Patchwork [02/10] alpha-linux-user: Work around hosted mmap allocation problems

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Submitter Richard Henderson
Date Aug. 3, 2012, 10:40 p.m.
Message ID <1344033657-9135-3-git-send-email-rth@twiddle.net>
Download mbox | patch
Permalink /patch/175054/
State New
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Richard Henderson - Aug. 3, 2012, 10:40 p.m.
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target-alpha/cpu.h |   15 +++++++++++++--
 1 files changed, 13 insertions(+), 2 deletions(-)

Patch

diff --git a/target-alpha/cpu.h b/target-alpha/cpu.h
index 99f9ee1..5689760 100644
--- a/target-alpha/cpu.h
+++ b/target-alpha/cpu.h
@@ -40,9 +40,20 @@ 
 
 #define TARGET_PAGE_BITS 13
 
+#ifdef CONFIG_USER_ONLY
+/* ??? The kernel likes to give addresses in high memory.  If the host has
+   more virtual address space than the guest, this can lead to impossible
+   allocations.  Honor the long-standing assumption that only kernel addrs
+   are negative, but otherwise allow allocations anywhere.  This could lead
+   to tricky emulation problems for programs doing tagged addressing, but
+   that's far fewer than encounter the impossible allocation problem.  */
+#define TARGET_PHYS_ADDR_SPACE_BITS  63
+#define TARGET_VIRT_ADDR_SPACE_BITS  63
+#else
 /* ??? EV4 has 34 phys addr bits, EV5 has 40, EV6 has 44.  */
-#define TARGET_PHYS_ADDR_SPACE_BITS	44
-#define TARGET_VIRT_ADDR_SPACE_BITS	(30 + TARGET_PAGE_BITS)
+#define TARGET_PHYS_ADDR_SPACE_BITS  44
+#define TARGET_VIRT_ADDR_SPACE_BITS  (30 + TARGET_PAGE_BITS)
+#endif
 
 /* Alpha major type */
 enum {