Merge tag 'riscv-for-linus-5.8-mw1' of git://git.kernel.org/pub/scm/l…

…inux/kernel/git/riscv/linux

Pull more RISC-V updates from Palmer Dabbelt:

 - Kconfig select statements are now sorted alphanumerically

 - first-level interrupts are now handled via a full irqchip driver

 - CPU hotplug is fixed

 - vDSO calls now use the common vDSO infrastructure

* tag 'riscv-for-linus-5.8-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: set the permission of vdso_data to read-only
  riscv: use vDSO common flow to reduce the latency of the time-related functions
  riscv: fix build warning of missing prototypes
  RISC-V: Don't mark init section as non-executable
  RISC-V: Force select RISCV_INTC for CONFIG_RISCV
  RISC-V: Remove do_IRQ() function
  clocksource/drivers/timer-riscv: Use per-CPU timer interrupt
  irqchip: RISC-V per-HART local interrupt controller driver
  RISC-V: Rename and move plic_find_hart_id() to arch directory
  RISC-V: self-contained IPI handling routine
  RISC-V: Sort select statements alphanumerically

arch/riscv/Kconfig

@@ -12,64 +12,70 @@ config 32BIT
 
 config RISCV
 	def_bool y
-	select OF
-	select OF_EARLY_FLATTREE
-	select OF_IRQ
+	select ARCH_CLOCKSOURCE_INIT
 	select ARCH_HAS_BINFMT_FLAT
+	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEBUG_WX
+	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_GIGANTIC_PAGE
+	select ARCH_HAS_MMIOWB
+	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_SET_DIRECT_MAP
+	select ARCH_HAS_SET_MEMORY
+	select ARCH_HAS_STRICT_KERNEL_RWX if MMU
+	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
 	select ARCH_WANT_FRAME_POINTERS
+	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
 	select CLONE_BACKWARDS
 	select COMMON_CLK
+	select EDAC_SUPPORT
+	select GENERIC_ARCH_TOPOLOGY if SMP
+	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_CLOCKEVENTS
+	select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
+	select GENERIC_IOREMAP
+	select GENERIC_IRQ_MULTI_HANDLER
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP
+	select GENERIC_PTDUMP if MMU
 	select GENERIC_SCHED_CLOCK
+	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_STRNCPY_FROM_USER if MMU
 	select GENERIC_STRNLEN_USER if MMU
-	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_ATOMIC64 if !64BIT
-	select GENERIC_IOREMAP
-	select GENERIC_PTDUMP if MMU
+	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
+	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_AUDITSYSCALL
+	select HAVE_ARCH_KASAN if MMU && 64BIT
+	select HAVE_ARCH_KGDB
+	select HAVE_ARCH_KGDB_QXFER_PKT
+	select HAVE_ARCH_MMAP_RND_BITS if MMU
 	select HAVE_ARCH_SECCOMP_FILTER
+	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ASM_MODVERSIONS
+	select HAVE_COPY_THREAD_TLS
 	select HAVE_DMA_CONTIGUOUS if MMU
+	select HAVE_EBPF_JIT if MMU
 	select HAVE_FUTEX_CMPXCHG if FUTEX
+	select HAVE_GENERIC_VDSO if MMU && 64BIT
+	select HAVE_PCI
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_SYSCALL_TRACEPOINTS
 	select IRQ_DOMAIN
-	select SPARSE_IRQ
-	select SYSCTL_EXCEPTION_TRACE
-	select HAVE_ARCH_TRACEHOOK
-	select HAVE_PCI
 	select MODULES_USE_ELF_RELA if MODULES
 	select MODULE_SECTIONS if MODULES
-	select THREAD_INFO_IN_TASK
+	select OF
+	select OF_EARLY_FLATTREE
+	select OF_IRQ
 	select PCI_DOMAINS_GENERIC if PCI
 	select PCI_MSI if PCI
+	select RISCV_INTC
 	select RISCV_TIMER
-	select GENERIC_IRQ_MULTI_HANDLER
-	select GENERIC_ARCH_TOPOLOGY if SMP
-	select ARCH_HAS_PTE_SPECIAL
-	select ARCH_HAS_MMIOWB
-	select ARCH_HAS_DEBUG_VIRTUAL if MMU
-	select HAVE_EBPF_JIT if MMU
-	select EDAC_SUPPORT
-	select ARCH_HAS_GIGANTIC_PAGE
-	select ARCH_HAS_SET_DIRECT_MAP
-	select ARCH_HAS_SET_MEMORY
-	select ARCH_HAS_STRICT_KERNEL_RWX if MMU
-	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
 	select SPARSEMEM_STATIC if 32BIT
-	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
-	select HAVE_ARCH_MMAP_RND_BITS if MMU
-	select ARCH_HAS_GCOV_PROFILE_ALL
-	select HAVE_COPY_THREAD_TLS
-	select HAVE_ARCH_KASAN if MMU && 64BIT
-	select HAVE_ARCH_KGDB
-	select HAVE_ARCH_KGDB_QXFER_PKT
+	select SPARSE_IRQ
+	select SYSCTL_EXCEPTION_TRACE
+	select THREAD_INFO_IN_TASK
 
 config ARCH_MMAP_RND_BITS_MIN
 	default 18 if 64BIT
@@ -196,11 +202,11 @@ config ARCH_RV64I
 	bool "RV64I"
 	select 64BIT
 	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
-	select HAVE_FUNCTION_TRACER
-	select HAVE_FUNCTION_GRAPH_TRACER
-	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_DYNAMIC_FTRACE if MMU
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
+	select HAVE_FTRACE_MCOUNT_RECORD
+	select HAVE_FUNCTION_GRAPH_TRACER
+	select HAVE_FUNCTION_TRACER
 	select SWIOTLB if MMU
 
 endchoice

arch/riscv/include/asm/clocksource.h

@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_CLOCKSOURCE_H
+#define _ASM_CLOCKSOURCE_H
+
+#include <asm/vdso/clocksource.h>
+
+#endif

arch/riscv/include/asm/irq.h

@@ -10,11 +10,6 @@
 #include <linux/interrupt.h>
 #include <linux/linkage.h>
 
-#define NR_IRQS         0
-
-void riscv_timer_interrupt(void);
-void riscv_software_interrupt(void);
-
 #include <asm-generic/irq.h>
 
 #endif /* _ASM_RISCV_IRQ_H */

arch/riscv/include/asm/processor.h

@@ -8,6 +8,8 @@
 
 #include <linux/const.h>
 
+#include <vdso/processor.h>
+
 #include <asm/ptrace.h>
 
 /*
@@ -58,23 +60,14 @@ static inline void release_thread(struct task_struct *dead_task)
 extern unsigned long get_wchan(struct task_struct *p);
 
 
-static inline void cpu_relax(void)
-{
-#ifdef __riscv_muldiv
-	int dummy;
-	/* In lieu of a halt instruction, induce a long-latency stall. */
-	__asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
-#endif
-	barrier();
-}
-
 static inline void wait_for_interrupt(void)
 {
 	__asm__ __volatile__ ("wfi");
 }
 
 struct device_node;
 int riscv_of_processor_hartid(struct device_node *node);
+int riscv_of_parent_hartid(struct device_node *node);
 
 extern void riscv_fill_hwcap(void);
 

arch/riscv/include/asm/smp.h

@@ -28,6 +28,9 @@ void show_ipi_stats(struct seq_file *p, int prec);
 /* SMP initialization hook for setup_arch */
 void __init setup_smp(void);
 
+/* Called from C code, this handles an IPI. */
+void handle_IPI(struct pt_regs *regs);
+
 /* Hook for the generic smp_call_function_many() routine. */
 void arch_send_call_function_ipi_mask(struct cpumask *mask);
 

arch/riscv/include/asm/vdso.h

@@ -10,8 +10,10 @@
 
 #include <linux/types.h>
 
+#ifndef GENERIC_TIME_VSYSCALL
 struct vdso_data {
 };
+#endif
 
 /*
  * The VDSO symbols are mapped into Linux so we can just use regular symbol

arch/riscv/include/asm/vdso/clocksource.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_VDSOCLOCKSOURCE_H
+#define __ASM_VDSOCLOCKSOURCE_H
+
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
+
+#endif

arch/riscv/include/asm/vdso/gettimeofday.h

@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_VDSO_GETTIMEOFDAY_H
+#define __ASM_VDSO_GETTIMEOFDAY_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/unistd.h>
+#include <asm/csr.h>
+#include <uapi/linux/time.h>
+
+#define VDSO_HAS_CLOCK_GETRES	1
+
+static __always_inline
+int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
+			  struct timezone *_tz)
+{
+	register struct __kernel_old_timeval *tv asm("a0") = _tv;
+	register struct timezone *tz asm("a1") = _tz;
+	register long ret asm("a0");
+	register long nr asm("a7") = __NR_gettimeofday;
+
+	asm volatile ("ecall\n"
+		      : "=r" (ret)
+		      : "r"(tv), "r"(tz), "r"(nr)
+		      : "memory");
+
+	return ret;
+}
+
+static __always_inline
+long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
+{
+	register clockid_t clkid asm("a0") = _clkid;
+	register struct __kernel_timespec *ts asm("a1") = _ts;
+	register long ret asm("a0");
+	register long nr asm("a7") = __NR_clock_gettime;
+
+	asm volatile ("ecall\n"
+		      : "=r" (ret)
+		      : "r"(clkid), "r"(ts), "r"(nr)
+		      : "memory");
+
+	return ret;
+}
+
+static __always_inline
+int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
+{
+	register clockid_t clkid asm("a0") = _clkid;
+	register struct __kernel_timespec *ts asm("a1") = _ts;
+	register long ret asm("a0");
+	register long nr asm("a7") = __NR_clock_getres;
+
+	asm volatile ("ecall\n"
+		      : "=r" (ret)
+		      : "r"(clkid), "r"(ts), "r"(nr)
+		      : "memory");
+
+	return ret;
+}
+
+static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
+{
+	/*
+	 * The purpose of csr_read(CSR_TIME) is to trap the system into
+	 * M-mode to obtain the value of CSR_TIME. Hence, unlike other
+	 * architecture, no fence instructions surround the csr_read()
+	 */
+	return csr_read(CSR_TIME);
+}
+
+static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
+{
+	return _vdso_data;
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_GETTIMEOFDAY_H */

arch/riscv/include/asm/vdso/processor.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_VDSO_PROCESSOR_H
+#define __ASM_VDSO_PROCESSOR_H
+
+#ifndef __ASSEMBLY__
+
+static inline void cpu_relax(void)
+{
+#ifdef __riscv_muldiv
+	int dummy;
+	/* In lieu of a halt instruction, induce a long-latency stall. */
+	__asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
+#endif
+	barrier();
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_PROCESSOR_H */

arch/riscv/include/asm/vdso/vsyscall.h

@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_VDSO_VSYSCALL_H
+#define __ASM_VDSO_VSYSCALL_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/timekeeper_internal.h>
+#include <vdso/datapage.h>
+
+extern struct vdso_data *vdso_data;
+
+/*
+ * Update the vDSO data page to keep in sync with kernel timekeeping.
+ */
+static __always_inline struct vdso_data *__riscv_get_k_vdso_data(void)
+{
+	return vdso_data;
+}
+
+#define __arch_get_k_vdso_data __riscv_get_k_vdso_data
+
+/* The asm-generic header needs to be included after the definitions above */
+#include <asm-generic/vdso/vsyscall.h>
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_VSYSCALL_H */

arch/riscv/kernel/cpu.c

@@ -44,6 +44,22 @@ int riscv_of_processor_hartid(struct device_node *node)
 	return hart;
 }
 
+/*
+ * Find hart ID of the CPU DT node under which given DT node falls.
+ *
+ * To achieve this, we walk up the DT tree until we find an active
+ * RISC-V core (HART) node and extract the cpuid from it.
+ */
+int riscv_of_parent_hartid(struct device_node *node)
+{
+	for (; node; node = node->parent) {
+		if (of_device_is_compatible(node, "riscv"))
+			return riscv_of_processor_hartid(node);
+	}
+
+	return -1;
+}
+
 #ifdef CONFIG_PROC_FS
 
 static void print_isa(struct seq_file *f, const char *isa)

arch/riscv/kernel/entry.S

@@ -106,7 +106,9 @@ _save_context:
 
 	/* Handle interrupts */
 	move a0, sp /* pt_regs */
-	tail do_IRQ
+	la a1, handle_arch_irq
+	REG_L a1, (a1)
+	jr a1
 1:
 	/*
 	 * Exceptions run with interrupts enabled or disabled depending on the