get_io_area leaves an IO_SIZE gap between mappings which is added to the vm_struct representing the mapping. __ioremap() uses the actual requested size (after alignment), while __iounmap() is passed the size from the vm_struct.
On 020/030, early termination descriptors are used to set up mappings of extent 'size', which are validated on unmapping. The unmapped gap of size IO_SIZE defeats the sanity check of the pmd tables, causing __iounmap to loop forever on 030. On 040/040, unmapping of page table entries does not check for a valid mapping, so the umapping loop always completes there. Adjust size to be unmapped by the gap that had been added in the vm_struct prior. This fixes the hang in atari_platform_init() reported a long time ago, and a similar one reported by Finn recently (addressed by removing ioremap() use from the SWIM driver. Tested on my Falcon in 030 mode - untested but should work the same on 040/060 (the extra page tables cleared there would never have been set up anyway). Comment on whether the gap size should be considered in looking for a suitable address to place the next mapping in get_io_area() would be welcome. Signed-off-by: Michael Schmitz <[email protected]> --- arch/m68k/mm/kmap.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/arch/m68k/mm/kmap.c b/arch/m68k/mm/kmap.c index c2a3832..3b420f6 100644 --- a/arch/m68k/mm/kmap.c +++ b/arch/m68k/mm/kmap.c @@ -89,7 +89,8 @@ static inline void free_io_area(void *addr) for (p = &iolist ; (tmp = *p) ; p = &tmp->next) { if (tmp->addr == addr) { *p = tmp->next; - __iounmap(tmp->addr, tmp->size); + /* remove gap added in get_io_area() */ + __iounmap(tmp->addr, tmp->size - IO_SIZE); kfree(tmp); return; } -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
