3e4d3af501
Keep the current interface but ignore the KM_type and use a stack based approach. The advantage is that we get rid of crappy code like: #define __KM_PTE \ (in_nmi() ? KM_NMI_PTE : \ in_irq() ? KM_IRQ_PTE : \ KM_PTE0) and in general can stop worrying about what context we're in and what kmap slots might be appropriate for that. The downside is that FRV kmap_atomic() gets more expensive. For now we use a CPP trick suggested by Andrew: #define kmap_atomic(page, args...) __kmap_atomic(page) to avoid having to touch all kmap_atomic() users in a single patch. [ not compiled on: - mn10300: the arch doesn't actually build with highmem to begin with ] [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c] Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Airlie <airlied@linux.ie> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
118 lines
3.3 KiB
C
118 lines
3.3 KiB
C
/*
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* Copyright © 2008 Ingo Molnar
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* 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 along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*/
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#include <asm/iomap.h>
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#include <asm/pat.h>
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#include <linux/module.h>
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#include <linux/highmem.h>
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static int is_io_mapping_possible(resource_size_t base, unsigned long size)
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{
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#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT)
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/* There is no way to map greater than 1 << 32 address without PAE */
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if (base + size > 0x100000000ULL)
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return 0;
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#endif
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return 1;
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}
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int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot)
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{
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unsigned long flag = _PAGE_CACHE_WC;
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int ret;
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if (!is_io_mapping_possible(base, size))
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return -EINVAL;
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ret = io_reserve_memtype(base, base + size, &flag);
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if (ret)
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return ret;
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*prot = __pgprot(__PAGE_KERNEL | flag);
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return 0;
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}
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EXPORT_SYMBOL_GPL(iomap_create_wc);
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void iomap_free(resource_size_t base, unsigned long size)
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{
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io_free_memtype(base, base + size);
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}
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EXPORT_SYMBOL_GPL(iomap_free);
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void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
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{
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unsigned long vaddr;
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int idx, type;
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pagefault_disable();
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type = kmap_atomic_idx_push();
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idx = type + KM_TYPE_NR * smp_processor_id();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
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arch_flush_lazy_mmu_mode();
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return (void *)vaddr;
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}
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/*
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* Map 'pfn' using protections 'prot'
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*/
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void __iomem *
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iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
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{
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/*
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* For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS.
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* PAGE_KERNEL_WC maps to PWT, which translates to uncached if the
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* MTRR is UC or WC. UC_MINUS gets the real intention, of the
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* user, which is "WC if the MTRR is WC, UC if you can't do that."
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*/
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if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC))
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prot = PAGE_KERNEL_UC_MINUS;
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return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
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}
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EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
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void
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iounmap_atomic(void __iomem *kvaddr)
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{
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unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
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if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
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vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
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int idx, type;
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type = kmap_atomic_idx_pop();
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idx = type + KM_TYPE_NR * smp_processor_id();
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#ifdef CONFIG_DEBUG_HIGHMEM
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WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
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#endif
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/*
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* Force other mappings to Oops if they'll try to access this
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* pte without first remap it. Keeping stale mappings around
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* is a bad idea also, in case the page changes cacheability
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* attributes or becomes a protected page in a hypervisor.
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*/
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kpte_clear_flush(kmap_pte-idx, vaddr);
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}
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pagefault_enable();
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}
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EXPORT_SYMBOL_GPL(iounmap_atomic);
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