Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755518AbbFKUYf (ORCPT ); Thu, 11 Jun 2015 16:24:35 -0400 Received: from mail-qg0-f65.google.com ([209.85.192.65]:33311 "EHLO mail-qg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752046AbbFKUYc (ORCPT ); Thu, 11 Jun 2015 16:24:32 -0400 From: "Luis R. Rodriguez" To: bp@suse.de Cc: mchehab@osg.samsung.com, tomi.valkeinen@ti.com, bhelgaas@google.com, luto@amacapital.net, linux-media@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, "Luis R. Rodriguez" , Andy Walls , Doug Ledford , Suresh Siddha , Ingo Molnar , Thomas Gleixner , Juergen Gross , Daniel Vetter , Dave Airlie , Antonino Daplas , Jean-Christophe Plagniol-Villard , Dave Hansen , Arnd Bergmann , "Michael S. Tsirkin" , Stefan Bader , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , konrad.wilk@oracle.com, toshi.kani@hp.com, =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= , xen-devel@lists.xensource.com Subject: [PATCH v7 1/3] ivtv: use arch_phys_wc_add() and require PAT disabled Date: Thu, 11 Jun 2015 13:19:52 -0700 Message-Id: <1434053994-2196-2-git-send-email-mcgrof@do-not-panic.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1434053994-2196-1-git-send-email-mcgrof@do-not-panic.com> References: <1434053994-2196-1-git-send-email-mcgrof@do-not-panic.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6394 Lines: 182 From: "Luis R. Rodriguez" 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 compromise given that the hardware is really rare these days, and perhaps only some lost souls in some third world country are expected to be using this feature of the device driver. Acked-by: Andy Walls Acked-by: Mauro Carvalho Chehab Cc: Andy Walls Cc: Doug Ledford Cc: Mauro Carvalho Chehab Cc: Andy Lutomirski Cc: Suresh Siddha Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Juergen Gross Cc: Daniel Vetter Cc: Dave Airlie Cc: Bjorn Helgaas Cc: Antonino Daplas Cc: Jean-Christophe Plagniol-Villard Cc: Tomi Valkeinen Cc: Dave Hansen Cc: Arnd Bergmann Cc: Michael S. Tsirkin Cc: Stefan Bader Cc: Ville Syrjälä Cc: Borislav Petkov Cc: konrad.wilk@oracle.com Cc: toshi.kani@hp.com Cc: Roger Pau Monné Cc: linux-media@vger.kernel.org Cc: xen-devel@lists.xensource.com Cc: linux-kernel@vger.kernel.org Signed-off-by: Luis R. Rodriguez --- drivers/media/pci/ivtv/Kconfig | 3 +++ drivers/media/pci/ivtv/ivtvfb.c | 58 ++++++++++++++++------------------------- 2 files changed, 26 insertions(+), 35 deletions(-) diff --git a/drivers/media/pci/ivtv/Kconfig b/drivers/media/pci/ivtv/Kconfig index dd6ee57e..6e5867c 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 . + In order to use this module, you will need to boot with PAT disabled + on x86 systems, using 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..4cb365d 100644 --- a/drivers/media/pci/ivtv/ivtvfb.c +++ b/drivers/media/pci/ivtv/ivtvfb.c @@ -44,8 +44,8 @@ #include #include -#ifdef CONFIG_MTRR -#include +#ifdef CONFIG_X86_64 +#include #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)) { @@ -1132,29 +1133,16 @@ 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 +1160,7 @@ 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; } @@ -1284,6 +1265,13 @@ static int __init ivtvfb_init(void) int registered = 0; int err; +#ifdef CONFIG_X86_64 + if (WARN(pat_enabled(), + "ivtvfb needs PAT disabled, boot with nopat kernel parameter\n")) { + return -ENODEV; + } +#endif + if (ivtvfb_card_id < -1 || ivtvfb_card_id >= IVTV_MAX_CARDS) { printk(KERN_ERR "ivtvfb: ivtvfb_card_id parameter is out of range (valid range: -1 - %d)\n", IVTV_MAX_CARDS - 1); -- 2.3.2.209.gd67f9d5.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/