Commit-ID: c43996f4001de629af4a4d6713782e883677e5b9
Gitweb: http://git.kernel.org/tip/c43996f4001de629af4a4d6713782e883677e5b9
Author: Luis R. Rodriguez <mcg...@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:23 -0700
Committer: Ingo Molnar <mi...@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:43 +0200
PCI: Add pci_ioremap_wc_bar()
This lets drivers take advantage of PAT when available. It
should help with the transition of converting video drivers over
to ioremap_wc() to help with the goal of eventually using
_PAGE_CACHE_UC over _PAGE_CACHE_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 <mcg...@suse.com>
Signed-off-by: Borislav Petkov <b...@suse.de>
Acked-by: Arnd Bergmann <a...@arndb.de>
Cc: <syrj...@sci.fi>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Antonino Daplas <adap...@gmail.com>
Cc: Bjorn Helgaas <bhelg...@google.com>
Cc: Daniel Vetter <daniel.vet...@ffwll.ch>
Cc: Dave Airlie <airl...@redhat.com>
Cc: Davidlohr Bueso <dbu...@suse.de>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Jean-Christophe Plagniol-Villard <plagn...@jcrosoft.com>
Cc: Juergen Gross <jgr...@suse.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Mel Gorman <mgor...@suse.de>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Suresh Siddha <sbsid...@gmail.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkei...@ti.com>
Cc: Toshi Kani <toshi.k...@hp.com>
Cc: Ville Syrjälä <syrj...@sci.fi>
Cc: Vlastimil Babka <vba...@suse.cz>
Cc: airl...@linux.ie
Cc: b...@kernel.crashing.org
Cc: dan.j.willi...@intel.com
Cc: konrad.w...@oracle.com
Cc: linux-fb...@vger.kernel.org
Cc: linux-...@vger.kernel.org
Cc: m...@redhat.com
Cc: vinod.k...@intel.com
Cc: xen-de...@lists.xensource.com
Link:
http://lkml.kernel.org/r/1440443613-13696-2-git-send-email-mcg...@do-not-panic.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
drivers/pci/pci.c | 14 ++++++++++++++
include/linux/pci.h | 1 +
2 files changed, 15 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0008c95..fdae37b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -138,6 +138,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int
bar)
return ioremap_nocache(res->start, resource_size(res));
}
EXPORT_SYMBOL_GPL(pci_ioremap_bar);
+
+void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
+{
+ /*
+ * Make sure the BAR is actually a memory resource, not an IO resource
+ */
+ if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
+ WARN_ON(1);
+ return NULL;
+ }
+ return ioremap_wc(pci_resource_start(pdev, bar),
+ pci_resource_len(pdev, bar));
+}
+EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
#endif
#define PCI_FIND_CAP_TTL 48
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8a0321a..985dd39 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1661,6 +1661,7 @@ static inline void pci_mmcfg_late_init(void) { }
int pci_ext_cfg_avail(void);
void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
+void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
#ifdef CONFIG_PCI_IOV
int pci_iov_virtfn_bus(struct pci_dev *dev, int id);
--
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