arm64: move TASK_* definitions to <asm/processor.h>

ILP32 series [1] introduces the dependency on <asm/is_compat.h> for
TASK_SIZE macro. Which in turn requires <asm/thread_info.h>, and
<asm/thread_info.h> include <asm/memory.h>, giving a circular dependency,
because TASK_SIZE is currently located in <asm/memory.h>.

In other architectures, TASK_SIZE is defined in <asm/processor.h>, and
moving TASK_SIZE there fixes the problem.

Discussion: https://patchwork.kernel.org/patch/9929107/

[1] https://github.com/norov/linux/tree/ilp32-next

CC: Will Deacon <will.deacon@arm.com>
CC: Laura Abbott <labbott@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/include/asm/memory.h

@@ -61,8 +61,6 @@
  * KIMAGE_VADDR - the virtual address of the start of the kernel image
  * VA_BITS - the maximum number of bits for virtual addresses.
  * VA_START - the first kernel virtual address.
- * TASK_SIZE - the maximum size of a user space task.
- * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
  */
 #define VA_BITS			(CONFIG_ARM64_VA_BITS)
 #define VA_START		(UL(0xffffffffffffffff) - \
@@ -77,19 +75,6 @@
 #define PCI_IO_END		(VMEMMAP_START - SZ_2M)
 #define PCI_IO_START		(PCI_IO_END - PCI_IO_SIZE)
 #define FIXADDR_TOP		(PCI_IO_START - SZ_2M)
-#define TASK_SIZE_64		(UL(1) << VA_BITS)
-
-#ifdef CONFIG_COMPAT
-#define TASK_SIZE_32		UL(0x100000000)
-#define TASK_SIZE		(test_thread_flag(TIF_32BIT) ? \
-				TASK_SIZE_32 : TASK_SIZE_64)
-#define TASK_SIZE_OF(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT) ? \
-				TASK_SIZE_32 : TASK_SIZE_64)
-#else
-#define TASK_SIZE		TASK_SIZE_64
-#endif /* CONFIG_COMPAT */
-
-#define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 4))
 
 #define KERNEL_START      _text
 #define KERNEL_END        _end

arch/arm64/include/asm/processor.h

@@ -19,6 +19,10 @@
 #ifndef __ASM_PROCESSOR_H
 #define __ASM_PROCESSOR_H
 
+#define TASK_SIZE_64		(UL(1) << VA_BITS)
+
+#ifndef __ASSEMBLY__
+
 /*
  * Default implementation of macro that returns current
  * instruction pointer ("program counter").
@@ -37,6 +41,22 @@
 #include <asm/ptrace.h>
 #include <asm/types.h>
 
+/*
+ * TASK_SIZE - the maximum size of a user space task.
+ * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
+ */
+#ifdef CONFIG_COMPAT
+#define TASK_SIZE_32		UL(0x100000000)
+#define TASK_SIZE		(test_thread_flag(TIF_32BIT) ? \
+				TASK_SIZE_32 : TASK_SIZE_64)
+#define TASK_SIZE_OF(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT) ? \
+				TASK_SIZE_32 : TASK_SIZE_64)
+#else
+#define TASK_SIZE		TASK_SIZE_64
+#endif /* CONFIG_COMPAT */
+
+#define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 4))
+
 #define STACK_TOP_MAX		TASK_SIZE_64
 #ifdef CONFIG_COMPAT
 #define AARCH32_VECTORS_BASE	0xffff0000
@@ -194,4 +214,5 @@ static inline void spin_lock_prefetch(const void *ptr)
 int cpu_enable_pan(void *__unused);
 int cpu_enable_cache_maint_trap(void *__unused);
 
+#endif /* __ASSEMBLY__ */
 #endif /* __ASM_PROCESSOR_H */

arch/arm64/kernel/entry.S

@@ -28,7 +28,7 @@
 #include <asm/errno.h>
 #include <asm/esr.h>
 #include <asm/irq.h>
-#include <asm/memory.h>
+#include <asm/processor.h>
 #include <asm/ptrace.h>
 #include <asm/thread_info.h>
 #include <asm/asm-uaccess.h>