4.18-stable review patch. If anyone has any objections, please let me know.
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From: Vivek Gautam vivek.gautam@codeaurora.org
commit d1e20222d5372e951bbb2fd3f6489ec4a6ea9b11 upstream.
Currently we check if the number of context banks is not equal to num_context_interrupts. However, there are booloaders such as, one on sdm845 that reserves few context banks and thus kernel views less than the total available context banks. So, although the hardware definition in device tree would mention the correct number of context interrupts, this number can be greater than the number of context banks visible to smmu in kernel. We should therefore error out only when the number of context banks is greater than the available number of context interrupts.
Signed-off-by: Vivek Gautam vivek.gautam@codeaurora.org Suggested-by: Tomasz Figa tfiga@chromium.org Cc: Robin Murphy robin.murphy@arm.com Cc: Will Deacon will.deacon@arm.com [will: drop useless printk] Signed-off-by: Will Deacon will.deacon@arm.com Cc: Jitendra Bhivare jitendra.bhivare@broadcom.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iommu/arm-smmu.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)
--- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -2103,12 +2103,16 @@ static int arm_smmu_device_probe(struct if (err) return err;
- if (smmu->version == ARM_SMMU_V2 && - smmu->num_context_banks != smmu->num_context_irqs) { - dev_err(dev, - "found only %d context interrupt(s) but %d required\n", - smmu->num_context_irqs, smmu->num_context_banks); - return -ENODEV; + if (smmu->version == ARM_SMMU_V2) { + if (smmu->num_context_banks > smmu->num_context_irqs) { + dev_err(dev, + "found only %d context irq(s) but %d required\n", + smmu->num_context_irqs, smmu->num_context_banks); + return -ENODEV; + } + + /* Ignore superfluous interrupts */ + smmu->num_context_irqs = smmu->num_context_banks; }
for (i = 0; i < smmu->num_global_irqs; ++i) {