Merge tag 'powerpc-5.2-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Slightly delayed due to the issue with printk() calling
  probe_kernel_read() interacting with our new user access prevention
  stuff, but all fixed now.

  The only out-of-area changes are the addition of a cpuhp_state, small
  additions to Documentation and MAINTAINERS updates.

  Highlights:

   - Support for Kernel Userspace Access/Execution Prevention (like
     SMAP/SMEP/PAN/PXN) on some 64-bit and 32-bit CPUs. This prevents
     the kernel from accidentally accessing userspace outside
     copy_to/from_user(), or ever executing userspace.

   - KASAN support on 32-bit.

   - Rework of where we map the kernel, vmalloc, etc. on 64-bit hash to
     use the same address ranges we use with the Radix MMU.

   - A rewrite into C of large parts of our idle handling code for
     64-bit Book3S (ie. power8 & power9).

   - A fast path entry for syscalls on 32-bit CPUs, for a 12-17% speedup
     in the null_syscall benchmark.

   - On 64-bit bare metal we have support for recovering from errors
     with the time base (our clocksource), however if that fails
     currently we hang in __delay() and never crash. We now have support
     for detecting that case and short circuiting __delay() so we at
     least panic() and reboot.

   - Add support for optionally enabling the DAWR on Power9, which had
     to be disabled by default due to a hardware erratum. This has the
     effect of enabling hardware breakpoints for GDB, the downside is a
     badly behaved program could crash the machine by pointing the DAWR
     at cache inhibited memory. This is opt-in obviously.

   - xmon, our crash handler, gets support for a read only mode where
     operations that could change memory or otherwise disturb the system
     are disabled.

  Plus many clean-ups, reworks and minor fixes etc.

  Thanks to: Christophe Leroy, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar,
  Anton Blanchard, Ben Hutchings, Bo YU, Breno Leitao, Cédric Le Goater,
  Christopher M. Riedl, Christoph Hellwig, Colin Ian King, David Gibson,
  Ganesh Goudar, Gautham R. Shenoy, George Spelvin, Greg Kroah-Hartman,
  Greg Kurz, Horia Geantă, Jagadeesh Pagadala, Joel Stanley, Joe
  Perches, Julia Lawall, Laurentiu Tudor, Laurent Vivier, Lukas Bulwahn,
  Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
  Neuling, Mukesh Ojha, Nathan Fontenot, Nathan Lynch, Nicholas Piggin,
  Nick Desaulniers, Oliver O'Halloran, Peng Hao, Qian Cai, Ravi
  Bangoria, Rick Lindsley, Russell Currey, Sachin Sant, Stewart Smith,
  Sukadev Bhattiprolu, Thomas Huth, Tobin C. Harding, Tyrel Datwyler,
  Valentin Schneider, Wei Yongjun, Wen Yang, YueHaibing"

* tag 'powerpc-5.2-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (205 commits)
  powerpc/64s: Use early_mmu_has_feature() in set_kuap()
  powerpc/book3s/64: check for NULL pointer in pgd_alloc()
  powerpc/mm: Fix hugetlb page initialization
  ocxl: Fix return value check in afu_ioctl()
  powerpc/mm: fix section mismatch for setup_kup()
  powerpc/mm: fix redundant inclusion of pgtable-frag.o in Makefile
  powerpc/mm: Fix makefile for KASAN
  powerpc/kasan: add missing/lost Makefile
  selftests/powerpc: Add a signal fuzzer selftest
  powerpc/booke64: set RI in default MSR
  ocxl: Provide global MMIO accessors for external drivers
  ocxl: move event_fd handling to frontend
  ocxl: afu_irq only deals with IRQ IDs, not offsets
  ocxl: Allow external drivers to use OpenCAPI contexts
  ocxl: Create a clear delineation between ocxl backend & frontend
  ocxl: Don't pass pci_dev around
  ocxl: Split pci.c
  ocxl: Remove some unused exported symbols
  ocxl: Remove superfluous 'extern' from headers
  ocxl: read_pasid never returns an error, so make it void
  ...

1 files changed, 40 insertions, 115 deletions

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index a9c934f2319b..cf54b784100d 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -44,6 +44,8 @@
 #include <asm/export.h>
 #include <asm/asm-405.h>
 
+#include "head_32.h"
+
 /* As with the other PowerPC ports, it is expected that when code
  * execution begins here, the following registers contain valid, yet
  * optional, information:
@@ -99,46 +101,6 @@ _ENTRY(saved_ksp_limit)
 	.space	4
 
 /*
- * Exception vector entry code. This code runs with address translation
- * turned off (i.e. using physical addresses). We assume SPRG_THREAD has
- * the physical address of the current task thread_struct.
- * Note that we have to have decremented r1 before we write to any fields
- * of the exception frame, since a critical interrupt could occur at any
- * time, and it will write to the area immediately below the current r1.
- */
-#define NORMAL_EXCEPTION_PROLOG						     \
-	mtspr	SPRN_SPRG_SCRATCH0,r10;	/* save two registers to work with */\
-	mtspr	SPRN_SPRG_SCRATCH1,r11;					     \
-	mtspr	SPRN_SPRG_SCRATCH2,r1;					     \
-	mfcr	r10;			/* save CR in r10 for now	   */\
-	mfspr	r11,SPRN_SRR1;		/* check whether user or kernel    */\
-	andi.	r11,r11,MSR_PR;						     \
-	beq	1f;							     \
-	mfspr	r1,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
-	lwz	r1,TASK_STACK-THREAD(r1); /* this thread's kernel stack   */\
-	addi	r1,r1,THREAD_SIZE;					     \
-1:	subi	r1,r1,INT_FRAME_SIZE;	/* Allocate an exception frame     */\
-	tophys(r11,r1);							     \
-	stw	r10,_CCR(r11);          /* save various registers	   */\
-	stw	r12,GPR12(r11);						     \
-	stw	r9,GPR9(r11);						     \
-	mfspr	r10,SPRN_SPRG_SCRATCH0;					     \
-	stw	r10,GPR10(r11);						     \
-	mfspr	r12,SPRN_SPRG_SCRATCH1;					     \
-	stw	r12,GPR11(r11);						     \
-	mflr	r10;							     \
-	stw	r10,_LINK(r11);						     \
-	mfspr	r10,SPRN_SPRG_SCRATCH2;					     \
-	mfspr	r12,SPRN_SRR0;						     \
-	stw	r10,GPR1(r11);						     \
-	mfspr	r9,SPRN_SRR1;						     \
-	stw	r10,0(r11);						     \
-	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
-	stw	r0,GPR0(r11);						     \
-	SAVE_4GPRS(3, r11);						     \
-	SAVE_2GPRS(7, r11)
-
-/*
  * Exception prolog for critical exceptions.  This is a little different
  * from the normal exception prolog above since a critical exception
  * can potentially occur at any point during normal exception processing.
@@ -177,6 +139,9 @@ _ENTRY(saved_ksp_limit)
 	tovirt(r1,r11);							     \
 	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
 	stw	r0,GPR0(r11);						     \
+	lis	r10, STACK_FRAME_REGS_MARKER@ha; /* exception frame marker */\
+	addi	r10, r10, STACK_FRAME_REGS_MARKER@l;			     \
+	stw	r10, 8(r11);						     \
 	SAVE_4GPRS(3, r11);						     \
 	SAVE_2GPRS(7, r11)
 
@@ -196,53 +161,12 @@ _ENTRY(saved_ksp_limit)
 /*
  * Exception vectors.
  */
-#define	START_EXCEPTION(n, label)					     \
-	. = n;								     \
-label:
-
-#define EXCEPTION(n, label, hdlr, xfer)				\
-	START_EXCEPTION(n, label);				\
-	NORMAL_EXCEPTION_PROLOG;				\
-	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
-	xfer(n, hdlr)
-
 #define CRITICAL_EXCEPTION(n, label, hdlr)			\
 	START_EXCEPTION(n, label);				\
 	CRITICAL_EXCEPTION_PROLOG;				\
 	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
 	EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
-			  NOCOPY, crit_transfer_to_handler,	\
-			  ret_from_crit_exc)
-
-#define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret)	\
-	li	r10,trap;					\
-	stw	r10,_TRAP(r11);					\
-	lis	r10,msr@h;					\
-	ori	r10,r10,msr@l;					\
-	copyee(r10, r9);					\
-	bl	tfer;		 				\
-	.long	hdlr;						\
-	.long	ret
-
-#define COPY_EE(d, s)		rlwimi d,s,0,16,16
-#define NOCOPY(d, s)
-
-#define EXC_XFER_STD(n, hdlr)		\
-	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \
-			  ret_from_except_full)
-
-#define EXC_XFER_LITE(n, hdlr)		\
-	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
-			  ret_from_except)
-
-#define EXC_XFER_EE(n, hdlr)		\
-	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
-			  ret_from_except_full)
-
-#define EXC_XFER_EE_LITE(n, hdlr)	\
-	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \
-			  ret_from_except)
-
+			  crit_transfer_to_handler, ret_from_crit_exc)
 
 /*
  * 0x0100 - Critical Interrupt Exception
@@ -393,7 +317,7 @@ label:
  * This is caused by a fetch from non-execute or guarded pages.
  */
 	START_EXCEPTION(0x0400, InstructionAccess)
-	NORMAL_EXCEPTION_PROLOG
+	EXCEPTION_PROLOG
 	mr	r4,r12			/* Pass SRR0 as arg2 */
 	li	r5,0			/* Pass zero as arg3 */
 	EXC_XFER_LITE(0x400, handle_page_fault)
@@ -403,33 +327,32 @@ label:
 
 /* 0x0600 - Alignment Exception */
 	START_EXCEPTION(0x0600, Alignment)
-	NORMAL_EXCEPTION_PROLOG
+	EXCEPTION_PROLOG
 	mfspr	r4,SPRN_DEAR		/* Grab the DEAR and save it */
 	stw	r4,_DEAR(r11)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_EE(0x600, alignment_exception)
+	EXC_XFER_STD(0x600, alignment_exception)
 
 /* 0x0700 - Program Exception */
 	START_EXCEPTION(0x0700, ProgramCheck)
-	NORMAL_EXCEPTION_PROLOG
+	EXCEPTION_PROLOG
 	mfspr	r4,SPRN_ESR		/* Grab the ESR and save it */
 	stw	r4,_ESR(r11)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0x700, program_check_exception)
 
-	EXCEPTION(0x0800, Trap_08, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0900, Trap_09, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0A00, Trap_0A, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0B00, Trap_0B, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x0800, Trap_08, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0900, Trap_09, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0A00, Trap_0A, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0B00, Trap_0B, unknown_exception, EXC_XFER_STD)
 
 /* 0x0C00 - System Call Exception */
 	START_EXCEPTION(0x0C00,	SystemCall)
-	NORMAL_EXCEPTION_PROLOG
-	EXC_XFER_EE_LITE(0xc00, DoSyscall)
+	SYSCALL_ENTRY	0xc00
 
-	EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_STD)
 
 /* 0x1000 - Programmable Interval Timer (PIT) Exception */
 	. = 0x1000
@@ -646,25 +569,25 @@ label:
 	mfspr	r10, SPRN_SPRG_SCRATCH0
 	b	InstructionAccess
 
-	EXCEPTION(0x1300, Trap_13, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1400, Trap_14, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1300, Trap_13, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1400, Trap_14, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_STD)
 #ifdef CONFIG_IBM405_ERR51
 	/* 405GP errata 51 */
 	START_EXCEPTION(0x1700, Trap_17)
 	b DTLBMiss
 #else
-	EXCEPTION(0x1700, Trap_17, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1700, Trap_17, unknown_exception, EXC_XFER_STD)
 #endif
-	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1A00, Trap_1A, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1B00, Trap_1B, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1C00, Trap_1C, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1D00, Trap_1D, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1E00, Trap_1E, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1F00, Trap_1F, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1A00, Trap_1A, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1B00, Trap_1B, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1C00, Trap_1C, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1D00, Trap_1D, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1E00, Trap_1E, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1F00, Trap_1F, unknown_exception, EXC_XFER_STD)
 
 /* Check for a single step debug exception while in an exception
  * handler before state has been saved.  This is to catch the case
@@ -726,11 +649,11 @@ label:
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_TEMPLATE(DebugException, 0x2002, \
 		(MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
-		NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
+		crit_transfer_to_handler, ret_from_crit_exc)
 
 	/* Programmable Interval Timer (PIT) Exception. (from 0x1000) */
 Decrementer:
-	NORMAL_EXCEPTION_PROLOG
+	EXCEPTION_PROLOG
 	lis	r0,TSR_PIS@h
 	mtspr	SPRN_TSR,r0		/* Clear the PIT exception */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
@@ -738,9 +661,9 @@ Decrementer:
 
 	/* Fixed Interval Timer (FIT) Exception. (from 0x1010) */
 FITException:
-	NORMAL_EXCEPTION_PROLOG
+	EXCEPTION_PROLOG
 	addi	r3,r1,STACK_FRAME_OVERHEAD;
-	EXC_XFER_EE(0x1010, unknown_exception)
+	EXC_XFER_STD(0x1010, unknown_exception)
 
 	/* Watchdog Timer (WDT) Exception. (from 0x1020) */
 WDTException:
@@ -748,15 +671,14 @@ WDTException:
 	addi	r3,r1,STACK_FRAME_OVERHEAD;
 	EXC_XFER_TEMPLATE(WatchdogException, 0x1020+2,
 	                  (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)),
-			  NOCOPY, crit_transfer_to_handler,
-			  ret_from_crit_exc)
+			  crit_transfer_to_handler, ret_from_crit_exc)
 
 /*
  * The other Data TLB exceptions bail out to this point
  * if they can't resolve the lightweight TLB fault.
  */
 DataAccess:
-	NORMAL_EXCEPTION_PROLOG
+	EXCEPTION_PROLOG
 	mfspr	r5,SPRN_ESR		/* Grab the ESR, save it, pass arg3 */
 	stw	r5,_ESR(r11)
 	mfspr	r4,SPRN_DEAR		/* Grab the DEAR, save it, pass arg2 */
@@ -848,6 +770,9 @@ start_here:
 /*
  * Decide what sort of machine this is and initialize the MMU.
  */
+#ifdef CONFIG_KASAN
+	bl	kasan_early_init
+#endif
 	li	r3,0
 	mr	r4,r31
 	bl	machine_init