Merge tag 'xtensa-20220325' of https://github.com/jcmvbkbc/linux-xtensa

Pull Xtensa updates from Max Filippov:

 - remove dependency on the compiler's libgcc

 - allow selection of internal kernel ABI via Kconfig

 - enable compiler plugins support for gcc-12 or newer

 - various minor cleanups and fixes

* tag 'xtensa-20220325' of https://github.com/jcmvbkbc/linux-xtensa:
  xtensa: define update_mmu_tlb function
  xtensa: fix xtensa_wsr always writing 0
  xtensa: enable plugin support
  xtensa: clean up kernel exit assembly code
  xtensa: rearrange NMI exit path
  xtensa: merge stack alignment definitions
  xtensa: fix DTC warning unit_address_format
  xtensa: fix stop_machine_cpuslocked call in patch_text
  xtensa: make secondary reset vector support conditional
  xtensa: add kernel ABI selection to Kconfig
  xtensa: don't link with libgcc
  xtensa: add helpers for division, remainder and shifts
  xtensa: add missing XCHAL_HAVE_WINDOWED check
  xtensa: use XCHAL_NUM_AREGS as pt_regs::areg size
  xtensa: rename PT_SIZE to PT_KERNEL_SIZE
  xtensa: Remove unused early_read_config_byte() et al declarations
  xtensa: use strscpy to copy strings
  net: xtensa: use strscpy to copy strings

10 files changed, 50 insertions, 76 deletions

diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile
index d4082c6a121b..5fd6cd15e0fb 100644
--- a/arch/xtensa/kernel/Makefile
+++ b/arch/xtensa/kernel/Makefile
@@ -13,7 +13,8 @@ obj-$(CONFIG_MMU) += pci-dma.o
 obj-$(CONFIG_PCI) += pci.o
 obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o
 obj-$(CONFIG_FUNCTION_TRACER) += mcount.o
-obj-$(CONFIG_SMP) += smp.o mxhead.o
+obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_SECONDARY_RESET_VECTOR) += mxhead.o
 obj-$(CONFIG_XTENSA_VARIANT_HAVE_PERF_EVENTS) += perf_event.o
 obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
 obj-$(CONFIG_S32C1I_SELFTEST) += s32c1i_selftest.o
diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index f1fd1390d069..37278e2785fb 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -63,7 +63,7 @@ int main(void)
 	DEFINE(PT_AREG15, offsetof (struct pt_regs, areg[15]));
 	DEFINE(PT_WINDOWBASE, offsetof (struct pt_regs, windowbase));
 	DEFINE(PT_WINDOWSTART, offsetof(struct pt_regs, windowstart));
-	DEFINE(PT_SIZE, sizeof(struct pt_regs));
+	DEFINE(PT_KERNEL_SIZE, offsetof(struct pt_regs, areg[16]));
 	DEFINE(PT_AREG_END, offsetof (struct pt_regs, areg[XCHAL_NUM_AREGS]));
 	DEFINE(PT_USER_SIZE, offsetof(struct pt_regs, areg[XCHAL_NUM_AREGS]));
 	DEFINE(PT_XTREGS_OPT, offsetof(struct pt_regs, xtregs_opt));
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index a1029a5b6a1d..6b6eff658795 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -341,8 +341,8 @@ KABI_W	_bbsi.l	a2, 3, 1f
 	/* Copy spill slots of a0 and a1 to imitate movsp
 	 * in order to keep exception stack continuous
 	 */
-	l32i	a3, a1, PT_SIZE
-	l32i	a0, a1, PT_SIZE + 4
+	l32i	a3, a1, PT_KERNEL_SIZE
+	l32i	a0, a1, PT_KERNEL_SIZE + 4
 	s32e	a3, a1, -16
 	s32e	a0, a1, -12
 #endif
@@ -488,11 +488,12 @@ KABI_W	or	a3, a3, a2
 common_exception_return:
 
 #if XTENSA_FAKE_NMI
-	l32i	a2, a1, PT_EXCCAUSE
-	movi	a3, EXCCAUSE_MAPPED_NMI
-	beq	a2, a3, .LNMIexit
+	l32i	abi_tmp0, a1, PT_EXCCAUSE
+	movi	abi_tmp1, EXCCAUSE_MAPPED_NMI
+	l32i	abi_saved1, a1, PT_PS
+	beq	abi_tmp0, abi_tmp1, .Lrestore_state
 #endif
-1:
+.Ltif_loop:
 	irq_save a2, a3
 #ifdef CONFIG_TRACE_IRQFLAGS
 	abi_call	trace_hardirqs_off
@@ -503,7 +504,7 @@ common_exception_return:
 	l32i	abi_saved1, a1, PT_PS
 	GET_THREAD_INFO(a2, a1)
 	l32i	a4, a2, TI_FLAGS
-	_bbci.l	abi_saved1, PS_UM_BIT, 6f
+	_bbci.l	abi_saved1, PS_UM_BIT, .Lexit_tif_loop_kernel
 
 	/* Specific to a user exception exit:
 	 * We need to check some flags for signal handling and rescheduling,
@@ -512,12 +513,12 @@ common_exception_return:
 	 * Note that we don't disable interrupts here. 
 	 */
 
-	_bbsi.l	a4, TIF_NEED_RESCHED, 3f
+	_bbsi.l	a4, TIF_NEED_RESCHED, .Lresched
 	movi	a2, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NOTIFY_SIGNAL
-	bnone	a4, a2, 5f
+	bnone	a4, a2, .Lexit_tif_loop_user
 
-2:	l32i	a4, a1, PT_DEPC
-	bgeui	a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 4f
+	l32i	a4, a1, PT_DEPC
+	bgeui	a4, VALID_DOUBLE_EXCEPTION_ADDRESS, .Lrestore_state
 
 	/* Call do_signal() */
 
@@ -527,48 +528,41 @@ common_exception_return:
 	rsil	a2, 0
 	mov	abi_arg0, a1
 	abi_call	do_notify_resume	# int do_notify_resume(struct pt_regs*)
-	j	1b
-
-3:	/* Reschedule */
+	j	.Ltif_loop
 
+.Lresched:
 #ifdef CONFIG_TRACE_IRQFLAGS
 	abi_call	trace_hardirqs_on
 #endif
 	rsil	a2, 0
 	abi_call	schedule	# void schedule (void)
-	j	1b
+	j	.Ltif_loop
 
+.Lexit_tif_loop_kernel:
 #ifdef CONFIG_PREEMPTION
-6:
-	_bbci.l	a4, TIF_NEED_RESCHED, 4f
+	_bbci.l	a4, TIF_NEED_RESCHED, .Lrestore_state
 
 	/* Check current_thread_info->preempt_count */
 
 	l32i	a4, a2, TI_PRE_COUNT
-	bnez	a4, 4f
+	bnez	a4, .Lrestore_state
 	abi_call	preempt_schedule_irq
-	j	4f
 #endif
+	j	.Lrestore_state
 
-#if XTENSA_FAKE_NMI
-.LNMIexit:
-	l32i	abi_saved1, a1, PT_PS
-	_bbci.l	abi_saved1, PS_UM_BIT, 4f
-#endif
-
-5:
+.Lexit_tif_loop_user:
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
-	_bbci.l	a4, TIF_DB_DISABLED, 7f
+	_bbci.l	a4, TIF_DB_DISABLED, 1f
 	abi_call	restore_dbreak
-7:
+1:
 #endif
 #ifdef CONFIG_DEBUG_TLB_SANITY
 	l32i	a4, a1, PT_DEPC
-	bgeui	a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 4f
+	bgeui	a4, VALID_DOUBLE_EXCEPTION_ADDRESS, .Lrestore_state
 	abi_call	check_tlb_sanity
 #endif
-6:
-4:
+
+.Lrestore_state:
 #ifdef CONFIG_TRACE_IRQFLAGS
 	extui	a4, abi_saved1, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH
 	bgei	a4, LOCKLEVEL, 1f
@@ -606,7 +600,7 @@ user_exception_exit:
 	rsr	a1, depc		# restore stack pointer
 	l32i	a2, a1, PT_WMASK	# register frames saved (in bits 4...9)
 	rotw	-1			# we restore a4..a7
-	_bltui	a6, 16, 1f		# only have to restore current window?
+	_bltui	a6, 16, .Lclear_regs	# only have to restore current window?
 
 	/* The working registers are a0 and a3.  We are restoring to
 	 * a4..a7.  Be careful not to destroy what we have just restored.
@@ -618,18 +612,19 @@ user_exception_exit:
 	mov	a2, a6
 	mov	a3, a5
 
-2:	rotw	-1			# a0..a3 become a4..a7
+1:	rotw	-1			# a0..a3 become a4..a7
 	addi	a3, a7, -4*4		# next iteration
 	addi	a2, a6, -16		# decrementing Y in WMASK
 	l32i	a4, a3, PT_AREG_END + 0
 	l32i	a5, a3, PT_AREG_END + 4
 	l32i	a6, a3, PT_AREG_END + 8
 	l32i	a7, a3, PT_AREG_END + 12
-	_bgeui	a2, 16, 2b
+	_bgeui	a2, 16, 1b
 
 	/* Clear unrestored registers (don't leak anything to user-land */
 
-1:	rsr	a0, windowbase
+.Lclear_regs:
+	rsr	a0, windowbase
 	rsr	a3, sar
 	sub	a3, a0, a3
 	beqz	a3, 2f
@@ -706,12 +701,12 @@ kernel_exception_exit:
 	addi    a0, a1, -16
 	l32i    a3, a0, 0
 	l32i    a4, a0, 4
-	s32i    a3, a1, PT_SIZE+0
-	s32i    a4, a1, PT_SIZE+4
+	s32i    a3, a1, PT_KERNEL_SIZE + 0
+	s32i    a4, a1, PT_KERNEL_SIZE + 4
 	l32i    a3, a0, 8
 	l32i    a4, a0, 12
-	s32i    a3, a1, PT_SIZE+8
-	s32i    a4, a1, PT_SIZE+12
+	s32i    a3, a1, PT_KERNEL_SIZE + 8
+	s32i    a4, a1, PT_KERNEL_SIZE + 12
 
 	/* Common exception exit.
 	 * We restore the special register and the current window frame, and
@@ -821,7 +816,7 @@ ENTRY(debug_exception)
 
 	bbsi.l	a2, PS_UM_BIT, 2f	# jump if user mode
 
-	addi	a2, a1, -16-PT_SIZE	# assume kernel stack
+	addi	a2, a1, -16 - PT_KERNEL_SIZE	# assume kernel stack
 3:
 	l32i	a0, a3, DT_DEBUG_SAVE
 	s32i	a1, a2, PT_AREG1
diff --git a/arch/xtensa/kernel/jump_label.c b/arch/xtensa/kernel/jump_label.c
index 61cf6497a646..0dde21e0d3de 100644
--- a/arch/xtensa/kernel/jump_label.c
+++ b/arch/xtensa/kernel/jump_label.c
@@ -61,7 +61,7 @@ static void patch_text(unsigned long addr, const void *data, size_t sz)
 			.data = data,
 		};
 		stop_machine_cpuslocked(patch_text_stop_machine,
-					&patch, NULL);
+					&patch, cpu_online_mask);
 	} else {
 		unsigned long flags;
 
diff --git a/arch/xtensa/kernel/mxhead.S b/arch/xtensa/kernel/mxhead.S
index 9f3843742726..b702c0908b1f 100644
--- a/arch/xtensa/kernel/mxhead.S
+++ b/arch/xtensa/kernel/mxhead.S
@@ -37,11 +37,13 @@ _SetupOCD:
 	 * xt-gdb to single step via DEBUG exceptions received directly
 	 * by ocd.
 	 */
+#if XCHAL_HAVE_WINDOWED
 	movi	a1, 1
 	movi	a0, 0
 	wsr	a1, windowstart
 	wsr	a0, windowbase
 	rsync
+#endif
 
 	movi	a1, LOCKLEVEL
 	wsr	a1, ps
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index bd80df890b1e..e8bfbca5f001 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -232,10 +232,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
 		p->thread.ra = MAKE_RA_FOR_CALL(
 				(unsigned long)ret_from_fork, 0x1);
 
-		/* This does not copy all the regs.
-		 * In a bout of brilliance or madness,
-		 * ARs beyond a0-a15 exist past the end of the struct.
-		 */
 		*childregs = *regs;
 		childregs->areg[1] = usp;
 		childregs->areg[2] = 0;
@@ -265,14 +261,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
 			childregs->wmask = 1;
 			childregs->windowstart = 1;
 			childregs->windowbase = 0;
-		} else {
-			int len = childregs->wmask & ~0xf;
-			memcpy(&childregs->areg[XCHAL_NUM_AREGS - len/4],
-			       &regs->areg[XCHAL_NUM_AREGS - len/4], len);
 		}
 
-		childregs->syscall = regs->syscall;
-
 		if (clone_flags & CLONE_SETTLS)
 			childregs->threadptr = tls;
 	} else {
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index 8db20cfb44ab..9191738f9941 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -140,7 +140,7 @@ __tagtable(BP_TAG_FDT, parse_tag_fdt);
 
 static int __init parse_tag_cmdline(const bp_tag_t* tag)
 {
-	strlcpy(command_line, (char *)(tag->data), COMMAND_LINE_SIZE);
+	strscpy(command_line, (char *)(tag->data), COMMAND_LINE_SIZE);
 	return 0;
 }
 
@@ -230,7 +230,7 @@ void __init early_init_devtree(void *params)
 	of_scan_flat_dt(xtensa_dt_io_area, NULL);
 
 	if (!command_line[0])
-		strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
+		strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
 }
 
 #endif /* CONFIG_USE_OF */
@@ -260,7 +260,7 @@ void __init init_arch(bp_tag_t *bp_start)
 
 #ifdef CONFIG_CMDLINE_BOOL
 	if (!command_line[0])
-		strlcpy(command_line, default_command_line, COMMAND_LINE_SIZE);
+		strscpy(command_line, default_command_line, COMMAND_LINE_SIZE);
 #endif
 
 	/* Early hook for platforms */
@@ -289,7 +289,7 @@ void __init setup_arch(char **cmdline_p)
 
 	*cmdline_p = command_line;
 	platform_setup(cmdline_p);
-	strlcpy(boot_command_line, *cmdline_p, COMMAND_LINE_SIZE);
+	strscpy(boot_command_line, *cmdline_p, COMMAND_LINE_SIZE);
 
 	/* Reserve some memory regions */
 
@@ -349,7 +349,7 @@ void __init setup_arch(char **cmdline_p)
 
 #endif /* CONFIG_VECTORS_ADDR */
 
-#ifdef CONFIG_SMP
+#ifdef CONFIG_SECONDARY_RESET_VECTOR
 	mem_reserve(__pa(_SecondaryResetVector_text_start),
 		    __pa(_SecondaryResetVector_text_end));
 #endif
diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S
index 407ece204e7c..1073fe4a584d 100644
--- a/arch/xtensa/kernel/vectors.S
+++ b/arch/xtensa/kernel/vectors.S
@@ -88,7 +88,7 @@ ENDPROC(_UserExceptionVector)
  * Kernel exception vector. (Exceptions with PS.UM == 0, PS.EXCM == 0)
  *
  * We get this exception when we were already in kernel space.
- * We decrement the current stack pointer (kernel) by PT_SIZE and
+ * We decrement the current stack pointer (kernel) by PT_KERNEL_SIZE and
  * jump to the first-level handler associated with the exception cause.
  *
  * Note: we need to preserve space for the spill region.
@@ -100,7 +100,7 @@ ENTRY(_KernelExceptionVector)
 
 	xsr	a3, excsave1		# save a3, and get dispatch table
 	wsr	a2, depc		# save a2
-	addi	a2, a1, -16-PT_SIZE	# adjust stack pointer
+	addi	a2, a1, -16 - PT_KERNEL_SIZE	# adjust stack pointer
 	s32i	a0, a2, PT_AREG0	# save a0 to ESF
 	rsr	a0, exccause		# retrieve exception cause
 	s32i	a0, a2, PT_DEPC		# mark it as a regular exception
diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index eee270a039a4..965a3952c47b 100644
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -207,7 +207,7 @@ SECTIONS
     RELOCATE_ENTRY(_xip_data, .data);
     RELOCATE_ENTRY(_xip_init_data, .init.data);
 #endif
-#if defined(CONFIG_SMP)
+#if defined(CONFIG_SECONDARY_RESET_VECTOR)
     RELOCATE_ENTRY(_SecondaryResetVector_text,
 		   .SecondaryResetVector.text);
 #endif
@@ -303,7 +303,7 @@ SECTIONS
 #define LAST .DoubleExceptionVector.text
 
 #endif
-#if defined(CONFIG_SMP)
+#if defined(CONFIG_SECONDARY_RESET_VECTOR)
 
   SECTION_VECTOR4 (_SecondaryResetVector_text,
 		  .SecondaryResetVector.text,
diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c
index d79edbb98d2a..b0bc8897c924 100644
--- a/arch/xtensa/kernel/xtensa_ksyms.c
+++ b/arch/xtensa/kernel/xtensa_ksyms.c
@@ -59,32 +59,18 @@ extern long long __ashldi3(long long, int);
 extern long long __lshrdi3(long long, int);
 extern int __divsi3(int, int);
 extern int __modsi3(int, int);
-extern long long __muldi3(long long, long long);
 extern int __mulsi3(int, int);
 extern unsigned int __udivsi3(unsigned int, unsigned int);
 extern unsigned int __umodsi3(unsigned int, unsigned int);
-extern unsigned long long __umoddi3(unsigned long long, unsigned long long);
-extern unsigned long long __udivdi3(unsigned long long, unsigned long long);
-extern int __ucmpdi2(int, int);
 
 EXPORT_SYMBOL(__ashldi3);
 EXPORT_SYMBOL(__ashrdi3);
 EXPORT_SYMBOL(__lshrdi3);
 EXPORT_SYMBOL(__divsi3);
 EXPORT_SYMBOL(__modsi3);
-EXPORT_SYMBOL(__muldi3);
 EXPORT_SYMBOL(__mulsi3);
 EXPORT_SYMBOL(__udivsi3);
 EXPORT_SYMBOL(__umodsi3);
-EXPORT_SYMBOL(__udivdi3);
-EXPORT_SYMBOL(__umoddi3);
-EXPORT_SYMBOL(__ucmpdi2);
-
-void __xtensa_libgcc_window_spill(void)
-{
-	BUG();
-}
-EXPORT_SYMBOL(__xtensa_libgcc_window_spill);
 
 unsigned int __sync_fetch_and_and_4(volatile void *p, unsigned int v)
 {