12be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt/* 22be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * Support for hardware-assisted userspace interrupt masking. 32be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * 42be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * Copyright (C) 2010 Paul Mundt 52be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * 62be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * This file is subject to the terms and conditions of the GNU General Public 72be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * License. See the file "COPYING" in the main directory of this archive 82be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * for more details. 92be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt */ 102be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt#define pr_fmt(fmt) "intc: " fmt 112be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 122be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt#include <linux/errno.h> 13f4e73bfcd9cca0b64cc8096175852936fb1d111fKay Sievers#include <linux/device.h> 142be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt#include <linux/init.h> 152be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt#include <linux/io.h> 16a102a0888799d389c033fe22db3f1e153390fcc5Nobuhiro Iwamatsu#include <linux/stat.h> 172be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt#include <asm/sizes.h> 182be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt#include "internals.h" 192be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 202be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundtstatic void __iomem *uimask; 212be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 222be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundtstatic ssize_t 23f4e73bfcd9cca0b64cc8096175852936fb1d111fKay Sieversshow_intc_userimask(struct device *dev, 24f4e73bfcd9cca0b64cc8096175852936fb1d111fKay Sievers struct device_attribute *attr, char *buf) 252be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt{ 262be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt return sprintf(buf, "%d\n", (__raw_readl(uimask) >> 4) & 0xf); 272be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt} 282be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 292be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundtstatic ssize_t 30f4e73bfcd9cca0b64cc8096175852936fb1d111fKay Sieversstore_intc_userimask(struct device *dev, 31f4e73bfcd9cca0b64cc8096175852936fb1d111fKay Sievers struct device_attribute *attr, 322be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt const char *buf, size_t count) 332be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt{ 342be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt unsigned long level; 352be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 362be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt level = simple_strtoul(buf, NULL, 10); 372be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 382be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt /* 392be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * Minimal acceptable IRQ levels are in the 2 - 16 range, but 402be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * these are chomped so as to not interfere with normal IRQs. 412be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * 422be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * Level 1 is a special case on some CPUs in that it's not 432be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * directly settable, but given that USERIMASK cuts off below a 442be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * certain level, we don't care about this limitation here. 452be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * Level 0 on the other hand equates to user masking disabled. 462be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * 472be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * We use the default priority level as a cut off so that only 482be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt * special case opt-in IRQs can be mangled. 492be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt */ 502be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt if (level >= intc_get_dfl_prio_level()) 512be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt return -EINVAL; 522be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 532be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt __raw_writel(0xa5 << 24 | level << 4, uimask); 542be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 552be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt return count; 562be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt} 572be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 58f4e73bfcd9cca0b64cc8096175852936fb1d111fKay Sieversstatic DEVICE_ATTR(userimask, S_IRUSR | S_IWUSR, 59f4e73bfcd9cca0b64cc8096175852936fb1d111fKay Sievers show_intc_userimask, store_intc_userimask); 602be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 612be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 622be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundtstatic int __init userimask_sysdev_init(void) 632be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt{ 642be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt if (unlikely(!uimask)) 652be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt return -ENXIO; 662be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 67f4e73bfcd9cca0b64cc8096175852936fb1d111fKay Sievers return device_create_file(intc_subsys.dev_root, &dev_attr_userimask); 682be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt} 692be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundtlate_initcall(userimask_sysdev_init); 702be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 712be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundtint register_intc_userimask(unsigned long addr) 722be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt{ 732be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt if (unlikely(uimask)) 742be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt return -EBUSY; 752be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 762be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt uimask = ioremap_nocache(addr, SZ_4K); 772be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt if (unlikely(!uimask)) 782be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt return -ENOMEM; 792be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 802be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt pr_info("userimask support registered for levels 0 -> %d\n", 812be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt intc_get_dfl_prio_level() - 1); 822be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt 832be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt return 0; 842be6bb0c79c7fbda3425b65ee51c558bbaf4cf91Paul Mundt} 85