ARM: implement debug_ll_io_init() (e5c5f2ad) · Commits · 戴 / test

When using DEBUG_LL, the UART's (or other HW's) registers are mapped into early page tables based on the results of assembly macro addruart. Later, when the page tables are replaced, the same virtual address must remain valid. Historically, this has been ensured by using defines from <mach/iomap.h> in both the implementation of addruart, and the machine's .map_io() function. However, with the move to single zImage, we wish to remove <mach/iomap.h>. To enable this, the macro addruart may be used when constructing the late page tables too; addruart is exposed as a C function debug_ll_addr(), and used to set up the required mapping in debug_ll_io_init(), which may called on an opt-in basis from a machine's .map_io() function. Signed-off-by:

Rob Herring <rob.herring@calxeda.com> [swarren: Mask map.virtual with PAGE_MASK. Checked for NULL results from debug_ll_addr (e.g. when selected UART isn't valid). Fixed compile when either !CONFIG_DEBUG_LL or CONFIG_DEBUG_SEMIHOSTING.] Signed-off-by:

Stephen Warren <swarren@nvidia.com> Signed-off-by:

Olof Johansson <olof@lixom.net>

arch/arm/include/asm/mach/map.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -40,6 +40,13 @@ extern void iotable_init(struct map_desc *, int);
		extern void vm_reserve_area_early(unsigned long addr, unsigned long size,
		void *caller);

		#ifdef CONFIG_DEBUG_LL
		extern void debug_ll_addr(unsigned long paddr, unsigned long vaddr);
		extern void debug_ll_io_init(void);
		#else
		static inline void debug_ll_io_init(void) {}
		#endif

		struct mem_type;
		extern const struct mem_type *get_mem_type(unsigned int type);
		/*

arch/arm/kernel/debug.S

+14 −0

Original line number	Diff line number	Diff line
		@@ -100,6 +100,13 @@ ENTRY(printch)
		b 1b
		ENDPROC(printch)

		ENTRY(debug_ll_addr)
		addruart r2, r3, ip
		str r2, [r0]
		str r3, [r1]
		mov pc, lr
		ENDPROC(debug_ll_addr)

		#else

		ENTRY(printascii)
		@@ -119,4 +126,11 @@ ENTRY(printch)
		mov pc, lr
		ENDPROC(printch)

		ENTRY(debug_ll_addr)
		mov r2, #0
		str r2, [r0]
		str r2, [r1]
		mov pc, lr
		ENDPROC(debug_ll_addr)

		#endif

arch/arm/mm/mmu.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -876,6 +876,22 @@ static void __init pci_reserve_io(void)
		#define pci_reserve_io() do { } while (0)
		#endif

		#ifdef CONFIG_DEBUG_LL
		void __init debug_ll_io_init(void)
		{
		struct map_desc map;

		debug_ll_addr(&map.pfn, &map.virtual);
		if (!map.pfn \|\| !map.virtual)
		return;
		map.pfn = __phys_to_pfn(map.pfn);
		map.virtual &= PAGE_MASK;
		map.length = PAGE_SIZE;
		map.type = MT_DEVICE;
		create_mapping(&map);
		}
		#endif

		static void * __initdata vmalloc_min =
		(void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);

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