[PATCH 4.4 40/56] MIPS: Fix CM region target definitions

[PATCH 4.4 40/56] MIPS: Fix CM region target definitions

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Paul Burton <paul.burton@mips.com>

commit 6a6cba1d945a7511cdfaf338526871195e420762 upstream.

The default CM target field in the GCR_BASE register is encoded with 0
meaning memory & 1 being reserved. However the definitions we use for
those bits effectively get these two values backwards - likely because
they were copied from the definitions for the CM regions where the
target is encoded differently. This results in use setting up GCR_BASE
with the reserved target value by default, rather than targeting memory
as intended. Although we currently seem to get away with this it's not a
great idea to rely upon.

Fix this by changing our macros to match the documentated target values.

The incorrect encoding became used as of commit 9f98f3dd0c51 ("MIPS: Add
generic CM probe & access code") in the Linux v3.15 cycle, and was
likely carried forwards from older but unused code introduced by
commit 39b8d5254246 ("[MIPS] Add support for MIPS CMP platform.") in the
v2.6.26 cycle.

Fixes: 9f98f3dd0c51 ("MIPS: Add generic CM probe & access code")
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: Matt Redfearn <matt.redfearn@mips.com>
Reviewed-by: James Hogan <jhogan@kernel.org>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.15+
Patchwork: https://patchwork.linux-mips.org/patch/17562/
Signed-off-by: James Hogan <jhogan@kernel.org>
[jhogan@kernel.org: Backported 3.15..4.13]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/mips/include/asm/mips-cm.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/mips/include/asm/mips-cm.h
+++ b/arch/mips/include/asm/mips-cm.h
@@ -238,8 +238,8 @@ BUILD_CM_Cx_R_(tcid_8_priority,	0x80)
 #define CM_GCR_BASE_GCRBASE_MSK			(_ULCAST_(0x1ffff) << 15)
 #define CM_GCR_BASE_CMDEFTGT_SHF		0
 #define CM_GCR_BASE_CMDEFTGT_MSK		(_ULCAST_(0x3) << 0)
-#define  CM_GCR_BASE_CMDEFTGT_DISABLED		0
-#define  CM_GCR_BASE_CMDEFTGT_MEM		1
+#define  CM_GCR_BASE_CMDEFTGT_MEM		0
+#define  CM_GCR_BASE_CMDEFTGT_RESERVED		1
 #define  CM_GCR_BASE_CMDEFTGT_IOCU0		2
 #define  CM_GCR_BASE_CMDEFTGT_IOCU1		3
 

[PATCH 4.4 41/56] MIPS: SMP: Use a completion event to signal CPU up

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Matt Redfearn <matt.redfearn@imgtec.com>

commit a00eeede507c975087b7b8df8cf2c9f88ba285de upstream.

If a secondary CPU failed to start, for any reason, the CPU requesting
the secondary to start would get stuck in the loop waiting for the
secondary to be present in the cpu_callin_map.

Rather than that, use a completion event to signal that the secondary
CPU has started and is waiting to synchronise counters.

Since the CPU presence will no longer be marked in cpu_callin_map,
remove the redundant test from arch_cpu_idle_dead().

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14502/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/process.c |    4 +---
 arch/mips/kernel/smp.c     |   15 +++++++++------
 2 files changed, 10 insertions(+), 9 deletions(-)

--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -49,9 +49,7 @@
 #ifdef CONFIG_HOTPLUG_CPU
 void arch_cpu_idle_dead(void)
 {
-	/* What the heck is this check doing ? */
-	if (!cpumask_test_cpu(smp_processor_id(), &cpu_callin_map))
-		play_dead();
+	play_dead();
 }
 #endif
 
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -64,6 +64,8 @@ EXPORT_SYMBOL(cpu_sibling_map);
 cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
 EXPORT_SYMBOL(cpu_core_map);
 
+static DECLARE_COMPLETION(cpu_running);
+
 /*
  * A logcal cpu mask containing only one VPE per core to
  * reduce the number of IPIs on large MT systems.
@@ -174,7 +176,7 @@ asmlinkage void start_secondary(void)
 	cpumask_set_cpu(cpu, &cpu_coherent_mask);
 	notify_cpu_starting(cpu);
 
-	cpumask_set_cpu(cpu, &cpu_callin_map);
+	complete(&cpu_running);
 	synchronise_count_slave(cpu);
 
 	set_cpu_online(cpu, true);
@@ -242,7 +244,6 @@ void smp_prepare_boot_cpu(void)
 {
 	set_cpu_possible(0, true);
 	set_cpu_online(0, true);
-	cpumask_set_cpu(0, &cpu_callin_map);
 }
 
 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
@@ -250,11 +251,13 @@ int __cpu_up(unsigned int cpu, struct ta
 	mp_ops->boot_secondary(cpu, tidle);
 
 	/*
-	 * Trust is futile.  We should really have timeouts ...
+	 * We must check for timeout here, as the CPU will not be marked
+	 * online until the counters are synchronised.
 	 */
-	while (!cpumask_test_cpu(cpu, &cpu_callin_map)) {
-		udelay(100);
-		schedule();
+	if (!wait_for_completion_timeout(&cpu_running,
+					 msecs_to_jiffies(1000))) {
+		pr_crit("CPU%u: failed to start\n", cpu);
+		return -EIO;
 	}
 
 	synchronise_count_master(cpu);

[PATCH 4.4 42/56] MIPS: Fix race on setting and getting cpu_online_mask

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>

commit 6f542ebeaee0ee552a902ce3892220fc22c7ec8e upstream.

While testing cpu hoptlug (cpu down and up in loops) on kernel 4.4, it was
observed that occasionally check for cpu online will fail in kernel/cpu.c,
_cpu_up:

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/tree/kernel/cpu.c?h=v4.4.79#n485
 518        /* Arch-specific enabling code. */
 519        ret = __cpu_up(cpu, idle);
 520
 521        if (ret != 0)
 522                goto out_notify;
 523        BUG_ON(!cpu_online(cpu));

Reason is race between start_secondary and _cpu_up. cpu_callin_map is set
before cpu_online_mask. In __cpu_up, cpu_callin_map is waited for, but cpu
online mask is not, resulting in race in which secondary processor started
and set cpu_callin_map, but not yet set the online mask,resulting in above
BUG being hit.

Upstream differs in the area. cpu_online check is in bringup_wait_for_ap,
which is after cpu reached AP_ONLINE_IDLE,where secondary passed its start
function. Nonetheless, fix makes start_secondary safe and not depending on
other locks throughout the code. It protects as well against cpu_online
checks put in between sometimes in the future.

Fix this by moving completion after all flags are set.

Signed-off-by: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Cc: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16925/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/smp.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -176,9 +176,6 @@ asmlinkage void start_secondary(void)
 	cpumask_set_cpu(cpu, &cpu_coherent_mask);
 	notify_cpu_starting(cpu);
 
-	complete(&cpu_running);
-	synchronise_count_slave(cpu);
-
 	set_cpu_online(cpu, true);
 
 	set_cpu_sibling_map(cpu);
@@ -186,6 +183,9 @@ asmlinkage void start_secondary(void)
 
 	calculate_cpu_foreign_map();
 
+	complete(&cpu_running);
+	synchronise_count_slave(cpu);
+
 	/*
 	 * irq will be enabled in ->smp_finish(), enabling it too early
 	 * is dangerous.

[PATCH 4.4 48/56] MIPS: AR7: Defer registration of GPIO

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jonas Gorski <jonas.gorski@gmail.com>

commit e6b03ab63b4d270e0249f96536fde632409dc1dc upstream.

When called from prom init code, ar7_gpio_init() will fail as it will
call gpiochip_add() which relies on a working kmalloc() to alloc
the gpio_desc array and kmalloc is not useable yet at prom init time.

Move ar7_gpio_init() to ar7_register_devices() (a device_initcall)
where kmalloc works.

Fixes: 14e85c0e69d5 ("gpio: remove gpio_descs global array")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: linux-mips@linux-mips.org
Cc: linux-serial@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17542/
Signed-off-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/ar7/platform.c |    4 ++++
 arch/mips/ar7/prom.c     |    2 --
 2 files changed, 4 insertions(+), 2 deletions(-)

--- a/arch/mips/ar7/platform.c
+++ b/arch/mips/ar7/platform.c
@@ -654,6 +654,10 @@ static int __init ar7_register_devices(v
 	u32 val;
 	int res;
 
+	res = ar7_gpio_init();
+	if (res)
+		pr_warn("unable to register gpios: %d\n", res);
+
 	res = ar7_register_uarts();
 	if (res)
 		pr_err("unable to setup uart(s): %d\n", res);
--- a/arch/mips/ar7/prom.c
+++ b/arch/mips/ar7/prom.c
@@ -246,8 +246,6 @@ void __init prom_init(void)
 	ar7_init_cmdline(fw_arg0, (char **)fw_arg1);
 	ar7_init_env((struct env_var *)fw_arg2);
 	console_config();
-
-	ar7_gpio_init();
 }
 
 #define PORT(offset) (KSEG1ADDR(AR7_REGS_UART0 + (offset * 4)))

[PATCH 4.4 49/56] MIPS: AR7: Ensure that serial ports are properly set up

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>

commit b084116f8587b222a2c5ef6dcd846f40f24b9420 upstream.

Without UPF_FIXED_TYPE, the data from the PORT_AR7 uart_config entry is
never copied, resulting in a dead port.

Fixes: 154615d55459 ("MIPS: AR7: Use correct UART port type")
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
[jonas.gorski: add Fixes tag]
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Cc: linux-mips@linux-mips.org
Cc: linux-serial@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17543/
Signed-off-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/ar7/platform.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/mips/ar7/platform.c
+++ b/arch/mips/ar7/platform.c
@@ -576,6 +576,7 @@ static int __init ar7_register_uarts(voi
 	uart_port.type		= PORT_AR7;
 	uart_port.uartclk	= clk_get_rate(bus_clk) / 2;
 	uart_port.iotype	= UPIO_MEM32;
+	uart_port.flags		= UPF_FIXED_TYPE;
 	uart_port.regshift	= 2;
 
 	uart_port.line		= 0;