forked from Minki/linux
2475ff9d2c
This patch adds support for "earlyprintk=" parameter on the kernel command line. The format is: earlyprintk=<name>[,<addr>][,<options>] where <name> is the name of the (UART) device, e.g. "pl011", <addr> is the I/O address. The <options> aren't currently used. The mapping of the earlyprintk device is done very early during kernel boot and there are restrictions on which functions it can call. A special early_io_map() function is added which creates the mapping from the pre-defined EARLY_IOBASE to the device I/O address passed via the kernel parameter. The pgd entry corresponding to EARLY_IOBASE is pre-populated in head.S during kernel boot. Only PL011 is currently supported and it is assumed that the interface is already initialised by the boot loader before the kernel is started. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
146 lines
4.4 KiB
C
146 lines
4.4 KiB
C
/*
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* Based on arch/arm/include/asm/memory.h
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*
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* Copyright (C) 2000-2002 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Note: this file should not be included by non-asm/.h files
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*/
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#ifndef __ASM_MEMORY_H
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#define __ASM_MEMORY_H
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#include <linux/compiler.h>
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#include <linux/const.h>
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#include <linux/types.h>
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#include <asm/sizes.h>
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/*
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* Allow for constants defined here to be used from assembly code
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* by prepending the UL suffix only with actual C code compilation.
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*/
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#define UL(x) _AC(x, UL)
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/*
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* PAGE_OFFSET - the virtual address of the start of the kernel image.
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* VA_BITS - the maximum number of bits for virtual addresses.
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* TASK_SIZE - the maximum size of a user space task.
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* TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
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* The module space lives between the addresses given by TASK_SIZE
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* and PAGE_OFFSET - it must be within 128MB of the kernel text.
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*/
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#define PAGE_OFFSET UL(0xffffffc000000000)
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#define MODULES_END (PAGE_OFFSET)
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#define MODULES_VADDR (MODULES_END - SZ_64M)
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#define EARLYCON_IOBASE (MODULES_VADDR - SZ_4M)
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#define VA_BITS (39)
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#define TASK_SIZE_64 (UL(1) << VA_BITS)
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#ifdef CONFIG_COMPAT
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#define TASK_SIZE_32 UL(0x100000000)
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#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
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TASK_SIZE_32 : TASK_SIZE_64)
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#else
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#define TASK_SIZE TASK_SIZE_64
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#endif /* CONFIG_COMPAT */
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#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
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#if TASK_SIZE_64 > MODULES_VADDR
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#error Top of 64-bit user space clashes with start of module space
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#endif
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/*
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* Physical vs virtual RAM address space conversion. These are
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* private definitions which should NOT be used outside memory.h
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* files. Use virt_to_phys/phys_to_virt/__pa/__va instead.
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*/
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#define __virt_to_phys(x) (((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET))
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#define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET))
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/*
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* Convert a physical address to a Page Frame Number and back
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*/
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#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >> PAGE_SHIFT))
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#define __pfn_to_phys(pfn) ((phys_addr_t)(pfn) << PAGE_SHIFT)
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/*
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* Convert a page to/from a physical address
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*/
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#define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page)))
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#define phys_to_page(phys) (pfn_to_page(__phys_to_pfn(phys)))
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/*
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* Memory types available.
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*/
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#define MT_DEVICE_nGnRnE 0
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#define MT_DEVICE_nGnRE 1
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#define MT_DEVICE_GRE 2
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#define MT_NORMAL_NC 3
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#define MT_NORMAL 4
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#ifndef __ASSEMBLY__
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extern phys_addr_t memstart_addr;
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/* PHYS_OFFSET - the physical address of the start of memory. */
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#define PHYS_OFFSET ({ memstart_addr; })
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/*
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* PFNs are used to describe any physical page; this means
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* PFN 0 == physical address 0.
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*
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* This is the PFN of the first RAM page in the kernel
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* direct-mapped view. We assume this is the first page
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* of RAM in the mem_map as well.
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*/
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#define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
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/*
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* Note: Drivers should NOT use these. They are the wrong
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* translation for translating DMA addresses. Use the driver
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* DMA support - see dma-mapping.h.
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*/
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static inline phys_addr_t virt_to_phys(const volatile void *x)
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{
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return __virt_to_phys((unsigned long)(x));
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}
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static inline void *phys_to_virt(phys_addr_t x)
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{
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return (void *)(__phys_to_virt(x));
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}
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/*
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* Drivers should NOT use these either.
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*/
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#define __pa(x) __virt_to_phys((unsigned long)(x))
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#define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
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#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
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/*
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* virt_to_page(k) convert a _valid_ virtual address to struct page *
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* virt_addr_valid(k) indicates whether a virtual address is valid
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*/
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#define ARCH_PFN_OFFSET PHYS_PFN_OFFSET
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#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
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#define virt_addr_valid(kaddr) (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
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((void *)(kaddr) < (void *)high_memory))
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#endif
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#include <asm-generic/memory_model.h>
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#endif
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