[PATCH v6 02/12] x86: fixmap: add permanent fixmap for xhci debug port

From: Lu Baolu
Date: Mon Jan 25 2016 - 23:18:36 EST


xHCI compatible USB3 host controller may provide debug capability
which enables low-level system debug over USB. In order to probing
this debug capability, Linux kernel needs to map and access the
mmio of the host controller during early boot.

This patch adds permenent fixmap pages in fixed_addresses table for
xHCI mmio access.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/fixmap.h | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 6d7d0e5..84298cb 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -77,6 +77,10 @@ enum fixed_addresses {
#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
FIX_OHCI1394_BASE,
#endif
+#ifdef CONFIG_EARLY_PRINTK_XDBC
+ FIX_XDBC_BASE,
+ FIX_XDBC_END = FIX_XDBC_BASE + 15,
+#endif
#ifdef CONFIG_X86_LOCAL_APIC
FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
#endif
--
2.1.4