[linux-2.6-block.git] / arch / unicore32 / mm / ioremap.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/arch/unicore32/mm/ioremap.c
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 * Copyright (C) 2001-2010 GUAN Xue-tao
 *
 * Re-map IO memory to kernel address space so that we can access it.
 *
 * This allows a driver to remap an arbitrary region of bus memory into
 * virtual space.  One should *only* use readl, writel, memcpy_toio and
 * so on with such remapped areas.
 *
 * Because UniCore only has a 32-bit address space we can't address the
 * whole of the (physical) PCI space at once.  PCI huge-mode addressing
 * allows us to circumvent this restriction by splitting PCI space into
 * two 2GB chunks and mapping only one at a time into processor memory.
 * We use MMU protection domains to trap any attempt to access the bank
 * that is not currently mapped.  (This isn't fully implemented yet.)
 */
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/io.h>

#include <asm/cputype.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <linux/sizes.h>

#include <mach/map.h>
#include "mm.h"

/*
 * Used by ioremap() and iounmap() code to mark (super)section-mapped
 * I/O regions in vm_struct->flags field.
 */
#define VM_UNICORE_SECTION_MAPPING	0x80000000

int ioremap_page(unsigned long virt, unsigned long phys,
		 const struct mem_type *mtype)
{
	return ioremap_page_range(virt, virt + PAGE_SIZE, phys,
				  __pgprot(mtype->prot_pte));
}
EXPORT_SYMBOL(ioremap_page);

/*
 * Section support is unsafe on SMP - If you iounmap and ioremap a region,
 * the other CPUs will not see this change until their next context switch.
 * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
 * which requires the new ioremap'd region to be referenced, the CPU will
 * reference the _old_ region.
 *
 * Note that get_vm_area_caller() allocates a guard 4K page, so we need to
 * mask the size back to 4MB aligned or we will overflow in the loop below.
 */
static void unmap_area_sections(unsigned long virt, unsigned long size)
{
	unsigned long addr = virt, end = virt + (size & ~(SZ_4M - 1));
	pgd_t *pgd;

	flush_cache_vunmap(addr, end);
	pgd = pgd_offset_k(addr);
	do {
		pmd_t pmd, *pmdp = pmd_offset((pud_t *)pgd, addr);

		pmd = *pmdp;
		if (!pmd_none(pmd)) {
			/*
			 * Clear the PMD from the page table, and
			 * increment the kvm sequence so others
			 * notice this change.
			 *
			 * Note: this is still racy on SMP machines.
			 */
			pmd_clear(pmdp);

			/*
			 * Free the page table, if there was one.
			 */
			if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
				pte_free_kernel(&init_mm, pmd_page_vaddr(pmd));
		}

		addr += PGDIR_SIZE;
		pgd++;
	} while (addr < end);

	flush_tlb_kernel_range(virt, end);
}

static int
remap_area_sections(unsigned long virt, unsigned long pfn,
		    size_t size, const struct mem_type *type)
{
	unsigned long addr = virt, end = virt + size;
	pgd_t *pgd;

	/*
	 * Remove and free any PTE-based mapping, and
	 * sync the current kernel mapping.
	 */
	unmap_area_sections(virt, size);

	pgd = pgd_offset_k(addr);
	do {
		pmd_t *pmd = pmd_offset((pud_t *)pgd, addr);

		set_pmd(pmd, __pmd(__pfn_to_phys(pfn) | type->prot_sect));
		pfn += SZ_4M >> PAGE_SHIFT;
		flush_pmd_entry(pmd);

		addr += PGDIR_SIZE;
		pgd++;
	} while (addr < end);

	return 0;
}

void __iomem *__uc32_ioremap_pfn_caller(unsigned long pfn,
	unsigned long offset, size_t size, unsigned int mtype, void *caller)
{
	const struct mem_type *type;
	int err;
	unsigned long addr;
	struct vm_struct *area;

	/*
	 * High mappings must be section aligned
	 */
	if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SECTION_MASK))
		return NULL;

	/*
	 * Don't allow RAM to be mapped
	 */
	if (pfn_valid(pfn)) {
		WARN(1, "BUG: Your driver calls ioremap() on\n"
			"system memory.  This leads to architecturally\n"
			"unpredictable behaviour, and ioremap() will fail in\n"
			"the next kernel release. Please fix your driver.\n");
		return NULL;
	}

	type = get_mem_type(mtype);
	if (!type)
		return NULL;

	/*
	 * Page align the mapping size, taking account of any offset.
	 */
	size = PAGE_ALIGN(offset + size);

	area = get_vm_area_caller(size, VM_IOREMAP, caller);
	if (!area)
		return NULL;
	addr = (unsigned long)area->addr;

	if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
		area->flags |= VM_UNICORE_SECTION_MAPPING;
		err = remap_area_sections(addr, pfn, size, type);
	} else
		err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn),
					 __pgprot(type->prot_pte));

	if (err) {
		vunmap((void *)addr);
		return NULL;
	}

	flush_cache_vmap(addr, addr + size);
	return (void __iomem *) (offset + addr);
}

void __iomem *__uc32_ioremap_caller(unsigned long phys_addr, size_t size,
	unsigned int mtype, void *caller)
{
	unsigned long last_addr;
	unsigned long offset = phys_addr & ~PAGE_MASK;
	unsigned long pfn = __phys_to_pfn(phys_addr);

	/*
	 * Don't allow wraparound or zero size
	 */
	last_addr = phys_addr + size - 1;
	if (!size || last_addr < phys_addr)
		return NULL;

	return __uc32_ioremap_pfn_caller(pfn, offset, size, mtype, caller);
}

/*
 * Remap an arbitrary physical address space into the kernel virtual
 * address space. Needed when the kernel wants to access high addresses
 * directly.
 *
 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 * have to convert them into an offset in a page-aligned mapping, but the
 * caller shouldn't need to know that small detail.
 */
void __iomem *
__uc32_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
		  unsigned int mtype)
{
	return __uc32_ioremap_pfn_caller(pfn, offset, size, mtype,
			__builtin_return_address(0));
}
EXPORT_SYMBOL(__uc32_ioremap_pfn);

void __iomem *
__uc32_ioremap(unsigned long phys_addr, size_t size)
{
	return __uc32_ioremap_caller(phys_addr, size, MT_DEVICE,
			__builtin_return_address(0));
}
EXPORT_SYMBOL(__uc32_ioremap);

void __uc32_iounmap(volatile void __iomem *io_addr)
{
	void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
	struct vm_struct *vm;

	/*
	 * If this is a section based mapping we need to handle it
	 * specially as the VM subsystem does not know how to handle
	 * such a beast. We need the lock here b/c we need to clear
	 * all the mappings before the area can be reclaimed
	 * by someone else.
	 */
	vm = find_vm_area(addr);
	if (vm && (vm->flags & VM_IOREMAP) &&
		(vm->flags & VM_UNICORE_SECTION_MAPPING))
		unmap_area_sections((unsigned long)vm->addr, vm->size);

	vunmap(addr);
}
EXPORT_SYMBOL(__uc32_iounmap);
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
b50f1704 G	2	/*
	3	* linux/arch/unicore32/mm/ioremap.c
	4	*
	5	* Code specific to PKUnity SoC and UniCore ISA
	6	*
	7	* Copyright (C) 2001-2010 GUAN Xue-tao
	8	*
b50f1704 G	9	* Re-map IO memory to kernel address space so that we can access it.
	10	*
	11	* This allows a driver to remap an arbitrary region of bus memory into
	12	* virtual space. One should only use readl, writel, memcpy_toio and
	13	* so on with such remapped areas.
	14	*
	15	* Because UniCore only has a 32-bit address space we can't address the
	16	* whole of the (physical) PCI space at once. PCI huge-mode addressing
	17	* allows us to circumvent this restriction by splitting PCI space into
	18	* two 2GB chunks and mapping only one at a time into processor memory.
	19	* We use MMU protection domains to trap any attempt to access the bank
	20	* that is not currently mapped. (This isn't fully implemented yet.)
	21	*/
	22	#include <linux/module.h>
	23	#include <linux/errno.h>
	24	#include <linux/mm.h>
	25	#include <linux/vmalloc.h>
	26	#include <linux/io.h>
	27
	28	#include <asm/cputype.h>
	29	#include <asm/cacheflush.h>
	30	#include <asm/mmu_context.h>
	31	#include <asm/pgalloc.h>
	32	#include <asm/tlbflush.h>
87dfb311	33	#include <linux/sizes.h>
b50f1704 G	34
	35	#include <mach/map.h>
	36	#include "mm.h"
	37
	38	/*
	39	* Used by ioremap() and iounmap() code to mark (super)section-mapped
	40	* I/O regions in vm_struct->flags field.
	41	*/
	42	#define VM_UNICORE_SECTION_MAPPING 0x80000000
	43
	44	int ioremap_page(unsigned long virt, unsigned long phys,
	45	const struct mem_type *mtype)
	46	{
	47	return ioremap_page_range(virt, virt + PAGE_SIZE, phys,
	48	__pgprot(mtype->prot_pte));
	49	}
	50	EXPORT_SYMBOL(ioremap_page);
	51
	52	/*
	53	* Section support is unsafe on SMP - If you iounmap and ioremap a region,
	54	* the other CPUs will not see this change until their next context switch.
	55	* Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
	56	* which requires the new ioremap'd region to be referenced, the CPU will
	57	* reference the _old_ region.
	58	*
	59	* Note that get_vm_area_caller() allocates a guard 4K page, so we need to
	60	* mask the size back to 4MB aligned or we will overflow in the loop below.
	61	*/
	62	static void unmap_area_sections(unsigned long virt, unsigned long size)
	63	{
	64	unsigned long addr = virt, end = virt + (size & ~(SZ_4M - 1));
	65	pgd_t *pgd;
	66
	67	flush_cache_vunmap(addr, end);
	68	pgd = pgd_offset_k(addr);
	69	do {
	70	pmd_t pmd, pmdp = pmd_offset((pud_t )pgd, addr);
	71
	72	pmd = *pmdp;
	73	if (!pmd_none(pmd)) {
	74	/*
	75	* Clear the PMD from the page table, and
	76	* increment the kvm sequence so others
	77	* notice this change.
	78	*
	79	* Note: this is still racy on SMP machines.
	80	*/
	81	pmd_clear(pmdp);
	82
	83	/*
	84	* Free the page table, if there was one.
	85	*/
	86	if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
	87	pte_free_kernel(&init_mm, pmd_page_vaddr(pmd));
	88	}
	89
	90	addr += PGDIR_SIZE;
	91	pgd++;
	92	} while (addr < end);
	93
	94	flush_tlb_kernel_range(virt, end);
	95	}
	96
	97	static int
98	remap_area_sections(unsigned long virt, unsigned long pfn,
99	size_t size, const struct mem_type *type)
100	{
101	unsigned long addr = virt, end = virt + size;
102	pgd_t *pgd;
103
104	/*
105	* Remove and free any PTE-based mapping, and
106	* sync the current kernel mapping.
107	*/
108	unmap_area_sections(virt, size);
109
110	pgd = pgd_offset_k(addr);
111	do {
112	pmd_t pmd = pmd_offset((pud_t )pgd, addr);
113
114	set_pmd(pmd, __pmd(__pfn_to_phys(pfn) \| type->prot_sect));
115	pfn += SZ_4M >> PAGE_SHIFT;
116	flush_pmd_entry(pmd);
117
118	addr += PGDIR_SIZE;
119	pgd++;
120	} while (addr < end);
121
122	return 0;
123	}
124
125	void __iomem *__uc32_ioremap_pfn_caller(unsigned long pfn,
126	unsigned long offset, size_t size, unsigned int mtype, void *caller)
127	{
128	const struct mem_type *type;
129	int err;
130	unsigned long addr;
131	struct vm_struct *area;
132
133	/*
134	* High mappings must be section aligned
135	*/
136	if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SECTION_MASK))
137	return NULL;
138
139	/*
140	* Don't allow RAM to be mapped
141	*/
2accff4e	142	if (pfn_valid(pfn)) {
acc8a1c0	143	WARN(1, "BUG: Your driver calls ioremap() on\n"
b50f1704 G	144	"system memory. This leads to architecturally\n"
	145	"unpredictable behaviour, and ioremap() will fail in\n"
	146	"the next kernel release. Please fix your driver.\n");
2accff4e AM	147	return NULL;
2accff4e AM	148	}
b50f1704 G	149
	150	type = get_mem_type(mtype);
	151	if (!type)
	152	return NULL;
	153
	154	/*
	155	* Page align the mapping size, taking account of any offset.
	156	*/
	157	size = PAGE_ALIGN(offset + size);
	158
	159	area = get_vm_area_caller(size, VM_IOREMAP, caller);
	160	if (!area)
	161	return NULL;
	162	addr = (unsigned long)area->addr;
	163
	164	if (!((__pfn_to_phys(pfn) \| size \| addr) & ~PMD_MASK)) {
	165	area->flags \|= VM_UNICORE_SECTION_MAPPING;
	166	err = remap_area_sections(addr, pfn, size, type);
	167	} else
	168	err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn),
	169	__pgprot(type->prot_pte));
	170
	171	if (err) {
	172	vunmap((void *)addr);
	173	return NULL;
	174	}
	175
	176	flush_cache_vmap(addr, addr + size);
	177	return (void __iomem *) (offset + addr);
	178	}
	179
	180	void __iomem *__uc32_ioremap_caller(unsigned long phys_addr, size_t size,
	181	unsigned int mtype, void *caller)
	182	{
	183	unsigned long last_addr;
	184	unsigned long offset = phys_addr & ~PAGE_MASK;
	185	unsigned long pfn = __phys_to_pfn(phys_addr);
	186
	187	/*
	188	* Don't allow wraparound or zero size
	189	*/
	190	last_addr = phys_addr + size - 1;
	191	if (!size \|\| last_addr < phys_addr)
	192	return NULL;
	193
	194	return __uc32_ioremap_pfn_caller(pfn, offset, size, mtype, caller);
	195	}
	196
	197	/*
	198	* Remap an arbitrary physical address space into the kernel virtual
	199	* address space. Needed when the kernel wants to access high addresses
	200	* directly.
	201	*
	202	* NOTE! We need to allow non-page-aligned mappings too: we will obviously
	203	* have to convert them into an offset in a page-aligned mapping, but the
	204	* caller shouldn't need to know that small detail.
	205	*/
	206	void __iomem *
	207	__uc32_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
	208	unsigned int mtype)
	209	{
	210	return __uc32_ioremap_pfn_caller(pfn, offset, size, mtype,
	211	__builtin_return_address(0));
	212	}
213	EXPORT_SYMBOL(__uc32_ioremap_pfn);
214
215	void __iomem *
216	__uc32_ioremap(unsigned long phys_addr, size_t size)
217	{
218	return __uc32_ioremap_caller(phys_addr, size, MT_DEVICE,
219	__builtin_return_address(0));
220	}
221	EXPORT_SYMBOL(__uc32_ioremap);
222
b50f1704 G	223	void __uc32_iounmap(volatile void __iomem *io_addr)
	224	{
	225	void addr = (void )(PAGE_MASK & (unsigned long)io_addr);
ef932473	226	struct vm_struct *vm;
b50f1704 G	227
	228	/*
	229	* If this is a section based mapping we need to handle it
	230	* specially as the VM subsystem does not know how to handle
	231	* such a beast. We need the lock here b/c we need to clear
	232	* all the mappings before the area can be reclaimed
	233	* by someone else.
	234	*/
ef932473 JK	235	vm = find_vm_area(addr);
	236	if (vm && (vm->flags & VM_IOREMAP) &&
	237	(vm->flags & VM_UNICORE_SECTION_MAPPING))
	238	unmap_area_sections((unsigned long)vm->addr, vm->size);
b50f1704 G	239
	240	vunmap(addr);
	241	}
	242	EXPORT_SYMBOL(__uc32_iounmap);