s390/pci: Do not mask MSI[-X] entries on teardown

The PCI core already ensures that the MSI[-X] state is correct when MSI[-X]
is disabled. For MSI the reset state is all entries unmasked and for MSI-X
all vectors are masked.

S390 masks all MSI entries and masks the already masked MSI-X entries
again. Remove it and let the device in the correct state.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20210729222542.939798136@linutronix.de

arch/s390/pci/pci_irq.c

@@ -365,10 +365,6 @@ void arch_teardown_msi_irqs(struct pci_dev *pdev)
 	for_each_pci_msi_entry(msi, pdev) {
 		if (!msi->irq)
 			continue;
-		if (msi->msi_attrib.is_msix)
-			__pci_msix_desc_mask_irq(msi, 1);
-		else
-			__pci_msi_desc_mask_irq(msi, 1, 1);
 		irq_set_msi_desc(msi->irq, NULL);
 		irq_free_desc(msi->irq);
 		msi->msg.address_lo = 0;

drivers/pci/msi.c

@@ -143,7 +143,7 @@ static inline __attribute_const__ u32 msi_mask(unsigned x)
  * reliably as devices without an INTx disable bit will then generate a
  * level IRQ which will never be cleared.
  */
-void __pci_msi_desc_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
+static void __pci_msi_desc_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
 {
 	raw_spinlock_t *lock = &desc->dev->msi_lock;
 	unsigned long flags;
@@ -180,7 +180,7 @@ static void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
  * file.  This saves a few milliseconds when initialising devices with lots
  * of MSI-X interrupts.
  */
-u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)
+static u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)
 {
 	u32 mask_bits = desc->masked;
 	void __iomem *desc_addr;

include/linux/msi.h

@@ -232,8 +232,6 @@ void free_msi_entry(struct msi_desc *entry);
 void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
 void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
 
-u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag);
-void __pci_msi_desc_mask_irq(struct msi_desc *desc, u32 mask, u32 flag);
 void pci_msi_mask_irq(struct irq_data *data);
 void pci_msi_unmask_irq(struct irq_data *data);