irqchip/gic-v3-its: Move minimum LPI requirements to individual busses

At the moment, the core ITS driver imposes the allocation to be
in chunks of 32. As we want to relax this on a per bus basis, let's
move the the the allocation constraints to each bus.

No functionnal change.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c b/drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c
index 4eca5c763766b50824734ae9af88da824badfeb2..606efa64adff5bb58d2f0f40ab4067aa14bb2f48 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c
@@ -45,6 +45,9 @@ static int its_fsl_mc_msi_prepare(struct irq_domain *msi_domain,
         */
        info->scratchpad[0].ul = mc_bus_dev->icid;
        msi_info = msi_get_domain_info(msi_domain->parent);
+
+       /* Allocate at least 32 MSIs, and always as a power of 2 */
+       nvec = max_t(int, 32, roundup_pow_of_two(nvec));
        return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
 }
 

diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index 25a98de5cfb2831fa61d33fd3be3ef30d3f4e534..75c3cafabc6a59b49ba542d8028876b776eca4b1 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -86,8 +86,10 @@ static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
        /* ITS specific DeviceID, as the core ITS ignores dev. */
        info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);
 
-       return msi_info->ops->msi_prepare(domain->parent,
-                                         dev, max(nvec, alias_count), info);
+       /* Allocate at least 32 MSIs, and always as a power of 2 */
+       nvec = max(nvec, alias_count);
+       nvec = max_t(int, 32, roundup_pow_of_two(nvec));
+       return msi_info->ops->msi_prepare(domain->parent, dev, nvec, info);
 }
 
 static struct msi_domain_ops its_pci_msi_ops = {

diff --git a/drivers/irqchip/irq-gic-v3-its-platform-msi.c b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
index 8881a053c173edfdb11ad322b9b60f9b61ef57aa..7b8e87b493fe5defd6ebd5968f92c856c8fdcc8c 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its-platform-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
@@ -73,6 +73,8 @@ static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
        /* ITS specific DeviceID, as the core ITS ignores dev. */
        info->scratchpad[0].ul = dev_id;
 
+       /* Allocate at least 32 MSIs, and always as a power of 2 */
+       nvec = max_t(int, 32, roundup_pow_of_two(nvec));
        return msi_info->ops->msi_prepare(domain->parent,
                                          dev, nvec, info);
 }

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 20244006cd8227a57308b51d84ddf66369f1c942..03ac8d05279dffb5a30490e06bcc4353b53d6ca7 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2200,12 +2200,15 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
        if (!its_alloc_device_table(its, dev_id))
                return NULL;
 
+       if (WARN_ON(!is_power_of_2(nvecs)))
+               nvecs = roundup_pow_of_two(nvecs);
+
        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        /*
-        * We allocate at least one chunk worth of LPIs bet device,
-        * and thus that many ITEs. The device may require less though.
+        * Even if the device wants a single LPI, the ITT must be
+        * sized as a power of two (and you need at least one bit...).
         */
-       nr_ites = max(IRQS_PER_CHUNK, roundup_pow_of_two(nvecs));
+       nr_ites = max(2, nvecs);
        sz = nr_ites * its->ite_size;
        sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1;
        itt = kzalloc(sz, GFP_KERNEL);
@@ -2861,7 +2864,7 @@ static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq
 
        BUG_ON(!vm);
 
-       bitmap = its_lpi_alloc_chunks(nr_irqs, &base, &nr_ids);
+       bitmap = its_lpi_alloc_chunks(roundup_pow_of_two(nr_irqs), &base, &nr_ids);
        if (!bitmap)
                return -ENOMEM;