Commit 809c9c3b authored by Yonatan Nachum's avatar Yonatan Nachum Committed by Leon Romanovsky
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RDMA/efa: Limit EQs to available MSI-X vectors



When creating EQs we take into consideration the max number of EQs the
device reported it can support and the number of available CPUs. There
are situations where the number of EQs the device reported it can
support and the PCI configuration of MSI-X is different, take it in
account as well when creating EQs.
Also request at least 1 MSI-X vector for the management queue and allow
the kernel to return a number of vectors in a range between 1 and the
max supported MSI-X vectors according to the PCI config.

Reviewed-by: default avatarMichael Margolin <mrgolin@amazon.com>
Reviewed-by: default avatarYonatan Goldhirsh <ygold@amazon.com>
Signed-off-by: default avatarYonatan Nachum <ynachum@amazon.com>
Link: https://lore.kernel.org/r/20240131093403.18624-1-ynachum@amazon.com


Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent a400073c
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+1 −0
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ struct efa_dev {
	u64 db_bar_addr;
	u64 db_bar_len;

	unsigned int num_irq_vectors;
	int admin_msix_vector_idx;
	struct efa_irq admin_irq;

+15 −17
Original line number Diff line number Diff line
@@ -322,7 +322,9 @@ static int efa_create_eqs(struct efa_dev *dev)
	int err;
	int i;

	neqs = min_t(unsigned int, neqs, num_online_cpus());
	neqs = min_t(unsigned int, neqs,
		     dev->num_irq_vectors - EFA_COMP_EQS_VEC_BASE);

	dev->neqs = neqs;
	dev->eqs = kcalloc(neqs, sizeof(*dev->eqs), GFP_KERNEL);
	if (!dev->eqs)
@@ -468,34 +470,30 @@ static void efa_disable_msix(struct efa_dev *dev)

static int efa_enable_msix(struct efa_dev *dev)
{
	int msix_vecs, irq_num;
	int max_vecs, num_vecs;

	/*
	 * Reserve the max msix vectors we might need, one vector is reserved
	 * for admin.
	 */
	msix_vecs = min_t(int, pci_msix_vec_count(dev->pdev),
	max_vecs = min_t(int, pci_msix_vec_count(dev->pdev),
			 num_online_cpus() + 1);
	dev_dbg(&dev->pdev->dev, "Trying to enable MSI-X, vectors %d\n",
		msix_vecs);
		max_vecs);

	dev->admin_msix_vector_idx = EFA_MGMNT_MSIX_VEC_IDX;
	irq_num = pci_alloc_irq_vectors(dev->pdev, msix_vecs,
					msix_vecs, PCI_IRQ_MSIX);
	num_vecs = pci_alloc_irq_vectors(dev->pdev, 1,
					 max_vecs, PCI_IRQ_MSIX);

	if (irq_num < 0) {
		dev_err(&dev->pdev->dev, "Failed to enable MSI-X. irq_num %d\n",
			irq_num);
	if (num_vecs < 0) {
		dev_err(&dev->pdev->dev, "Failed to enable MSI-X. error %d\n",
			num_vecs);
		return -ENOSPC;
	}

	if (irq_num != msix_vecs) {
		efa_disable_msix(dev);
		dev_err(&dev->pdev->dev,
			"Allocated %d MSI-X (out of %d requested)\n",
			irq_num, msix_vecs);
		return -ENOSPC;
	}
	dev_dbg(&dev->pdev->dev, "Allocated %d MSI-X vectors\n", num_vecs);

	dev->num_irq_vectors = num_vecs;

	return 0;
}