 0x2 0x00000000>;
+	};
+
+	soc {
+	};
+
+	hfclk: hfclk {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <33333333>;
+		clock-output-names = "hfclk";
+	};
+
+	rtcclk: rtcclk {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <RTCCLK_FREQ>;
+		clock-output-names = "rtcclk";
+	};
+};
+
+&qspi0 {
+	flash@0 {
+		compatible = "issi,is25wp256", "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <50000000>;
+		m25p,fast-read;
+		spi-tx-bus-width = <4>;
+		spi-rx-bus-width = <4>;
+	};
+};
+
+&qspi2 {
+	status = "okay";
+	mmc@0 {
+		compatible = "mmc-spi-slot";
+		reg = <0>;
+		spi-max-frequency = <20000000>;
+		voltage-ranges = <3300 3300>;
+		disable-wp;
+	};
+};

arch/riscv/configs/defconfig

@@ -49,6 +49,8 @@ CONFIG_SERIAL_8250=y
 CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
+CONFIG_SERIAL_SIFIVE=y
+CONFIG_SERIAL_SIFIVE_CONSOLE=y
 CONFIG_HVC_RISCV_SBI=y
 # CONFIG_PTP_1588_CLOCK is not set
 CONFIG_DRM=y
@@ -64,6 +66,8 @@ CONFIG_USB_OHCI_HCD_PLATFORM=y
 CONFIG_USB_STORAGE=y
 CONFIG_USB_UAS=y
 CONFIG_VIRTIO_MMIO=y
+CONFIG_CLK_SIFIVE=y
+CONFIG_CLK_SIFIVE_FU540_PRCI=y
 CONFIG_SIFIVE_PLIC=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y

arch/riscv/include/asm/bitops.h

@@ -15,11 +15,6 @@
 #include <asm/barrier.h>
 #include <asm/bitsperlong.h>
 
-#ifndef smp_mb__before_clear_bit
-#define smp_mb__before_clear_bit()  smp_mb()
-#define smp_mb__after_clear_bit()   smp_mb()
-#endif /* smp_mb__before_clear_bit */
-
 #include <asm-generic/bitops/__ffs.h>
 #include <asm-generic/bitops/ffz.h>
 #include <asm-generic/bitops/fls.h>

arch/riscv/kernel/reset.c

@@ -13,6 +13,7 @@ static void default_power_off(void)
 }
 
 void (*pm_power_off)(void) = default_power_off;
+EXPORT_SYMBOL(pm_power_off);
 
 void machine_restart(char *cmd)
 {

arch/riscv/lib/delay.c

@@ -80,7 +80,7 @@ EXPORT_SYMBOL(__delay);
 
 void udelay(unsigned long usecs)
 {
-	unsigned long ucycles = usecs * lpj_fine * UDELAY_MULT;
+	u64 ucycles = (u64)usecs * lpj_fine * UDELAY_MULT;
 
 	if (unlikely(usecs > MAX_UDELAY_US)) {
 		__delay((u64)usecs * riscv_timebase / 1000000ULL);

arch/riscv/mm/fault.c

@@ -16,6 +16,7 @@
 
 #include <asm/pgalloc.h>
 #include <asm/ptrace.h>
+#include <asm/tlbflush.h>
 
 /*
  * This routine handles page faults.  It determines the address and the
@@ -265,6 +266,18 @@ vmalloc_fault:
 		pte_k = pte_offset_kernel(pmd_k, addr);
 		if (!pte_present(*pte_k))
 			goto no_context;
+
+		/*
+		 * The kernel assumes that TLBs don't cache invalid
+		 * entries, but in RISC-V, SFENCE.VMA specifies an
+		 * ordering constraint, not a cache flush; it is
+		 * necessary even after writing invalid entries.
+		 * Relying on flush_tlb_fix_spurious_fault would
+		 * suffice, but the extra traps reduce
+		 * performance. So, eagerly SFENCE.VMA.
+		 */
+		local_flush_tlb_page(addr);
+
 		return;
 	}
 }