unicore32 core architecture: mm related: generic codes
This patch includes generic codes for memory management.
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/unicore32/mm/ioremap.c b/arch/unicore32/mm/ioremap.c
new file mode 100644
index 0000000..b7a6055
--- /dev/null
+++ b/arch/unicore32/mm/ioremap.c
@@ -0,0 +1,261 @@
+/*
+ * linux/arch/unicore32/mm/ioremap.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *
+ * 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 <asm/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)) {
+ printk(KERN_WARNING "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");
+ WARN_ON(1);
+ }
+
+ 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 __iomem *
+__uc32_ioremap_cached(unsigned long phys_addr, size_t size)
+{
+ return __uc32_ioremap_caller(phys_addr, size, MT_DEVICE_CACHED,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(__uc32_ioremap_cached);
+
+void __uc32_iounmap(volatile void __iomem *io_addr)
+{
+ void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
+ struct vm_struct **p, *tmp;
+
+ /*
+ * 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.
+ */
+ write_lock(&vmlist_lock);
+ for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) {
+ if ((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) {
+ if (tmp->flags & VM_UNICORE_SECTION_MAPPING) {
+ unmap_area_sections((unsigned long)tmp->addr,
+ tmp->size);
+ }
+ break;
+ }
+ }
+ write_unlock(&vmlist_lock);
+
+ vunmap(addr);
+}
+EXPORT_SYMBOL(__uc32_iounmap);