Merge remote-tracking branch 'remotes/agraf/tags/signed-ppc-for-upstream' into staging

Patch queue for ppc - 2015-06-03

Highlights this time around:

  - sPAPR: endian fixes, speedups, bug fixes, hotplug basics
  - add default ram size capability for machines (sPAPR defaults to 512MB now)

# gpg: Signature made Wed Jun  3 22:59:09 2015 BST using RSA key ID 03FEDC60
# gpg: Good signature from "Alexander Graf <agraf@suse.de>"
# gpg:                 aka "Alexander Graf <alex@csgraf.de>"

* remotes/agraf/tags/signed-ppc-for-upstream: (40 commits)
  softmmu: support up to 12 MMU modes
  tcg: add TCG_TARGET_TLB_DISPLACEMENT_BITS
  tci: do not use CPUArchState in tcg-target.h
  Add David Gibson for sPAPR in MAINTAINERS file
  pseries: Enable in-kernel H_LOGICAL_CI_{LOAD, STORE} implementations
  spapr: override default ram size to 512MB
  machine: add default_ram_size to machine class
  spapr_pci: emit hotplug add/remove events during hotplug
  spapr_pci: enable basic hotplug operations
  pci: make pci_bar useable outside pci.c
  spapr_pci: create DRConnectors for each PCI slot during PHB realize
  spapr_pci: add dynamic-reconfiguration option for spapr-pci-host-bridge
  spapr_drc: add spapr_drc_populate_dt()
  spapr_events: event-scan RTAS interface
  spapr_events: re-use EPOW event infrastructure for hotplug events
  spapr_rtas: add ibm, configure-connector RTAS interface
  spapr: add rtas_st_buffer_direct() helper
  spapr_rtas: add get-sensor-state RTAS interface
  spapr_rtas: add set-indicator RTAS interface
  spapr_rtas: add get/set-power-level RTAS interfaces
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 33 insertions, 2 deletions

diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
index 3f56546066..d5aecaf49e 100644
--- a/include/exec/cpu-defs.h
+++ b/include/exec/cpu-defs.h
@@ -27,6 +27,7 @@
 #include <inttypes.h>
 #include "qemu/osdep.h"
 #include "qemu/queue.h"
+#include "tcg-target.h"
 #ifndef CONFIG_USER_ONLY
 #include "exec/hwaddr.h"
 #endif
@@ -70,8 +71,6 @@ typedef uint64_t target_ulong;
 #define TB_JMP_PAGE_MASK (TB_JMP_CACHE_SIZE - TB_JMP_PAGE_SIZE)
 
 #if !defined(CONFIG_USER_ONLY)
-#define CPU_TLB_BITS 8
-#define CPU_TLB_SIZE (1 << CPU_TLB_BITS)
 /* use a fully associative victim tlb of 8 entries */
 #define CPU_VTLB_SIZE 8
 
@@ -81,6 +80,38 @@ typedef uint64_t target_ulong;
 #define CPU_TLB_ENTRY_BITS 5
 #endif
 
+/* TCG_TARGET_TLB_DISPLACEMENT_BITS is used in CPU_TLB_BITS to ensure that
+ * the TLB is not unnecessarily small, but still small enough for the
+ * TLB lookup instruction sequence used by the TCG target.
+ *
+ * TCG will have to generate an operand as large as the distance between
+ * env and the tlb_table[NB_MMU_MODES - 1][0].addend.  For simplicity,
+ * the TCG targets just round everything up to the next power of two, and
+ * count bits.  This works because: 1) the size of each TLB is a largish
+ * power of two, 2) and because the limit of the displacement is really close
+ * to a power of two, 3) the offset of tlb_table[0][0] inside env is smaller
+ * than the size of a TLB.
+ *
+ * For example, the maximum displacement 0xFFF0 on PPC and MIPS, but TCG
+ * just says "the displacement is 16 bits".  TCG_TARGET_TLB_DISPLACEMENT_BITS
+ * then ensures that tlb_table at least 0x8000 bytes large ("not unnecessarily
+ * small": 2^15).  The operand then will come up smaller than 0xFFF0 without
+ * any particular care, because the TLB for a single MMU mode is larger than
+ * 0x10000-0xFFF0=16 bytes.  In the end, the maximum value of the operand
+ * could be something like 0xC000 (the offset of the last TLB table) plus
+ * 0x18 (the offset of the addend field in each TLB entry) plus the offset
+ * of tlb_table inside env (which is non-trivial but not huge).
+ */
+#define CPU_TLB_BITS                                             \
+    MIN(8,                                                       \
+        TCG_TARGET_TLB_DISPLACEMENT_BITS - CPU_TLB_ENTRY_BITS -  \
+        (NB_MMU_MODES <= 1 ? 0 :                                 \
+         NB_MMU_MODES <= 2 ? 1 :                                 \
+         NB_MMU_MODES <= 4 ? 2 :                                 \
+         NB_MMU_MODES <= 8 ? 3 : 4))
+
+#define CPU_TLB_SIZE (1 << CPU_TLB_BITS)
+
 typedef struct CPUTLBEntry {
     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not