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| author | Marc Zyngier <marc.zyngier@arm.com> | 2018-08-24 16:06:36 +0100 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2018-08-24 08:50:29 -0700 |
| commit | 3fc7c5c0cff3150e471f5fd12f59971c6d2c6513 (patch) | |
| tree | 34f6108a8a74f52907f0a5c74b9f6d879643ffca | |
| parent | 7db7a8f5638a2ffe0c0c0d55b5186b6191fd6af7 (diff) | |
| download | linux-3fc7c5c0cff3150e471f5fd12f59971c6d2c6513.tar.bz2 | |
iommu/rockchip: Handle errors returned from PM framework
pm_runtime_get_if_in_use can fail: either PM has been disabled
altogether (-EINVAL), or the device hasn't been enabled yet (0).
Sadly, the Rockchip IOMMU driver tends to conflate the two things
by considering a non-zero return value as successful.
This has the consequence of hiding other bugs, so let's handle this
case throughout the driver, with a WARN_ON_ONCE so that we can try
and work out what happened.
Fixes: 0f181d3cf7d98 ("iommu/rockchip: Add runtime PM support")
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
| -rw-r--r-- | drivers/iommu/rockchip-iommu.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c index 054cd2c8e9c8..4e0f9b61cd7f 100644 --- a/drivers/iommu/rockchip-iommu.c +++ b/drivers/iommu/rockchip-iommu.c @@ -521,10 +521,11 @@ static irqreturn_t rk_iommu_irq(int irq, void *dev_id) u32 int_status; dma_addr_t iova; irqreturn_t ret = IRQ_NONE; - int i; + int i, err; - if (WARN_ON(!pm_runtime_get_if_in_use(iommu->dev))) - return 0; + err = pm_runtime_get_if_in_use(iommu->dev); + if (WARN_ON_ONCE(err <= 0)) + return ret; if (WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks))) goto out; @@ -620,11 +621,15 @@ static void rk_iommu_zap_iova(struct rk_iommu_domain *rk_domain, spin_lock_irqsave(&rk_domain->iommus_lock, flags); list_for_each(pos, &rk_domain->iommus) { struct rk_iommu *iommu; + int ret; iommu = list_entry(pos, struct rk_iommu, node); /* Only zap TLBs of IOMMUs that are powered on. */ - if (pm_runtime_get_if_in_use(iommu->dev)) { + ret = pm_runtime_get_if_in_use(iommu->dev); + if (WARN_ON_ONCE(ret < 0)) + continue; + if (ret) { WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks)); rk_iommu_zap_lines(iommu, iova, size); @@ -891,6 +896,7 @@ static void rk_iommu_detach_device(struct iommu_domain *domain, struct rk_iommu *iommu; struct rk_iommu_domain *rk_domain = to_rk_domain(domain); unsigned long flags; + int ret; /* Allow 'virtual devices' (eg drm) to detach from domain */ iommu = rk_iommu_from_dev(dev); @@ -909,7 +915,9 @@ static void rk_iommu_detach_device(struct iommu_domain *domain, list_del_init(&iommu->node); spin_unlock_irqrestore(&rk_domain->iommus_lock, flags); - if (pm_runtime_get_if_in_use(iommu->dev)) { + ret = pm_runtime_get_if_in_use(iommu->dev); + WARN_ON_ONCE(ret < 0); + if (ret > 0) { rk_iommu_disable(iommu); pm_runtime_put(iommu->dev); } @@ -946,7 +954,8 @@ static int rk_iommu_attach_device(struct iommu_domain *domain, list_add_tail(&iommu->node, &rk_domain->iommus); spin_unlock_irqrestore(&rk_domain->iommus_lock, flags); - if (!pm_runtime_get_if_in_use(iommu->dev)) + ret = pm_runtime_get_if_in_use(iommu->dev); + if (!ret || WARN_ON_ONCE(ret < 0)) return 0; ret = rk_iommu_enable(iommu); |