summaryrefslogtreecommitdiff
path: root/include/asm-generic/pci_iomap.h
AgeCommit message (Collapse)Author
2015-08-25PCI: Add pci_iomap_wc() variantsLuis R. Rodriguez
PCI BARs tell us whether prefetching is safe, but they don't say anything about write combining (WC). WC changes ordering rules and allows writes to be collapsed, so it's not safe in general to use it on a prefetchable region. Add pci_iomap_wc() and pci_iomap_wc_range() so drivers can take advantage of write combining when they know it's safe. On architectures that don't fully support WC, e.g., x86 without PAT, drivers for legacy framebuffers may get some of the benefit by using arch_phys_wc_add() in addition to pci_iomap_wc(). But arch_phys_wc_add() is unreliable and should be avoided in general. On x86, it uses MTRRs, which are limited in number and size, so the results will vary based on driver loading order. The goals of adding pci_iomap_wc() are to: - Give drivers an architecture-independent way to use WC so they can stop using interfaces like mtrr_add() (on x86, pci_iomap_wc() uses PAT when available). - Move toward using _PAGE_CACHE_MODE_UC, not _PAGE_CACHE_MODE_UC_MINUS, on x86 on ioremap_nocache() (see de33c442ed2a ("x86 PAT: fix performance drop for glx, use UC minus for ioremap(), ioremap_nocache() and pci_mmap_page_range()"). Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> [ Move IORESOURCE_IO check up, space out statements for better readability. ] Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: <roger.pau@citrix.com> Cc: <syrjala@sci.fi> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Antonino Daplas <adaplas@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Airlie <airlied@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roger Pau Monné <roger.pau@citrix.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stefan Bader <stefan.bader@canonical.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Ville Syrjälä <syrjala@sci.fi> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: airlied@linux.ie Cc: benh@kernel.crashing.org Cc: dan.j.williams@intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: konrad.wilk@oracle.com Cc: linux-arch@vger.kernel.org Cc: linux-fbdev@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: venkatesh.pallipadi@intel.com Cc: vinod.koul@intel.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1440443613-13696-6-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-21pci: add pci_iomap_rangeMichael S. Tsirkin
Virtio drivers should map the part of the BAR they need, not necessarily all of it. Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-pci@vger.kernel.org Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-02-27[PARISC] fix compile break caused by iomap: make IOPORT/PCI mapping ↵James Bottomley
functions conditional The problem in commit fea80311a939a746533a6d7e7c3183729d6a3faf Author: Randy Dunlap <rdunlap@xenotime.net> Date: Sun Jul 24 11:39:14 2011 -0700 iomap: make IOPORT/PCI mapping functions conditional is that if your architecture supplies pci_iomap/pci_iounmap, it expects always to supply them. Adding empty body defitions in the !CONFIG_PCI case, which is what this patch does, breaks the parisc compile because the functions become doubly defined. It took us a while to spot this, because we don't actually build !CONFIG_PCI very often (only if someone is brave enough to test the snake/asp machines). Since the note in the commit log says this is to fix a CONFIG_GENERIC_IOMAP issue (which it does because CONFIG_GENERIC_IOMAP supplies pci_iounmap only if CONFIG_PCI is set), there should actually have been a condition upon this. This should make sure no other architecture's !CONFIG_PCI compile breaks in the same way as parisc. The fix had to be updated to take account of the GENERIC_PCI_IOMAP separation. Reported-by: Rolf Eike Beer <eike@sf-mail.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-01-31lib: add NO_GENERIC_PCI_IOPORT_MAPMichael S. Tsirkin
Some architectures need to override the way IO port mapping is done on PCI devices. Supply a generic macro that calls ioport_map, and make it possible for architectures to override. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2011-11-28lib: add GENERIC_PCI_IOMAPMichael S. Tsirkin
Many architectures want a generic pci_iomap but not the rest of iomap.c. Split that to a separate .c file and add a new config symbol. select automatically by GENERIC_IOMAP. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>