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[PATCH v9 3/5] drm: handle HAS_IOPORT dependencies

Niklas Schnelle posted 5 patches 1 month ago
[PATCH v9 3/5] drm: handle HAS_IOPORT dependencies
Posted by Niklas Schnelle 1 month ago 
In a future patch HAS_IOPORT=n will disable inb()/outb() and friends at
compile time. 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: Arnd Bergmann <arnd@kernel.org>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com> # xe
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
 drivers/gpu/drm/gma500/Kconfig |  2 +-
 drivers/gpu/drm/qxl/Kconfig    |  2 +-
 drivers/gpu/drm/tiny/bochs.c   | 19 ++++++++++++++-----
 drivers/gpu/drm/tiny/cirrus.c  |  2 ++
 drivers/gpu/drm/xe/Kconfig     |  2 +-
 5 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/gma500/Kconfig b/drivers/gpu/drm/gma500/Kconfig
index efb4a2dd2f80885cb59c925d09401002278d7d61..23b7c14de5e29238ece939d5822d8a9ffc4675cc 100644
--- a/drivers/gpu/drm/gma500/Kconfig
+++ b/drivers/gpu/drm/gma500/Kconfig
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config DRM_GMA500
 	tristate "Intel GMA500/600/3600/3650 KMS Framebuffer"
-	depends on DRM && PCI && X86 && MMU
+	depends on DRM && PCI && X86 && MMU && HAS_IOPORT
 	select DRM_KMS_HELPER
 	select FB_IOMEM_HELPERS if DRM_FBDEV_EMULATION
 	select I2C
diff --git a/drivers/gpu/drm/qxl/Kconfig b/drivers/gpu/drm/qxl/Kconfig
index ca3f51c2a8fe1a383f8a2479f04b5c0b3fb14e44..17d6927e5e23402786117fd0f99186978956c1c2 100644
--- a/drivers/gpu/drm/qxl/Kconfig
+++ b/drivers/gpu/drm/qxl/Kconfig
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config DRM_QXL
 	tristate "QXL virtual GPU"
-	depends on DRM && PCI && MMU
+	depends on DRM && PCI && MMU && 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 31fc5d839e106ea4d5c8fe42d1bfc3c70291e3fb..e738bb85831667f55c436e21e761435def113b9a 100644
--- a/drivers/gpu/drm/tiny/bochs.c
+++ b/drivers/gpu/drm/tiny/bochs.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <linux/bug.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 
@@ -95,12 +96,17 @@ struct bochs_device {
 
 /* ---------------------------------------------------------------------- */
 
+static __always_inline bool bochs_uses_mmio(struct bochs_device *bochs)
+{
+	return !IS_ENABLED(CONFIG_HAS_IOPORT) || bochs->mmio;
+}
+
 static void bochs_vga_writeb(struct bochs_device *bochs, u16 ioport, u8 val)
 {
 	if (WARN_ON(ioport < 0x3c0 || ioport > 0x3df))
 		return;
 
-	if (bochs->mmio) {
+	if (bochs_uses_mmio(bochs)) {
 		int offset = ioport - 0x3c0 + 0x400;
 
 		writeb(val, bochs->mmio + offset);
@@ -114,7 +120,7 @@ static u8 bochs_vga_readb(struct bochs_device *bochs, u16 ioport)
 	if (WARN_ON(ioport < 0x3c0 || ioport > 0x3df))
 		return 0xff;
 
-	if (bochs->mmio) {
+	if (bochs_uses_mmio(bochs)) {
 		int offset = ioport - 0x3c0 + 0x400;
 
 		return readb(bochs->mmio + offset);
@@ -127,7 +133,7 @@ static u16 bochs_dispi_read(struct bochs_device *bochs, u16 reg)
 {
 	u16 ret = 0;
 
-	if (bochs->mmio) {
+	if (bochs_uses_mmio(bochs)) {
 		int offset = 0x500 + (reg << 1);
 
 		ret = readw(bochs->mmio + offset);
@@ -140,7 +146,7 @@ static u16 bochs_dispi_read(struct bochs_device *bochs, u16 reg)
 
 static void bochs_dispi_write(struct bochs_device *bochs, u16 reg, u16 val)
 {
-	if (bochs->mmio) {
+	if (bochs_uses_mmio(bochs)) {
 		int offset = 0x500 + (reg << 1);
 
 		writew(val, bochs->mmio + offset);
@@ -228,7 +234,7 @@ static int bochs_hw_init(struct drm_device *dev)
 			DRM_ERROR("Cannot map mmio region\n");
 			return -ENOMEM;
 		}
-	} else {
+	} else if (IS_ENABLED(CONFIG_HAS_IOPORT)) {
 		ioaddr = VBE_DISPI_IOPORT_INDEX;
 		iosize = 2;
 		if (!request_region(ioaddr, iosize, "bochs-drm")) {
@@ -236,6 +242,9 @@ static int bochs_hw_init(struct drm_device *dev)
 			return -EBUSY;
 		}
 		bochs->ioports = 1;
+	} else {
+		dev_err(dev->dev, "I/O ports are not supported\n");
+		return -EIO;
 	}
 
 	id = bochs_dispi_read(bochs, VBE_DISPI_INDEX_ID);
diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
index 751326e3d9c374baf72115492aeefff2b73869f0..e31e1df029ab0272c4a1ff0ab3eb026ca679b560 100644
--- a/drivers/gpu/drm/tiny/cirrus.c
+++ b/drivers/gpu/drm/tiny/cirrus.c
@@ -509,8 +509,10 @@ static void cirrus_crtc_helper_atomic_enable(struct drm_crtc *crtc,
 
 	cirrus_mode_set(cirrus, &crtc_state->mode);
 
+#ifdef CONFIG_HAS_IOPORT
 	/* Unblank (needed on S3 resume, vgabios doesn't do it then) */
 	outb(VGA_AR_ENABLE_DISPLAY, VGA_ATT_W);
+#endif
 
 	drm_dev_exit(idx);
 }
diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
index 7bbe46a98ff1f449bc2af30686585a00e9e8af93..116f58774135fc3a9f37d6d72d41340f5c812297 100644
--- a/drivers/gpu/drm/xe/Kconfig
+++ b/drivers/gpu/drm/xe/Kconfig
@@ -49,7 +49,7 @@ config DRM_XE
 
 config DRM_XE_DISPLAY
 	bool "Enable display support"
-	depends on DRM_XE && DRM_XE=m
+	depends on DRM_XE && DRM_XE=m && HAS_IOPORT
 	select FB_IOMEM_HELPERS
 	select I2C
 	select I2C_ALGOBIT

-- 
2.45.2
Re: [PATCH v9 3/5] drm: handle HAS_IOPORT dependencies
Posted by Thomas Zimmermann 1 month ago 

Am 24.10.24 um 19:54 schrieb Niklas Schnelle:
> In a future patch HAS_IOPORT=n will disable inb()/outb() and friends at
> compile time. 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: Arnd Bergmann <arnd@kernel.org>
> Acked-by: Lucas De Marchi <lucas.demarchi@intel.com> # xe
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

> ---
>   drivers/gpu/drm/gma500/Kconfig |  2 +-
>   drivers/gpu/drm/qxl/Kconfig    |  2 +-
>   drivers/gpu/drm/tiny/bochs.c   | 19 ++++++++++++++-----
>   drivers/gpu/drm/tiny/cirrus.c  |  2 ++
>   drivers/gpu/drm/xe/Kconfig     |  2 +-
>   5 files changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/gma500/Kconfig b/drivers/gpu/drm/gma500/Kconfig
> index efb4a2dd2f80885cb59c925d09401002278d7d61..23b7c14de5e29238ece939d5822d8a9ffc4675cc 100644
> --- a/drivers/gpu/drm/gma500/Kconfig
> +++ b/drivers/gpu/drm/gma500/Kconfig
> @@ -1,7 +1,7 @@
>   # SPDX-License-Identifier: GPL-2.0-only
>   config DRM_GMA500
>   	tristate "Intel GMA500/600/3600/3650 KMS Framebuffer"
> -	depends on DRM && PCI && X86 && MMU
> +	depends on DRM && PCI && X86 && MMU && HAS_IOPORT
>   	select DRM_KMS_HELPER
>   	select FB_IOMEM_HELPERS if DRM_FBDEV_EMULATION
>   	select I2C
> diff --git a/drivers/gpu/drm/qxl/Kconfig b/drivers/gpu/drm/qxl/Kconfig
> index ca3f51c2a8fe1a383f8a2479f04b5c0b3fb14e44..17d6927e5e23402786117fd0f99186978956c1c2 100644
> --- a/drivers/gpu/drm/qxl/Kconfig
> +++ b/drivers/gpu/drm/qxl/Kconfig
> @@ -1,7 +1,7 @@
>   # SPDX-License-Identifier: GPL-2.0-only
>   config DRM_QXL
>   	tristate "QXL virtual GPU"
> -	depends on DRM && PCI && MMU
> +	depends on DRM && PCI && MMU && 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 31fc5d839e106ea4d5c8fe42d1bfc3c70291e3fb..e738bb85831667f55c436e21e761435def113b9a 100644
> --- a/drivers/gpu/drm/tiny/bochs.c
> +++ b/drivers/gpu/drm/tiny/bochs.c
> @@ -1,5 +1,6 @@
>   // SPDX-License-Identifier: GPL-2.0-or-later
>   
> +#include <linux/bug.h>
>   #include <linux/module.h>
>   #include <linux/pci.h>
>   
> @@ -95,12 +96,17 @@ struct bochs_device {
>   
>   /* ---------------------------------------------------------------------- */
>   
> +static __always_inline bool bochs_uses_mmio(struct bochs_device *bochs)
> +{
> +	return !IS_ENABLED(CONFIG_HAS_IOPORT) || bochs->mmio;
> +}
> +
>   static void bochs_vga_writeb(struct bochs_device *bochs, u16 ioport, u8 val)
>   {
>   	if (WARN_ON(ioport < 0x3c0 || ioport > 0x3df))
>   		return;
>   
> -	if (bochs->mmio) {
> +	if (bochs_uses_mmio(bochs)) {
>   		int offset = ioport - 0x3c0 + 0x400;
>   
>   		writeb(val, bochs->mmio + offset);
> @@ -114,7 +120,7 @@ static u8 bochs_vga_readb(struct bochs_device *bochs, u16 ioport)
>   	if (WARN_ON(ioport < 0x3c0 || ioport > 0x3df))
>   		return 0xff;
>   
> -	if (bochs->mmio) {
> +	if (bochs_uses_mmio(bochs)) {
>   		int offset = ioport - 0x3c0 + 0x400;
>   
>   		return readb(bochs->mmio + offset);
> @@ -127,7 +133,7 @@ static u16 bochs_dispi_read(struct bochs_device *bochs, u16 reg)
>   {
>   	u16 ret = 0;
>   
> -	if (bochs->mmio) {
> +	if (bochs_uses_mmio(bochs)) {
>   		int offset = 0x500 + (reg << 1);
>   
>   		ret = readw(bochs->mmio + offset);
> @@ -140,7 +146,7 @@ static u16 bochs_dispi_read(struct bochs_device *bochs, u16 reg)
>   
>   static void bochs_dispi_write(struct bochs_device *bochs, u16 reg, u16 val)
>   {
> -	if (bochs->mmio) {
> +	if (bochs_uses_mmio(bochs)) {
>   		int offset = 0x500 + (reg << 1);
>   
>   		writew(val, bochs->mmio + offset);
> @@ -228,7 +234,7 @@ static int bochs_hw_init(struct drm_device *dev)
>   			DRM_ERROR("Cannot map mmio region\n");
>   			return -ENOMEM;
>   		}
> -	} else {
> +	} else if (IS_ENABLED(CONFIG_HAS_IOPORT)) {
>   		ioaddr = VBE_DISPI_IOPORT_INDEX;
>   		iosize = 2;
>   		if (!request_region(ioaddr, iosize, "bochs-drm")) {
> @@ -236,6 +242,9 @@ static int bochs_hw_init(struct drm_device *dev)
>   			return -EBUSY;
>   		}
>   		bochs->ioports = 1;
> +	} else {
> +		dev_err(dev->dev, "I/O ports are not supported\n");
> +		return -EIO;
>   	}
>   
>   	id = bochs_dispi_read(bochs, VBE_DISPI_INDEX_ID);
> diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
> index 751326e3d9c374baf72115492aeefff2b73869f0..e31e1df029ab0272c4a1ff0ab3eb026ca679b560 100644
> --- a/drivers/gpu/drm/tiny/cirrus.c
> +++ b/drivers/gpu/drm/tiny/cirrus.c
> @@ -509,8 +509,10 @@ static void cirrus_crtc_helper_atomic_enable(struct drm_crtc *crtc,
>   
>   	cirrus_mode_set(cirrus, &crtc_state->mode);
>   
> +#ifdef CONFIG_HAS_IOPORT
>   	/* Unblank (needed on S3 resume, vgabios doesn't do it then) */
>   	outb(VGA_AR_ENABLE_DISPLAY, VGA_ATT_W);
> +#endif
>   
>   	drm_dev_exit(idx);
>   }
> diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
> index 7bbe46a98ff1f449bc2af30686585a00e9e8af93..116f58774135fc3a9f37d6d72d41340f5c812297 100644
> --- a/drivers/gpu/drm/xe/Kconfig
> +++ b/drivers/gpu/drm/xe/Kconfig
> @@ -49,7 +49,7 @@ config DRM_XE
>   
>   config DRM_XE_DISPLAY
>   	bool "Enable display support"
> -	depends on DRM_XE && DRM_XE=m
> +	depends on DRM_XE && DRM_XE=m && HAS_IOPORT
>   	select FB_IOMEM_HELPERS
>   	select I2C
>   	select I2C_ALGOBIT
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

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