From b0b0b8b897f8e12b2368e868bd7cdc5742d5c5a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Mon, 10 Jan 2022 02:49:58 +0100
Subject: [PATCH] PCI: aardvark: Fix support for MSI interrupts
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Git-commit: b0b0b8b897f8e12b2368e868bd7cdc5742d5c5a9
Patch-mainline: v5.18-rc1
References: git-fixes

Aardvark hardware supports Multi-MSI and MSI_FLAG_MULTI_PCI_MSI is already
set for the MSI chip. But when allocating MSI interrupt numbers for
Multi-MSI, the numbers need to be properly aligned, otherwise endpoint
devices send MSI interrupt with incorrect numbers.

Fix this issue by using function bitmap_find_free_region() instead of
bitmap_find_next_zero_area().

To ensure that aligned MSI interrupt numbers are used by endpoint devices,
we cannot use Linux virtual irq numbers (as they are random and not
properly aligned). Instead we need to use the aligned hwirq numbers.

This change fixes receiving MSI interrupts on Armada 3720 boards and
allows using NVMe disks which use Multi-MSI feature with 3 interrupts.

Without this NVMe disks freeze booting as linux nvme-core.c is waiting
60s for an interrupt.

Link: https://lore.kernel.org/r/20220110015018.26359-4-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/pci/controller/pci-aardvark.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 3cf36baa215a..3a7f4c3757ce 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1180,7 +1180,7 @@ static void advk_msi_irq_compose_msi_msg(struct irq_data *data,
 
 	msg->address_lo = lower_32_bits(msi_msg);
 	msg->address_hi = upper_32_bits(msi_msg);
-	msg->data = data->irq;
+	msg->data = data->hwirq;
 }
 
 static int advk_msi_set_affinity(struct irq_data *irq_data,
@@ -1197,15 +1197,11 @@ static int advk_msi_irq_domain_alloc(struct irq_domain *domain,
 	int hwirq, i;
 
 	mutex_lock(&pcie->msi_used_lock);
-	hwirq = bitmap_find_next_zero_area(pcie->msi_used, MSI_IRQ_NUM,
-					   0, nr_irqs, 0);
-	if (hwirq >= MSI_IRQ_NUM) {
-		mutex_unlock(&pcie->msi_used_lock);
-		return -ENOSPC;
-	}
-
-	bitmap_set(pcie->msi_used, hwirq, nr_irqs);
+	hwirq = bitmap_find_free_region(pcie->msi_used, MSI_IRQ_NUM,
+					order_base_2(nr_irqs));
 	mutex_unlock(&pcie->msi_used_lock);
+	if (hwirq < 0)
+		return -ENOSPC;
 
 	for (i = 0; i < nr_irqs; i++)
 		irq_domain_set_info(domain, virq + i, hwirq + i,
@@ -1223,7 +1219,7 @@ static void advk_msi_irq_domain_free(struct irq_domain *domain,
 	struct advk_pcie *pcie = domain->host_data;
 
 	mutex_lock(&pcie->msi_used_lock);
-	bitmap_clear(pcie->msi_used, d->hwirq, nr_irqs);
+	bitmap_release_region(pcie->msi_used, d->hwirq, order_base_2(nr_irqs));
 	mutex_unlock(&pcie->msi_used_lock);
 }
 
-- 
2.31.1