Thomas Zimmermann
2023-May-22 12:38 UTC
[PATCH v5 09/44] drm: handle HAS_IOPORT dependencies
Hi Am 22.05.23 um 12:50 schrieb Niklas Schnelle:> 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.I think we should consider making cirrus depend on HAS_IOPORT. The driver is only for qemu's cirrus emulation, which IIRC can only be enabled for i586. And it has all been deprecated long ago.> > Co-developed-by: Arnd Bergmann <arnd at kernel.org> > Signed-off-by: Arnd Bergmann <arnd at kernel.org> > Signed-off-by: Niklas Schnelle <schnelle at linux.ibm.com> > --- > drivers/gpu/drm/qxl/Kconfig | 1 + > drivers/gpu/drm/tiny/bochs.c | 17 +++++++++++++++++ > drivers/gpu/drm/tiny/cirrus.c | 2 ++ > 3 files changed, 20 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 d254679a136e..3710339407cc 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>Why not <linux/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); > +#endifWould it be feasible to define inb, inw, outb and outw at the top of bochs.c if no HAS_IOPORT has been set? That would avoid the ifdef branching within the code.> } > } > > @@ -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");Use drm_err() here. Best regards Thomas> + 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 594bc472862f..c65fea049bc7 100644 > --- a/drivers/gpu/drm/tiny/cirrus.c > +++ b/drivers/gpu/drm/tiny/cirrus.c > @@ -508,8 +508,10 @@ 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); > }-- 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) -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_signature Type: application/pgp-signature Size: 840 bytes Desc: OpenPGP digital signature URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20230522/b78a1317/attachment.sig>
On Mon, May 22, 2023, at 14:38, Thomas Zimmermann wrote:> Am 22.05.23 um 12:50 schrieb Niklas Schnelle:>> 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. > > I think we should consider making cirrus depend on HAS_IOPORT. The > driver is only for qemu's cirrus emulation, which IIRC can only be > enabled for i586. And it has all been deprecated long ago.I tried it out in arm64 debvm, and both the kernel and Xorg drivers are detected just fine according to the log. I only get a black screen, which could be the result of a missing VGA BIOS or the missing unblank Port I/O in the driver (I doubt the VGA ports are hooked up on arm64 qemu), but there is a good chance that it's currently working for someone else. Arnd
Hi,> > 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. > > I think we should consider making cirrus depend on HAS_IOPORT. The driver is > only for qemu's cirrus emulation, which IIRC can only be enabled for i586.Agree. cirrus is x86 only (both i386 / x86_64 though). Just require HAS_IOPORT and be done with it.> And it has all been deprecated long ago.The fact that cirrus used to be the qemu default for many years is pretty much the only reason it is still somewhat relevant today ... take care, Gerd