RISC-V additional updates for v5.4-rc1

Some additional RISC-V updates for v5.4-rc1.  This includes one
 significant fix:
 
 - Prevent interrupts from being unconditionally re-enabled during
   exception handling if they were disabled in the context in which the
   exception occurred
 
 Also a few other fixes:
 
 - Fix a build error when sparse memory support is manually enabled
 
 - Prevent CPUs beyond CONFIG_NR_CPUS from being enabled in early boot
 
 And a few minor improvements:
 
 - DT improvements: in the FU540 SoC DT files, improve U-Boot
   compatibility by adding an "ethernet0" alias, drop an unnecessary
   property from the DT files, and add support for the PWM device
 
 - KVM preparation: add a KVM-related macro for future RISC-V KVM
   support, and export some symbols required to build KVM support as
   modules
 
 - defconfig additions: build more drivers by default for QEMU
   configurations
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Merge tag 'riscv/for-v5.4-rc1-b' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Paul Walmsley:
 "Some additional RISC-V updates.

  This includes one significant fix:

   - Prevent interrupts from being unconditionally re-enabled during
     exception handling if they were disabled in the context in which
     the exception occurred

  Also a few other fixes:

   - Fix a build error when sparse memory support is manually enabled

   - Prevent CPUs beyond CONFIG_NR_CPUS from being enabled in early boot

  And a few minor improvements:

   - DT improvements: in the FU540 SoC DT files, improve U-Boot
     compatibility by adding an "ethernet0" alias, drop an unnecessary
     property from the DT files, and add support for the PWM device

   - KVM preparation: add a KVM-related macro for future RISC-V KVM
     support, and export some symbols required to build KVM support as
     modules

   - defconfig additions: build more drivers by default for QEMU
     configurations"

* tag 'riscv/for-v5.4-rc1-b' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Avoid interrupts being erroneously enabled in handle_exception()
  riscv: dts: sifive: Drop "clock-frequency" property of cpu nodes
  riscv: dts: sifive: Add ethernet0 to the aliases node
  RISC-V: Export kernel symbols for kvm
  KVM: RISC-V: Add KVM_REG_RISCV for ONE_REG interface
  arch/riscv: disable excess harts before picking main boot hart
  RISC-V: Enable VIRTIO drivers in RV64 and RV32 defconfig
  RISC-V: Fix building error when CONFIG_SPARSEMEM_MANUAL=y
  riscv: dts: Add DT support for SiFive FU540 PWM driver

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

@@ -13,6 +13,7 @@
 	aliases {
 		serial0 = &uart0;
 		serial1 = &uart1;
+		ethernet0 = &eth0;
 	};
 
 	chosen {
@@ -60,7 +61,6 @@
 			};
 		};
 		cpu2: cpu@2 {
-			clock-frequency = <0>;
 			compatible = "sifive,u54-mc", "sifive,rocket0", "riscv";
 			d-cache-block-size = <64>;
 			d-cache-sets = <64>;
@@ -84,7 +84,6 @@
 			};
 		};
 		cpu3: cpu@3 {
-			clock-frequency = <0>;
 			compatible = "sifive,u54-mc", "sifive,rocket0", "riscv";
 			d-cache-block-size = <64>;
 			d-cache-sets = <64>;
@@ -108,7 +107,6 @@
 			};
 		};
 		cpu4: cpu@4 {
-			clock-frequency = <0>;
 			compatible = "sifive,u54-mc", "sifive,rocket0", "riscv";
 			d-cache-block-size = <64>;
 			d-cache-sets = <64>;
@@ -230,6 +228,24 @@
 			#size-cells = <0>;
 			status = "disabled";
 		};
+		pwm0: pwm@10020000 {
+			compatible = "sifive,fu540-c000-pwm", "sifive,pwm0";
+			reg = <0x0 0x10020000 0x0 0x1000>;
+			interrupt-parent = <&plic0>;
+			interrupts = <42 43 44 45>;
+			clocks = <&prci PRCI_CLK_TLCLK>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+		pwm1: pwm@10021000 {
+			compatible = "sifive,fu540-c000-pwm", "sifive,pwm0";
+			reg = <0x0 0x10021000 0x0 0x1000>;
+			interrupt-parent = <&plic0>;
+			interrupts = <46 47 48 49>;
+			clocks = <&prci PRCI_CLK_TLCLK>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
 
 	};
 };

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

@@ -85,3 +85,11 @@
 		reg = <0>;
 	};
 };
+
+&pwm0 {
+	status = "okay";
+};
+
+&pwm1 {
+	status = "okay";
+};

arch/riscv/configs/defconfig

@@ -29,6 +29,8 @@ CONFIG_IP_PNP_DHCP=y
 CONFIG_IP_PNP_BOOTP=y
 CONFIG_IP_PNP_RARP=y
 CONFIG_NETLINK_DIAG=y
+CONFIG_NET_9P=y
+CONFIG_NET_9P_VIRTIO=y
 CONFIG_PCI=y
 CONFIG_PCIEPORTBUS=y
 CONFIG_PCI_HOST_GENERIC=y
@@ -39,6 +41,7 @@ CONFIG_BLK_DEV_LOOP=y
 CONFIG_VIRTIO_BLK=y
 CONFIG_BLK_DEV_SD=y
 CONFIG_BLK_DEV_SR=y
+CONFIG_SCSI_VIRTIO=y
 CONFIG_ATA=y
 CONFIG_SATA_AHCI=y
 CONFIG_SATA_AHCI_PLATFORM=y
@@ -54,6 +57,7 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
 CONFIG_HVC_RISCV_SBI=y
+CONFIG_VIRTIO_CONSOLE=y
 CONFIG_HW_RANDOM=y
 CONFIG_HW_RANDOM_VIRTIO=y
 CONFIG_SPI=y
@@ -61,6 +65,7 @@ CONFIG_SPI_SIFIVE=y
 # CONFIG_PTP_1588_CLOCK is not set
 CONFIG_DRM=y
 CONFIG_DRM_RADEON=y
+CONFIG_DRM_VIRTIO_GPU=y
 CONFIG_FRAMEBUFFER_CONSOLE=y
 CONFIG_USB=y
 CONFIG_USB_XHCI_HCD=y
@@ -73,7 +78,12 @@ CONFIG_USB_STORAGE=y
 CONFIG_USB_UAS=y
 CONFIG_MMC=y
 CONFIG_MMC_SPI=y
+CONFIG_VIRTIO_PCI=y
+CONFIG_VIRTIO_BALLOON=y
+CONFIG_VIRTIO_INPUT=y
 CONFIG_VIRTIO_MMIO=y
+CONFIG_RPMSG_CHAR=y
+CONFIG_RPMSG_VIRTIO=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_AUTOFS4_FS=y
@@ -86,6 +96,7 @@ CONFIG_NFS_V4=y
 CONFIG_NFS_V4_1=y
 CONFIG_NFS_V4_2=y
 CONFIG_ROOT_NFS=y
+CONFIG_9P_FS=y
 CONFIG_CRYPTO_USER_API_HASH=y
 CONFIG_CRYPTO_DEV_VIRTIO=y
 CONFIG_PRINTK_TIME=y

arch/riscv/configs/rv32_defconfig

@@ -29,6 +29,8 @@ CONFIG_IP_PNP_DHCP=y
 CONFIG_IP_PNP_BOOTP=y
 CONFIG_IP_PNP_RARP=y
 CONFIG_NETLINK_DIAG=y
+CONFIG_NET_9P=y
+CONFIG_NET_9P_VIRTIO=y
 CONFIG_PCI=y
 CONFIG_PCIEPORTBUS=y
 CONFIG_PCI_HOST_GENERIC=y
@@ -39,6 +41,7 @@ CONFIG_BLK_DEV_LOOP=y
 CONFIG_VIRTIO_BLK=y
 CONFIG_BLK_DEV_SD=y
 CONFIG_BLK_DEV_SR=y
+CONFIG_SCSI_VIRTIO=y
 CONFIG_ATA=y
 CONFIG_SATA_AHCI=y
 CONFIG_SATA_AHCI_PLATFORM=y
@@ -54,11 +57,13 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
 CONFIG_HVC_RISCV_SBI=y
+CONFIG_VIRTIO_CONSOLE=y
 CONFIG_HW_RANDOM=y
 CONFIG_HW_RANDOM_VIRTIO=y
 # CONFIG_PTP_1588_CLOCK is not set
 CONFIG_DRM=y
 CONFIG_DRM_RADEON=y
+CONFIG_DRM_VIRTIO_GPU=y
 CONFIG_FRAMEBUFFER_CONSOLE=y
 CONFIG_USB=y
 CONFIG_USB_XHCI_HCD=y
@@ -69,7 +74,12 @@ CONFIG_USB_OHCI_HCD=y
 CONFIG_USB_OHCI_HCD_PLATFORM=y
 CONFIG_USB_STORAGE=y
 CONFIG_USB_UAS=y
+CONFIG_VIRTIO_PCI=y
+CONFIG_VIRTIO_BALLOON=y
+CONFIG_VIRTIO_INPUT=y
 CONFIG_VIRTIO_MMIO=y
+CONFIG_RPMSG_CHAR=y
+CONFIG_RPMSG_VIRTIO=y
 CONFIG_SIFIVE_PLIC=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
@@ -83,6 +93,7 @@ CONFIG_NFS_V4=y
 CONFIG_NFS_V4_1=y
 CONFIG_NFS_V4_2=y
 CONFIG_ROOT_NFS=y
+CONFIG_9P_FS=y
 CONFIG_CRYPTO_USER_API_HASH=y
 CONFIG_CRYPTO_DEV_VIRTIO=y
 CONFIG_PRINTK_TIME=y

arch/riscv/include/asm/pgtable.h

@@ -83,6 +83,18 @@ extern pgd_t swapper_pg_dir[];
 #define __S110	PAGE_SHARED_EXEC
 #define __S111	PAGE_SHARED_EXEC
 
+#define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
+#define VMALLOC_END      (PAGE_OFFSET - 1)
+#define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
+
+#define FIXADDR_TOP      VMALLOC_START
+#ifdef CONFIG_64BIT
+#define FIXADDR_SIZE     PMD_SIZE
+#else
+#define FIXADDR_SIZE     PGDIR_SIZE
+#endif
+#define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
+
 /*
  * Roughly size the vmemmap space to be large enough to fit enough
  * struct pages to map half the virtual address space. Then
@@ -424,18 +436,6 @@ extern void *dtb_early_va;
 extern void setup_bootmem(void);
 extern void paging_init(void);
 
-#define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
-#define VMALLOC_END      (PAGE_OFFSET - 1)
-#define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
-
-#define FIXADDR_TOP      VMALLOC_START
-#ifdef CONFIG_64BIT
-#define FIXADDR_SIZE     PMD_SIZE
-#else
-#define FIXADDR_SIZE     PGDIR_SIZE
-#endif
-#define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
-
 /*
  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.

arch/riscv/kernel/entry.S

@@ -166,9 +166,13 @@ ENTRY(handle_exception)
 	move a0, sp /* pt_regs */
 	tail do_IRQ
 1:
-	/* Exceptions run with interrupts enabled */
+	/* Exceptions run with interrupts enabled or disabled
+	   depending on the state of sstatus.SR_SPIE */
+	andi t0, s1, SR_SPIE
+	beqz t0, 1f
 	csrs CSR_SSTATUS, SR_SIE
 
+1:
 	/* Handle syscalls */
 	li t0, EXC_SYSCALL
 	beq s4, t0, handle_syscall

arch/riscv/kernel/head.S

@@ -63,6 +63,11 @@ _start_kernel:
 	li t0, SR_FS
 	csrc CSR_SSTATUS, t0
 
+#ifdef CONFIG_SMP
+	li t0, CONFIG_NR_CPUS
+	bgeu a0, t0, .Lsecondary_park
+#endif
+
 	/* Pick one hart to run the main boot sequence */
 	la a3, hart_lottery
 	li a2, 1
@@ -154,9 +159,6 @@ relocate:
 
 .Lsecondary_start:
 #ifdef CONFIG_SMP
-	li a1, CONFIG_NR_CPUS
-	bgeu a0, a1, .Lsecondary_park
-
 	/* Set trap vector to spin forever to help debug */
 	la a3, .Lsecondary_park
 	csrw CSR_STVEC, a3

arch/riscv/kernel/smp.c

@@ -206,3 +206,4 @@ void smp_send_reschedule(int cpu)
 {
 	send_ipi_single(cpu, IPI_RESCHEDULE);
 }
+EXPORT_SYMBOL_GPL(smp_send_reschedule);

arch/riscv/kernel/time.c

@@ -9,6 +9,7 @@
 #include <asm/sbi.h>
 
 unsigned long riscv_timebase;
+EXPORT_SYMBOL_GPL(riscv_timebase);
 
 void __init time_init(void)
 {

include/uapi/linux/kvm.h

@@ -1146,6 +1146,7 @@ struct kvm_dirty_tlb {
 #define KVM_REG_S390		0x5000000000000000ULL
 #define KVM_REG_ARM64		0x6000000000000000ULL
 #define KVM_REG_MIPS		0x7000000000000000ULL
+#define KVM_REG_RISCV		0x8000000000000000ULL
 
 #define KVM_REG_SIZE_SHIFT	52
 #define KVM_REG_SIZE_MASK	0x00f0000000000000ULL