Merge tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Add powerpc qspinlock implementation optimised for large system
   scalability and paravirt. See the merge message for more details

 - Enable objtool to be built on powerpc to generate mcount locations

 - Use a temporary mm for code patching with the Radix MMU, so the
   writable mapping is restricted to the patching CPU

 - Add an option to build the 64-bit big-endian kernel with the ELFv2
   ABI

 - Sanitise user registers on interrupt entry on 64-bit Book3S

 - Many other small features and fixes

Thanks to Aboorva Devarajan, Angel Iglesias, Benjamin Gray, Bjorn
Helgaas, Bo Liu, Chen Lifu, Christoph Hellwig, Christophe JAILLET,
Christophe Leroy, Christopher M. Riedl, Colin Ian King, Deming Wang,
Disha Goel, Dmitry Torokhov, Finn Thain, Geert Uytterhoeven, Gustavo A.
R. Silva, Haowen Bai, Joel Stanley, Jordan Niethe, Julia Lawall, Kajol
Jain, Laurent Dufour, Li zeming, Miaoqian Lin, Michael Jeanson, Nathan
Lynch, Naveen N. Rao, Nayna Jain, Nicholas Miehlbradt, Nicholas Piggin,
Pali Rohár, Randy Dunlap, Rohan McLure, Russell Currey, Sathvika
Vasireddy, Shaomin Deng, Stephen Kitt, Stephen Rothwell, Thomas
Weißschuh, Tiezhu Yang, Uwe Kleine-König, Xie Shaowen, Xiu Jianfeng,
XueBing Chen, Yang Yingliang, Zhang Jiaming, ruanjinjie, Jessica Yu,
and Wolfram Sang.

* tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (181 commits)
  powerpc/code-patching: Fix oops with DEBUG_VM enabled
  powerpc/qspinlock: Fix 32-bit build
  powerpc/prom: Fix 32-bit build
  powerpc/rtas: mandate RTAS syscall filtering
  powerpc/rtas: define pr_fmt and convert printk call sites
  powerpc/rtas: clean up includes
  powerpc/rtas: clean up rtas_error_log_max initialization
  powerpc/pseries/eeh: use correct API for error log size
  powerpc/rtas: avoid scheduling in rtas_os_term()
  powerpc/rtas: avoid device tree lookups in rtas_os_term()
  powerpc/rtasd: use correct OF API for event scan rate
  powerpc/rtas: document rtas_call()
  powerpc/pseries: unregister VPA when hot unplugging a CPU
  powerpc/pseries: reset the RCU watchdogs after a LPM
  powerpc: Take in account addition CPU node when building kexec FDT
  powerpc: export the CPU node count
  powerpc/cpuidle: Set CPUIDLE_FLAG_POLLING for snooze state
  powerpc/dts/fsl: Fix pca954x i2c-mux node names
  cxl: Remove unnecessary cxl_pci_window_alignment()
  selftests/powerpc: Fix resource leaks
  ...

1 files changed, 126 insertions, 66 deletions

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index e847f9b1c5b9..deded51a7978 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -7,43 +7,35 @@
  * Copyright (C) 2001 IBM.
  */
 
-#include <linux/stdarg.h>
-#include <linux/kernel.h>
-#include <linux/types.h>
-#include <linux/spinlock.h>
-#include <linux/export.h>
-#include <linux/init.h>
+#define pr_fmt(fmt)	"rtas: " fmt
+
 #include <linux/capability.h>
 #include <linux/delay.h>
-#include <linux/cpu.h>
-#include <linux/sched.h>
-#include <linux/smp.h>
-#include <linux/completion.h>
-#include <linux/cpumask.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
 #include <linux/memblock.h>
-#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
 #include <linux/reboot.h>
+#include <linux/sched.h>
 #include <linux/security.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/stdarg.h>
 #include <linux/syscalls.h>
-#include <linux/of.h>
-#include <linux/of_fdt.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
 
+#include <asm/delay.h>
+#include <asm/firmware.h>
 #include <asm/interrupt.h>
-#include <asm/rtas.h>
-#include <asm/hvcall.h>
 #include <asm/machdep.h>
-#include <asm/firmware.h>
+#include <asm/mmu.h>
 #include <asm/page.h>
-#include <asm/param.h>
-#include <asm/delay.h>
-#include <linux/uaccess.h>
-#include <asm/udbg.h>
-#include <asm/syscalls.h>
-#include <asm/smp.h>
-#include <linux/atomic.h>
+#include <asm/rtas.h>
 #include <asm/time.h>
-#include <asm/mmu.h>
-#include <asm/topology.h>
+#include <asm/udbg.h>
 
 /* This is here deliberately so it's only used in this file */
 void enter_rtas(unsigned long);
@@ -353,6 +345,9 @@ int rtas_service_present(const char *service)
 EXPORT_SYMBOL(rtas_service_present);
 
 #ifdef CONFIG_RTAS_ERROR_LOGGING
+
+static u32 rtas_error_log_max __ro_after_init = RTAS_ERROR_LOG_MAX;
+
 /*
  * Return the firmware-specified size of the error log buffer
  *  for all rtas calls that require an error buffer argument.
@@ -360,21 +355,30 @@ EXPORT_SYMBOL(rtas_service_present);
  */
 int rtas_get_error_log_max(void)
 {
-	static int rtas_error_log_max;
-	if (rtas_error_log_max)
-		return rtas_error_log_max;
-
-	rtas_error_log_max = rtas_token ("rtas-error-log-max");
-	if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
-	    (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
-		printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
-			rtas_error_log_max);
-		rtas_error_log_max = RTAS_ERROR_LOG_MAX;
-	}
 	return rtas_error_log_max;
 }
 EXPORT_SYMBOL(rtas_get_error_log_max);
 
+static void __init init_error_log_max(void)
+{
+	static const char propname[] __initconst = "rtas-error-log-max";
+	u32 max;
+
+	if (of_property_read_u32(rtas.dev, propname, &max)) {
+		pr_warn("%s not found, using default of %u\n",
+			propname, RTAS_ERROR_LOG_MAX);
+		max = RTAS_ERROR_LOG_MAX;
+	}
+
+	if (max > RTAS_ERROR_LOG_MAX) {
+		pr_warn("%s = %u, clamping max error log size to %u\n",
+			propname, max, RTAS_ERROR_LOG_MAX);
+		max = RTAS_ERROR_LOG_MAX;
+	}
+
+	rtas_error_log_max = max;
+}
+
 
 static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
 static int rtas_last_error_token;
@@ -432,6 +436,7 @@ static char *__fetch_rtas_last_error(char *altbuf)
 #else /* CONFIG_RTAS_ERROR_LOGGING */
 #define __fetch_rtas_last_error(x)	NULL
 #define get_errorlog_buffer()		NULL
+static void __init init_error_log_max(void) {}
 #endif
 
 
@@ -467,6 +472,64 @@ void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
 static int ibm_open_errinjct_token;
 static int ibm_errinjct_token;
 
+/**
+ * rtas_call() - Invoke an RTAS firmware function.
+ * @token: Identifies the function being invoked.
+ * @nargs: Number of input parameters. Does not include token.
+ * @nret: Number of output parameters, including the call status.
+ * @outputs: Array of @nret output words.
+ * @....: List of @nargs input parameters.
+ *
+ * Invokes the RTAS function indicated by @token, which the caller
+ * should obtain via rtas_token().
+ *
+ * The @nargs and @nret arguments must match the number of input and
+ * output parameters specified for the RTAS function.
+ *
+ * rtas_call() returns RTAS status codes, not conventional Linux errno
+ * values. Callers must translate any failure to an appropriate errno
+ * in syscall context. Most callers of RTAS functions that can return
+ * -2 or 990x should use rtas_busy_delay() to correctly handle those
+ * statuses before calling again.
+ *
+ * The return value descriptions are adapted from 7.2.8 [RTAS] Return
+ * Codes of the PAPR and CHRP specifications.
+ *
+ * Context: Process context preferably, interrupt context if
+ *          necessary.  Acquires an internal spinlock and may perform
+ *          GFP_ATOMIC slab allocation in error path. Unsafe for NMI
+ *          context.
+ * Return:
+ * *                          0 - RTAS function call succeeded.
+ * *                         -1 - RTAS function encountered a hardware or
+ *                                platform error, or the token is invalid,
+ *                                or the function is restricted by kernel policy.
+ * *                         -2 - Specs say "A necessary hardware device was busy,
+ *                                and the requested function could not be
+ *                                performed. The operation should be retried at
+ *                                a later time." This is misleading, at least with
+ *                                respect to current RTAS implementations. What it
+ *                                usually means in practice is that the function
+ *                                could not be completed while meeting RTAS's
+ *                                deadline for returning control to the OS (250us
+ *                                for PAPR/PowerVM, typically), but the call may be
+ *                                immediately reattempted to resume work on it.
+ * *                         -3 - Parameter error.
+ * *                         -7 - Unexpected state change.
+ * *                9000...9899 - Vendor-specific success codes.
+ * *                9900...9905 - Advisory extended delay. Caller should try
+ *                                again after ~10^x ms has elapsed, where x is
+ *                                the last digit of the status [0-5]. Again going
+ *                                beyond the PAPR text, 990x on PowerVM indicates
+ *                                contention for RTAS-internal resources. Other
+ *                                RTAS call sequences in progress should be
+ *                                allowed to complete before reattempting the
+ *                                call.
+ * *                      -9000 - Multi-level isolation error.
+ * *              -9999...-9004 - Vendor-specific error codes.
+ * * Additional negative values - Function-specific error.
+ * * Additional positive values - Function-specific success.
+ */
 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
 {
 	va_list list;
@@ -657,8 +720,7 @@ static int rtas_error_rc(int rtas_rc)
 			rc = -ENODEV;
 			break;
 		default:
-			printk(KERN_ERR "%s: unexpected RTAS error %d\n",
-					__func__, rtas_rc);
+			pr_err("%s: unexpected error %d\n", __func__, rtas_rc);
 			rc = -ERANGE;
 			break;
 	}
@@ -862,8 +924,8 @@ void __noreturn rtas_restart(char *cmd)
 {
 	if (rtas_flash_term_hook)
 		rtas_flash_term_hook(SYS_RESTART);
-	printk("RTAS system-reboot returned %d\n",
-	       rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
+	pr_emerg("system-reboot returned %d\n",
+		 rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
 	for (;;);
 }
 
@@ -872,8 +934,8 @@ void rtas_power_off(void)
 	if (rtas_flash_term_hook)
 		rtas_flash_term_hook(SYS_POWER_OFF);
 	/* allow power on only with power button press */
-	printk("RTAS power-off returned %d\n",
-	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
+	pr_emerg("power-off returned %d\n",
+		 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
 	for (;;);
 }
 
@@ -882,13 +944,14 @@ void __noreturn rtas_halt(void)
 	if (rtas_flash_term_hook)
 		rtas_flash_term_hook(SYS_HALT);
 	/* allow power on only with power button press */
-	printk("RTAS power-off returned %d\n",
-	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
+	pr_emerg("power-off returned %d\n",
+		 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
 	for (;;);
 }
 
 /* Must be in the RMO region, so we place it here */
 static char rtas_os_term_buf[2048];
+static s32 ibm_os_term_token = RTAS_UNKNOWN_SERVICE;
 
 void rtas_os_term(char *str)
 {
@@ -900,19 +963,23 @@ void rtas_os_term(char *str)
 	 * this property may terminate the partition which we want to avoid
 	 * since it interferes with panic_timeout.
 	 */
-	if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") ||
-	    RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term"))
+	if (ibm_os_term_token == RTAS_UNKNOWN_SERVICE)
 		return;
 
 	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
 
+	/*
+	 * Keep calling as long as RTAS returns a "try again" status,
+	 * but don't use rtas_busy_delay(), which potentially
+	 * schedules.
+	 */
 	do {
-		status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
+		status = rtas_call(ibm_os_term_token, 1, 1, NULL,
 				   __pa(rtas_os_term_buf));
-	} while (rtas_busy_delay(status));
+	} while (rtas_busy_delay_time(status));
 
 	if (status != 0)
-		printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
+		pr_emerg("ibm,os-term call failed %d\n", status);
 }
 
 /**
@@ -983,8 +1050,6 @@ noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log
 	return NULL;
 }
 
-#ifdef CONFIG_PPC_RTAS_FILTER
-
 /*
  * The sys_rtas syscall, as originally designed, allows root to pass
  * arbitrary physical addresses to RTAS calls. A number of RTAS calls
@@ -1133,20 +1198,6 @@ static void __init rtas_syscall_filter_init(void)
 		rtas_filters[i].token = rtas_token(rtas_filters[i].name);
 }
 
-#else
-
-static bool block_rtas_call(int token, int nargs,
-			    struct rtas_args *args)
-{
-	return false;
-}
-
-static void __init rtas_syscall_filter_init(void)
-{
-}
-
-#endif /* CONFIG_PPC_RTAS_FILTER */
-
 /* We assume to be passed big endian arguments */
 SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
 {
@@ -1277,6 +1328,15 @@ void __init rtas_initialize(void)
 	no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
 	rtas.entry = no_entry ? rtas.base : entry;
 
+	init_error_log_max();
+
+	/*
+	 * Discover these now to avoid device tree lookups in the
+	 * panic path.
+	 */
+	if (of_property_read_bool(rtas.dev, "ibm,extended-os-term"))
+		ibm_os_term_token = rtas_token("ibm,os-term");
+
 	/* If RTAS was found, allocate the RMO buffer for it and look for
 	 * the stop-self token if any
 	 */