diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/sh/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/sh/intc.c | 69 |
2 files changed, 80 insertions, 2 deletions
diff --git a/drivers/sh/Kconfig b/drivers/sh/Kconfig new file mode 100644 index 0000000..22c3cda --- /dev/null +++ b/drivers/sh/Kconfig @@ -0,0 +1,13 @@ +config INTC_USERIMASK + bool "Userspace interrupt masking support" + depends on ARCH_SHMOBILE || (SUPERH && CPU_SH4A) + help + This enables support for hardware-assisted userspace hardirq + masking. + + SH-4A and newer interrupt blocks all support a special shadowed + page with all non-masking registers obscured when mapped in to + userspace. This is primarily for use by userspace device + drivers that are using special priority levels. + + If in doubt, say N. diff --git a/drivers/sh/intc.c b/drivers/sh/intc.c index 65e1582..77d10ac 100644 --- a/drivers/sh/intc.c +++ b/drivers/sh/intc.c @@ -27,6 +27,7 @@ #include <linux/topology.h> #include <linux/bitmap.h> #include <linux/cpumask.h> +#include <asm/sizes.h> #define _INTC_MK(fn, mode, addr_e, addr_d, width, shift) \ ((shift) | ((width) << 5) | ((fn) << 9) | ((mode) << 13) | \ @@ -94,7 +95,8 @@ static DEFINE_SPINLOCK(vector_lock); #define SMP_NR(d, x) 1 #endif -static unsigned int intc_prio_level[NR_IRQS]; /* for now */ +static unsigned int intc_prio_level[NR_IRQS]; /* for now */ +static unsigned int default_prio_level = 2; /* 2 - 16 */ static unsigned long ack_handle[NR_IRQS]; static inline struct intc_desc_int *get_intc_desc(unsigned int irq) @@ -787,7 +789,7 @@ static void __init intc_register_irq(struct intc_desc *desc, /* set priority level * - this needs to be at least 2 for 5-bit priorities on 7780 */ - intc_prio_level[irq] = 2; + intc_prio_level[irq] = default_prio_level; /* enable secondary masking method if present */ if (data[!primary]) @@ -1037,6 +1039,64 @@ err0: return -ENOMEM; } +#ifdef CONFIG_INTC_USERIMASK +static void __iomem *uimask; + +int register_intc_userimask(unsigned long addr) +{ + if (unlikely(uimask)) + return -EBUSY; + + uimask = ioremap_nocache(addr, SZ_4K); + if (unlikely(!uimask)) + return -ENOMEM; + + pr_info("intc: userimask support registered for levels 0 -> %d\n", + default_prio_level - 1); + + return 0; +} + +static ssize_t +show_intc_userimask(struct sysdev_class *cls, + struct sysdev_class_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", (__raw_readl(uimask) >> 4) & 0xf); +} + +static ssize_t +store_intc_userimask(struct sysdev_class *cls, + struct sysdev_class_attribute *attr, + const char *buf, size_t count) +{ + unsigned long level; + + level = simple_strtoul(buf, NULL, 10); + + /* + * Minimal acceptable IRQ levels are in the 2 - 16 range, but + * these are chomped so as to not interfere with normal IRQs. + * + * Level 1 is a special case on some CPUs in that it's not + * directly settable, but given that USERIMASK cuts off below a + * certain level, we don't care about this limitation here. + * Level 0 on the other hand equates to user masking disabled. + * + * We use default_prio_level as a cut off so that only special + * case opt-in IRQs can be mangled. + */ + if (level >= default_prio_level) + return -EINVAL; + + __raw_writel(0xa5 << 24 | level << 4, uimask); + + return count; +} + +static SYSDEV_CLASS_ATTR(userimask, S_IRUSR | S_IWUSR, + show_intc_userimask, store_intc_userimask); +#endif + static ssize_t show_intc_name(struct sys_device *dev, struct sysdev_attribute *attr, char *buf) { @@ -1108,6 +1168,11 @@ static int __init register_intc_sysdevs(void) int id = 0; error = sysdev_class_register(&intc_sysdev_class); +#ifdef CONFIG_INTC_USERIMASK + if (!error && uimask) + error = sysdev_class_create_file(&intc_sysdev_class, + &attr_userimask); +#endif if (!error) { list_for_each_entry(d, &intc_list, list) { d->sysdev.id = id; |
