From b1a504a6500df50e83b701b7946b34fce27ad8a3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Fri, 6 Mar 2020 16:01:40 +0100 Subject: powerpc/xive: Use XIVE_BAD_IRQ instead of zero to catch non configured IPIs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When a CPU is brought up, an IPI number is allocated and recorded under the XIVE CPU structure. Invalid IPI numbers are tracked with interrupt number 0x0. On the PowerNV platform, the interrupt number space starts at 0x10 and this works fine. However, on the sPAPR platform, it is possible to allocate the interrupt number 0x0 and this raises an issue when CPU 0 is unplugged. The XIVE spapr driver tracks allocated interrupt numbers in a bitmask and it is not correctly updated when interrupt number 0x0 is freed. It stays allocated and it is then impossible to reallocate. Fix by using the XIVE_BAD_IRQ value instead of zero on both platforms. Reported-by: David Gibson Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson Tested-by: David Gibson Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200306150143.5551-2-clg@kaod.org --- arch/powerpc/sysdev/xive/native.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/sysdev/xive/native.c') diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c index 0ff6b739052c..50e1a8e02497 100644 --- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -312,7 +312,7 @@ static void xive_native_put_ipi(unsigned int cpu, struct xive_cpu *xc) s64 rc; /* Free the IPI */ - if (!xc->hw_ipi) + if (xc->hw_ipi == XIVE_BAD_IRQ) return; for (;;) { rc = opal_xive_free_irq(xc->hw_ipi); @@ -320,7 +320,7 @@ static void xive_native_put_ipi(unsigned int cpu, struct xive_cpu *xc) msleep(OPAL_BUSY_DELAY_MS); continue; } - xc->hw_ipi = 0; + xc->hw_ipi = XIVE_BAD_IRQ; break; } } -- cgit v1.2.3 From 930914b7d528fc6b0249bffc00564100bcf6ef75 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Fri, 6 Mar 2020 16:01:43 +0100 Subject: powerpc/xive: Add a debugfs file to dump internal XIVE state MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As does XMON, the debugfs file /sys/kernel/debug/powerpc/xive exposes the XIVE internal state of the machine CPUs and interrupts. Available on the PowerNV and sPAPR platforms. Signed-off-by: Cédric Le Goater [mpe: Make the debugfs file 0400] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200306150143.5551-5-clg@kaod.org --- arch/powerpc/sysdev/xive/native.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/powerpc/sysdev/xive/native.c') diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c index 50e1a8e02497..5218fdc4b29a 100644 --- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -19,6 +19,7 @@ #include #include +#include #include #include #include @@ -850,3 +851,5 @@ int xive_native_get_vp_state(u32 vp_id, u64 *out_state) return 0; } EXPORT_SYMBOL_GPL(xive_native_get_vp_state); + +machine_arch_initcall(powernv, xive_core_debug_init); -- cgit v1.2.3