From 27fc26f99e63bcbe42176f08eaf590bff81a2e1c Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Thu, 31 Jul 2014 15:57:27 +0100 Subject: [PATCH] staging: comedi: ii_pci20kc: request and ioremap memory The "ii_pci20kc" module is a comedi driver for Intelligent Instruments PCI-20001C carrier board and modules. Despite the name, this is actually an ISA board and uses 1K of ISA memory space (below 1M) for the main board plus up to three modules. The address is set by hardware jumpers. When the board is attached to Comedi via the `COMEDI_DEVCONFIG` ioctl and the driver's legacy "attach" handler, the base address is passed in. The driver currently uses that address as-is, which is a bad idea. It doesn't even reserve the memory region. Fix that by sanity checking the passed in address, reserving the memory region and ioremapping it. Replace the current "detach" handler `comedi_legacy_detach()` with a new handler `ii20k_detach()` which unmaps the memory and releases the region. Signed-off-by: Ian Abbott Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/ii_pci20kc.c | 32 +++++++++++++++++++-- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/drivers/staging/comedi/drivers/ii_pci20kc.c b/drivers/staging/comedi/drivers/ii_pci20kc.c index b1f44b31162b..687db433e131 100644 --- a/drivers/staging/comedi/drivers/ii_pci20kc.c +++ b/drivers/staging/comedi/drivers/ii_pci20kc.c @@ -33,6 +33,7 @@ /* * Register I/O map */ +#define II20K_SIZE 0x400 #define II20K_MOD_OFFSET 0x100 #define II20K_ID_REG 0x00 #define II20K_ID_MOD1_EMPTY (1 << 7) @@ -439,12 +440,29 @@ static int ii20k_attach(struct comedi_device *dev, struct comedi_devconfig *it) { struct comedi_subdevice *s; + unsigned int membase; unsigned char id; bool has_dio; int ret; - /* FIXME: this doesn't seem right, should 'mmio' be ioremap'ed? */ - dev->mmio = (void __iomem *)(unsigned long)it->options[0]; + membase = it->options[0]; + if (!membase || (membase & ~(0x100000 - II20K_SIZE))) { + dev_warn(dev->class_dev, + "%s: invalid memory address specified\n", + dev->board_name); + return -EINVAL; + } + + if (!request_mem_region(membase, II20K_SIZE, dev->board_name)) { + dev_warn(dev->class_dev, "%s: I/O mem conflict (%#x,%u)\n", + dev->board_name, membase, II20K_SIZE); + return -EIO; + } + dev->iobase = membase; /* actually, a memory address */ + + dev->mmio = ioremap(membase, II20K_SIZE); + if (!dev->mmio) + return -ENOMEM; id = readb(dev->mmio + II20K_ID_REG); switch (id & II20K_ID_MASK) { @@ -509,11 +527,19 @@ static int ii20k_attach(struct comedi_device *dev, return 0; } +static void ii20k_detach(struct comedi_device *dev) +{ + if (dev->mmio) + iounmap(dev->mmio); + if (dev->iobase) /* actually, a memory address */ + release_mem_region(dev->iobase, II20K_SIZE); +} + static struct comedi_driver ii20k_driver = { .driver_name = "ii_pci20kc", .module = THIS_MODULE, .attach = ii20k_attach, - .detach = comedi_legacy_detach, + .detach = ii20k_detach, }; module_comedi_driver(ii20k_driver); -- 2.20.1