Re: [PATCH v2 2/8] VMCI: dma dg: add MMIO access to registers
> On 4 Feb 2022, at 16.12, Greg KH wrote:
>
> 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
>> Signed-off-by: Jorgen Hansen
>> ---
>> 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(>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(>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(>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(>dev, "Failed to reserve/map IO
>> regions\n");
>> +return error;
>> +}
>> +iobase = pcim_iomap_table(pdev)[0];
>> +}
>>
>> -dev_info(>dev, "Found VMCI PCI device at %#lx, irq %u\n",
>> - (unsigned long)iobase, pdev->irq);
>> +dev_info(>dev, "Found VMCI PCI device at %#lx, %#lx, irq %u\n",
Re: [PATCH v2 2/8] VMCI: dma dg: add MMIO access to registers
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
> Signed-off-by: Jorgen Hansen
> ---
> 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(>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(>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(>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(>dev, "Failed to reserve/map IO
> regions\n");
> + return error;
> + }
> + iobase = pcim_iomap_table(pdev)[0];
> + }
>
> - dev_info(>dev, "Found VMCI PCI device at %#lx, irq %u\n",
> - (unsigned long)iobase, pdev->irq);
> + dev_info(>dev, "Found VMCI PCI device at %#lx, %#lx, irq %u\n",
> + (unsigned long)iobase, (unsigned long)mmio_base, pdev->irq);
Why are you
[PATCH v2 2/8] VMCI: dma dg: add MMIO access to registers
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
Signed-off-by: Jorgen Hansen
---
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(>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(>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(>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(>dev, "Failed to reserve/map IO
regions\n");
+ return error;
+ }
+ iobase = pcim_iomap_table(pdev)[0];
+ }
- dev_info(>dev, "Found VMCI PCI device at %#lx, irq %u\n",
-(unsigned long)iobase, pdev->irq);
+ dev_info(>dev, "Found VMCI PCI device at %#lx, %#lx, irq %u\n",
+(unsigned long)iobase, (unsigned long)mmio_base, pdev->irq);
vmci_dev = devm_kzalloc(>dev, sizeof(*vmci_dev), GFP_KERNEL);
if (!vmci_dev) {
@@ -466,6 +499,7 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
