Subject: Re: mlx4 2.6.31-rc5: SW2HW_EQ failed.

From: Roland Dreier <[email-masked]>
Date: Wed, 19 Aug 2009 14:42:28 -0700

I took another look at the patch I sent and found a couple of bugs in it
(seems original authors didn't really test on a system with 32 CPUs).
Anyway the patch below seems to work on a test system with 32 possible
CPUs (including unloading).

Let me know how it works for you.

Thanks,
  Roland

commit 75e8522a04e982623d67b959d2e545974f36c323
Author: Eli Cohen <[email-masked]>
Date:   Wed Aug 19 14:15:59 2009 -0700

    mlx4_core: Allocate and map sufficient ICM memory for EQ context
    
    The current implementation allocates a single host page for EQ context
    memory, which was OK when we only allocated a few EQs.  However, since
    we now allocate an EQ for each CPU core, this patch removes the
    hard-coded limit and makes the allocation depend on EQ entry size and
    the number of required EQs.
    
    Signed-off-by: Eli Cohen <[email-masked]>
    Signed-off-by: Roland Dreier <[email-masked]>

diff --git a/drivers/net/mlx4/eq.c b/drivers/net/mlx4/eq.c
index c11a052..fffe1ea 100644
--- a/drivers/net/mlx4/eq.c
+++ b/drivers/net/mlx4/eq.c
@@ -529,31 +529,46 @@ int mlx4_map_eq_icm(struct mlx4_dev *dev, u64 icm_virt)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	int ret;
+	int host_pages;
+	unsigned off;
 
-	/*
-	 * We assume that mapping one page is enough for the whole EQ
-	 * context table.  This is fine with all current HCAs, because
-	 * we only use 32 EQs and each EQ uses 64 bytes of context
-	 * memory, or 1 KB total.
-	 */
+	host_pages = PAGE_ALIGN(min_t(int, dev->caps.num_eqs, num_possible_cpus() + 1) *
+				dev->caps.eqc_entry_size) >> PAGE_SHIFT;
+	priv->eq_table.order    = order_base_2(host_pages);
 	priv->eq_table.icm_virt = icm_virt;
-	priv->eq_table.icm_page = alloc_page(GFP_HIGHUSER);
-	if (!priv->eq_table.icm_page)
-		return -ENOMEM;
+	priv->eq_table.icm_page = alloc_pages(GFP_HIGHUSER, priv->eq_table.order);
+	if (!priv->eq_table.icm_page) {
+		ret = -ENOMEM;
+		goto err;
+	}
 	priv->eq_table.icm_dma  = pci_map_page(dev->pdev, priv->eq_table.icm_page, 0,
-					       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+					       PAGE_SIZE << priv->eq_table.order,
+					       PCI_DMA_BIDIRECTIONAL);
 	if (pci_dma_mapping_error(dev->pdev, priv->eq_table.icm_dma)) {
-		__free_page(priv->eq_table.icm_page);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto err_free;
 	}
 
-	ret = mlx4_MAP_ICM_page(dev, priv->eq_table.icm_dma, icm_virt);
-	if (ret) {
-		pci_unmap_page(dev->pdev, priv->eq_table.icm_dma, PAGE_SIZE,
-			       PCI_DMA_BIDIRECTIONAL);
-		__free_page(priv->eq_table.icm_page);
+	for (off = 0; off < PAGE_SIZE << priv->eq_table.order; off += MLX4_ICM_PAGE_SIZE) {
+		ret = mlx4_MAP_ICM_page(dev, priv->eq_table.icm_dma + off,
+					icm_virt + off);
+		if (ret)
+			goto err_unmap;
 	}
 
+	return 0;
+
+err_unmap:
+	if (off)
+		mlx4_UNMAP_ICM(dev, priv->eq_table.icm_virt, off / MLX4_ICM_PAGE_SIZE);
+	pci_unmap_page(dev->pdev, priv->eq_table.icm_dma,
+		       PAGE_SIZE << priv->eq_table.order,
+		       PCI_DMA_BIDIRECTIONAL);
+
+err_free:
+	__free_pages(priv->eq_table.icm_page, priv->eq_table.order);
+
+err:
 	return ret;
 }
 
@@ -561,10 +576,11 @@ void mlx4_unmap_eq_icm(struct mlx4_dev *dev)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 
-	mlx4_UNMAP_ICM(dev, priv->eq_table.icm_virt, 1);
-	pci_unmap_page(dev->pdev, priv->eq_table.icm_dma, PAGE_SIZE,
-		       PCI_DMA_BIDIRECTIONAL);
-	__free_page(priv->eq_table.icm_page);
+	mlx4_UNMAP_ICM(dev, priv->eq_table.icm_virt,
+		       (PAGE_SIZE / MLX4_ICM_PAGE_SIZE) << priv->eq_table.order);
+	pci_unmap_page(dev->pdev, priv->eq_table.icm_dma,
+		       PAGE_SIZE << priv->eq_table.order, PCI_DMA_BIDIRECTIONAL);
+	__free_pages(priv->eq_table.icm_page, priv->eq_table.order);
 }
 
 int mlx4_alloc_eq_table(struct mlx4_dev *dev)
diff --git a/drivers/net/mlx4/main.c b/drivers/net/mlx4/main.c
index 5c1afe0..474d1f3 100644
--- a/drivers/net/mlx4/main.c
+++ b/drivers/net/mlx4/main.c
@@ -207,6 +207,7 @@ static int mlx4_dev_cap(struct mlx4_dev *dev, struct mlx4_dev_cap *dev_cap)
 	dev->caps.max_cqes	     = dev_cap->max_cq_sz - 1;
 	dev->caps.reserved_cqs	     = dev_cap->reserved_cqs;
 	dev->caps.reserved_eqs	     = dev_cap->reserved_eqs;
+	dev->caps.eqc_entry_size     = dev_cap->eqc_entry_sz;
 	dev->caps.mtts_per_seg	     = 1 << log_mtts_per_seg;
 	dev->caps.reserved_mtts	     = DIV_ROUND_UP(dev_cap->reserved_mtts,
 						    dev->caps.mtts_per_seg);
diff --git a/drivers/net/mlx4/mlx4.h b/drivers/net/mlx4/mlx4.h
index 5bd79c2..34bcc11 100644
--- a/drivers/net/mlx4/mlx4.h
+++ b/drivers/net/mlx4/mlx4.h
@@ -210,6 +210,7 @@ struct mlx4_eq_table {
 	dma_addr_t		icm_dma;
 	struct mlx4_icm_table	cmpt_table;
 	int			have_irq;
+	int			order;
 	u8			inta_pin;
 };
 
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index ce7cc6c..8923c9b 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -206,6 +206,7 @@ struct mlx4_caps {
 	int			max_cqes;
 	int			reserved_cqs;
 	int			num_eqs;
+	int			eqc_entry_size;
 	int			reserved_eqs;
 	int			num_comp_vectors;
 	int			num_mpts;