Merge tag 'riscv-for-linus-5.18-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Palmer Dabbelt:
 "This has a handful of new features:

   - Support for CURRENT_STACK_POINTER, which enables some extra stack
     debugging for HARDENED_USERCOPY.

   - Support for the new SBI CPU idle extension, via cpuidle and suspend
     drivers.

   - Profiling has been enabled in the defconfigs.

  but is mostly fixes and cleanups"

* tag 'riscv-for-linus-5.18-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (21 commits)
  RISC-V: K210 defconfigs: Drop redundant MEMBARRIER=n
  RISC-V: defconfig: Drop redundant SBI HVC and earlycon
  Documentation: riscv: remove non-existent directory from table of contents
  riscv: cpu.c: don't use kernel-doc markers for comments
  RISC-V: Enable profiling by default
  RISC-V: module: fix apply_r_riscv_rcv_branch_rela typo
  RISC-V: Declare per cpu boot data as static
  RISC-V: Fix a comment typo in riscv_of_parent_hartid()
  riscv: Increase stack size under KASAN
  riscv: Fix fill_callchain return value
  riscv: dts: canaan: Fix SPI3 bus width
  riscv: Rename "sp_in_global" to "current_stack_pointer"
  riscv module: remove (NOLOAD)
  RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine
  dt-bindings: Add common bindings for ARM and RISC-V idle states
  cpuidle: Add RISC-V SBI CPU idle driver
  cpuidle: Factor-out power domain related code from PSCI domain driver
  RISC-V: Add SBI HSM suspend related defines
  RISC-V: Add arch functions for non-retentive suspend entry/exit
  RISC-V: Rename relocate() and make it global
  ...

11 files changed, 231 insertions, 35 deletions

diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index e0133d113216..87adbe47bc15 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -48,6 +48,8 @@ obj-$(CONFIG_RISCV_BOOT_SPINWAIT) += cpu_ops_spinwait.o
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_MODULE_SECTIONS)	+= module-sections.o
 
+obj-$(CONFIG_CPU_PM)		+= suspend_entry.o suspend.o
+
 obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o ftrace.o
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= mcount-dyn.o
 
diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
index df0519a64eaf..df9444397908 100644
--- a/arch/riscv/kernel/asm-offsets.c
+++ b/arch/riscv/kernel/asm-offsets.c
@@ -13,6 +13,7 @@
 #include <asm/thread_info.h>
 #include <asm/ptrace.h>
 #include <asm/cpu_ops_sbi.h>
+#include <asm/suspend.h>
 
 void asm_offsets(void);
 
@@ -113,6 +114,8 @@ void asm_offsets(void)
 	OFFSET(PT_BADADDR, pt_regs, badaddr);
 	OFFSET(PT_CAUSE, pt_regs, cause);
 
+	OFFSET(SUSPEND_CONTEXT_REGS, suspend_context, regs);
+
 	OFFSET(KVM_ARCH_GUEST_ZERO, kvm_vcpu_arch, guest_context.zero);
 	OFFSET(KVM_ARCH_GUEST_RA, kvm_vcpu_arch, guest_context.ra);
 	OFFSET(KVM_ARCH_GUEST_SP, kvm_vcpu_arch, guest_context.sp);
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index d2a936195295..ccb617791e56 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -69,11 +69,11 @@ int riscv_of_parent_hartid(struct device_node *node)
 		.uprop = #UPROP,				\
 		.isa_ext_id = EXTID,				\
 	}
-/**
+/*
  * Here are the ordering rules of extension naming defined by RISC-V
  * specification :
  * 1. All extensions should be separated from other multi-letter extensions
- *    from other multi-letter extensions by an underscore.
+ *    by an underscore.
  * 2. The first letter following the 'Z' conventionally indicates the most
  *    closely related alphabetical extension category, IMAFDQLCBKJTPVH.
  *    If multiple 'Z' extensions are named, they should be ordered first
@@ -110,7 +110,7 @@ static void print_isa_ext(struct seq_file *f)
 	}
 }
 
-/**
+/*
  * These are the only valid base (single letter) ISA extensions as per the spec.
  * It also specifies the canonical order in which it appears in the spec.
  * Some of the extension may just be a place holder for now (B, K, P, J).
diff --git a/arch/riscv/kernel/cpu_ops_sbi.c b/arch/riscv/kernel/cpu_ops_sbi.c
index 2e16f6732cdf..4f5a6f84e2a4 100644
--- a/arch/riscv/kernel/cpu_ops_sbi.c
+++ b/arch/riscv/kernel/cpu_ops_sbi.c
@@ -21,7 +21,7 @@ const struct cpu_operations cpu_ops_sbi;
  * be invoked from multiple threads in parallel. Define a per cpu data
  * to handle that.
  */
-DEFINE_PER_CPU(struct sbi_hart_boot_data, boot_data);
+static DEFINE_PER_CPU(struct sbi_hart_boot_data, boot_data);
 
 static int sbi_hsm_hart_start(unsigned long hartid, unsigned long saddr,
 			      unsigned long priv)
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index ec07f991866a..893b8bb69391 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -16,26 +16,6 @@
 #include <asm/image.h>
 #include "efi-header.S"
 
-#ifdef CONFIG_XIP_KERNEL
-.macro XIP_FIXUP_OFFSET reg
-	REG_L t0, _xip_fixup
-	add \reg, \reg, t0
-.endm
-.macro XIP_FIXUP_FLASH_OFFSET reg
-	la t0, __data_loc
-	REG_L t1, _xip_phys_offset
-	sub \reg, \reg, t1
-	add \reg, \reg, t0
-.endm
-_xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - XIP_OFFSET
-_xip_phys_offset: .dword CONFIG_XIP_PHYS_ADDR + XIP_OFFSET
-#else
-.macro XIP_FIXUP_OFFSET reg
-.endm
-.macro XIP_FIXUP_FLASH_OFFSET reg
-.endm
-#endif /* CONFIG_XIP_KERNEL */
-
 __HEAD
 ENTRY(_start)
 	/*
@@ -89,7 +69,8 @@ pe_head_start:
 
 .align 2
 #ifdef CONFIG_MMU
-relocate:
+	.global relocate_enable_mmu
+relocate_enable_mmu:
 	/* Relocate return address */
 	la a1, kernel_map
 	XIP_FIXUP_OFFSET a1
@@ -184,7 +165,7 @@ secondary_start_sbi:
 	/* Enable virtual memory and relocate to virtual address */
 	la a0, swapper_pg_dir
 	XIP_FIXUP_OFFSET a0
-	call relocate
+	call relocate_enable_mmu
 #endif
 	call setup_trap_vector
 	tail smp_callin
@@ -328,7 +309,7 @@ clear_bss_done:
 #ifdef CONFIG_MMU
 	la a0, early_pg_dir
 	XIP_FIXUP_OFFSET a0
-	call relocate
+	call relocate_enable_mmu
 #endif /* CONFIG_MMU */
 
 	call setup_trap_vector
diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 4a48287513c3..c29cef90d1dd 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -69,7 +69,7 @@ static int apply_r_riscv_jal_rela(struct module *me, u32 *location,
 	return 0;
 }
 
-static int apply_r_riscv_rcv_branch_rela(struct module *me, u32 *location,
+static int apply_r_riscv_rvc_branch_rela(struct module *me, u32 *location,
 					 Elf_Addr v)
 {
 	ptrdiff_t offset = (void *)v - (void *)location;
@@ -301,7 +301,7 @@ static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
 	[R_RISCV_64]			= apply_r_riscv_64_rela,
 	[R_RISCV_BRANCH]		= apply_r_riscv_branch_rela,
 	[R_RISCV_JAL]			= apply_r_riscv_jal_rela,
-	[R_RISCV_RVC_BRANCH]		= apply_r_riscv_rcv_branch_rela,
+	[R_RISCV_RVC_BRANCH]		= apply_r_riscv_rvc_branch_rela,
 	[R_RISCV_RVC_JUMP]		= apply_r_riscv_rvc_jump_rela,
 	[R_RISCV_PCREL_HI20]		= apply_r_riscv_pcrel_hi20_rela,
 	[R_RISCV_PCREL_LO12_I]		= apply_r_riscv_pcrel_lo12_i_rela,
diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c
index 55faa4991b87..3348a61de7d9 100644
--- a/arch/riscv/kernel/perf_callchain.c
+++ b/arch/riscv/kernel/perf_callchain.c
@@ -68,7 +68,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
 
 static bool fill_callchain(void *entry, unsigned long pc)
 {
-	return perf_callchain_store(entry, pc);
+	return perf_callchain_store(entry, pc) == 0;
 }
 
 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 03ac3aa611f5..504b496787aa 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -23,6 +23,7 @@
 #include <asm/string.h>
 #include <asm/switch_to.h>
 #include <asm/thread_info.h>
+#include <asm/cpuidle.h>
 
 register unsigned long gp_in_global __asm__("gp");
 
@@ -37,7 +38,7 @@ extern asmlinkage void ret_from_kernel_thread(void);
 
 void arch_cpu_idle(void)
 {
-	wait_for_interrupt();
+	cpu_do_idle();
 	raw_local_irq_enable();
 }
 
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 14d2b53ec322..08d11a53f39e 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -14,8 +14,6 @@
 
 #include <asm/stacktrace.h>
 
-register unsigned long sp_in_global __asm__("sp");
-
 #ifdef CONFIG_FRAME_POINTER
 
 void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
@@ -30,7 +28,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 		pc = instruction_pointer(regs);
 	} else if (task == NULL || task == current) {
 		fp = (unsigned long)__builtin_frame_address(0);
-		sp = sp_in_global;
+		sp = current_stack_pointer;
 		pc = (unsigned long)walk_stackframe;
 	} else {
 		/* task blocked in __switch_to */
@@ -78,7 +76,7 @@ void notrace walk_stackframe(struct task_struct *task,
 		sp = user_stack_pointer(regs);
 		pc = instruction_pointer(regs);
 	} else if (task == NULL || task == current) {
-		sp = sp_in_global;
+		sp = current_stack_pointer;
 		pc = (unsigned long)walk_stackframe;
 	} else {
 		/* task blocked in __switch_to */
diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c
new file mode 100644
index 000000000000..9ba24fb8cc93
--- /dev/null
+++ b/arch/riscv/kernel/suspend.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/ftrace.h>
+#include <asm/csr.h>
+#include <asm/suspend.h>
+
+static void suspend_save_csrs(struct suspend_context *context)
+{
+	context->scratch = csr_read(CSR_SCRATCH);
+	context->tvec = csr_read(CSR_TVEC);
+	context->ie = csr_read(CSR_IE);
+
+	/*
+	 * No need to save/restore IP CSR (i.e. MIP or SIP) because:
+	 *
+	 * 1. For no-MMU (M-mode) kernel, the bits in MIP are set by
+	 *    external devices (such as interrupt controller, timer, etc).
+	 * 2. For MMU (S-mode) kernel, the bits in SIP are set by
+	 *    M-mode firmware and external devices (such as interrupt
+	 *    controller, etc).
+	 */
+
+#ifdef CONFIG_MMU
+	context->satp = csr_read(CSR_SATP);
+#endif
+}
+
+static void suspend_restore_csrs(struct suspend_context *context)
+{
+	csr_write(CSR_SCRATCH, context->scratch);
+	csr_write(CSR_TVEC, context->tvec);
+	csr_write(CSR_IE, context->ie);
+
+#ifdef CONFIG_MMU
+	csr_write(CSR_SATP, context->satp);
+#endif
+}
+
+int cpu_suspend(unsigned long arg,
+		int (*finish)(unsigned long arg,
+			      unsigned long entry,
+			      unsigned long context))
+{
+	int rc = 0;
+	struct suspend_context context = { 0 };
+
+	/* Finisher should be non-NULL */
+	if (!finish)
+		return -EINVAL;
+
+	/* Save additional CSRs*/
+	suspend_save_csrs(&context);
+
+	/*
+	 * Function graph tracer state gets incosistent when the kernel
+	 * calls functions that never return (aka finishers) hence disable
+	 * graph tracing during their execution.
+	 */
+	pause_graph_tracing();
+
+	/* Save context on stack */
+	if (__cpu_suspend_enter(&context)) {
+		/* Call the finisher */
+		rc = finish(arg, __pa_symbol(__cpu_resume_enter),
+			    (ulong)&context);
+
+		/*
+		 * Should never reach here, unless the suspend finisher
+		 * fails. Successful cpu_suspend() should return from
+		 * __cpu_resume_entry()
+		 */
+		if (!rc)
+			rc = -EOPNOTSUPP;
+	}
+
+	/* Enable function graph tracer */
+	unpause_graph_tracing();
+
+	/* Restore additional CSRs */
+	suspend_restore_csrs(&context);
+
+	return rc;
+}
diff --git a/arch/riscv/kernel/suspend_entry.S b/arch/riscv/kernel/suspend_entry.S
new file mode 100644
index 000000000000..4b07b809a2b8
--- /dev/null
+++ b/arch/riscv/kernel/suspend_entry.S
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/csr.h>
+
+	.text
+	.altmacro
+	.option norelax
+
+ENTRY(__cpu_suspend_enter)
+	/* Save registers (except A0 and T0-T6) */
+	REG_S	ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
+	REG_S	sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
+	REG_S	gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
+	REG_S	tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
+	REG_S	s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
+	REG_S	s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
+	REG_S	a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
+	REG_S	a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
+	REG_S	a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
+	REG_S	a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
+	REG_S	a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
+	REG_S	a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
+	REG_S	a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
+	REG_S	s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
+	REG_S	s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
+	REG_S	s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
+	REG_S	s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
+	REG_S	s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
+	REG_S	s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
+	REG_S	s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
+	REG_S	s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
+	REG_S	s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
+	REG_S	s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
+
+	/* Save CSRs */
+	csrr	t0, CSR_EPC
+	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
+	csrr	t0, CSR_STATUS
+	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
+	csrr	t0, CSR_TVAL
+	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
+	csrr	t0, CSR_CAUSE
+	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
+
+	/* Return non-zero value */
+	li	a0, 1
+
+	/* Return to C code */
+	ret
+END(__cpu_suspend_enter)
+
+ENTRY(__cpu_resume_enter)
+	/* Load the global pointer */
+	.option push
+	.option norelax
+		la gp, __global_pointer$
+	.option pop
+
+#ifdef CONFIG_MMU
+	/* Save A0 and A1 */
+	add	t0, a0, zero
+	add	t1, a1, zero
+
+	/* Enable MMU */
+	la	a0, swapper_pg_dir
+	XIP_FIXUP_OFFSET a0
+	call	relocate_enable_mmu
+
+	/* Restore A0 and A1 */
+	add	a0, t0, zero
+	add	a1, t1, zero
+#endif
+
+	/* Make A0 point to suspend context */
+	add	a0, a1, zero
+
+	/* Restore CSRs */
+	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
+	csrw	CSR_EPC, t0
+	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
+	csrw	CSR_STATUS, t0
+	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
+	csrw	CSR_TVAL, t0
+	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
+	csrw	CSR_CAUSE, t0
+
+	/* Restore registers (except A0 and T0-T6) */
+	REG_L	ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
+	REG_L	sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
+	REG_L	gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
+	REG_L	tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
+	REG_L	s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
+	REG_L	s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
+	REG_L	a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
+	REG_L	a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
+	REG_L	a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
+	REG_L	a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
+	REG_L	a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
+	REG_L	a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
+	REG_L	a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
+	REG_L	s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
+	REG_L	s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
+	REG_L	s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
+	REG_L	s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
+	REG_L	s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
+	REG_L	s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
+	REG_L	s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
+	REG_L	s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
+	REG_L	s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
+	REG_L	s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
+
+	/* Return zero value */
+	add	a0, zero, zero
+
+	/* Return to C code */
+	ret
+END(__cpu_resume_enter)