Merge tag 'xtensa-next-20130508' of git://github.com/czankel/xtensa-linux

Pull xtensa updates from Chris Zankel:
 "Support for the latest MMU architecture that allows for a larger
  accessible memory region, and various bug-fixes"

* tag 'xtensa-next-20130508' of git://github.com/czankel/xtensa-linux:
  xtensa: Switch to asm-generic/linkage.h
  xtensa: fix redboot load address
  xtensa: ISS: fix timer_lock usage in rs_open
  xtensa: disable IRQs while IRQ handler is running
  xtensa: enable lockdep support
  xtensa: fix arch_irqs_disabled_flags implementation
  xtensa: add irq flags trace support
  xtensa: provide custom CALLER_ADDR* implementations
  xtensa: add stacktrace support
  xtensa: clean up stpill_registers
  xtensa: don't use a7 in simcalls
  xtensa: don't attempt to use unconfigured timers
  xtensa: provide default platform_pcibios_init implementation
  xtensa: remove KCORE_ELF again
  xtensa: document MMUv3 setup sequence
  xtensa: add MMU v3 support
  xtensa: fix ibreakenable register update
  xtensa: fix oprofile building as module

33 files changed, 819 insertions, 254 deletions

diff --git a/Documentation/xtensa/mmu.txt b/Documentation/xtensa/mmu.txt
new file mode 100644
index 000000000000..2b1af7606d57
--- /dev/null
+++ b/Documentation/xtensa/mmu.txt
@@ -0,0 +1,46 @@
+MMUv3 initialization sequence.
+
+The code in the initialize_mmu macro sets up MMUv3 memory mapping
+identically to MMUv2 fixed memory mapping. Depending on
+CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX symbol this code is
+located in one of the following address ranges:
+
+    0xF0000000..0xFFFFFFFF (will keep same address in MMU v2 layout;
+                         typically ROM)
+    0x00000000..0x07FFFFFF (system RAM; this code is actually linked
+                         at 0xD0000000..0xD7FFFFFF [cached]
+                         or 0xD8000000..0xDFFFFFFF [uncached];
+                         in any case, initially runs elsewhere
+                         than linked, so have to be careful)
+
+The code has the following assumptions:
+  This code fragment is run only on an MMU v3.
+  TLBs are in their reset state.
+  ITLBCFG and DTLBCFG are zero (reset state).
+  RASID is 0x04030201 (reset state).
+  PS.RING is zero (reset state).
+  LITBASE is zero (reset state, PC-relative literals); required to be PIC.
+
+TLB setup proceeds along the following steps.
+
+  Legend:
+    VA = virtual address (two upper nibbles of it);
+    PA = physical address (two upper nibbles of it);
+    pc = physical range that contains this code;
+
+After step 2, we jump to virtual address in 0x40000000..0x5fffffff
+that corresponds to next instruction to execute in this code.
+After step 4, we jump to intended (linked) address of this code.
+
+    Step 0     Step1     Step 2     Step3     Step 4     Step5
+ ============  =====  ============  =====  ============  =====
+   VA      PA     PA    VA      PA     PA    VA      PA     PA
+ ------    --     --  ------    --     --  ------    --     --
+ E0..FF -> E0  -> E0  E0..FF -> E0         F0..FF -> F0  -> F0
+ C0..DF -> C0  -> C0  C0..DF -> C0         E0..EF -> F0  -> F0
+ A0..BF -> A0  -> A0  A0..BF -> A0         D8..DF -> 00  -> 00
+ 80..9F -> 80  -> 80  80..9F -> 80         D0..D7 -> 00  -> 00
+ 60..7F -> 60  -> 60  60..7F -> 60
+ 40..5F -> 40         40..5F -> pc  -> pc  40..5F -> pc
+ 20..3F -> 20  -> 20  20..3F -> 20
+ 00..1F -> 00  -> 00  00..1F -> 00
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index acdfc615cca2..0a1b95f81a32 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -1,11 +1,9 @@
-config FRAME_POINTER
-        def_bool n
-
 config ZONE_DMA
         def_bool y
 
 config XTENSA
         def_bool y
+        select ARCH_WANT_FRAME_POINTERS
         select HAVE_IDE
         select GENERIC_ATOMIC64
         select HAVE_GENERIC_HARDIRQS
@@ -49,6 +47,15 @@ config HZ
 source "init/Kconfig"
 source "kernel/Kconfig.freezer"
 
+config LOCKDEP_SUPPORT
+        def_bool y
+
+config STACKTRACE_SUPPORT
+        def_bool y
+
+config TRACE_IRQFLAGS_SUPPORT
+        def_bool y
+
 config MMU
         def_bool n
 
@@ -100,6 +107,35 @@ config MATH_EMULATION
         help
         Can we use information of configuration file?
 
+config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+        bool "Initialize Xtensa MMU inside the Linux kernel code"
+        default y
+        help
+          Earlier version initialized the MMU in the exception vector
+          before jumping to _startup in head.S and had an advantage that
+          it was possible to place a software breakpoint at 'reset' and
+          then enter your normal kernel breakpoints once the MMU was mapped
+          to the kernel mappings (0XC0000000).
+
+          This unfortunately doesn't work for U-Boot and likley also wont
+          work for using KEXEC to have a hot kernel ready for doing a
+          KDUMP.
+
+          So now the MMU is initialized in head.S but it's necessary to
+          use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup.
+          xt-gdb can't place a Software Breakpoint in the  0XD region prior
+          to mapping the MMU and after mapping even if the area of low memory
+          was mapped gdb wouldn't remove the breakpoint on hitting it as the
+          PC wouldn't match. Since Hardware Breakpoints are recommended for
+          Linux configurations it seems reasonable to just assume they exist
+          and leave this older mechanism for unfortunate souls that choose
+          not to follow Tensilica's recommendation.
+
+          Selecting this will cause U-Boot to set the KERNEL Load and Entry
+          address at 0x00003000 instead of the mapped std of 0xD0003000.
+
+          If in doubt, say Y.
+
 endmenu
 
 config XTENSA_CALIBRATE_CCOUNT
@@ -249,21 +285,6 @@ endmenu
 
 menu "Executable file formats"
 
-# only elf supported
-config KCORE_ELF
-        def_bool y
-        depends on PROC_FS
-        help
-          If you enabled support for /proc file system then the file
-          /proc/kcore will contain the kernel core image in ELF format. This
-          can be used in gdb:
-
-          $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
-
-          This is especially useful if you have compiled the kernel with the
-          "-g" option to preserve debugging information. It is mainly used
-          for examining kernel data structures on the live kernel.
-