The implementation of pci_iounmap() is currently scattered over two files, drivers/pci/iomap.c and lib/iomap.c. Additionally, architectures can define their own version.
To have only one version, it's necessary to create a helper function, iomem_is_ioport(), that tells pci_iounmap() whether the passed address points to an ioport or normal memory.
iomem_is_ioport() can be provided through two different ways: 1. The architecture itself provides it. As of today, the version coming from lib/iomap.c de facto is the x86-specific version and comes into play when CONFIG_GENERIC_IOMAP is selected. This rather confusing naming is an artifact left by the removal of IA64. 2. As a default version in include/asm-generic/io.h for those architectures that don't use CONFIG_GENERIC_IOMAP, but also don't provide their own version of iomem_is_ioport().
Once all architectures that support ports provide iomem_is_ioport(), the arch-specific definitions for pci_iounmap() can be removed and the archs can use the generic implementation, instead.
Create a unified version of pci_iounmap() in drivers/pci/iomap.c. Provide the function iomem_is_ioport() in include/asm-generic/io.h (generic) and lib/iomap.c ("pseudo-generic" for x86).
Remove the CONFIG_GENERIC_IOMAP guard around ARCH_WANTS_GENERIC_PCI_IOUNMAP so that configs that set CONFIG_GENERIC_PCI_IOMAP without CONFIG_GENERIC_IOMAP still get the function.
Add TODOs for follow-up work on the "generic is not generic but x86-spcific"-Problem.
Suggested-by: Arnd Bergmann arnd@kernel.org Signed-off-by: Philipp Stanner pstanner@redhat.com --- drivers/pci/iomap.c | 46 ++++++++++++------------------------- include/asm-generic/io.h | 27 ++++++++++++++++++++-- include/asm-generic/iomap.h | 21 +++++++++++++++++ lib/iomap.c | 28 ++++++++++++++++------ 4 files changed, 82 insertions(+), 40 deletions(-)
diff --git a/drivers/pci/iomap.c b/drivers/pci/iomap.c index 91285fcff1ba..439ba2e9710f 100644 --- a/drivers/pci/iomap.c +++ b/drivers/pci/iomap.c @@ -135,44 +135,28 @@ void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen) EXPORT_SYMBOL_GPL(pci_iomap_wc);
/* - * pci_iounmap() somewhat illogically comes from lib/iomap.c for the - * CONFIG_GENERIC_IOMAP case, because that's the code that knows about - * the different IOMAP ranges. + * This check is still necessary due to legacy reasons. * - * But if the architecture does not use the generic iomap code, and if - * it has _not_ defined it's own private pci_iounmap function, we define - * it here. - * - * NOTE! This default implementation assumes that if the architecture - * support ioport mapping (HAS_IOPORT_MAP), the ioport mapping will - * be fixed to the range [ PCI_IOBASE, PCI_IOBASE+IO_SPACE_LIMIT [, - * and does not need unmapping with 'ioport_unmap()'. - * - * If you have different rules for your architecture, you need to - * implement your own pci_iounmap() that knows the rules for where - * and how IO vs MEM get mapped. - * - * This code is odd, and the ARCH_HAS/ARCH_WANTS #define logic comes - * from legacy <asm-generic/io.h> header file behavior. In particular, - * it would seem to make sense to do the iounmap(p) for the non-IO-space - * case here regardless, but that's not what the old header file code - * did. Probably incorrectly, but this is meant to be bug-for-bug - * compatible. + * TODO: Have all architectures that provide their own pci_iounmap() provide + * iomem_is_ioport() instead. Remove this #if afterwards. */ #if defined(ARCH_WANTS_GENERIC_PCI_IOUNMAP)
-void pci_iounmap(struct pci_dev *dev, void __iomem *p) +/** + * pci_iounmap - Unmapp a mapping + * @dev: PCI device the mapping belongs to + * @addr: start address of the mapping + * + * Unmapp a PIO or MMIO mapping. + */ +void pci_iounmap(struct pci_dev *dev, void __iomem *addr) { -#ifdef ARCH_HAS_GENERIC_IOPORT_MAP - uintptr_t start = (uintptr_t) PCI_IOBASE; - uintptr_t addr = (uintptr_t) p; - - if (addr >= start && addr < start + IO_SPACE_LIMIT) { - ioport_unmap(p); + if (iomem_is_ioport(addr)) { + ioport_unmap(addr); return; } -#endif - iounmap(p); + + iounmap(addr); } EXPORT_SYMBOL(pci_iounmap);
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index bac63e874c7b..58c7bf4080da 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -1129,11 +1129,34 @@ extern void ioport_unmap(void __iomem *p); #endif /* CONFIG_GENERIC_IOMAP */ #endif /* CONFIG_HAS_IOPORT_MAP */
-#ifndef CONFIG_GENERIC_IOMAP +/* + * TODO: + * remove this once all architectures replaced their pci_iounmap() with + * a custom implementation of iomem_is_ioport(). + */ #ifndef pci_iounmap +#define pci_iounmap pci_iounmap #define ARCH_WANTS_GENERIC_PCI_IOUNMAP +#endif /* pci_iounmap */ + +/* + * This function is a helper only needed for the generic pci_iounmap(). + * It's provided here if the architecture does not provide its own version. + */ +#ifndef iomem_is_ioport +#define iomem_is_ioport iomem_is_ioport +static inline bool iomem_is_ioport(void __iomem *addr_raw) +{ +#ifdef CONFIG_HAS_IOPORT + uintptr_t start = (uintptr_t)PCI_IOBASE; + uintptr_t addr = (uintptr_t)addr_raw; + + if (addr >= start && addr < start + IO_SPACE_LIMIT) + return true; #endif -#endif + return false; +} +#endif /* iomem_is_ioport */
#ifndef xlate_dev_mem_ptr #define xlate_dev_mem_ptr xlate_dev_mem_ptr diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h index 196087a8126e..2cdc6988a102 100644 --- a/include/asm-generic/iomap.h +++ b/include/asm-generic/iomap.h @@ -110,6 +110,27 @@ static inline void __iomem *ioremap_np(phys_addr_t offset, size_t size) } #endif
+/* + * If CONFIG_GENERIC_IOMAP is selected and the architecture does NOT provide its + * own version, ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT makes sure that the generic + * version from asm-generic/io.h is NOT used and instead the second "generic" + * version from lib/iomap.c is used. + * + * There are currently two generic versions because of a difficult cleanup + * process. Namely, the version in lib/iomap.c once was really generic when IA64 + * still existed. Today, it's only really used by x86. + * + * TODO: Move the version from lib/iomap.c to x86 specific code. Then, remove + * this ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT-mechanism. + */ +#ifdef CONFIG_GENERIC_IOMAP +#ifndef iomem_is_ioport +#define iomem_is_ioport iomem_is_ioport +bool iomem_is_ioport(void __iomem *addr); +#define ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT +#endif /* iomem_is_ioport */ +#endif /* CONFIG_GENERIC_IOMAP */ + #include <asm-generic/pci_iomap.h>
#endif diff --git a/lib/iomap.c b/lib/iomap.c index 4f8b31baa575..eb9a879ebf42 100644 --- a/lib/iomap.c +++ b/lib/iomap.c @@ -418,12 +418,26 @@ EXPORT_SYMBOL(ioport_map); EXPORT_SYMBOL(ioport_unmap); #endif /* CONFIG_HAS_IOPORT_MAP */
-#ifdef CONFIG_PCI -/* Hide the details if this is a MMIO or PIO address space and just do what - * you expect in the correct way. */ -void pci_iounmap(struct pci_dev *dev, void __iomem * addr) +/* + * If CONFIG_GENERIC_IOMAP is selected and the architecture does NOT provide its + * own version, ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT makes sure that the generic + * version from asm-generic/io.h is NOT used and instead the second "generic" + * version from this file here is used. + * + * There are currently two generic versions because of a difficult cleanup + * process. Namely, the version in lib/iomap.c once was really generic when IA64 + * still existed. Today, it's only really used by x86. + * + * TODO: Move this function to x86-specific code. + */ +#if defined(ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT) +bool iomem_is_ioport(void __iomem *addr) { - IO_COND(addr, /* nothing */, iounmap(addr)); + unsigned long port = (unsigned long __force)addr; + + if (port > PIO_OFFSET && port < PIO_RESERVED) + return true; + + return false; } -EXPORT_SYMBOL(pci_iounmap); -#endif /* CONFIG_PCI */ +#endif /* ARCH_WANTS_GENERIC_IOMEM_IS_IOPORT */