On Thu, Feb 03, 2022 at 05:12:31AM -0800, Jorgen Hansen wrote:
> Detect the support for MMIO access through examination of the length
> of the region requested in BAR1. If it is 256KB, the VMCI device
> supports MMIO access to registers.
>
> If MMIO access is supported, map the area of the region used for
> MMIO access (64KB size at offset 128KB).
>
> Add wrapper functions for accessing 32 bit register accesses through
> either MMIO or IO ports based on device configuration.
>
> Sending and receiving datagrams through iowrite8_rep/ioread8_rep is
> left unchanged for now, and will be addressed in a later change.
>
> Reviewed-by: Vishnu Dasa <vdasa@xxxxxxxxxx>
> Signed-off-by: Jorgen Hansen <jhansen@xxxxxxxxxx>
> ---
> drivers/misc/vmw_vmci/vmci_guest.c | 68 ++++++++++++++++++++++--------
> include/linux/vmw_vmci_defs.h | 12 ++++++
> 2 files changed, 62 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c
> index 1018dc77269d..38ee7ed32ab9 100644
> --- a/drivers/misc/vmw_vmci/vmci_guest.c
> +++ b/drivers/misc/vmw_vmci/vmci_guest.c
> @@ -45,6 +45,7 @@ static u32 vm_context_id = VMCI_INVALID_ID;
> struct vmci_guest_device {
> struct device *dev; /* PCI device we are attached to */
> void __iomem *iobase;
> + void __iomem *mmio_base;
>
> bool exclusive_vectors;
>
> @@ -89,6 +90,21 @@ u32 vmci_get_vm_context_id(void)
> return vm_context_id;
> }
>
> +static unsigned int vmci_read_reg(struct vmci_guest_device *dev, u32 reg)
> +{
> + if (dev->mmio_base != NULL)
> + return readl(dev->mmio_base + reg);
> + return ioread32(dev->iobase + reg);
> +}
> +
> +static void vmci_write_reg(struct vmci_guest_device *dev, u32 val, u32 reg)
> +{
> + if (dev->mmio_base != NULL)
> + writel(val, dev->mmio_base + reg);
> + else
> + iowrite32(val, dev->iobase + reg);
> +}
> +
> /*
> * VM to hypervisor call mechanism. We use the standard VMware naming
> * convention since shared code is calling this function as well.
> @@ -116,7 +132,7 @@ int vmci_send_datagram(struct vmci_datagram *dg)
> if (vmci_dev_g) {
> iowrite8_rep(vmci_dev_g->iobase + VMCI_DATA_OUT_ADDR,
> dg, VMCI_DG_SIZE(dg));
> - result = ioread32(vmci_dev_g->iobase + VMCI_RESULT_LOW_ADDR);
> + result = vmci_read_reg(vmci_dev_g, VMCI_RESULT_LOW_ADDR);
> } else {
> result = VMCI_ERROR_UNAVAILABLE;
> }
> @@ -384,7 +400,7 @@ static irqreturn_t vmci_interrupt(int irq, void *_dev)
> unsigned int icr;
>
> /* Acknowledge interrupt and determine what needs doing. */
> - icr = ioread32(dev->iobase + VMCI_ICR_ADDR);
> + icr = vmci_read_reg(dev, VMCI_ICR_ADDR);
> if (icr == 0 || icr == ~0)
> return IRQ_NONE;
>
> @@ -429,7 +445,8 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
> const struct pci_device_id *id)
> {
> struct vmci_guest_device *vmci_dev;
> - void __iomem *iobase;
> + void __iomem *iobase = NULL;
> + void __iomem *mmio_base = NULL;
> unsigned int capabilities;
> unsigned int caps_in_use;
> unsigned long cmd;
> @@ -445,16 +462,32 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
> return error;
> }
>
> - error = pcim_iomap_regions(pdev, 1 << 0, KBUILD_MODNAME);
> - if (error) {
> - dev_err(&pdev->dev, "Failed to reserve/map IO regions\n");
> - return error;
> + /*
> + * The VMCI device with mmio access to registers requests 256KB
> + * for BAR1. If present, driver will use new VMCI device
> + * functionality for register access and datagram send/recv.
> + */
> +
> + if (pci_resource_len(pdev, 1) == VMCI_WITH_MMIO_ACCESS_BAR_SIZE) {
> + dev_info(&pdev->dev, "MMIO register access is available\n");
> + mmio_base = pci_iomap_range(pdev, 1, VMCI_MMIO_ACCESS_OFFSET,
> + VMCI_MMIO_ACCESS_SIZE);
> + /* If the map fails, we fall back to IOIO access. */
> + if (!mmio_base)
> + dev_warn(&pdev->dev, "Failed to map MMIO register access\n");
> }
>
> - iobase = pcim_iomap_table(pdev)[0];
> + if (!mmio_base) {
> + error = pcim_iomap_regions(pdev, BIT(0), KBUILD_MODNAME);
> + if (error) {
> + dev_err(&pdev->dev, "Failed to reserve/map IO regions\n");
> + return error;
> + }
> + iobase = pcim_iomap_table(pdev)[0];
> + }
>
> - dev_info(&pdev->dev, "Found VMCI PCI device at %#lx, irq %u\n",
> - (unsigned long)iobase, pdev->irq);
> + dev_info(&pdev->dev, "Found VMCI PCI device at %#lx, %#lx, irq %u\n",
> + (unsigned long)iobase, (unsigned long)mmio_base, pdev->irq);
Why are you printing iomem addresses to userspace? Are you sure that is
ok? Who is going to use it?
thanks,
greg k-h
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