Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm

Pull second set of ARM updates from Russell King:
 "This is the second set of ARM updates for this merge window.

  Contained within are changes to allow the kernel to boot in hypervisor
  mode on CPUs supporting virtualization, and cache flushing support to
  the point of inner sharable unification, which are used by the
  suspend/resume code to avoid having to do a full cache flush.

  Also included is one fix for VFP code identified by Michael Olbrich."

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: vfp: fix saving d16-d31 vfp registers on v6+ kernels
  ARM: 7549/1: HYP: fix boot on some ARM1136 cores
  ARM: 7542/1: mm: fix cache LoUIS API for xscale and feroceon
  ARM: mm: update __v7_setup() to the new LoUIS cache maintenance API
  ARM: kernel: update __cpu_disable to use cache LoUIS maintenance API
  ARM: kernel: update cpu_suspend code to use cache LoUIS operations
  ARM: mm: rename jump labels in v7_flush_dcache_all function
  ARM: mm: implement LoUIS API for cache maintenance ops
  ARM: virt: arch_timers: enable access to physical timers
  ARM: virt: Add CONFIG_ARM_VIRT_EXT option
  ARM: virt: Add boot-time diagnostics
  ARM: virt: Update documentation for hyp mode entry support
  ARM: zImage/virt: hyp mode entry support for the zImage loader
  ARM: virt: allow the kernel to be entered in HYP mode
  ARM: opcodes: add __ERET/__MSR_ELR_HYP instruction encoding

6 files changed, 279 insertions, 5 deletions

diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 5dfef9d97ed9..5bbec7b8183e 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -81,4 +81,6 @@ head-y			:= head$(MMUEXT).o
 obj-$(CONFIG_DEBUG_LL)  += debug.o
 obj-$(CONFIG_EARLY_PRINTK)      += early_printk.o
 
+obj-$(CONFIG_ARM_VIRT_EXT)      += hyp-stub.o
+
 extra-y := $(head-y) vmlinux.lds
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 9874d0741191..4eee351f4668 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -83,8 +83,12 @@ ENTRY(stext)
  THUMB( .thumb                  )       @ switch to Thumb now.
  THUMB(1:                       )
 
-        setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
-                                                @ and irqs disabled
+#ifdef CONFIG_ARM_VIRT_EXT
+        bl      __hyp_stub_install
+#endif
+        @ ensure svc mode and all interrupts masked
+        safe_svcmode_maskall r9
+
         mrc     p15, 0, r9, c0, c0              @ get processor id
         bl      __lookup_processor_type         @ r5=procinfo r9=cpuid
         movs    r10, r5                         @ invalid processor (r5=0)?
@@ -326,7 +330,11 @@ ENTRY(secondary_startup)
          * the processor type - there is no need to check the machine type
          * as it has already been validated by the primary processor.
          */
-        setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9
+#ifdef CONFIG_ARM_VIRT_EXT
+        bl      __hyp_stub_install
+#endif
+        safe_svcmode_maskall r9
+
         mrc     p15, 0, r9, c0, c0              @ get processor id
         bl      __lookup_processor_type
         movs    r10, r5                         @ invalid processor?
diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
new file mode 100644
index 000000000000..65b2417aebce
--- /dev/null
+++ b/arch/arm/kernel/hyp-stub.S
@@ -0,0 +1,223 @@
+/*
+ * Copyright (c) 2012 Linaro Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/virt.h>
+
+#ifndef ZIMAGE
+/*
+ * For the kernel proper, we need to find out the CPU boot mode long after
+ * boot, so we need to store it in a writable variable.
+ *
+ * This is not in .bss, because we set it sufficiently early that the boot-time
+ * zeroing of .bss would clobber it.
+ */
+.data
+ENTRY(__boot_cpu_mode)
+        .long   0
+.text
+
+        /*
+         * Save the primary CPU boot mode. Requires 3 scratch registers.
+         */
+        .macro  store_primary_cpu_mode  reg1, reg2, reg3
+        mrs     \reg1, cpsr
+        and     \reg1, \reg1, #MODE_MASK
+        adr     \reg2, .L__boot_cpu_mode_offset
+        ldr     \reg3, [\reg2]
+        str     \reg1, [\reg2, \reg3]
+        .endm
+
+        /*
+         * Compare the current mode with the one saved on the primary CPU.
+         * If they don't match, record that fact. The Z bit indicates
+         * if there's a match or not.
+         * Requires 3 additionnal scratch registers.
+         */
+        .macro  compare_cpu_mode_with_primary mode, reg1, reg2, reg3
+        adr     \reg2, .L__boot_cpu_mode_offset
+        ldr     \reg3, [\reg2]
+        ldr     \reg1, [\reg2, \reg3]
+        cmp     \mode, \reg1            @ matches primary CPU boot mode?
+        orrne   r7, r7, #BOOT_CPU_MODE_MISMATCH
+        strne   r7, [r5, r6]            @ record what happened and give up
+        .endm
+
+#else   /* ZIMAGE */
+
+        .macro  store_primary_cpu_mode  reg1:req, reg2:req, reg3:req
+        .endm
+
+/*
+ * The zImage loader only runs on one CPU, so we don't bother with mult-CPU
+ * consistency checking:
+ */
+        .macro  compare_cpu_mode_with_primary mode, reg1, reg2, reg3
+        cmp     \mode, \mode
+        .endm
+
+#endif /* ZIMAGE */
+
+/*
+ * Hypervisor stub installation functions.
+ *
+ * These must be called with the MMU and D-cache off.
+ * They are not ABI compliant and are only intended to be called from the kernel
+ * entry points in head.S.
+ */
+@ Call this from the primary CPU
+ENTRY(__hyp_stub_install)
+        store_primary_cpu_mode  r4, r5, r6
+ENDPROC(__hyp_stub_install)
+
+        @ fall through...
+
+@ Secondary CPUs should call here
+ENTRY(__hyp_stub_install_secondary)
+        mrs     r4, cpsr
+        and     r4, r4, #MODE_MASK
+
+        /*
+         * If the secondary has booted with a different mode, give up
+         * immediately.
+         */
+        compare_cpu_mode_with_primary   r4, r5, r6, r7
+        bxne    lr
+
+        /*
+         * Once we have given up on one CPU, we do not try to install the
+         * stub hypervisor on the remaining ones: because the saved boot mode
+         * is modified, it can't compare equal to the CPSR mode field any
+         * more.
+         *
+         * Otherwise...
+         */
+
+        cmp     r4, #HYP_MODE
+        bxne    lr                      @ give up if the CPU is not in HYP mode
+
+/*
+ * Configure HSCTLR to set correct exception endianness/instruction set
+ * state etc.
+ * Turn off all traps
+ * Eventually, CPU-specific code might be needed -- assume not for now
+ *
+ * This code relies on the "eret" instruction to synchronize the
+ * various coprocessor accesses.
+ */
+        @ Now install the hypervisor stub:
+        adr     r7, __hyp_stub_vectors
+        mcr     p15, 4, r7, c12, c0, 0  @ set hypervisor vector base (HVBAR)
+
+        @ Disable all traps, so we don't get any nasty surprise
+        mov     r7, #0
+        mcr     p15, 4, r7, c1, c1, 0   @ HCR
+        mcr     p15, 4, r7, c1, c1, 2   @ HCPTR
+        mcr     p15, 4, r7, c1, c1, 3   @ HSTR
+
+THUMB(  orr     r7, #(1 << 30)  )       @ HSCTLR.TE
+#ifdef CONFIG_CPU_BIG_ENDIAN
+        orr     r7, #(1 << 9)           @ HSCTLR.EE
+#endif
+        mcr     p15, 4, r7, c1, c0, 0   @ HSCTLR
+
+        mrc     p15, 4, r7, c1, c1, 1   @ HDCR
+        and     r7, #0x1f               @ Preserve HPMN
+        mcr     p15, 4, r7, c1, c1, 1   @ HDCR
+
+#if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER)
+        @ make CNTP_* and CNTPCT accessible from PL1
+        mrc     p15, 0, r7, c0, c1, 1   @ ID_PFR1
+        lsr     r7, #16
+        and     r7, #0xf
+        cmp     r7, #1
+        bne     1f
+        mrc     p15, 4, r7, c14, c1, 0  @ CNTHCTL
+        orr     r7, r7, #3              @ PL1PCEN | PL1PCTEN
+        mcr     p15, 4, r7, c14, c1, 0  @ CNTHCTL
+1:
+#endif
+
+        bic     r7, r4, #MODE_MASK
+        orr     r7, r7, #SVC_MODE
+THUMB(  orr     r7, r7, #PSR_T_BIT      )
+        msr     spsr_cxsf, r7           @ This is SPSR_hyp.
+
+        __MSR_ELR_HYP(14)               @ msr elr_hyp, lr
+        __ERET                          @ return, switching to SVC mode
+                                        @ The boot CPU mode is left in r4.
+ENDPROC(__hyp_stub_install_secondary)
+
+__hyp_stub_do_trap:
+        cmp     r0, #-1
+        mrceq   p15, 4, r0, c12, c0, 0  @ get HVBAR
+        mcrne   p15, 4, r0, c12, c0, 0  @ set HVBAR
+        __ERET
+ENDPROC(__hyp_stub_do_trap)
+
+/*
+ * __hyp_set_vectors: Call this after boot to set the initial hypervisor
+ * vectors as part of hypervisor installation.  On an SMP system, this should
+ * be called on each CPU.
+ *
+ * r0 must be the physical address of the new vector table (which must lie in
+ * the bottom 4GB of physical address space.
+ *
+ * r0 must be 32-byte aligned.
+ *
+ * Before calling this, you must check that the stub hypervisor is installed
+ * everywhere, by waiting for any secondary CPUs to be brought up and then
+ * checking that BOOT_CPU_MODE_HAVE_HYP(__boot_cpu_mode) is true.
+ *
+ * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
+ * something else went wrong... in such cases, trying to install a new
+ * hypervisor is unlikely to work as desired.
+ *
+ * When you call into your shiny new hypervisor, sp_hyp will contain junk,
+ * so you will need to set that to something sensible at the new hypervisor's
+ * initialisation entry point.
+ */
+ENTRY(__hyp_get_vectors)
+        mov     r0, #-1
+ENDPROC(__hyp_get_vectors)
+        @ fall through
+ENTRY(__hyp_set_vectors)
+        __HVC(0)
+        bx      lr
+ENDPROC(__hyp_set_vectors)
+
+#ifndef ZIMAGE
+.align 2
+.L__boot_cpu_mode_offset:
+        .long   __boot_cpu_mode - .
+#endif
+
+.align 5
+__hyp_stub_vectors:
+__hyp_stub_reset:       W(b)    .
+__hyp_stub_und:         W(b)    .
+__hyp_stub_svc:         W(b)    .
+__hyp_stub_pabort:      W(b)    .
+__hyp_stub_dabort:      W(b)    .
+__hyp_stub_trap:        W(b)    __hyp_stub_do_trap
+__hyp_stub_irq:         W(b)    .
+__hyp_stub_fiq:         W(b)    .
+ENDPROC(__hyp_stub_vectors)
+
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index febafa0f552d..da1d1aa20ad9 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -53,6 +53,7 @@
 #include <asm/traps.h>
 #include <asm/unwind.h>
 #include <asm/memblock.h>
+#include <asm/virt.h>
 
 #include "atags.h"
 #include "tcm.h"
@@ -703,6 +704,21 @@ static int __init meminfo_cmp(const void *_a, const void *_b)
         return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
 }
 
+void __init hyp_mode_check(void)
+{
+#ifdef CONFIG_ARM_VIRT_EXT
+        if (is_hyp_mode_available()) {
+                pr_info("CPU: All CPU(s) started in HYP mode.\n");
+                pr_info("CPU: Virtualization extensions available.\n");
+        } else if (is_hyp_mode_mismatched()) {
+                pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n",
+                        __boot_cpu_mode & MODE_MASK);
+                pr_warn("CPU: This may indicate a broken bootloader or firmware.\n");
+        } else
+                pr_info("CPU: All CPU(s) started in SVC mode.\n");
+#endif
+}
+
 void __init setup_arch(char **cmdline_p)
 {
         struct machine_desc *mdesc;
@@ -748,6 +764,10 @@ void __init setup_arch(char **cmdline_p)
                 smp_init_cpus();
         }
 #endif
+
+        if (!is_smp())
+                hyp_mode_check();
+
         reserve_crashkernel();
 
         tcm_init();
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index d100eacdb798..8e20754dd31d 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -43,6 +43,7 @@
 #include <asm/ptrace.h>
 #include <asm/localtimer.h>
 #include <asm/smp_plat.h>
+#include <asm/virt.h>
 #include <asm/mach/arch.h>
 
 /*
@@ -202,8 +203,11 @@ int __cpuinit __cpu_disable(void)
         /*
          * Flush user cache and TLB mappings, and then remove this CPU
          * from the vm mask set of all processes.
+         *
+         * Caches are flushed to the Level of Unification Inner Shareable
+         * to write-back dirty lines to unified caches shared by all CPUs.
          */
-        flush_cache_all();
+        flush_cache_louis();
         local_flush_tlb_all();
 
         clear_tasks_mm_cpumask(cpu);
@@ -355,6 +359,8 @@ void __init smp_cpus_done(unsigned int max_cpus)
                num_online_cpus(),
                bogosum / (500000/HZ),
                (bogosum / (5000/HZ)) % 100);
+
+        hyp_mode_check();
 }
 
 void __init smp_prepare_boot_cpu(void)
diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c
index 1794cc3b0f18..358bca3a995e 100644
--- a/arch/arm/kernel/suspend.c
+++ b/arch/arm/kernel/suspend.c
@@ -17,6 +17,8 @@ extern void cpu_resume_mmu(void);
  */
 void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
 {
+        u32 *ctx = ptr;
+
         *save_ptr = virt_to_phys(ptr);
 
         /* This must correspond to the LDM in cpu_resume() assembly */
@@ -26,7 +28,20 @@ void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
 
         cpu_do_suspend(ptr);
 
-        flush_cache_all();
+        flush_cache_louis();
+
+        /*
+         * flush_cache_louis does not guarantee that
+         * save_ptr and ptr are cleaned to main memory,
+         * just up to the Level of Unification Inner Shareable.
+         * Since the context pointer and context itself
+         * are to be retrieved with the MMU off that
+         * data must be cleaned from all cache levels
+         * to main memory using "area" cache primitives.
+        */
+        __cpuc_flush_dcache_area(ctx, ptrsz);
+        __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr));
+
         outer_clean_range(*save_ptr, *save_ptr + ptrsz);
         outer_clean_range(virt_to_phys(save_ptr),
                           virt_to_phys(save_ptr) + sizeof(*save_ptr));