d0d98eedee
Several drivers currently use mtrr_add through various #ifdef guards and/or drm wrappers. The vast majority of them want to add WC MTRRs on x86 systems and don't actually need the MTRR if PAT (i.e. ioremap_wc, etc) are working. arch_phys_wc_add and arch_phys_wc_del are new functions, available on all architectures and configurations, that add WC MTRRs on x86 if needed (and handle errors) and do nothing at all otherwise. They're also easier to use than mtrr_add and mtrr_del, so the call sites can be simplified. As an added benefit, this will avoid wasting MTRRs and possibly warning pointlessly on PAT-supporting systems. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Dave Airlie <airlied@redhat.com>
105 lines
3.1 KiB
C
105 lines
3.1 KiB
C
/*
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* Copyright 2006 PathScale, Inc. All Rights Reserved.
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*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License
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* as 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, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#ifndef _LINUX_IO_H
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#define _LINUX_IO_H
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#include <linux/types.h>
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#include <asm/io.h>
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#include <asm/page.h>
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struct device;
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void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
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void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
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#ifdef CONFIG_MMU
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int ioremap_page_range(unsigned long addr, unsigned long end,
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phys_addr_t phys_addr, pgprot_t prot);
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#else
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static inline int ioremap_page_range(unsigned long addr, unsigned long end,
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phys_addr_t phys_addr, pgprot_t prot)
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{
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return 0;
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}
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#endif
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/*
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* Managed iomap interface
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*/
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#ifdef CONFIG_HAS_IOPORT
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void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
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unsigned int nr);
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void devm_ioport_unmap(struct device *dev, void __iomem *addr);
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#else
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static inline void __iomem *devm_ioport_map(struct device *dev,
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unsigned long port,
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unsigned int nr)
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{
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return NULL;
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}
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static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
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{
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}
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#endif
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void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
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unsigned long size);
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void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
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unsigned long size);
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void devm_iounmap(struct device *dev, void __iomem *addr);
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int check_signature(const volatile void __iomem *io_addr,
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const unsigned char *signature, int length);
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void devm_ioremap_release(struct device *dev, void *res);
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/*
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* Some systems do not have legacy ISA devices.
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* /dev/port is not a valid interface on these systems.
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* So for those archs, <asm/io.h> should define the following symbol.
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*/
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#ifndef arch_has_dev_port
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#define arch_has_dev_port() (1)
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#endif
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/*
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* Some systems (x86 without PAT) have a somewhat reliable way to mark a
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* physical address range such that uncached mappings will actually
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* end up write-combining. This facility should be used in conjunction
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* with pgprot_writecombine, ioremap-wc, or set_memory_wc, since it has
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* no effect if the per-page mechanisms are functional.
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* (On x86 without PAT, these functions manipulate MTRRs.)
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*
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* arch_phys_del_wc(0) or arch_phys_del_wc(any error code) is guaranteed
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* to have no effect.
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*/
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#ifndef arch_phys_wc_add
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static inline int __must_check arch_phys_wc_add(unsigned long base,
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unsigned long size)
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{
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return 0; /* It worked (i.e. did nothing). */
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}
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static inline void arch_phys_wc_del(int handle)
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{
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}
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#define arch_phys_wc_add arch_phys_wc_add
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#endif
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#endif /* _LINUX_IO_H */
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