Merge tag 'loongarch-fixes-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Fix bugs about idle, kernel_page_present(), IP checksum and KVM, plus
  some trival cleanups"

* tag 'loongarch-fixes-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: KVM: Set host with kernel mode when switch to VM mode
  LoongArch: KVM: Remove duplicated cache attribute setting
  LoongArch: KVM: Fix typo issue about GCFG feature detection
  LoongArch: csum: Fix OoB access in IP checksum code for negative lengths
  LoongArch: Remove the deprecated notifier hook mechanism
  LoongArch: Use str_yes_no() helper function for /proc/cpuinfo
  LoongArch: Fix kernel_page_present() for KPRANGE/XKPRANGE
  LoongArch: Fix idle VS timer enqueue

Author: torvalds

arch/loongarch/include/asm/cpu-info.h

@@ -76,27 +76,6 @@ extern const char *__cpu_full_name[];
 #define cpu_family_string()	__cpu_family[raw_smp_processor_id()]
 #define cpu_full_name_string()	__cpu_full_name[raw_smp_processor_id()]
 
-struct seq_file;
-struct notifier_block;
-
-extern int register_proc_cpuinfo_notifier(struct notifier_block *nb);
-extern int proc_cpuinfo_notifier_call_chain(unsigned long val, void *v);
-
-#define proc_cpuinfo_notifier(fn, pri)					\
-({									\
-	static struct notifier_block fn##_nb = {			\
-		.notifier_call = fn,					\
-		.priority = pri						\
-	};								\
-									\
-	register_proc_cpuinfo_notifier(&fn##_nb);			\
-})
-
-struct proc_cpuinfo_notifier_args {
-	struct seq_file *m;
-	unsigned long n;
-};
-
 static inline bool cpus_are_siblings(int cpua, int cpub)
 {
 	struct cpuinfo_loongarch *infoa = &cpu_data[cpua];

arch/loongarch/include/asm/smp.h

@@ -77,6 +77,8 @@ extern int __cpu_logical_map[NR_CPUS];
 #define SMP_IRQ_WORK		BIT(ACTION_IRQ_WORK)
 #define SMP_CLEAR_VECTOR	BIT(ACTION_CLEAR_VECTOR)
 
+struct seq_file;
+
 struct secondary_data {
 	unsigned long stack;
 	unsigned long thread_info;

arch/loongarch/kernel/genex.S

@@ -18,28 +18,30 @@
 
 	.align	5
 SYM_FUNC_START(__arch_cpu_idle)
-	/* start of rollback region */
-	LONG_L	t0, tp, TI_FLAGS
-	nop
-	andi	t0, t0, _TIF_NEED_RESCHED
-	bnez	t0, 1f
-	nop
-	nop
-	nop
+	/* start of idle interrupt region */
+	ori	t0, zero, CSR_CRMD_IE
+	/* idle instruction needs irq enabled */
+	csrxchg	t0, t0, LOONGARCH_CSR_CRMD
+	/*
+	 * If an interrupt lands here; between enabling interrupts above and
+	 * going idle on the next instruction, we must *NOT* go idle since the
+	 * interrupt could have set TIF_NEED_RESCHED or caused an timer to need
+	 * reprogramming. Fall through -- see handle_vint() below -- and have
+	 * the idle loop take care of things.
+	 */
 	idle	0
-	/* end of rollback region */
+	/* end of idle interrupt region */
 1:	jr	ra
 SYM_FUNC_END(__arch_cpu_idle)
 
 SYM_CODE_START(handle_vint)
 	UNWIND_HINT_UNDEFINED
 	BACKUP_T0T1
 	SAVE_ALL
-	la_abs	t1, __arch_cpu_idle
+	la_abs	t1, 1b
 	LONG_L	t0, sp, PT_ERA
-	/* 32 byte rollback region */
-	ori	t0, t0, 0x1f
-	xori	t0, t0, 0x1f
+	/* 3 instructions idle interrupt region */
+	ori	t0, t0, 0b1100
 	bne	t0, t1, 1f
 	LONG_S	t0, sp, PT_ERA
 1:	move	a0, sp

arch/loongarch/kernel/idle.c

@@ -11,7 +11,6 @@
 
 void __cpuidle arch_cpu_idle(void)
 {
-	raw_local_irq_enable();
-	__arch_cpu_idle(); /* idle instruction needs irq enabled */
+	__arch_cpu_idle();
 	raw_local_irq_disable();
 }

arch/loongarch/kernel/proc.c

@@ -13,28 +13,12 @@
 #include <asm/processor.h>
 #include <asm/time.h>
 
-/*
- * No lock; only written during early bootup by CPU 0.
- */
-static RAW_NOTIFIER_HEAD(proc_cpuinfo_chain);
-
-int __ref register_proc_cpuinfo_notifier(struct notifier_block *nb)
-{
-	return raw_notifier_chain_register(&proc_cpuinfo_chain, nb);
-}
-
-int proc_cpuinfo_notifier_call_chain(unsigned long val, void *v)
-{
-	return raw_notifier_call_chain(&proc_cpuinfo_chain, val, v);
-}
-
 static int show_cpuinfo(struct seq_file *m, void *v)
 {
 	unsigned long n = (unsigned long) v - 1;
 	unsigned int isa = cpu_data[n].isa_level;
 	unsigned int version = cpu_data[n].processor_id & 0xff;
 	unsigned int fp_version = cpu_data[n].fpu_vers;
-	struct proc_cpuinfo_notifier_args proc_cpuinfo_notifier_args;
 
 #ifdef CONFIG_SMP
 	if (!cpu_online(n))
@@ -91,20 +75,13 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 	if (cpu_has_lbt_mips)	seq_printf(m, " lbt_mips");
 	seq_printf(m, "\n");
 
-	seq_printf(m, "Hardware Watchpoint\t: %s",
-		      cpu_has_watch ? "yes, " : "no\n");
+	seq_printf(m, "Hardware Watchpoint\t: %s", str_yes_no(cpu_has_watch));
 	if (cpu_has_watch) {
-		seq_printf(m, "iwatch count: %d, dwatch count: %d\n",
+		seq_printf(m, ", iwatch count: %d, dwatch count: %d",
 		      cpu_data[n].watch_ireg_count, cpu_data[n].watch_dreg_count);
 	}
 
-	proc_cpuinfo_notifier_args.m = m;
-	proc_cpuinfo_notifier_args.n = n;
-
-	raw_notifier_call_chain(&proc_cpuinfo_chain, 0,
-				&proc_cpuinfo_notifier_args);
-
-	seq_printf(m, "\n");
+	seq_printf(m, "\n\n");
 
 	return 0;
 }

arch/loongarch/kernel/reset.c

@@ -33,7 +33,7 @@ void machine_halt(void)
 	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
 
 	while (true) {
-		__arch_cpu_idle();
+		__asm__ __volatile__("idle 0" : : : "memory");
 	}
 }
 
@@ -53,7 +53,7 @@ void machine_power_off(void)
 #endif
 
 	while (true) {
-		__arch_cpu_idle();
+		__asm__ __volatile__("idle 0" : : : "memory");
 	}
 }
 
@@ -74,6 +74,6 @@ void machine_restart(char *command)
 		acpi_reboot();
 
 	while (true) {
-		__arch_cpu_idle();
+		__asm__ __volatile__("idle 0" : : : "memory");
 	}
 }

arch/loongarch/kvm/main.c

@@ -303,9 +303,9 @@ int kvm_arch_enable_virtualization_cpu(void)
 	 * TOE=0:       Trap on Exception.
 	 * TIT=0:       Trap on Timer.
 	 */
-	if (env & CSR_GCFG_GCIP_ALL)
+	if (env & CSR_GCFG_GCIP_SECURE)
 		gcfg |= CSR_GCFG_GCI_SECURE;
-	if (env & CSR_GCFG_MATC_ROOT)
+	if (env & CSR_GCFG_MATP_ROOT)
 		gcfg |= CSR_GCFG_MATC_ROOT;
 
 	write_csr_gcfg(gcfg);

arch/loongarch/kvm/switch.S

@@ -85,7 +85,7 @@
 	 * Guest CRMD comes from separate GCSR_CRMD register
 	 */
 	ori	t0, zero, CSR_PRMD_PIE
-	csrxchg	t0, t0,   LOONGARCH_CSR_PRMD
+	csrwr	t0, LOONGARCH_CSR_PRMD
 
 	/* Set PVM bit to setup ertn to guest context */
 	ori	t0, zero, CSR_GSTAT_PVM

arch/loongarch/kvm/vcpu.c

@@ -1548,9 +1548,6 @@ static int _kvm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 
 	/* Restore timer state regardless */
 	kvm_restore_timer(vcpu);
-
-	/* Control guest page CCA attribute */
-	change_csr_gcfg(CSR_GCFG_MATC_MASK, CSR_GCFG_MATC_ROOT);
 	kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
 
 	/* Restore hardware PMU CSRs */

arch/loongarch/lib/csum.c

@@ -25,7 +25,7 @@ unsigned int __no_sanitize_address do_csum(const unsigned char *buff, int len)
 	const u64 *ptr;
 	u64 data, sum64 = 0;
 
-	if (unlikely(len == 0))
+	if (unlikely(len <= 0))
 		return 0;
 
 	offset = (unsigned long)buff & 7;