From cc68f2177fcbfe2dbe5e9514789b96ba5995ec1e Mon Sep 17 00:00:00 2001 From: Jorgen Hansen Date: Mon, 7 Feb 2022 02:27:22 -0800 Subject: [PATCH] VMCI: dma dg: register dummy IRQ handlers for DMA datagrams Register dummy interrupt handlers for DMA datagrams in preparation for DMA datagram receive operations. Reviewed-by: Vishnu Dasa Signed-off-by: Jorgen Hansen Link: https://lore.kernel.org/r/20220207102725.2742-6-jhansen@vmware.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/vmw_vmci/vmci_guest.c | 42 +++++++++++++++++++++++++++--- include/linux/vmw_vmci_defs.h | 14 ++++++++-- 2 files changed, 51 insertions(+), 5 deletions(-) diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c index ced187e7ac08..acef19c562b3 100644 --- a/drivers/misc/vmw_vmci/vmci_guest.c +++ b/drivers/misc/vmw_vmci/vmci_guest.c @@ -414,6 +414,9 @@ static irqreturn_t vmci_interrupt(int irq, void *_dev) icr &= ~VMCI_ICR_NOTIFICATION; } + if (icr & VMCI_ICR_DMA_DATAGRAM) + icr &= ~VMCI_ICR_DMA_DATAGRAM; + if (icr != 0) dev_warn(dev->dev, "Ignoring unknown interrupt cause (%d)\n", @@ -438,6 +441,16 @@ static irqreturn_t vmci_interrupt_bm(int irq, void *_dev) return IRQ_HANDLED; } +/* + * Interrupt handler for MSI-X interrupt vector VMCI_INTR_DMA_DATAGRAM, + * which is for the completion of a DMA datagram send or receive operation. + * Will only get called if we are using MSI-X with exclusive vectors. + */ +static irqreturn_t vmci_interrupt_dma_datagram(int irq, void *_dev) +{ + return IRQ_HANDLED; +} + /* * Most of the initialization at module load time is done here. */ @@ -447,6 +460,7 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, struct vmci_guest_device *vmci_dev; void __iomem *iobase = NULL; void __iomem *mmio_base = NULL; + unsigned int num_irq_vectors; unsigned int capabilities; unsigned int caps_in_use; unsigned long cmd; @@ -627,8 +641,12 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, * Enable interrupts. Try MSI-X first, then MSI, and then fallback on * legacy interrupts. */ - error = pci_alloc_irq_vectors(pdev, VMCI_MAX_INTRS, VMCI_MAX_INTRS, - PCI_IRQ_MSIX); + if (vmci_dev->mmio_base != NULL) + num_irq_vectors = VMCI_MAX_INTRS; + else + num_irq_vectors = VMCI_MAX_INTRS_NOTIFICATION; + error = pci_alloc_irq_vectors(pdev, num_irq_vectors, num_irq_vectors, + PCI_IRQ_MSIX); if (error < 0) { error = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_MSI | PCI_IRQ_LEGACY); @@ -666,6 +684,17 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, pci_irq_vector(pdev, 1), error); goto err_free_irq; } + if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM) { + error = request_irq(pci_irq_vector(pdev, 2), + vmci_interrupt_dma_datagram, + 0, KBUILD_MODNAME, vmci_dev); + if (error) { + dev_err(&pdev->dev, + "Failed to allocate irq %u: %d\n", + pci_irq_vector(pdev, 2), error); + goto err_free_bm_irq; + } + } } dev_dbg(&pdev->dev, "Registered device\n"); @@ -676,6 +705,8 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, cmd = VMCI_IMR_DATAGRAM; if (caps_in_use & VMCI_CAPS_NOTIFICATIONS) cmd |= VMCI_IMR_NOTIFICATION; + if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM) + cmd |= VMCI_IMR_DMA_DATAGRAM; vmci_write_reg(vmci_dev, cmd, VMCI_IMR_ADDR); /* Enable interrupts. */ @@ -686,6 +717,8 @@ static int vmci_guest_probe_device(struct pci_dev *pdev, vmci_call_vsock_callback(false); return 0; +err_free_bm_irq: + free_irq(pci_irq_vector(pdev, 1), vmci_dev); err_free_irq: free_irq(pci_irq_vector(pdev, 0), vmci_dev); tasklet_kill(&vmci_dev->datagram_tasklet); @@ -751,8 +784,11 @@ static void vmci_guest_remove_device(struct pci_dev *pdev) * MSI-X, we might have multiple vectors, each with their own * IRQ, which we must free too. */ - if (vmci_dev->exclusive_vectors) + if (vmci_dev->exclusive_vectors) { free_irq(pci_irq_vector(pdev, 1), vmci_dev); + if (vmci_dev->mmio_base != NULL) + free_irq(pci_irq_vector(pdev, 2), vmci_dev); + } free_irq(pci_irq_vector(pdev, 0), vmci_dev); pci_free_irq_vectors(pdev); diff --git a/include/linux/vmw_vmci_defs.h b/include/linux/vmw_vmci_defs.h index 4167779469fd..2b70c024dacb 100644 --- a/include/linux/vmw_vmci_defs.h +++ b/include/linux/vmw_vmci_defs.h @@ -45,13 +45,22 @@ /* Interrupt Cause register bits. */ #define VMCI_ICR_DATAGRAM BIT(0) #define VMCI_ICR_NOTIFICATION BIT(1) +#define VMCI_ICR_DMA_DATAGRAM BIT(2) /* Interrupt Mask register bits. */ #define VMCI_IMR_DATAGRAM BIT(0) #define VMCI_IMR_NOTIFICATION BIT(1) +#define VMCI_IMR_DMA_DATAGRAM BIT(2) -/* Maximum MSI/MSI-X interrupt vectors in the device. */ -#define VMCI_MAX_INTRS 2 +/* + * Maximum MSI/MSI-X interrupt vectors in the device. + * If VMCI_CAPS_DMA_DATAGRAM is supported by the device, + * VMCI_MAX_INTRS_DMA_DATAGRAM vectors are available, + * otherwise only VMCI_MAX_INTRS_NOTIFICATION. + */ +#define VMCI_MAX_INTRS_NOTIFICATION 2 +#define VMCI_MAX_INTRS_DMA_DATAGRAM 3 +#define VMCI_MAX_INTRS VMCI_MAX_INTRS_DMA_DATAGRAM /* * Supported interrupt vectors. There is one for each ICR value above, @@ -60,6 +69,7 @@ enum { VMCI_INTR_DATAGRAM = 0, VMCI_INTR_NOTIFICATION = 1, + VMCI_INTR_DMA_DATAGRAM = 2, }; /*