[PATCH AUTOSEL 5.8 106/132] asm-generic/io.h: Fix !CONFIG_GENERIC_IOMAP pci_iounmap() implementation

Sasha Levin
2020-10-26T23:56:18Z

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

[ Upstream commit f5810e5c329238b8553ebd98b914bdbefd8e6737 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/asm-generic/io.h | 39 +++++++++++++++++++++++++++------------
1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 30a3aab312e6c..89057394e1862 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -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
*/
--
2.25.1