diff mbox series

[v3,07/38] drm: handle HAS_IOPORT dependencies

Message ID 20230314121216.413434-8-schnelle@linux.ibm.com
State New
Headers
Series Kconfig: Introduce HAS_IOPORT config option |

Commit Message

Niklas Schnelle March 14, 2023, 12:11 p.m. UTC 
  In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
not being declared. We thus need to add HAS_IOPORT as dependency for
those drivers using them. In the bochs driver there is optional MMIO
support detected at runtime, warn if this isn't taken when
HAS_IOPORT is not defined.

There is also a direct and hard coded use in cirrus.c which according to
the comment is only necessary during resume.  Let's just skip this as
for example s390 which doesn't have I/O port support also doesen't
support suspend/resume.

Co-developed-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
 drivers/gpu/drm/qxl/Kconfig   |  1 +
 drivers/gpu/drm/tiny/bochs.c  | 19 +++++++++++++++++++
 drivers/gpu/drm/tiny/cirrus.c |  2 ++
 3 files changed, 22 insertions(+)

Comments

Jani Nikula March 15, 2023, 11:54 a.m. UTC | #1 
On Tue, 14 Mar 2023, Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> not being declared. We thus need to add HAS_IOPORT as dependency for
> those drivers using them. In the bochs driver there is optional MMIO
> support detected at runtime, warn if this isn't taken when
> HAS_IOPORT is not defined.

Not that I care a whole lot, but there should really only be one warning
or even failure to probe at bochs_hw_init() for !bochs->mmio &&
!IS_ENABLED(CONFIG_HAS_IOPORT), not warnings all over the place.

Moreover, the config macro is CONFIG_HAS_IOPORT instead of HAS_IOPORT
that you check for below.

BR,
Jani.

> There is also a direct and hard coded use in cirrus.c which according to
> the comment is only necessary during resume.  Let's just skip this as
> for example s390 which doesn't have I/O port support also doesen't
> support suspend/resume.
>
> Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> ---
>  drivers/gpu/drm/qxl/Kconfig   |  1 +
>  drivers/gpu/drm/tiny/bochs.c  | 19 +++++++++++++++++++
>  drivers/gpu/drm/tiny/cirrus.c |  2 ++
>  3 files changed, 22 insertions(+)
>
> diff --git a/drivers/gpu/drm/qxl/Kconfig b/drivers/gpu/drm/qxl/Kconfig
> index ca3f51c2a8fe..d0e0d440c8d9 100644
> --- a/drivers/gpu/drm/qxl/Kconfig
> +++ b/drivers/gpu/drm/qxl/Kconfig
> @@ -2,6 +2,7 @@
>  config DRM_QXL
>  	tristate "QXL virtual GPU"
>  	depends on DRM && PCI && MMU
> +	depends on HAS_IOPORT
>  	select DRM_KMS_HELPER
>  	select DRM_TTM
>  	select DRM_TTM_HELPER
> diff --git a/drivers/gpu/drm/tiny/bochs.c b/drivers/gpu/drm/tiny/bochs.c
> index 024346054c70..da4a5d53b003 100644
> --- a/drivers/gpu/drm/tiny/bochs.c
> +++ b/drivers/gpu/drm/tiny/bochs.c
> @@ -2,6 +2,7 @@
>  
>  #include <linux/module.h>
>  #include <linux/pci.h>
> +#include <asm/bug.h>
>  
>  #include <drm/drm_aperture.h>
>  #include <drm/drm_atomic_helper.h>
> @@ -105,7 +106,11 @@ static void bochs_vga_writeb(struct bochs_device *bochs, u16 ioport, u8 val)
>  
>  		writeb(val, bochs->mmio + offset);
>  	} else {
> +#ifdef HAS_IOPORT
>  		outb(val, ioport);
> +#else
> +		WARN_ONCE(1, "Non-MMIO bochs device needs HAS_IOPORT");
> +#endif
>  	}
>  }
>  
> @@ -119,7 +124,12 @@ static u8 bochs_vga_readb(struct bochs_device *bochs, u16 ioport)
>  
>  		return readb(bochs->mmio + offset);
>  	} else {
> +#ifdef HAS_IOPORT
>  		return inb(ioport);
> +#else
> +		WARN_ONCE(1, "Non-MMIO bochs device needs HAS_IOPORT");
> +		return 0xff;
> +#endif
>  	}
>  }
>  
> @@ -132,8 +142,13 @@ static u16 bochs_dispi_read(struct bochs_device *bochs, u16 reg)
>  
>  		ret = readw(bochs->mmio + offset);
>  	} else {
> +#ifdef HAS_IOPORT
>  		outw(reg, VBE_DISPI_IOPORT_INDEX);
>  		ret = inw(VBE_DISPI_IOPORT_DATA);
> +#else
> +		WARN_ONCE(1, "Non-MMIO bochs device needs HAS_IOPORT");
> +		ret = 0xffff;
> +#endif
>  	}
>  	return ret;
>  }
> @@ -145,8 +160,12 @@ static void bochs_dispi_write(struct bochs_device *bochs, u16 reg, u16 val)
>  
>  		writew(val, bochs->mmio + offset);
>  	} else {
> +#ifdef HAS_IOPORT
>  		outw(reg, VBE_DISPI_IOPORT_INDEX);
>  		outw(val, VBE_DISPI_IOPORT_DATA);
> +#else
> +		WARN_ONCE(1, "Non-MMIO bochs device needs HAS_IOPORT");
> +#endif
>  	}
>  }
>  
> diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
> index accfa52e78c5..9da89732c5ac 100644
> --- a/drivers/gpu/drm/tiny/cirrus.c
> +++ b/drivers/gpu/drm/tiny/cirrus.c
> @@ -308,8 +308,10 @@ static int cirrus_mode_set(struct cirrus_device *cirrus,
>  
>  	cirrus_set_start_address(cirrus, 0);
>  
> +#ifdef CONFIG_HAS_IOPORT
>  	/* Unblank (needed on S3 resume, vgabios doesn't do it then) */
>  	outb(0x20, 0x3c0);
> +#endif
>  
>  	drm_dev_exit(idx);
>  	return 0;
Niklas Schnelle March 23, 2023, 3:05 p.m. UTC | #2 
On Wed, 2023-03-15 at 13:54 +0200, Jani Nikula wrote:
> On Tue, 14 Mar 2023, Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > not being declared. We thus need to add HAS_IOPORT as dependency for
> > those drivers using them. In the bochs driver there is optional MMIO
> > support detected at runtime, warn if this isn't taken when
> > HAS_IOPORT is not defined.
> 
> Not that I care a whole lot, but there should really only be one warning
> or even failure to probe at bochs_hw_init() for !bochs->mmio &&
> !IS_ENABLED(CONFIG_HAS_IOPORT), not warnings all over the place.
> 
> Moreover, the config macro is CONFIG_HAS_IOPORT instead of HAS_IOPORT
> that you check for below.
> 
> BR,
> Jani.
> 

Good Find! Yes the #ifdefs need CONFIG_HAS_IOPORT I even had it
correctly for cirrus in the same patch. For v4 I remove the separate
warnings and instead went with the below:

@@ -229,6 +242,10 @@ static int bochs_hw_init(struct drm_device *dev)
                        return -ENOMEM;
                }
        } else {
+               if (!IS_ENABLED(CONFIG_HAS_IOPORT)) {
+                       DRM_ERROR("I/O ports are not supported\n");
+                       return -EIO;
+               }
                ioaddr = VBE_DISPI_IOPORT_INDEX;
                iosize = 2;
                if (!request_region(ioaddr, iosize, "bochs-drm")) {


Thanks,
Niklas
diff mbox series

Patch

diff --git a/drivers/gpu/drm/qxl/Kconfig b/drivers/gpu/drm/qxl/Kconfig
index ca3f51c2a8fe..d0e0d440c8d9 100644
--- a/drivers/gpu/drm/qxl/Kconfig
+++ b/drivers/gpu/drm/qxl/Kconfig
@@ -2,6 +2,7 @@ 
 config DRM_QXL
 	tristate "QXL virtual GPU"
 	depends on DRM && PCI && MMU
+	depends on HAS_IOPORT
 	select DRM_KMS_HELPER
 	select DRM_TTM
 	select DRM_TTM_HELPER
diff --git a/drivers/gpu/drm/tiny/bochs.c b/drivers/gpu/drm/tiny/bochs.c
index 024346054c70..da4a5d53b003 100644
--- a/drivers/gpu/drm/tiny/bochs.c
+++ b/drivers/gpu/drm/tiny/bochs.c
@@ -2,6 +2,7 @@ 
 
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <asm/bug.h>
 
 #include <drm/drm_aperture.h>
 #include <drm/drm_atomic_helper.h>
@@ -105,7 +106,11 @@  static void bochs_vga_writeb(struct bochs_device *bochs, u16 ioport, u8 val)
 
 		writeb(val, bochs->mmio + offset);
 	} else {
+#ifdef HAS_IOPORT
 		outb(val, ioport);
+#else
+		WARN_ONCE(1, "Non-MMIO bochs device needs HAS_IOPORT");
+#endif
 	}
 }
 
@@ -119,7 +124,12 @@  static u8 bochs_vga_readb(struct bochs_device *bochs, u16 ioport)
 
 		return readb(bochs->mmio + offset);
 	} else {
+#ifdef HAS_IOPORT
 		return inb(ioport);
+#else
+		WARN_ONCE(1, "Non-MMIO bochs device needs HAS_IOPORT");
+		return 0xff;
+#endif
 	}
 }
 
@@ -132,8 +142,13 @@  static u16 bochs_dispi_read(struct bochs_device *bochs, u16 reg)
 
 		ret = readw(bochs->mmio + offset);
 	} else {
+#ifdef HAS_IOPORT
 		outw(reg, VBE_DISPI_IOPORT_INDEX);
 		ret = inw(VBE_DISPI_IOPORT_DATA);
+#else
+		WARN_ONCE(1, "Non-MMIO bochs device needs HAS_IOPORT");
+		ret = 0xffff;
+#endif
 	}
 	return ret;
 }
@@ -145,8 +160,12 @@  static void bochs_dispi_write(struct bochs_device *bochs, u16 reg, u16 val)
 
 		writew(val, bochs->mmio + offset);
 	} else {
+#ifdef HAS_IOPORT
 		outw(reg, VBE_DISPI_IOPORT_INDEX);
 		outw(val, VBE_DISPI_IOPORT_DATA);
+#else
+		WARN_ONCE(1, "Non-MMIO bochs device needs HAS_IOPORT");
+#endif
 	}
 }
 
diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
index accfa52e78c5..9da89732c5ac 100644
--- a/drivers/gpu/drm/tiny/cirrus.c
+++ b/drivers/gpu/drm/tiny/cirrus.c
@@ -308,8 +308,10 @@  static int cirrus_mode_set(struct cirrus_device *cirrus,
 
 	cirrus_set_start_address(cirrus, 0);
 
+#ifdef CONFIG_HAS_IOPORT
 	/* Unblank (needed on S3 resume, vgabios doesn't do it then) */
 	outb(0x20, 0x3c0);
+#endif
 
 	drm_dev_exit(idx);
 	return 0;