2024-04-04 12:03:22

by Niklas Schnelle

[permalink] [raw]
Subject: [PATCH 1/1] drm: handle HAS_IOPORT dependencies

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 <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
---
Note: This patch does not depend any not-yet-mainline HAS_IOPORT changes
and may be merged via subsystem specific trees at your earliest
convenience.

v5->v6: Added HAS_IOPORT for xe driver which copied some I/O port use from
existing intel drivers.

drivers/gpu/drm/qxl/Kconfig | 1 +
drivers/gpu/drm/tiny/bochs.c | 17 +++++++++++++++++
drivers/gpu/drm/tiny/cirrus.c | 2 ++
drivers/gpu/drm/xe/Kconfig | 2 +-
4 files changed, 21 insertions(+), 1 deletion(-)

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 c23c9f0cf49c..9ac3b455ddce 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 +106,9 @@ static void bochs_vga_writeb(struct bochs_device *bochs, u16 ioport, u8 val)

writeb(val, bochs->mmio + offset);
} else {
+#ifdef CONFIG_HAS_IOPORT
outb(val, ioport);
+#endif
}
}

@@ -119,7 +122,11 @@ static u8 bochs_vga_readb(struct bochs_device *bochs, u16 ioport)

return readb(bochs->mmio + offset);
} else {
+#ifdef CONFIG_HAS_IOPORT
return inb(ioport);
+#else
+ return 0xff;
+#endif
}
}

@@ -132,8 +139,12 @@ static u16 bochs_dispi_read(struct bochs_device *bochs, u16 reg)

ret = readw(bochs->mmio + offset);
} else {
+#ifdef CONFIG_HAS_IOPORT
outw(reg, VBE_DISPI_IOPORT_INDEX);
ret = inw(VBE_DISPI_IOPORT_DATA);
+#else
+ ret = 0xffff;
+#endif
}
return ret;
}
@@ -145,8 +156,10 @@ static void bochs_dispi_write(struct bochs_device *bochs, u16 reg, u16 val)

writew(val, bochs->mmio + offset);
} else {
+#ifdef CONFIG_HAS_IOPORT
outw(reg, VBE_DISPI_IOPORT_INDEX);
outw(val, VBE_DISPI_IOPORT_DATA);
+#endif
}
}

@@ -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")) {
diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
index 4e3a152f897a..716e1480c30f 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 1a556d087e63..519906b8e3de 100644
--- a/drivers/gpu/drm/xe/Kconfig
+++ b/drivers/gpu/drm/xe/Kconfig
@@ -48,7 +48,7 @@ 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
--
2.40.1