4.14-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 3a58ac65e2d7969bcdf1b6acb70fa4d12a88e53e ] IO_SPACE_LIMIT is the ending address of the PCI IO space, i.e something like 0xfffff (and not 0x100000). Therefore, when offset = 0xf0000 is passed as argument, this function fails even though the offset + SZ_64K fits below the IO_SPACE_LIMIT. This makes the last chunk of 64 KB of the I/O space not usable as it cannot be mapped. This patch fixes that by substracing 1 to offset + SZ_64K, so that we compare the addrss of the last byte of the I/O space against IO_SPACE_LIMIT instead of the address of the first byte of what is after the I/O space. Fixes: c2794437091a4 ("ARM: Add fixed PCI i/o mapping") Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx> Acked-by: Nicolas Pitre <nico@xxxxxxxxxx> Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/arm/mm/ioremap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c index fc91205ff46c..5bf9443cfbaa 100644 --- a/arch/arm/mm/ioremap.c +++ b/arch/arm/mm/ioremap.c @@ -473,7 +473,7 @@ void pci_ioremap_set_mem_type(int mem_type) int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr) { - BUG_ON(offset + SZ_64K > IO_SPACE_LIMIT); + BUG_ON(offset + SZ_64K - 1 > IO_SPACE_LIMIT); return ioremap_page_range(PCI_IO_VIRT_BASE + offset, PCI_IO_VIRT_BASE + offset + SZ_64K, -- 2.17.1