| Message ID | 1429731182-6974-1-git-send-email-mcgrof@do-not-panic.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Luis, Sorry for the late reply. Thank you for the patch! See my comments below: On Wed, 2015-04-22 at 12:33 -0700, Luis R. Rodriguez wrote: > From: "Luis R. Rodriguez" <mcgrof@suse.com> > > We are burrying direct access to MTRR code support on > x86 in order to take advantage of PAT. In the future we > also want to make the default behaviour of ioremap_nocache() > to use strong UC, use of mtrr_add() on those systems > would make write-combining void. > > In order to help both enable us to later make strong > UC default and in order to phase out direct MTRR access > code port the driver over to arch_phys_wc_add() and > annotate that the device driver requires systems to > boot with PAT disabled, with the nopat kernel parameter. > > This is a worthy comprmise given that the hardware is > really rare these days, I'm OK with the compromise solution. It makes sense. > and perhaps only some lost souls > in some third world country are expected to be using this > feature of the device driver. > > Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> > Cc: Andy Lutomirski <luto@amacapital.net> > Cc: Andy Walls <awalls@md.metrocast.net> > Cc: Suresh Siddha <sbsiddha@gmail.com> > Cc: Ingo Molnar <mingo@elte.hu> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Juergen Gross <jgross@suse.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Dave Airlie <airlied@redhat.com> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Antonino Daplas <adaplas@gmail.com> > Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> > Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Stefan Bader <stefan.bader@canonical.com> > Cc: Ville Syrjälä <syrjala@sci.fi> > Cc: Mel Gorman <mgorman@suse.de> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Borislav Petkov <bp@suse.de> > Cc: Davidlohr Bueso <dbueso@suse.de> > Cc: konrad.wilk@oracle.com > Cc: ville.syrjala@linux.intel.com > Cc: david.vrabel@citrix.com > Cc: jbeulich@suse.com > Cc: toshi.kani@hp.com > Cc: Roger Pau Monné <roger.pau@citrix.com> > Cc: linux-fbdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: ivtv-devel@ivtvdriver.org > Cc: linux-media@vger.kernel.org > Cc: xen-devel@lists.xensource.com > Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> > --- > drivers/media/pci/ivtv/Kconfig | 3 +++ > drivers/media/pci/ivtv/ivtvfb.c | 59 +++++++++++++++++------------------------ > 2 files changed, 27 insertions(+), 35 deletions(-) > > diff --git a/drivers/media/pci/ivtv/Kconfig b/drivers/media/pci/ivtv/Kconfig > index dd6ee57e..b2a7f88 100644 > --- a/drivers/media/pci/ivtv/Kconfig > +++ b/drivers/media/pci/ivtv/Kconfig > @@ -57,5 +57,8 @@ config VIDEO_FB_IVTV > This is used in the Hauppauge PVR-350 card. There is a driver > homepage at <http://www.ivtvdriver.org>. > > + If you have this hardware you will need to boot with PAT disabled > + on your x86 systems, use the nopat kernel parameter. > + > To compile this driver as a module, choose M here: the > module will be called ivtvfb. > diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c > index 9ff1230..552408b 100644 > --- a/drivers/media/pci/ivtv/ivtvfb.c > +++ b/drivers/media/pci/ivtv/ivtvfb.c > @@ -44,8 +44,8 @@ > #include <linux/ivtvfb.h> > #include <linux/slab.h> > > -#ifdef CONFIG_MTRR > -#include <asm/mtrr.h> > +#ifdef CONFIG_X86_64 > +#include <asm/pat.h> > #endif > > #include "ivtv-driver.h" > @@ -155,12 +155,11 @@ struct osd_info { > /* Buffer size */ > u32 video_buffer_size; > > -#ifdef CONFIG_MTRR > /* video_base rounded down as required by hardware MTRRs */ > unsigned long fb_start_aligned_physaddr; > /* video_base rounded up as required by hardware MTRRs */ > unsigned long fb_end_aligned_physaddr; > -#endif > + int wc_cookie; > > /* Store the buffer offset */ > int set_osd_coords_x; > @@ -1099,6 +1098,8 @@ static int ivtvfb_init_vidmode(struct ivtv *itv) > static int ivtvfb_init_io(struct ivtv *itv) > { > struct osd_info *oi = itv->osd_info; > + /* Find the largest power of two that maps the whole buffer */ > + int size_shift = 31; > > mutex_lock(&itv->serialize_lock); > if (ivtv_init_on_first_open(itv)) { > @@ -1120,6 +1121,7 @@ static int ivtvfb_init_io(struct ivtv *itv) > oi->video_buffer_size = 1704960; > > oi->video_pbase = itv->base_addr + IVTV_DECODER_OFFSET + oi->video_rbase; > + /* XXX: split this for PAT */ Please remove this comment. It is prescriptive of a particular solution, and probably not the one I'm going to implement. The ivtv main driver alreay splits the encoder, decoder, and register regions into 3 mappings. The final solution will set the whole 8 MB decoder region mapping to WC, and then fix up all calls in the ivtvfb and ivtv drivers where writes to the decoder memory with WC enabled could be a problem. Also many other places in the driver need audit in a conversion to work with PAT, so no need to call out this one location with a comment. > oi->video_vbase = itv->dec_mem + oi->video_rbase; > > if (!oi->video_vbase) { > @@ -1132,29 +1134,16 @@ static int ivtvfb_init_io(struct ivtv *itv) > oi->video_pbase, oi->video_vbase, > oi->video_buffer_size / 1024); > > -#ifdef CONFIG_MTRR > - { > - /* Find the largest power of two that maps the whole buffer */ > - int size_shift = 31; > - > - while (!(oi->video_buffer_size & (1 << size_shift))) { > - size_shift--; > - } > - size_shift++; > - oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1); > - oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size; > - oi->fb_end_aligned_physaddr += (1 << size_shift) - 1; > - oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1); > - if (mtrr_add(oi->fb_start_aligned_physaddr, > - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr, > - MTRR_TYPE_WRCOMB, 1) < 0) { > - IVTVFB_INFO("disabled mttr\n"); > - oi->fb_start_aligned_physaddr = 0; > - oi->fb_end_aligned_physaddr = 0; > - } > - } > -#endif > - > + while (!(oi->video_buffer_size & (1 << size_shift))) > + size_shift--; > + size_shift++; > + oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1); > + oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size; > + oi->fb_end_aligned_physaddr += (1 << size_shift) - 1; > + oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1); > + oi->wc_cookie = arch_phys_wc_add(oi->fb_start_aligned_physaddr, > + oi->fb_end_aligned_physaddr - > + oi->fb_start_aligned_physaddr); > /* Blank the entire osd. */ > memset_io(oi->video_vbase, 0, oi->video_buffer_size); > > @@ -1172,14 +1161,7 @@ static void ivtvfb_release_buffers (struct ivtv *itv) > > /* Release pseudo palette */ > kfree(oi->ivtvfb_info.pseudo_palette); > - > -#ifdef CONFIG_MTRR > - if (oi->fb_end_aligned_physaddr) { > - mtrr_del(-1, oi->fb_start_aligned_physaddr, > - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr); > - } > -#endif > - > + arch_phys_wc_del(oi->wc_cookie); > kfree(oi); > itv->osd_info = NULL; > } > @@ -1190,6 +1172,13 @@ static int ivtvfb_init_card(struct ivtv *itv) > { > int rc; > > +#ifdef CONFIG_X86_64 > + if (WARN(pat_enabled, This check might be better placed in ivtvfb_init(). This check is going to have the same result for every PVR-350 card in the system that is found by ivtvfb. > + "ivtv needs PAT disabled, boot with nopat kernel parameter\n")) { This needs to read "ivtvfb needs [...]" to avoid user confusion with the main ivtv driver module. This change is the only one I really care about. Then I can give my Ack. Regards, Andy > + return EINVAL; > + } > +#endif > + > if (itv->osd_info) { > IVTVFB_ERR("Card %d already initialised\n", ivtvfb_card_id); > return -EBUSY; -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Apr 25, 2015 at 07:12:05AM -0400, Andy Walls wrote: > Hi Luis, > > Sorry for the late reply. > > Thank you for the patch! See my comments below: > > On Wed, 2015-04-22 at 12:33 -0700, Luis R. Rodriguez wrote: > > From: "Luis R. Rodriguez" <mcgrof@suse.com> > > > > We are burrying direct access to MTRR code support on > > x86 in order to take advantage of PAT. In the future we > > also want to make the default behaviour of ioremap_nocache() > > to use strong UC, use of mtrr_add() on those systems > > would make write-combining void. > > > > In order to help both enable us to later make strong > > UC default and in order to phase out direct MTRR access > > code port the driver over to arch_phys_wc_add() and > > annotate that the device driver requires systems to > > boot with PAT disabled, with the nopat kernel parameter. > > > > This is a worthy comprmise given that the hardware is > > really rare these days, > > I'm OK with the compromise solution. It makes sense. OK great! > > diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c > > index 9ff1230..552408b 100644 > > --- a/drivers/media/pci/ivtv/ivtvfb.c > > +++ b/drivers/media/pci/ivtv/ivtvfb.c > > @@ -1120,6 +1121,7 @@ static int ivtvfb_init_io(struct ivtv *itv) > > oi->video_buffer_size = 1704960; > > > > oi->video_pbase = itv->base_addr + IVTV_DECODER_OFFSET + oi->video_rbase; > > + /* XXX: split this for PAT */ > > Please remove this comment. Done. > > @@ -1190,6 +1172,13 @@ static int ivtvfb_init_card(struct ivtv *itv) > > { > > int rc; > > > > +#ifdef CONFIG_X86_64 > > + if (WARN(pat_enabled, > > This check might be better placed in ivtvfb_init(). This check is going > to have the same result for every PVR-350 card in the system that is > found by ivtvfb. OK moved! > > + "ivtv needs PAT disabled, boot with nopat kernel parameter\n")) { > > This needs to read "ivtvfb needs [...]" to avoid user confusion with the > main ivtv driver module. OK! > This change is the only one I really care about. Then I can give my > Ack. OK! Luis -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/pci/ivtv/Kconfig b/drivers/media/pci/ivtv/Kconfig index dd6ee57e..b2a7f88 100644 --- a/drivers/media/pci/ivtv/Kconfig +++ b/drivers/media/pci/ivtv/Kconfig @@ -57,5 +57,8 @@ config VIDEO_FB_IVTV This is used in the Hauppauge PVR-350 card. There is a driver homepage at <http://www.ivtvdriver.org>. + If you have this hardware you will need to boot with PAT disabled + on your x86 systems, use the nopat kernel parameter. + To compile this driver as a module, choose M here: the module will be called ivtvfb. diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c index 9ff1230..552408b 100644 --- a/drivers/media/pci/ivtv/ivtvfb.c +++ b/drivers/media/pci/ivtv/ivtvfb.c @@ -44,8 +44,8 @@ #include <linux/ivtvfb.h> #include <linux/slab.h> -#ifdef CONFIG_MTRR -#include <asm/mtrr.h> +#ifdef CONFIG_X86_64 +#include <asm/pat.h> #endif #include "ivtv-driver.h" @@ -155,12 +155,11 @@ struct osd_info { /* Buffer size */ u32 video_buffer_size; -#ifdef CONFIG_MTRR /* video_base rounded down as required by hardware MTRRs */ unsigned long fb_start_aligned_physaddr; /* video_base rounded up as required by hardware MTRRs */ unsigned long fb_end_aligned_physaddr; -#endif + int wc_cookie; /* Store the buffer offset */ int set_osd_coords_x; @@ -1099,6 +1098,8 @@ static int ivtvfb_init_vidmode(struct ivtv *itv) static int ivtvfb_init_io(struct ivtv *itv) { struct osd_info *oi = itv->osd_info; + /* Find the largest power of two that maps the whole buffer */ + int size_shift = 31; mutex_lock(&itv->serialize_lock); if (ivtv_init_on_first_open(itv)) { @@ -1120,6 +1121,7 @@ static int ivtvfb_init_io(struct ivtv *itv) oi->video_buffer_size = 1704960; oi->video_pbase = itv->base_addr + IVTV_DECODER_OFFSET + oi->video_rbase; + /* XXX: split this for PAT */ oi->video_vbase = itv->dec_mem + oi->video_rbase; if (!oi->video_vbase) { @@ -1132,29 +1134,16 @@ static int ivtvfb_init_io(struct ivtv *itv) oi->video_pbase, oi->video_vbase, oi->video_buffer_size / 1024); -#ifdef CONFIG_MTRR - { - /* Find the largest power of two that maps the whole buffer */ - int size_shift = 31; - - while (!(oi->video_buffer_size & (1 << size_shift))) { - size_shift--; - } - size_shift++; - oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1); - oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size; - oi->fb_end_aligned_physaddr += (1 << size_shift) - 1; - oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1); - if (mtrr_add(oi->fb_start_aligned_physaddr, - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr, - MTRR_TYPE_WRCOMB, 1) < 0) { - IVTVFB_INFO("disabled mttr\n"); - oi->fb_start_aligned_physaddr = 0; - oi->fb_end_aligned_physaddr = 0; - } - } -#endif - + while (!(oi->video_buffer_size & (1 << size_shift))) + size_shift--; + size_shift++; + oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1); + oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size; + oi->fb_end_aligned_physaddr += (1 << size_shift) - 1; + oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1); + oi->wc_cookie = arch_phys_wc_add(oi->fb_start_aligned_physaddr, + oi->fb_end_aligned_physaddr - + oi->fb_start_aligned_physaddr); /* Blank the entire osd. */ memset_io(oi->video_vbase, 0, oi->video_buffer_size); @@ -1172,14 +1161,7 @@ static void ivtvfb_release_buffers (struct ivtv *itv) /* Release pseudo palette */ kfree(oi->ivtvfb_info.pseudo_palette); - -#ifdef CONFIG_MTRR - if (oi->fb_end_aligned_physaddr) { - mtrr_del(-1, oi->fb_start_aligned_physaddr, - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr); - } -#endif - + arch_phys_wc_del(oi->wc_cookie); kfree(oi); itv->osd_info = NULL; } @@ -1190,6 +1172,13 @@ static int ivtvfb_init_card(struct ivtv *itv) { int rc; +#ifdef CONFIG_X86_64 + if (WARN(pat_enabled, + "ivtv needs PAT disabled, boot with nopat kernel parameter\n")) { + return EINVAL; + } +#endif + if (itv->osd_info) { IVTVFB_ERR("Card %d already initialised\n", ivtvfb_card_id); return -EBUSY;