[PATCH RESEND V5 1/3] misc/pvpanic: return 0 for empty body register function

[PATCH RESEND V5 1/3] misc/pvpanic: return 0 for empty body register function

[Peng Hao]

Return 0 for empty body register function normally.

Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
---
v4 --> v5 : resolve kbuild issue: handle all typo "drvier/driver" 
            in funtion name. 

v3 --> v4 : use pcim* function instead of pci* function.
            handle typo "drvier/driver" in funtion name. 

v2 --> v3 : resolve kbuild issue : a uninitialized variable in some path.

v2 --> v1 : resolve kbuild issue : arch=sh don't support pci, adjust
            CONFIG_PCI macro. 

v1 : QEMU community requires additional PCI devices to simulate PVPANIC devices
so that some architectures can not occupy precious less than 4G of memory 
space.

 drivers/misc/pvpanic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c
index 3150dc2..f84ed30 100644
--- a/drivers/misc/pvpanic.c
+++ b/drivers/misc/pvpanic.c
@@ -125,7 +125,7 @@ static void pvpanic_unregister_acpi_driver(void)
 #else
 static int pvpanic_register_acpi_driver(void)
 {
-	return -ENODEV;
+	return 0;
 }
 
 static void pvpanic_unregister_acpi_driver(void) {}
-- 
1.8.3.1

[PATCH RESEND V5 2/3] misc/pvpanic : add pci interface for pvpanic

[Peng Hao]

Support pvpanic as a pci device in guest kernel.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
[Use pcim_* API. - Andy]
Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
---
 drivers/misc/pvpanic.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 70 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c
index f84ed30..c30bf62 100644
--- a/drivers/misc/pvpanic.c
+++ b/drivers/misc/pvpanic.c
@@ -13,9 +13,12 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/types.h>
 
+#define PCI_VENDOR_ID_REDHAT             0x1b36
+#define PCI_DEVICE_ID_REDHAT_PVPANIC     0x0101
 static void __iomem *base;
 
 #define PVPANIC_PANICKED        (1 << 0)
@@ -172,12 +175,76 @@ static int pvpanic_mmio_remove(struct platform_device *pdev)
 	.remove = pvpanic_mmio_remove,
 };
 
+#ifdef CONFIG_PCI
+static const struct pci_device_id pvpanic_pci_id_tbl[]  = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_PVPANIC),},
+	{}
+};
+
+static int pvpanic_pci_probe(struct pci_dev *pdev,
+			     const struct pci_device_id *ent)
+{
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret < 0)
+		return ret;
+
+	ret = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
+	if (ret)
+		return ret;
+
+	base = pcim_iomap_table(pdev)[0];
+
+	atomic_notifier_chain_register(&panic_notifier_list,
+				       &pvpanic_panic_nb);
+	return 0;
+}
+
+static void pvpanic_pci_remove(struct pci_dev *pdev)
+{
+	atomic_notifier_chain_unregister(&panic_notifier_list,
+					 &pvpanic_panic_nb);
+}
+
+static struct pci_driver pvpanic_pci_driver = {
+	.name =         "pvpanic-pci",
+	.id_table =     pvpanic_pci_id_tbl,
+	.probe =        pvpanic_pci_probe,
+	.remove =       pvpanic_pci_remove,
+};
+
+static int pvpanic_register_pci_driver(void)
+{
+	return pci_register_driver(&pvpanic_pci_driver);
+}
+
+static void pvpanic_unregister_pci_driver(void)
+{
+	pci_unregister_driver(&pvpanic_pci_driver);
+}
+#else
+static int pvpanic_register_pci_driver(void)
+{
+	return 0;
+}
+
+static void pvpanic_unregister_pci_driver(void) {}
+#endif
+
 static int __init pvpanic_mmio_init(void)
 {
+	int r1, r2;
+
 	if (acpi_disabled)
-		return platform_driver_register(&pvpanic_mmio_driver);
+		r1 = platform_driver_register(&pvpanic_mmio_driver);
+	else
+		r1 = pvpanic_register_acpi_driver();
+	r2 = pvpanic_register_pci_driver();
+	if (r1 && r2) /* all drivers register failed */
+		return 1;
 	else
-		return pvpanic_register_acpi_driver();
+		return 0;
 }
 
 static void __exit pvpanic_mmio_exit(void)
@@ -186,6 +253,7 @@ static void __exit pvpanic_mmio_exit(void)
 		platform_driver_unregister(&pvpanic_mmio_driver);
 	else
 		pvpanic_unregister_acpi_driver();
+	pvpanic_unregister_pci_driver();
 }
 
 module_init(pvpanic_mmio_init);
-- 
1.8.3.1

[PATCH RESEND V5 3/3] misc/pvpanic : add pci dependency in Kconfig

[Peng Hao]

Add PCI dependency for pvpanic in Kconfig.

Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
---
 drivers/misc/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index f417b06..5ff8ca4 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -515,7 +515,7 @@ config MISC_RTSX
 
 config PVPANIC
 	tristate "pvpanic device support"
-	depends on HAS_IOMEM && (ACPI || OF)
+	depends on HAS_IOMEM && (ACPI || OF || PCI)
 	help
 	  This driver provides support for the pvpanic device.  pvpanic is
 	  a paravirtualized device provided by QEMU; it lets a virtual machine
-- 
1.8.3.1

Re: [PATCH RESEND V5 2/3] misc/pvpanic : add pci interface for pvpanic

[Andy Shevchenko]

On Thu, Dec 20, 2018 at 6:57 AM Peng Hao <peng.hao2@zte.com.cn> wrote:
>
> Support pvpanic as a pci device in guest kernel.
>

After my vacation followed by holidays I hardly remember what I suggested.
Looking to this code I would recommend to split it in a way how it's
done for ChipIdea USB driver, for example.
(drivers/usb/chipidea if I'm not mistaken)

> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> [Use pcim_* API. - Andy]
> Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
> ---
>  drivers/misc/pvpanic.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 70 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c
> index f84ed30..c30bf62 100644
> --- a/drivers/misc/pvpanic.c
> +++ b/drivers/misc/pvpanic.c
> @@ -13,9 +13,12 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_address.h>
> +#include <linux/pci.h>
>  #include <linux/platform_device.h>
>  #include <linux/types.h>
>
> +#define PCI_VENDOR_ID_REDHAT             0x1b36
> +#define PCI_DEVICE_ID_REDHAT_PVPANIC     0x0101
>  static void __iomem *base;
>
>  #define PVPANIC_PANICKED        (1 << 0)
> @@ -172,12 +175,76 @@ static int pvpanic_mmio_remove(struct platform_device *pdev)
>         .remove = pvpanic_mmio_remove,
>  };
>
> +#ifdef CONFIG_PCI
> +static const struct pci_device_id pvpanic_pci_id_tbl[]  = {
> +       { PCI_DEVICE(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_PVPANIC),},
> +       {}
> +};
> +
> +static int pvpanic_pci_probe(struct pci_dev *pdev,
> +                            const struct pci_device_id *ent)
> +{
> +       int ret;
> +
> +       ret = pcim_enable_device(pdev);
> +       if (ret < 0)
> +               return ret;
> +
> +       ret = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
> +       if (ret)
> +               return ret;
> +
> +       base = pcim_iomap_table(pdev)[0];
> +
> +       atomic_notifier_chain_register(&panic_notifier_list,
> +                                      &pvpanic_panic_nb);
> +       return 0;
> +}
> +
> +static void pvpanic_pci_remove(struct pci_dev *pdev)
> +{
> +       atomic_notifier_chain_unregister(&panic_notifier_list,
> +                                        &pvpanic_panic_nb);
> +}
> +
> +static struct pci_driver pvpanic_pci_driver = {
> +       .name =         "pvpanic-pci",
> +       .id_table =     pvpanic_pci_id_tbl,
> +       .probe =        pvpanic_pci_probe,
> +       .remove =       pvpanic_pci_remove,
> +};
> +
> +static int pvpanic_register_pci_driver(void)
> +{
> +       return pci_register_driver(&pvpanic_pci_driver);
> +}
> +
> +static void pvpanic_unregister_pci_driver(void)
> +{
> +       pci_unregister_driver(&pvpanic_pci_driver);
> +}
> +#else
> +static int pvpanic_register_pci_driver(void)
> +{
> +       return 0;
> +}
> +
> +static void pvpanic_unregister_pci_driver(void) {}
> +#endif
> +
>  static int __init pvpanic_mmio_init(void)
>  {
> +       int r1, r2;
> +
>         if (acpi_disabled)
> -               return platform_driver_register(&pvpanic_mmio_driver);
> +               r1 = platform_driver_register(&pvpanic_mmio_driver);
> +       else
> +               r1 = pvpanic_register_acpi_driver();
> +       r2 = pvpanic_register_pci_driver();
> +       if (r1 && r2) /* all drivers register failed */
> +               return 1;
>         else
> -               return pvpanic_register_acpi_driver();
> +               return 0;
>  }
>
>  static void __exit pvpanic_mmio_exit(void)
> @@ -186,6 +253,7 @@ static void __exit pvpanic_mmio_exit(void)
>                 platform_driver_unregister(&pvpanic_mmio_driver);
>         else
>                 pvpanic_unregister_acpi_driver();
> +       pvpanic_unregister_pci_driver();
>  }
>
>  module_init(pvpanic_mmio_init);
> --
> 1.8.3.1
>


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH RESEND V5 1/3] misc/pvpanic: return 0 for empty body register function

[Greg KH]

On Thu, Dec 20, 2018 at 01:14:46PM +0800, Peng Hao wrote:
> Return 0 for empty body register function normally.
> 
> Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
> ---
> v4 --> v5 : resolve kbuild issue: handle all typo "drvier/driver" 
>             in funtion name. 
> 
> v3 --> v4 : use pcim* function instead of pci* function.
>             handle typo "drvier/driver" in funtion name. 
> 
> v2 --> v3 : resolve kbuild issue : a uninitialized variable in some path.
> 
> v2 --> v1 : resolve kbuild issue : arch=sh don't support pci, adjust
>             CONFIG_PCI macro. 
> 
> v1 : QEMU community requires additional PCI devices to simulate PVPANIC devices
> so that some architectures can not occupy precious less than 4G of memory 
> space.
> 
>  drivers/misc/pvpanic.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c
> index 3150dc2..f84ed30 100644
> --- a/drivers/misc/pvpanic.c
> +++ b/drivers/misc/pvpanic.c
> @@ -125,7 +125,7 @@ static void pvpanic_unregister_acpi_driver(void)
>  #else
>  static int pvpanic_register_acpi_driver(void)
>  {
> -	return -ENODEV;
> +	return 0;

No, you want -ENODEV as this can only happen if acpi is enabled, and you
are on an kernel without acpi.

But, that can not happen, as if CONFIG_ACPI is not set, then
acpi_disabled is always set to 1, and then this can never be called.

So I don't see why this needs to be changed at all.

thanks,

greg k-h