Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:

 - Rejig task/thread info to place thread info in task struct

 - Amba bus cleanups (removing unused functions)

 - Handle Amba device probe without IRQ domains

 - Parse linux,usable-memory-range in decompressor

 - Mark OCRAM as read-only after initialisation

 - Refactor page fault handling

 - Fix PXN handling with LPAE kernels

 - Warning and build fixes from Arnd

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (32 commits)
  ARM: 9151/1: Thumb2: avoid __builtin_thread_pointer() on Clang
  ARM: 9150/1: Fix PID_IN_CONTEXTIDR regression when THREAD_INFO_IN_TASK=y
  ARM: 9147/1: add printf format attribute to early_print()
  ARM: 9146/1: RiscPC needs older gcc version
  ARM: 9145/1: patch: fix BE32 compilation
  ARM: 9144/1: forbid ftrace with clang and thumb2_kernel
  ARM: 9143/1: add CONFIG_PHYS_OFFSET default values
  ARM: 9142/1: kasan: work around LPAE build warning
  ARM: 9140/1: allow compile-testing without machine record
  ARM: 9137/1: disallow CONFIG_THUMB with ARMv4
  ARM: 9136/1: ARMv7-M uses BE-8, not BE-32
  ARM: 9135/1: kprobes: address gcc -Wempty-body warning
  ARM: 9101/1: sa1100/assabet: convert LEDs to gpiod APIs
  ARM: 9131/1: mm: Fix PXN process with LPAE feature
  ARM: 9130/1: mm: Provide die_kernel_fault() helper
  ARM: 9126/1: mm: Kill page table base print in show_pte()
  ARM: 9127/1: mm: Cleanup access_error()
  ARM: 9129/1: mm: Kill task_struct argument for __do_page_fault()
  ARM: 9128/1: mm: Refactor the __do_page_fault()
  ARM: imx6: mark OCRAM mapping read-only
  ...

arch/arm/Kconfig

@@ -91,7 +91,7 @@ config ARM
 	select HAVE_FAST_GUP if ARM_LPAE
 	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
 	select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
-	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
+	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !(THUMB2_KERNEL && CC_IS_CLANG)
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_GCC_PLUGINS
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
@@ -126,6 +126,7 @@ config ARM
 	select PERF_USE_VMALLOC
 	select RTC_LIB
 	select SYS_SUPPORTS_APM_EMULATION
+	select THREAD_INFO_IN_TASK if CURRENT_POINTER_IN_TPIDRURO
 	select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
 	# Above selects are sorted alphabetically; please add new ones
 	# according to that.  Thanks.
@@ -265,10 +266,12 @@ config PHYS_OFFSET
 	hex "Physical address of main memory" if MMU
 	depends on !ARM_PATCH_PHYS_VIRT
 	default DRAM_BASE if !MMU
-	default 0x00000000 if ARCH_FOOTBRIDGE
+	default 0x00000000 if ARCH_FOOTBRIDGE || ARCH_IXP4XX
 	default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
-	default 0x20000000 if ARCH_S5PV210
-	default 0xc0000000 if ARCH_SA1100
+	default 0x30000000 if ARCH_S3C24XX
+	default 0xa0000000 if ARCH_IOP32X || ARCH_PXA
+	default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100
+	default 0
 	help
 	  Please provide the physical address corresponding to the
 	  location of main memory in your system.
@@ -433,6 +436,7 @@ config ARCH_PXA
 config ARCH_RPC
 	bool "RiscPC"
 	depends on MMU
+	depends on !CC_IS_CLANG && GCC_VERSION < 90100 && GCC_VERSION >= 60000
 	select ARCH_ACORN
 	select ARCH_MAY_HAVE_PC_FDC
 	select ARCH_SPARSEMEM_ENABLE
@@ -1158,6 +1162,11 @@ config SMP_ON_UP
 
 	  If you don't know what to do here, say Y.
 
+
+config CURRENT_POINTER_IN_TPIDRURO
+	def_bool y
+	depends on SMP && CPU_32v6K && !CPU_V6
+
 config ARM_CPU_TOPOLOGY
 	bool "Support cpu topology definition"
 	depends on SMP && CPU_V7
@@ -1601,7 +1610,7 @@ config XEN
 
 config STACKPROTECTOR_PER_TASK
 	bool "Use a unique stack canary value for each task"
-	depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
+	depends on GCC_PLUGINS && STACKPROTECTOR && THREAD_INFO_IN_TASK && !XIP_DEFLATED_DATA
 	select GCC_PLUGIN_ARM_SSP_PER_TASK
 	default y
 	help

arch/arm/Makefile

@@ -113,6 +113,10 @@ ifeq ($(CONFIG_CC_IS_CLANG),y)
 CFLAGS_ABI	+= -meabi gnu
 endif
 
+ifeq ($(CONFIG_CURRENT_POINTER_IN_TPIDRURO),y)
+CFLAGS_ABI	+= -mtp=cp15
+endif
+
 # Accept old syntax despite ".syntax unified"
 AFLAGS_NOWARN	:=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
 
@@ -273,11 +277,8 @@ ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
 prepare: stack_protector_prepare
 stack_protector_prepare: prepare0
 	$(eval SSP_PLUGIN_CFLAGS := \
-		-fplugin-arg-arm_ssp_per_task_plugin-tso=$(shell	\
-			awk '{if ($$2 == "THREAD_SZ_ORDER") print $$3;}'\
-				include/generated/asm-offsets.h)	\
 		-fplugin-arg-arm_ssp_per_task_plugin-offset=$(shell	\
-			awk '{if ($$2 == "TI_STACK_CANARY") print $$3;}'\
+			awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}'\
 				include/generated/asm-offsets.h))
 	$(eval KBUILD_CFLAGS += $(SSP_PLUGIN_CFLAGS))
 	$(eval GCC_PLUGINS_CFLAGS += $(SSP_PLUGIN_CFLAGS))

arch/arm/boot/compressed/fdt_check_mem_start.c

@@ -55,16 +55,17 @@ static uint64_t get_val(const fdt32_t *cells, uint32_t ncells)
  * DTB, and, if out-of-range, replace it by the real start address.
  * To preserve backwards compatibility (systems reserving a block of memory
  * at the start of physical memory, kdump, ...), the traditional method is
- * always used if it yields a valid address.
+ * used if it yields a valid address, unless the "linux,usable-memory-range"
+ * property is present.
  *
  * Return value: start address of physical memory to use
  */
 uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
 {
-	uint32_t addr_cells, size_cells, base;
+	uint32_t addr_cells, size_cells, usable_base, base;
 	uint32_t fdt_mem_start = 0xffffffff;
-	const fdt32_t *reg, *endp;
-	uint64_t size, end;
+	const fdt32_t *usable, *reg, *endp;
+	uint64_t size, usable_end, end;
 	const char *type;
 	int offset, len;
 
@@ -80,6 +81,27 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
 	if (addr_cells > 2 || size_cells > 2)
 		return mem_start;
 
+	/*
+	 * Usable memory in case of a crash dump kernel
+	 * This property describes a limitation: memory within this range is
+	 * only valid when also described through another mechanism
+	 */
+	usable = get_prop(fdt, "/chosen", "linux,usable-memory-range",
+			  (addr_cells + size_cells) * sizeof(fdt32_t));
+	if (usable) {
+		size = get_val(usable + addr_cells, size_cells);
+		if (!size)
+			return mem_start;
+
+		if (addr_cells > 1 && fdt32_ld(usable)) {
+			/* Outside 32-bit address space */
+			return mem_start;
+		}
+
+		usable_base = fdt32_ld(usable + addr_cells - 1);
+		usable_end = usable_base + size;
+	}
+
 	/* Walk all memory nodes and regions */
 	for (offset = fdt_next_node(fdt, -1, NULL); offset >= 0;
 	     offset = fdt_next_node(fdt, offset, NULL)) {
@@ -107,7 +129,20 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
 
 			base = fdt32_ld(reg + addr_cells - 1);
 			end = base + size;
-			if (mem_start >= base && mem_start < end) {
+			if (usable) {
+				/*
+				 * Clip to usable range, which takes precedence
+				 * over mem_start
+				 */
+				if (base < usable_base)
+					base = usable_base;
+
+				if (end > usable_end)
+					end = usable_end;
+
+				if (end <= base)
+					continue;
+			} else if (mem_start >= base && mem_start < end) {
 				/* Calculated address is valid, use it */
 				return mem_start;
 			}
@@ -123,7 +158,8 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)
 	}
 
 	/*
-	 * The calculated address is not usable.
+	 * The calculated address is not usable, or was overridden by the
+	 * "linux,usable-memory-range" property.
 	 * Use the lowest usable physical memory address from the DTB instead,
 	 * and make sure this is a multiple of 2 MiB for phys/virt patching.
 	 */

arch/arm/common/scoop.c

@@ -240,9 +240,6 @@ static int scoop_remove(struct platform_device *pdev)
 {
 	struct scoop_dev *sdev = platform_get_drvdata(pdev);
 
-	if (!sdev)
-		return -EINVAL;
-
 	if (sdev->gpio.base != -1)
 		gpiochip_remove(&sdev->gpio);
 

arch/arm/include/asm/assembler.h

@@ -199,14 +199,43 @@
 	.endm
 	.endr
 
+	.macro	get_current, rd
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+	mrc	p15, 0, \rd, c13, c0, 3		@ get TPIDRURO register
+#else
+	get_thread_info \rd
+	ldr	\rd, [\rd, #TI_TASK]
+#endif
+	.endm
+
+	.macro	set_current, rn
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+	mcr	p15, 0, \rn, c13, c0, 3		@ set TPIDRURO register
+#endif
+	.endm
+
+	.macro	reload_current, t1:req, t2:req
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+	adr_l	\t1, __entry_task		@ get __entry_task base address
+	mrc	p15, 0, \t2, c13, c0, 4		@ get per-CPU offset
+	ldr	\t1, [\t1, \t2]			@ load variable
+	mcr	p15, 0, \t1, c13, c0, 3		@ store in TPIDRURO
+#endif
+	.endm
+
 /*
  * Get current thread_info.
  */
 	.macro	get_thread_info, rd
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	/* thread_info is the first member of struct task_struct */
+	get_current \rd
+#else
  ARM(	mov	\rd, sp, lsr #THREAD_SIZE_ORDER + PAGE_SHIFT	)
  THUMB(	mov	\rd, sp			)
  THUMB(	lsr	\rd, \rd, #THREAD_SIZE_ORDER + PAGE_SHIFT	)
 	mov	\rd, \rd, lsl #THREAD_SIZE_ORDER + PAGE_SHIFT
+#endif
 	.endm
 
 /*

arch/arm/include/asm/current.h

@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2021 Keith Packard <[email protected]>
+ * Copyright (c) 2021 Google, LLC <[email protected]>
+ */
+
+#ifndef _ASM_ARM_CURRENT_H
+#define _ASM_ARM_CURRENT_H
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+static inline void set_current(struct task_struct *cur)
+{
+	if (!IS_ENABLED(CONFIG_CURRENT_POINTER_IN_TPIDRURO))
+		return;
+
+	/* Set TPIDRURO */
+	asm("mcr p15, 0, %0, c13, c0, 3" :: "r"(cur) : "memory");
+}
+
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+
+static inline struct task_struct *get_current(void)
+{
+	struct task_struct *cur;
+
+#if __has_builtin(__builtin_thread_pointer) && \
+    !(defined(CONFIG_THUMB2_KERNEL) && \
+      defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 130001)
+	/*
+	 * Use the __builtin helper when available - this results in better
+	 * code, especially when using GCC in combination with the per-task
+	 * stack protector, as the compiler will recognize that it needs to
+	 * load the TLS register only once in every function.
+	 *
+	 * Clang < 13.0.1 gets this wrong for Thumb2 builds:
+	 * https://github.com/ClangBuiltLinux/linux/issues/1485
+	 */
+	cur = __builtin_thread_pointer();
+#else
+	asm("mrc p15, 0, %0, c13, c0, 3" : "=r"(cur));
+#endif
+	return cur;
+}
+
+#define current get_current()
+#else
+#include <asm-generic/current.h>
+#endif /* CONFIG_CURRENT_POINTER_IN_TPIDRURO */
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_ARM_CURRENT_H */

arch/arm/include/asm/io.h

@@ -138,6 +138,7 @@ extern void __iomem *__arm_ioremap_caller(phys_addr_t, size_t, unsigned int,
 	void *);
 extern void __iomem *__arm_ioremap_pfn(unsigned long, unsigned long, size_t, unsigned int);
 extern void __iomem *__arm_ioremap_exec(phys_addr_t, size_t, bool cached);
+void __arm_iomem_set_ro(void __iomem *ptr, size_t size);
 extern void __iounmap(volatile void __iomem *addr);
 
 extern void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t,

arch/arm/include/asm/opcodes.h

@@ -110,12 +110,17 @@ extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr);
 #define __opcode_to_mem_thumb16(x) ___opcode_identity16(x)
 #define ___asm_opcode_to_mem_arm(x) ___asm_opcode_identity32(x)
 #define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_identity16(x)
-#ifndef CONFIG_CPU_ENDIAN_BE32
+#ifdef CONFIG_CPU_ENDIAN_BE32
+#ifndef __ASSEMBLY__
 /*
  * On BE32 systems, using 32-bit accesses to store Thumb instructions will not
  * work in all cases, due to alignment constraints.  For now, a correct
- * version is not provided for BE32.
+ * version is not provided for BE32, but the prototype needs to be there
+ * to compile patch.c.
  */
+extern __u32 __opcode_to_mem_thumb32(__u32);
+#endif
+#else
 #define __opcode_to_mem_thumb32(x) ___opcode_swahw32(x)
 #define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahw32(x)
 #endif

arch/arm/include/asm/setup.h

@@ -19,7 +19,7 @@
 static const struct tagtable __tagtable_##fn __tag = { tag, fn }
 
 extern int arm_add_memory(u64 start, u64 size);
-extern void early_print(const char *str, ...);
+extern __printf(1, 2) void early_print(const char *str, ...);
 extern void dump_machine_table(void);
 
 #ifdef CONFIG_ATAGS_PROC

arch/arm/include/asm/smp.h

@@ -48,7 +48,7 @@ extern void set_smp_ipi_range(int ipi_base, int nr_ipi);
  * Called from platform specific assembly code, this is the
  * secondary CPU entry point.
  */
-asmlinkage void secondary_start_kernel(void);
+asmlinkage void secondary_start_kernel(struct task_struct *task);
 
 
 /*
@@ -61,6 +61,7 @@ struct secondary_data {
 	};
 	unsigned long swapper_pg_dir;
 	void *stack;
+	struct task_struct *task;
 };
 extern struct secondary_data secondary_data;
 extern void secondary_startup(void);

arch/arm/include/asm/stackprotector.h

@@ -39,8 +39,6 @@ static __always_inline void boot_init_stack_canary(void)
 	current->stack_canary = canary;
 #ifndef CONFIG_STACKPROTECTOR_PER_TASK
 	__stack_chk_guard = current->stack_canary;
-#else
-	current_thread_info()->stack_canary = current->stack_canary;
 #endif
 }
 

arch/arm/include/asm/switch_to.h

@@ -23,9 +23,25 @@
  */
 extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
 
+static inline void set_ti_cpu(struct task_struct *p)
+{
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	/*
+	 * The core code no longer maintains the thread_info::cpu field once
+	 * CONFIG_THREAD_INFO_IN_TASK is in effect, but we rely on it for
+	 * raw_smp_processor_id(), which cannot access struct task_struct*
+	 * directly for reasons of circular #inclusion hell.
+	 */
+	task_thread_info(p)->cpu = task_cpu(p);
+#endif
+}
+
 #define switch_to(prev,next,last)					\
 do {									\
 	__complete_pending_tlbi();					\
+	set_ti_cpu(next);						\
+	if (IS_ENABLED(CONFIG_CURRENT_POINTER_IN_TPIDRURO))		\
+		__this_cpu_write(__entry_task, next);			\
 	last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));	\
 } while (0)