[PATCH] MIPS: malta: register UP SMP ops if all else fails

From: Paul Burton
Date: Tue Sep 22 2015 - 14:59:13 EST


If we fail to register any real SMP implementations, fall back to
registering the dummy UP implementation. Otherwise when we build an SMP
kernel & run it on a system where the SMP implementations fail to probe
(eg. QEMU) the kernel will perform a NULL dereference attempting to call
mp_ops->smp_setup() from plat_smp_setup().

Notably this fixes booting kernels with CPS SMP enabled on QEMU, which
doesn't currently implement the CM, CPC or GIC.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---

arch/mips/Kconfig | 1 +
arch/mips/mti-malta/malta-init.c | 1 +
2 files changed, 2 insertions(+)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e3aa5b0..71d2a88 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -424,6 +424,7 @@ config MIPS_MALTA
select MIPS_L1_CACHE_SHIFT_6
select PCI_GT64XXX_PCI0
select MIPS_MSC
+ select SMP_UP if SMP
select SWAP_IO_SPACE
select SYS_HAS_CPU_MIPS32_R1
select SYS_HAS_CPU_MIPS32_R2
diff --git a/arch/mips/mti-malta/malta-init.c b/arch/mips/mti-malta/malta-init.c
index 53c2478..571148c 100644
--- a/arch/mips/mti-malta/malta-init.c
+++ b/arch/mips/mti-malta/malta-init.c
@@ -302,6 +302,7 @@ mips_pci_controller:
return;
if (!register_vsmp_smp_ops())
return;
+ register_up_smp_ops();
}

void platform_early_l2_init(void)
--
2.5.3

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