Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

Pull Tile arch updates from Chris Metcalf:
 "These changes bring in a bunch of new functionality that has been
  maintained internally at Tilera over the last year, plus other stray
  bits of work that I've taken into the tile tree from other folks.

  The changes include some PCI root complex work, interrupt-driven
  console support, support for performing fast-path unaligned data
  fixups by kernel-based JIT code generation, CONFIG_PREEMPT support,
  vDSO support for gettimeofday(), a serial driver for the tilegx
  on-chip UART, KGDB support, more optimized string routines, support
  for ftrace and kprobes, improved ASLR, and many bug fixes.

  We also remove support for the old TILE64 chip, which is no longer
  buildable"

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (85 commits)
  tile: refresh tile defconfig files
  tile: rework <asm/cmpxchg.h>
  tile PCI RC: make default consistent DMA mask 32-bit
  tile: add null check for kzalloc in tile/kernel/setup.c
  tile: make __write_once a synonym for __read_mostly
  tile: remove support for TILE64
  tile: use asm-generic/bitops/builtin-*.h
  tile: eliminate no-op "noatomichash" boot argument
  tile: use standard tile_bundle_bits type in traps.c
  tile: simplify code referencing hypervisor API addresses
  tile: change <asm/system.h> to <asm/switch_to.h> in comments
  tile: mark pcibios_init() as __init
  tile: check for correct compiler earlier in asm-offsets.c
  tile: use standard 'generic-y' model for <asm/hw_irq.h>
  tile: use asm-generic version of <asm/local64.h>
  tile PCI RC: add comment about "PCI hole" problem
  tile: remove DEBUG_EXTRA_FLAGS kernel config option
  tile: add virt_to_kpte() API and clean up and document behavior
  tile: support FRAME_POINTER
  tile: support reporting Tilera hypervisor statistics
  ...

1 files changed, 76 insertions, 59 deletions

diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index f7f99f90cbe0..111d5a9b76f1 100644
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -34,6 +34,7 @@
 #include <linux/hugetlb.h>
 #include <linux/syscalls.h>
 #include <linux/uaccess.h>
+#include <linux/kdebug.h>
 
 #include <asm/pgalloc.h>
 #include <asm/sections.h>
@@ -122,10 +123,9 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
 	pmd_k = pmd_offset(pud_k, address);
 	if (!pmd_present(*pmd_k))
 		return NULL;
-	if (!pmd_present(*pmd)) {
+	if (!pmd_present(*pmd))
 		set_pmd(pmd, *pmd_k);
-		arch_flush_lazy_mmu_mode();
-	} else
+	else
 		BUG_ON(pmd_ptfn(*pmd) != pmd_ptfn(*pmd_k));
 	return pmd_k;
 }
@@ -283,7 +283,7 @@ static int handle_page_fault(struct pt_regs *regs,
 	flags = (FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
 		 (write ? FAULT_FLAG_WRITE : 0));
 
-	is_kernel_mode = (EX1_PL(regs->ex1) != USER_PL);
+	is_kernel_mode = !user_mode(regs);
 
 	tsk = validate_current();
 
@@ -466,28 +466,15 @@ good_area:
 		}
 	}
 
-#if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC()
-	/*
-	 * If this was an asynchronous fault,
-	 * restart the appropriate engine.
-	 */
-	switch (fault_num) {
 #if CHIP_HAS_TILE_DMA()
+	/* If this was a DMA TLB fault, restart the DMA engine. */
+	switch (fault_num) {
 	case INT_DMATLB_MISS:
 	case INT_DMATLB_MISS_DWNCL:
 	case INT_DMATLB_ACCESS:
 	case INT_DMATLB_ACCESS_DWNCL:
 		__insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK);
 		break;
-#endif
-#if CHIP_HAS_SN_PROC()
-	case INT_SNITLB_MISS:
-	case INT_SNITLB_MISS_DWNCL:
-		__insn_mtspr(SPR_SNCTL,
-			     __insn_mfspr(SPR_SNCTL) &
-			     ~SPR_SNCTL__FRZPROC_MASK);
-		break;
-#endif
 	}
 #endif
 
@@ -722,8 +709,60 @@ void do_page_fault(struct pt_regs *regs, int fault_num,
 {
 	int is_page_fault;
 
+#ifdef CONFIG_KPROBES
+	/*
+	 * This is to notify the fault handler of the kprobes.  The
+	 * exception code is redundant as it is also carried in REGS,
+	 * but we pass it anyhow.
+	 */
+	if (notify_die(DIE_PAGE_FAULT, "page fault", regs, -1,
+		       regs->faultnum, SIGSEGV) == NOTIFY_STOP)
+		return;
+#endif
+
+#ifdef __tilegx__
+	/*
+	 * We don't need early do_page_fault_ics() support, since unlike
+	 * Pro we don't need to worry about unlocking the atomic locks.
+	 * There is only one current case in GX where we touch any memory
+	 * under ICS other than our own kernel stack, and we handle that
+	 * here.  (If we crash due to trying to touch our own stack,
+	 * we're in too much trouble for C code to help out anyway.)
+	 */
+	if (write & ~1) {
+		unsigned long pc = write & ~1;
+		if (pc >= (unsigned long) __start_unalign_asm_code &&
+		    pc < (unsigned long) __end_unalign_asm_code) {
+			struct thread_info *ti = current_thread_info();
+			/*
+			 * Our EX_CONTEXT is still what it was from the
+			 * initial unalign exception, but now we've faulted
+			 * on the JIT page.  We would like to complete the
+			 * page fault however is appropriate, and then retry
+			 * the instruction that caused the unalign exception.
+			 * Our state has been "corrupted" by setting the low
+			 * bit in "sp", and stashing r0..r3 in the
+			 * thread_info area, so we revert all of that, then
+			 * continue as if this were a normal page fault.
+			 */
+			regs->sp &= ~1UL;
+			regs->regs[0] = ti->unalign_jit_tmp[0];
+			regs->regs[1] = ti->unalign_jit_tmp[1];
+			regs->regs[2] = ti->unalign_jit_tmp[2];
+			regs->regs[3] = ti->unalign_jit_tmp[3];
+			write &= 1;
+		} else {
+			pr_alert("%s/%d: ICS set at page fault at %#lx: %#lx\n",
+				 current->comm, current->pid, pc, address);
+			show_regs(regs);
+			do_group_exit(SIGKILL);
+			return;
+		}
+	}
+#else
 	/* This case should have been handled by do_page_fault_ics(). */
 	BUG_ON(write & ~1);
+#endif
 
 #if CHIP_HAS_TILE_DMA()
 	/*
@@ -752,10 +791,6 @@ void do_page_fault(struct pt_regs *regs, int fault_num,
 	case INT_DMATLB_MISS:
 	case INT_DMATLB_MISS_DWNCL:
 #endif
-#if CHIP_HAS_SN_PROC()
-	case INT_SNITLB_MISS:
-	case INT_SNITLB_MISS_DWNCL:
-#endif
 		is_page_fault = 1;
 		break;
 
@@ -771,8 +806,8 @@ void do_page_fault(struct pt_regs *regs, int fault_num,
 		panic("Bad fault number %d in do_page_fault", fault_num);
 	}
 
-#if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC()
-	if (EX1_PL(regs->ex1) != USER_PL) {
+#if CHIP_HAS_TILE_DMA()
+	if (!user_mode(regs)) {
 		struct async_tlb *async;
 		switch (fault_num) {
 #if CHIP_HAS_TILE_DMA()
@@ -783,12 +818,6 @@ void do_page_fault(struct pt_regs *regs, int fault_num,
 			async = &current->thread.dma_async_tlb;
 			break;
 #endif
-#if CHIP_HAS_SN_PROC()
-		case INT_SNITLB_MISS:
-		case INT_SNITLB_MISS_DWNCL:
-			async = &current->thread.sn_async_tlb;
-			break;
-#endif
 		default:
 			async = NULL;
 		}
@@ -821,14 +850,22 @@ void do_page_fault(struct pt_regs *regs, int fault_num,
 }
 
 
-#if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC()
+#if CHIP_HAS_TILE_DMA()
 /*
- * Check an async_tlb structure to see if a deferred fault is waiting,
- * and if so pass it to the page-fault code.
+ * This routine effectively re-issues asynchronous page faults
+ * when we are returning to user space.
  */
-static void handle_async_page_fault(struct pt_regs *regs,
-				    struct async_tlb *async)
+void do_async_page_fault(struct pt_regs *regs)
 {
+	struct async_tlb *async = &current->thread.dma_async_tlb;
+
+	/*
+	 * Clear thread flag early.  If we re-interrupt while processing
+	 * code here, we will reset it and recall this routine before
+	 * returning to user space.
+	 */
+	clear_thread_flag(TIF_ASYNC_TLB);
+
 	if (async->fault_num) {
 		/*
 		 * Clear async->fault_num before calling the page-fault
@@ -842,35 +879,15 @@ static void handle_async_page_fault(struct pt_regs *regs,
 				  async->address, async->is_write);
 	}
 }
-
-/*
- * This routine effectively re-issues asynchronous page faults
- * when we are returning to user space.
- */
-void do_async_page_fault(struct pt_regs *regs)
-{
-	/*
-	 * Clear thread flag early.  If we re-interrupt while processing
-	 * code here, we will reset it and recall this routine before
-	 * returning to user space.
-	 */
-	clear_thread_flag(TIF_ASYNC_TLB);
-
-#if CHIP_HAS_TILE_DMA()
-	handle_async_page_fault(regs, &current->thread.dma_async_tlb);
-#endif
-#if CHIP_HAS_SN_PROC()
-	handle_async_page_fault(regs, &current->thread.sn_async_tlb);
-#endif
-}
-#endif /* CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC() */
+#endif /* CHIP_HAS_TILE_DMA() */
 
 
 void vmalloc_sync_all(void)
 {
 #ifdef __tilegx__
 	/* Currently all L1 kernel pmd's are static and shared. */
-	BUG_ON(pgd_index(VMALLOC_END) != pgd_index(VMALLOC_START));
+	BUILD_BUG_ON(pgd_index(VMALLOC_END - PAGE_SIZE) !=
+		     pgd_index(VMALLOC_START));
 #else
 	/*
 	 * Note that races in the updates of insync and start aren't