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| author | Marc Zyngier | 2018-05-31 10:01:59 +0200 |
|---|---|---|
| committer | Marc Zyngier | 2018-07-16 15:22:19 +0200 |
| commit | 12b2905af183c931bedcab4292c81d3a415e080f (patch) | |
| tree | 6c3e17b3d69030ff654f77a5d5dbf7df74889ead | |
| parent | irqchip/gic-v3: Expose GICD_TYPER in the rdist structure (diff) | |
| download | kernel-qcow2-linux-12b2905af183c931bedcab4292c81d3a415e080f.tar.gz kernel-qcow2-linux-12b2905af183c931bedcab4292c81d3a415e080f.tar.xz kernel-qcow2-linux-12b2905af183c931bedcab4292c81d3a415e080f.zip | |
irqchip/gic-v3-its: Honor hypervisor enforced LPI range
A recent extension to the GIC architecture allows a hypervisor to
arbitrarily reduce the number of LPIs available to a guest, no
matter what the GIC says about the valid range of IntIDs.
Let's factor in this information when computing the number of
available LPIs
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its.c | 9 | ||||
| -rw-r--r-- | include/linux/irqchip/arm-gic-v3.h | 1 |
2 files changed, 10 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index efe6d1a6c32e..f56c84977241 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -1541,8 +1541,17 @@ out: static int __init its_lpi_init(u32 id_bits) { u32 lpis = (1UL << id_bits) - 8192; + u32 numlpis; int err; + numlpis = 1UL << GICD_TYPER_NUM_LPIS(gic_rdists->gicd_typer); + + if (numlpis > 2 && !WARN_ON(numlpis > lpis)) { + lpis = numlpis; + pr_info("ITS: Using hypervisor restricted LPI range [%u]\n", + lpis); + } + /* * Initializing the allocator is just the same as freeing the * full range of LPIs. diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h index 396cd99af02f..9d2ea3e907d0 100644 --- a/include/linux/irqchip/arm-gic-v3.h +++ b/include/linux/irqchip/arm-gic-v3.h @@ -73,6 +73,7 @@ #define GICD_TYPER_MBIS (1U << 16) #define GICD_TYPER_ID_BITS(typer) ((((typer) >> 19) & 0x1f) + 1) +#define GICD_TYPER_NUM_LPIS(typer) ((((typer) >> 11) & 0x1f) + 1) #define GICD_TYPER_IRQS(typer) ((((typer) & 0x1f) + 1) * 32) #define GICD_IROUTER_SPI_MODE_ONE (0U << 31) |