irqchip: irq-mips-gic: Provide function to map GIC user section

The GIC provides a "user-mode visible" section containing a mirror of
the counter registers which can be mapped into user memory. This will
be used by the VDSO time function implementations, so provide a
function to map it in.

When the GIC is not enabled in Kconfig a dummy inline version of this
function is provided, along with "#define gic_present 0", so that we
don't have to litter the VDSO code with ifdefs.

[markos.chandras@imgtec.com:
  - Move mapping code to arch/mips/kernel/vdso.c and use a resource
    type to get the GIC usermode information
  - Avoid renaming function arguments and use __gic_base_addr to hold
    the base GIC address prior to ioremap.]
[ralf@linux-mips.org: Fix up gic_get_usm_range() to compile and make inline
again.]

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/11281/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/irqchip/mips-gic.h b/include/linux/irqchip/mips-gic.h
index 4e6861605050..ce824db48d64 100644
--- a/include/linux/irqchip/mips-gic.h
+++ b/include/linux/irqchip/mips-gic.h
@@ -9,6 +9,7 @@
 #define __LINUX_IRQCHIP_MIPS_GIC_H
 
 #include <linux/clocksource.h>
+#include <linux/ioport.h>
 
 #define GIC_MAX_INTRS			256
 
@@ -245,6 +246,8 @@
 #define GIC_SHARED_TO_HWIRQ(x)	(GIC_SHARED_HWIRQ_BASE + (x))
 #define GIC_HWIRQ_TO_SHARED(x)	((x) - GIC_SHARED_HWIRQ_BASE)
 
+#ifdef CONFIG_MIPS_GIC
+
 extern unsigned int gic_present;
 
 extern void gic_init(unsigned long gic_base_addr,
@@ -264,4 +267,18 @@ extern unsigned int plat_ipi_resched_int_xlate(unsigned int);
 extern int gic_get_c0_compare_int(void);
 extern int gic_get_c0_perfcount_int(void);
 extern int gic_get_c0_fdc_int(void);
+extern int gic_get_usm_range(struct resource *gic_usm_res);
+
+#else /* CONFIG_MIPS_GIC */
+
+#define gic_present	0
+
+static inline int gic_get_usm_range(struct resource *gic_usm_res)
+{
+	/* Shouldn't be called. */
+	return -1;
+}
+
+#endif /* CONFIG_MIPS_GIC */
+
 #endif /* __LINUX_IRQCHIP_MIPS_GIC_H */