Merge tag 'riscv/for-v5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Paul Walmsley:

 - Two patches to fix significant bugs in floating point register
   context handling

 - A minor fix in RISC-V flush_tlb_page(), to supply a valid end address
   to flush_tlb_range()

 - Two minor defconfig additions: to build the virtio hwrng driver by
   default (for QEMU targets), and to partially synchronize the 32-bit
   defconfig with the 64-bit defconfig

* tag 'riscv/for-v5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Make __fstate_clean() work correctly.
  riscv: Correct the initialized flow of FP register
  riscv: defconfig: Update the defconfig
  riscv: rv32_defconfig: Update the defconfig
  riscv: fix flush_tlb_range() end address for flush_tlb_page()

5 files changed, 30 insertions, 5 deletions

diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig
index 93205c0bf71d..3efff552a261 100644
--- a/arch/riscv/configs/defconfig
+++ b/arch/riscv/configs/defconfig
@@ -54,6 +54,8 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
 CONFIG_HVC_RISCV_SBI=y
+CONFIG_HW_RANDOM=y
+CONFIG_HW_RANDOM_VIRTIO=y
 CONFIG_SPI=y
 CONFIG_SPI_SIFIVE=y
 # CONFIG_PTP_1588_CLOCK is not set
diff --git a/arch/riscv/configs/rv32_defconfig b/arch/riscv/configs/rv32_defconfig
index d5449ef805a3..7da93e494445 100644
--- a/arch/riscv/configs/rv32_defconfig
+++ b/arch/riscv/configs/rv32_defconfig
@@ -34,6 +34,7 @@ CONFIG_PCIEPORTBUS=y
 CONFIG_PCI_HOST_GENERIC=y
 CONFIG_PCIE_XILINX=y
 CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
 CONFIG_BLK_DEV_LOOP=y
 CONFIG_VIRTIO_BLK=y
 CONFIG_BLK_DEV_SD=y
@@ -53,6 +54,8 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
 CONFIG_HVC_RISCV_SBI=y
+CONFIG_HW_RANDOM=y
+CONFIG_HW_RANDOM_VIRTIO=y
 # CONFIG_PTP_1588_CLOCK is not set
 CONFIG_DRM=y
 CONFIG_DRM_RADEON=y
diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
index 853b65ef656d..f0227bdce0f0 100644
--- a/arch/riscv/include/asm/switch_to.h
+++ b/arch/riscv/include/asm/switch_to.h
@@ -16,7 +16,13 @@ extern void __fstate_restore(struct task_struct *restore_from);
 
 static inline void __fstate_clean(struct pt_regs *regs)
 {
-	regs->sstatus |= (regs->sstatus & ~(SR_FS)) | SR_FS_CLEAN;
+	regs->sstatus = (regs->sstatus & ~SR_FS) | SR_FS_CLEAN;
+}
+
+static inline void fstate_off(struct task_struct *task,
+			      struct pt_regs *regs)
+{
+	regs->sstatus = (regs->sstatus & ~SR_FS) | SR_FS_OFF;
 }
 
 static inline void fstate_save(struct task_struct *task,
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index 687dd19735a7..4d9bbe8438bf 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -53,10 +53,17 @@ static inline void remote_sfence_vma(struct cpumask *cmask, unsigned long start,
 }
 
 #define flush_tlb_all() sbi_remote_sfence_vma(NULL, 0, -1)
-#define flush_tlb_page(vma, addr) flush_tlb_range(vma, addr, 0)
+
 #define flush_tlb_range(vma, start, end) \
 	remote_sfence_vma(mm_cpumask((vma)->vm_mm), start, (end) - (start))
-#define flush_tlb_mm(mm) \
+
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+				  unsigned long addr)
+{
+	flush_tlb_range(vma, addr, addr + PAGE_SIZE);
+}
+
+#define flush_tlb_mm(mm)				\
 	remote_sfence_vma(mm_cpumask(mm), 0, -1)
 
 #endif /* CONFIG_SMP */
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index f23794bd1e90..fb3a082362eb 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -64,8 +64,14 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
 	unsigned long sp)
 {
 	regs->sstatus = SR_SPIE;
-	if (has_fpu)
+	if (has_fpu) {
 		regs->sstatus |= SR_FS_INITIAL;
+		/*
+		 * Restore the initial value to the FP register
+		 * before starting the user program.
+		 */
+		fstate_restore(current, regs);
+	}
 	regs->sepc = pc;
 	regs->sp = sp;
 	set_fs(USER_DS);
@@ -75,10 +81,11 @@ void flush_thread(void)
 {
 #ifdef CONFIG_FPU
 	/*
-	 * Reset FPU context
+	 * Reset FPU state and context
 	 *	frm: round to nearest, ties to even (IEEE default)
 	 *	fflags: accrued exceptions cleared
 	 */
+	fstate_off(current, task_pt_regs(current));
 	memset(&current->thread.fstate, 0, sizeof(current->thread.fstate));
 #endif
 }