Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:
 "A few fixes for ARM.  Some of these are correctness issues:
   - TLBs must be flushed after the old mappings are removed by the DMA
     mapping code, but before the new mappings are established.
   - An off-by-one entry error in the Keystone LPAE setup code.

  Fixes include:
   - ensuring that the identity mapping for LPAE does not remove the
     kernel image from the identity map.
   - preventing userspace from trapping into kgdb.
   - fixing a preemption issue in the Intel iwmmxt code.
   - fixing a build error with nommu.

  Other changes include:
   - Adding a note about which areas of memory are expected to be
     accessible while the identity mapping tables are in place"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8124/1: don't enter kgdb when userspace executes a kgdb break instruction
  ARM: idmap: add identity mapping usage note
  ARM: 8115/1: LPAE: reduce damage caused by idmap to virtual memory layout
  ARM: fix alignment of keystone page table fixup
  ARM: 8112/1: only select ARM_PATCH_PHYS_VIRT if MMU is enabled
  ARM: 8100/1: Fix preemption disable in iwmmxt_task_enable()
  ARM: DMA: ensure that old section mappings are flushed from the TLB

6 files changed, 43 insertions, 17 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 88acf8bc1490..290f02ee0157 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -313,7 +313,7 @@ config ARCH_MULTIPLATFORM
 config ARCH_INTEGRATOR
         bool "ARM Ltd. Integrator family"
         select ARM_AMBA
-        select ARM_PATCH_PHYS_VIRT
+        select ARM_PATCH_PHYS_VIRT if MMU
         select AUTO_ZRELADDR
         select COMMON_CLK
         select COMMON_CLK_VERSATILE
@@ -659,7 +659,7 @@ config ARCH_MSM
 config ARCH_SHMOBILE_LEGACY
         bool "Renesas ARM SoCs (non-multiplatform)"
         select ARCH_SHMOBILE
-        select ARM_PATCH_PHYS_VIRT
+        select ARM_PATCH_PHYS_VIRT if MMU
         select CLKDEV_LOOKUP
         select GENERIC_CLOCKEVENTS
         select HAVE_ARM_SCU if SMP
diff --git a/arch/arm/kernel/iwmmxt.S b/arch/arm/kernel/iwmmxt.S
index a5599cfc43cb..2b32978ae905 100644
--- a/arch/arm/kernel/iwmmxt.S
+++ b/arch/arm/kernel/iwmmxt.S
@@ -94,13 +94,19 @@ ENTRY(iwmmxt_task_enable)
 
         mrc     p15, 0, r2, c2, c0, 0
         mov     r2, r2                          @ cpwait
+        bl      concan_save
 
-        teq     r1, #0                          @ test for last ownership
-        mov     lr, r9                          @ normal exit from exception
-        beq     concan_load                     @ no owner, skip save
+#ifdef CONFIG_PREEMPT_COUNT
+        get_thread_info r10
+#endif
+4:      dec_preempt_count r10, r3
+        mov     pc, r9                          @ normal exit from exception
 
 concan_save:
 
+        teq     r1, #0                          @ test for last ownership
+        beq     concan_load                     @ no owner, skip save
+
         tmrc    r2, wCon
 
         @ CUP? wCx
@@ -138,7 +144,7 @@ concan_dump:
         wstrd   wR15, [r1, #MMX_WR15]
 
 2:      teq     r0, #0                          @ anything to load?
-        beq     3f
+        moveq   pc, lr                          @ if not, return
 
 concan_load:
 
@@ -171,14 +177,9 @@ concan_load:
         @ clear CUP/MUP (only if r1 != 0)
         teq     r1, #0
         mov     r2, #0
-        beq     3f
-        tmcr    wCon, r2
+        moveq   pc, lr
 
-3:
-#ifdef CONFIG_PREEMPT_COUNT
-        get_thread_info r10
-#endif
-4:      dec_preempt_count r10, r3
+        tmcr    wCon, r2
         mov     pc, lr
 
 /*
diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
index 778c2f7024ff..a74b53c1b7df 100644
--- a/arch/arm/kernel/kgdb.c
+++ b/arch/arm/kernel/kgdb.c
@@ -160,12 +160,16 @@ static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
 static struct undef_hook kgdb_brkpt_hook = {
         .instr_mask             = 0xffffffff,
         .instr_val              = KGDB_BREAKINST,
+        .cpsr_mask              = MODE_MASK,
+        .cpsr_val               = SVC_MODE,
         .fn                     = kgdb_brk_fn
 };
 
 static struct undef_hook kgdb_compiled_brkpt_hook = {
         .instr_mask             = 0xffffffff,
         .instr_val              = KGDB_COMPILED_BREAK,
+        .cpsr_mask              = MODE_MASK,
+        .cpsr_val               = SVC_MODE,
         .fn                     = kgdb_compiled_brk_fn
 };
 
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4c88935654ca..1f88db06b133 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -461,12 +461,21 @@ void __init dma_contiguous_remap(void)
                 map.type = MT_MEMORY_DMA_READY;
 
                 /*
-                 * Clear previous low-memory mapping
+                 * Clear previous low-memory mapping to ensure that the
+                 * TLB does not see any conflicting entries, then flush
+                 * the TLB of the old entries before creating new mappings.
+                 *
+                 * This ensures that any speculatively loaded TLB entries
+                 * (even though they may be rare) can not cause any problems,
+                 * and ensures that this code is architecturally compliant.
                  */
                 for (addr = __phys_to_virt(start); addr < __phys_to_virt(end);
                      addr += PMD_SIZE)
                         pmd_clear(pmd_off_k(addr));
 
+                flush_tlb_kernel_range(__phys_to_virt(start),
+                                       __phys_to_virt(end));
+
                 iotable_init(&map, 1);
         }
 }
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 8e0e52eb76b5..c447ec70e868 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -9,6 +9,11 @@
 #include <asm/sections.h>
 #include <asm/system_info.h>
 
+/*
+ * Note: accesses outside of the kernel image and the identity map area
+ * are not supported on any CPU using the idmap tables as its current
+ * page tables.
+ */
 pgd_t *idmap_pgd;
 phys_addr_t (*arch_virt_to_idmap) (unsigned long x);
 
@@ -25,6 +30,13 @@ static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
                         pr_warning("Failed to allocate identity pmd.\n");
                         return;
                 }
+                /*
+                 * Copy the original PMD to ensure that the PMD entries for
+                 * the kernel image are preserved.
+                 */
+                if (!pud_none(*pud))
+                        memcpy(pmd, pmd_offset(pud, 0),
+                               PTRS_PER_PMD * sizeof(pmd_t));
                 pud_populate(&init_mm, pud, pmd);
                 pmd += pmd_index(addr);
         } else
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index ab14b79b03f0..6e3ba8d112a2 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1406,8 +1406,8 @@ void __init early_paging_init(const struct machine_desc *mdesc,
                 return;
 
         /* remap kernel code and data */
-        map_start = init_mm.start_code;
-        map_end   = init_mm.brk;
+        map_start = init_mm.start_code & PMD_MASK;
+        map_end   = ALIGN(init_mm.brk, PMD_SIZE);
 
         /* get a handle on things... */
         pgd0 = pgd_offset_k(0);
@@ -1442,7 +1442,7 @@ void __init early_paging_init(const struct machine_desc *mdesc,
         }
 
         /* remap pmds for kernel mapping */
-        phys = __pa(map_start) & PMD_MASK;
+        phys = __pa(map_start);
         do {
                 *pmdk++ = __pmd(phys | pmdprot);
                 phys += PMD_SIZE;