Commit f5810e5c authored Sep 16, 2020 by Lorenzo Pieralisi

asm-generic/io.h: Fix !CONFIG_GENERIC_IOMAP pci_iounmap() implementation



For arches that do not select CONFIG_GENERIC_IOMAP, the current
pci_iounmap() function does nothing causing obvious memory leaks
for mapped regions that are backed by MMIO physical space.

In order to detect if a mapped pointer is IO vs MMIO, a check must made
available to the pci_iounmap() function so that it can actually detect
whether the pointer has to be unmapped.

In configurations where CONFIG_HAS_IOPORT_MAP && !CONFIG_GENERIC_IOMAP,
a mapped port is detected using an ioport_map() stub defined in
asm-generic/io.h.

Use the same logic to implement a stub (ie __pci_ioport_unmap()) that
detects if the passed in pointer in pci_iounmap() is IO vs MMIO to
iounmap conditionally and call it in pci_iounmap() fixing the issue.

Leave __pci_ioport_unmap() as a NOP for all other config options.

Tested-by: George Cherian <george.cherian@marvell.com>
Link: https://lore.kernel.org/lkml/20200905024811.74701-1-yangyingliang@huawei.com
Link: https://lore.kernel.org/lkml/20200824132046.3114383-1-george.cherian@marvell.com
Link: https://lore.kernel.org/r/a9daf8d8444d0ebd00bc6d64e336ec49dbb50784.1600254147.git.lorenzo.pieralisi@arm.com


Reported-by: George Cherian <george.cherian@marvell.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: George Cherian <george.cherian@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>

parent 1d29b36a

include/asm-generic/io.h

+27 −12

Original line number	Diff line number	Diff line
		@@ -911,18 +911,6 @@ static inline void iowrite64_rep(volatile void __iomem *addr,
		#include <linux/vmalloc.h>
		#define __io_virt(x) ((void __force *)(x))

		#ifndef CONFIG_GENERIC_IOMAP
		struct pci_dev;
		extern void __iomem pci_iomap(struct pci_dev dev, int bar, unsigned long max);

		#ifndef pci_iounmap
		#define pci_iounmap pci_iounmap
		static inline void pci_iounmap(struct pci_dev dev, void __iomem p)
		{
		}
		#endif
		#endif /* CONFIG_GENERIC_IOMAP */

		/*
		* Change virtual addresses to physical addresses and vv.
		* These are pretty trivial
		@@ -1016,6 +1004,16 @@ static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
		port &= IO_SPACE_LIMIT;
		return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
		}
		#define __pci_ioport_unmap __pci_ioport_unmap
		static inline void __pci_ioport_unmap(void __iomem *p)
		{
		uintptr_t start = (uintptr_t) PCI_IOBASE;
		uintptr_t addr = (uintptr_t) p;

		if (addr >= start && addr < start + IO_SPACE_LIMIT)
		return;
		iounmap(p);
		}
		#endif

		#ifndef ioport_unmap
		@@ -1030,6 +1028,23 @@ extern void ioport_unmap(void __iomem *p);
		#endif /* CONFIG_GENERIC_IOMAP */
		#endif /* CONFIG_HAS_IOPORT_MAP */

		#ifndef CONFIG_GENERIC_IOMAP
		struct pci_dev;
		extern void __iomem pci_iomap(struct pci_dev dev, int bar, unsigned long max);

		#ifndef __pci_ioport_unmap
		static inline void __pci_ioport_unmap(void __iomem *p) {}
		#endif

		#ifndef pci_iounmap
		#define pci_iounmap pci_iounmap
		static inline void pci_iounmap(struct pci_dev dev, void __iomem p)
		{
		__pci_ioport_unmap(p);
		}
		#endif
		#endif /* CONFIG_GENERIC_IOMAP */

		/*
		* Convert a virtual cached pointer to an uncached pointer
		*/

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