arm64: Fix overlapping VA allocations

PCI IO space was intended to be 16MiB, at 32MiB below MODULES_VADDR, but
commit d1e6dc91b532d3d3 ("arm64: Add architectural support for PCI")
extended this to cover the full 32MiB. The final 8KiB of this 32MiB is
also allocated for the fixmap, allowing for potential clashes between
the two.

This change was masked by assumptions in mem_init and the page table
dumping code, which assumed the I/O space to be 16MiB long through
seaparte hard-coded definitions.

This patch changes the definition of the PCI I/O space allocation to
live in asm/memory.h, along with the other VA space allocations. As the
fixmap allocation depends on the number of fixmap entries, this is moved
below the PCI I/O space allocation. Both the fixmap and PCI I/O space
are guarded with 2MB of padding. Sites assuming the I/O space was 16MiB
are moved over use new PCI_IO_{START,END} definitions, which will keep
in sync with the size of the IO space (now restored to 16MiB).

As a useful side effect, the use of the new PCI_IO_{START,END}
definitions prevents a build issue in the dumping code due to a (now
redundant) missing include of io.h for PCI_IOBASE.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
[catalin.marinas@arm.com: reorder FIXADDR and PCI_IO address_markers_idx enum]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

2 files changed, 7 insertions, 6 deletions

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index cf33f33333cc..77d39a1b6f8d 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -36,10 +36,10 @@ enum address_markers_idx {
 	VMEMMAP_START_NR,
 	VMEMMAP_END_NR,
 #endif
-	PCI_START_NR,
-	PCI_END_NR,
 	FIXADDR_START_NR,
 	FIXADDR_END_NR,
+	PCI_START_NR,
+	PCI_END_NR,
 	MODULES_START_NR,
 	MODUELS_END_NR,
 	KERNEL_SPACE_NR,
@@ -52,10 +52,10 @@ static struct addr_marker address_markers[] = {
 	{ 0,			"vmemmap start" },
 	{ 0,			"vmemmap end" },
 #endif
-	{ (unsigned long) PCI_IOBASE,		"PCI I/O start" },
-	{ (unsigned long) PCI_IOBASE + SZ_16M,	"PCI I/O end" },
 	{ FIXADDR_START,	"Fixmap start" },
 	{ FIXADDR_TOP,		"Fixmap end" },
+	{ PCI_IO_START,		"PCI I/O start" },
+	{ PCI_IO_END,		"PCI I/O end" },
 	{ MODULES_VADDR,	"Modules start" },
 	{ MODULES_END,		"Modules end" },
 	{ PAGE_OFFSET,		"Kernel Mapping" },
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 43cccb5101c0..a8dfb40eefa8 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -35,6 +35,7 @@
 #include <linux/efi.h>
 
 #include <asm/fixmap.h>
+#include <asm/memory.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
 #include <asm/sizes.h>
@@ -296,8 +297,8 @@ void __init mem_init(void)
 		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld GB maximum)\n"
 		  "              0x%16lx - 0x%16lx   (%6ld MB actual)\n"
 #endif
-		  "    PCI I/O : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 		  "    fixed   : 0x%16lx - 0x%16lx   (%6ld KB)\n"
+		  "    PCI I/O : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 		  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 		  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 		  "      .init : 0x%p" " - 0x%p" "   (%6ld KB)\n"
@@ -310,8 +311,8 @@ void __init mem_init(void)
 		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
 		      (unsigned long)virt_to_page(high_memory)),
 #endif
-		  MLM((unsigned long)PCI_IOBASE, (unsigned long)PCI_IOBASE + SZ_16M),
 		  MLK(FIXADDR_START, FIXADDR_TOP),
+		  MLM(PCI_IO_START, PCI_IO_END),
 		  MLM(MODULES_VADDR, MODULES_END),
 		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
 		  MLK_ROUNDUP(__init_begin, __init_end),