ARM: Enable GICv2m on 32-bit virt machine

qemu implementation of "virt" includes GICv2m. This series allows to use it also on ARM32 architecture.

v3 => v4:
- Split into two patches as requested by Marc Zyngier
- Use specialized word extraction macros instead of #ifdef

v1 => v2:
Added verbose explanation in commit message

v2 => v3:
Fixed build warning in irq-gic-v2m.c

v1 => v2:
Added verbose explanation in commit message

Pavel Fedin (2):
ARM: Enable GICv2m on 32-bit virt machine
ARM: Fix GICv2m build warning on 32 bits

 arch/arm/Kconfig              | 1 +
 arch/arm/include/asm/Kbuild   | 1 +
 drivers/irqchip/irq-gic-v2m.c | 4 ++--
 3 files changed, 4 insertions(+), 2 deletions(-)

2.4.4

msi.h is added because it is required by linux/msi.h if CONFIG_GENERIC_MSI_IRQ_DOMAIN is defined. It gets enabled by the following KConfig dependency chain:
ARM_GIC_V2M => PCI_MSI_IRQ_DOMAIN => GENERIC_MSI_IRQ_DOMAIN

---
 arch/arm/Kconfig            | 1 +
 arch/arm/include/asm/Kbuild | 1 +
 2 files changed, 2 insertions(+)

index 45df48b..1091025 100644
@@ -815,6 +815,7 @@ config ARCH_VIRT
 	bool "Dummy Virtual Machine" if ARCH_MULTI_V7
 	select ARM_AMBA
 	select ARM_GIC
+	select ARM_GIC_V2M if PCI_MSI
 	select ARM_PSCI
 	select HAVE_ARM_ARCH_TIMER
 

index 3c4596d..01806f5 100644
@@ -14,6 +14,7 @@ generic-y += local.h
 generic-y += local64.h
 generic-y += mcs_spinlock.h
 generic-y += msgbuf.h
+generic-y += msi.h
 generic-y += param.h
 generic-y += parport.h
 generic-y += poll.h

2.4.4

After GICv2m was enabled for 32-bit ARM kernel, a warning popped up:

drivers/irqchip/irq-gic-v2m.c: In function ?gicv2m_compose_msi_msg?:
drivers/irqchip/irq-gic-v2m.c:100:2: warning: right shift count >= width of type [enabled by default]
msg->address_hi = (u32) (addr >> 32);
^

This patch fixes it by using proper macros for splitting up the value.

---
 drivers/irqchip/irq-gic-v2m.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index fdf7065..9055b02 100644
@@ -97,8 +97,8 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 	struct v2m_data *v2m = irq_data_get_irq_chip_data(data);
 	phys_addr_t addr = v2m->res.start + V2M_MSI_SETSPI_NS;
 
-	msg->address_hi = (u32) (addr >> 32);
-	msg->address_lo = (u32) (addr);
+	msg->address_hi = upper_32_bits(addr);
+	msg->address_lo = lower_32_bits(addr);
 	msg->data = data->hwirq;
 }
 

2.4.4