[PATCH 00/16] Another 16 L2C patches

[PATCH 00/16] Another 16 L2C patches

[Russell King - ARM Linux]

So, in response to Matt Porter's complaint about breaking prima2, here's
another 16 patches which changes the way the L2 cache is initialised on
many platforms.  This series moves towards a situation where the generic
code initialises the L2 cache itself, with as little help as possible
from board specific code.

A number of platforms are left alone because they're more complex -
these should still eventually be converted.

At some point in the near future, I will see about sorting out their
ordering wrt the previous patch set.  For the time being, they apply
on top of the existing l2c changes.

 arch/arm/include/asm/mach/arch.h  |  3 +++
 arch/arm/kernel/irq.c             | 12 ++++++++++++
 arch/arm/mach-bcm/bcm_5301x.c     |  9 ++-------
 arch/arm/mach-berlin/berlin.c     | 17 ++++++-----------
 arch/arm/mach-exynos/exynos.c     |  8 ++------
 arch/arm/mach-highbank/highbank.c |  9 +++------
 arch/arm/mach-imx/mach-vf610.c    |  9 ++-------
 arch/arm/mach-mvebu/board-v7.c    |  9 ++++++---
 arch/arm/mach-nomadik/cpu-8815.c  | 13 +++----------
 arch/arm/mach-prima2/Makefile     |  1 -
 arch/arm/mach-prima2/common.c     |  6 ++++++
 arch/arm/mach-prima2/l2x0.c       | 17 -----------------
 arch/arm/mach-rockchip/rockchip.c |  9 ++-------
 arch/arm/mach-socfpga/socfpga.c   |  9 ++-------
 arch/arm/mach-sti/board-dt.c      | 20 +++++---------------
 arch/arm/mach-tegra/tegra.c       | 12 +++---------
 arch/arm/mach-vexpress/v2m.c      |  3 ++-
 arch/arm/mach-zynq/common.c       |  8 +++-----
 18 files changed, 62 insertions(+), 112 deletions(-)


-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

[PATCH 01/16] ARM: l2c: bcm - remove UL (needs folding into earlier patch)

[Russell King]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-bcm/bcm_5301x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-bcm/bcm_5301x.c b/arch/arm/mach-bcm/bcm_5301x.c
index edff69761e04..6bc9c31b1b0b 100644
--- a/arch/arm/mach-bcm/bcm_5301x.c
+++ b/arch/arm/mach-bcm/bcm_5301x.c
@@ -45,7 +45,7 @@ static void __init bcm5301x_init_early(void)
 
 static void __init bcm5301x_dt_init(void)
 {
-	l2x0_of_init(0, ~0UL);
+	l2x0_of_init(0, ~0);
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 }
 
-- 
1.8.3.1

[PATCH 02/16] ARM: l2c: add platform independent core L2 cache initialisation

[Russell King]

Add a hook into the core ARM code to perform L2 cache initialisation
in a platform independent manner.  Platforms still get to indicate
their auxiliary control register values and mask, but the
initialisation call will now be made from generic code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/include/asm/mach/arch.h |  3 +++
 arch/arm/kernel/irq.c            | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
index 17a3fa2979e8..5249cc3c52f4 100644
--- a/arch/arm/include/asm/mach/arch.h
+++ b/arch/arm/include/asm/mach/arch.h
@@ -45,6 +45,9 @@ struct machine_desc {
 	unsigned char		reserve_lp1 :1;	/* never has lp1	*/
 	unsigned char		reserve_lp2 :1;	/* never has lp2	*/
 	enum reboot_mode	reboot_mode;	/* default restart mode	*/
+	unsigned		l2c_aux_val;	/* L2 cache aux value	*/
+	unsigned		l2c_aux_mask;	/* L2 cache aux mask	*/
+	void			(*l2c_write_sec)(unsigned long, unsigned);
 	struct smp_operations	*smp;		/* SMP operations	*/
 	bool			(*smp_init)(void);
 	void			(*fixup)(struct tag *, char **,
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 9723d17b8f38..2c4257604513 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -37,6 +37,7 @@
 #include <linux/proc_fs.h>
 #include <linux/export.h>
 
+#include <asm/hardware/cache-l2x0.h>
 #include <asm/exception.h>
 #include <asm/mach/arch.h>
 #include <asm/mach/irq.h>
@@ -115,10 +116,21 @@ EXPORT_SYMBOL_GPL(set_irq_flags);
 
 void __init init_IRQ(void)
 {
+	int ret;
+
 	if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
 		irqchip_init();
 	else
 		machine_desc->init_irq();
+
+	if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
+	    (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
+		outer_cache.write_sec = machine_desc->l2c_write_sec;
+		ret = l2x0_of_init(machine_desc->l2c_aux_val,
+				   machine_desc->l2c_aux_mask);
+		if (ret)
+			pr_err("L2C: failed to init: %d\n", ret);
+	}
 }
 
 #ifdef CONFIG_MULTI_IRQ_HANDLER
-- 
1.8.3.1

[PATCH 03/16] ARM: l2c: convert rockchip to generic l2c initialisation

[Russell King]

This also allows us to eliminate the .init_machine function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-rockchip/rockchip.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-rockchip/rockchip.c b/arch/arm/mach-rockchip/rockchip.c
index d252efe3747b..138b9975313a 100644
--- a/arch/arm/mach-rockchip/rockchip.c
+++ b/arch/arm/mach-rockchip/rockchip.c
@@ -24,12 +24,6 @@
 #include <asm/hardware/cache-l2x0.h>
 #include "core.h"
 
-static void __init rockchip_dt_init(void)
-{
-	l2x0_of_init(0, ~0);
-	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
-}
-
 static const char * const rockchip_board_dt_compat[] = {
 	"rockchip,rk2928",
 	"rockchip,rk3066a",
@@ -39,7 +33,8 @@ static const char * const rockchip_board_dt_compat[] = {
 };
 
 DT_MACHINE_START(ROCKCHIP_DT, "Rockchip Cortex-A9 (Device Tree)")
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.smp		= smp_ops(rockchip_smp_ops),
-	.init_machine	= rockchip_dt_init,
 	.dt_compat	= rockchip_board_dt_compat,
 MACHINE_END
-- 
1.8.3.1

[PATCH 04/16] ARM: l2c: convert nomadik to generic l2c initialisation

[Russell King]

This also allows us to eliminate the .init_machine function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-nomadik/cpu-8815.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/arm/mach-nomadik/cpu-8815.c b/arch/arm/mach-nomadik/cpu-8815.c
index 0f245bcc6b7e..9116ca476d7c 100644
--- a/arch/arm/mach-nomadik/cpu-8815.c
+++ b/arch/arm/mach-nomadik/cpu-8815.c
@@ -143,23 +143,16 @@ static int __init cpu8815_mmcsd_init(void)
 }
 device_initcall(cpu8815_mmcsd_init);
 
-static void __init cpu8815_init_of(void)
-{
-#ifdef CONFIG_CACHE_L2X0
-	/* At full speed latency must be >=2, so 0x249 in low bits */
-	l2x0_of_init(0x00700249, 0xfe0fefff);
-#endif
-	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
-}
-
 static const char * cpu8815_board_compat[] = {
 	"calaosystems,usb-s8815",
 	NULL,
 };
 
 DT_MACHINE_START(NOMADIK_DT, "Nomadik STn8815")
+	/* At full speed latency must be >=2, so 0x249 in low bits */
+	.l2c_aux_val	= 0x00700249,
+	.l2c_aux_mask	= 0xfe0fefff,
 	.map_io		= cpu8815_map_io,
-	.init_machine	= cpu8815_init_of,
 	.restart	= cpu8815_restart,
 	.dt_compat      = cpu8815_board_compat,
 MACHINE_END
-- 
1.8.3.1

[PATCH 05/16] ARM: l2c: convert zynq to generic l2c initialisation

[Russell King]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-zynq/common.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c
index 1e617a6dedc3..d1e992e6403e 100644
--- a/arch/arm/mach-zynq/common.c
+++ b/arch/arm/mach-zynq/common.c
@@ -67,11 +67,6 @@ static void __init zynq_init_machine(void)
 {
 	struct platform_device_info devinfo = { .name = "cpufreq-cpu0", };
 
-	/*
-	 * 64KB way size, 8-way associativity, parity disabled
-	 */
-	l2x0_of_init(0x02000000, 0xf0ffffff);
-
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 
 	platform_device_register(&zynq_cpuidle_device);
@@ -133,6 +128,9 @@ static const char * const zynq_dt_match[] = {
 };
 
 DT_MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform")
+	/* 64KB way size, 8-way associativity, parity disabled */
+	.l2c_aux_val	= 0x02000000,
+	.l2c_aux_mask	= 0xf0ffffff,
 	.smp		= smp_ops(zynq_smp_ops),
 	.map_io		= zynq_map_io,
 	.init_irq	= zynq_irq_init,
-- 
1.8.3.1

[PATCH 06/16] ARM: l2c: convert highbank to generic l2c initialisation

[Russell King]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-highbank/highbank.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/arm/mach-highbank/highbank.c b/arch/arm/mach-highbank/highbank.c
index 245e588859ec..8c35ae4ff176 100644
--- a/arch/arm/mach-highbank/highbank.c
+++ b/arch/arm/mach-highbank/highbank.c
@@ -66,12 +66,6 @@ static void __init highbank_init_irq(void)
 
 	if (of_find_compatible_node(NULL, NULL, "arm,cortex-a9"))
 		highbank_scu_map_io();
-
-	/* Enable PL310 L2 Cache controller */
-	if (IS_ENABLED(CONFIG_CACHE_L2X0)) {
-		outer_cache.write_sec = highbank_l2c310_write_sec;
-		l2x0_of_init(0, ~0);
-	}
 }
 
 static void highbank_power_off(void)
@@ -185,6 +179,9 @@ DT_MACHINE_START(HIGHBANK, "Highbank")
 #if defined(CONFIG_ZONE_DMA) && defined(CONFIG_ARM_LPAE)
 	.dma_zone_size	= (4ULL * SZ_1G),
 #endif
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
+	.l2c_write_sec	= highbank_l2c310_write_sec,
 	.init_irq	= highbank_init_irq,
 	.init_machine	= highbank_init,
 	.dt_compat	= highbank_match,
-- 
1.8.3.1

[PATCH 07/16] ARM: l2c: convert tegra to generic l2c initialisation

[Russell King]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-tegra/tegra.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c
index 1bc49f9db015..d90065e2552a 100644
--- a/arch/arm/mach-tegra/tegra.c
+++ b/arch/arm/mach-tegra/tegra.c
@@ -70,20 +70,12 @@ u32 tegra_uart_config[3] = {
 	0,
 };
 
-static void __init tegra_init_cache(void)
-{
-#ifdef CONFIG_CACHE_L2X0
-	l2x0_of_init(0x3c400001, 0xc20fc3fe);
-#endif
-}
-
 static void __init tegra_init_early(void)
 {
 	of_register_trusted_foundations();
 	tegra_apb_io_init();
 	tegra_init_fuse();
 	tegra_cpu_reset_handler_init();
-	tegra_init_cache();
 	tegra_powergate_init();
 	tegra_hotplug_init();
 }
@@ -171,8 +163,10 @@ static const char * const tegra_dt_board_compat[] = {
 };
 
 DT_MACHINE_START(TEGRA_DT, "NVIDIA Tegra SoC (Flattened Device Tree)")
-	.map_io		= tegra_map_common_io,
 	.smp		= smp_ops(tegra_smp_ops),
+	.l2c_aux_val	= 0x3c400001,
+	.l2c_aux_mask	= 0xc20fc3fe,
+	.map_io		= tegra_map_common_io,
 	.init_early	= tegra_init_early,
 	.init_irq	= tegra_dt_init_irq,
 	.init_machine	= tegra_dt_init,
-- 
1.8.3.1

[PATCH 08/16] ARM: l2c: convert prima2 to generic l2c initialisation

[Russell King]

Along with this change, we can delete l2x0.c from prima2.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-prima2/Makefile |  1 -
 arch/arm/mach-prima2/common.c |  6 ++++++
 arch/arm/mach-prima2/l2x0.c   | 17 -----------------
 3 files changed, 6 insertions(+), 18 deletions(-)
 delete mode 100644 arch/arm/mach-prima2/l2x0.c

diff --git a/arch/arm/mach-prima2/Makefile b/arch/arm/mach-prima2/Makefile
index 7a6b4a323125..8846e7d87ea5 100644
--- a/arch/arm/mach-prima2/Makefile
+++ b/arch/arm/mach-prima2/Makefile
@@ -2,7 +2,6 @@ obj-y += rstc.o
 obj-y += common.o
 obj-y += rtciobrg.o
 obj-$(CONFIG_DEBUG_LL) += lluart.o
-obj-$(CONFIG_CACHE_L2X0) += l2x0.o
 obj-$(CONFIG_SUSPEND) += pm.o sleep.o
 obj-$(CONFIG_SMP) += platsmp.o headsmp.o
 obj-$(CONFIG_HOTPLUG_CPU)  += hotplug.o
diff --git a/arch/arm/mach-prima2/common.c b/arch/arm/mach-prima2/common.c
index 47c7819edb9b..1cdb8b565cfe 100644
--- a/arch/arm/mach-prima2/common.c
+++ b/arch/arm/mach-prima2/common.c
@@ -34,6 +34,8 @@ static const char *atlas6_dt_match[] __initconst = {
 
 DT_MACHINE_START(ATLAS6_DT, "Generic ATLAS6 (Flattened Device Tree)")
 	/* Maintainer: Barry Song <baohua.song@csr.com> */
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.map_io         = sirfsoc_map_io,
 	.init_late	= sirfsoc_init_late,
 	.dt_compat      = atlas6_dt_match,
@@ -48,6 +50,8 @@ static const char *prima2_dt_match[] __initconst = {
 
 DT_MACHINE_START(PRIMA2_DT, "Generic PRIMA2 (Flattened Device Tree)")
 	/* Maintainer: Barry Song <baohua.song@csr.com> */
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.map_io         = sirfsoc_map_io,
 	.dma_zone_size	= SZ_256M,
 	.init_late	= sirfsoc_init_late,
@@ -64,6 +68,8 @@ static const char *marco_dt_match[] __initconst = {
 DT_MACHINE_START(MARCO_DT, "Generic MARCO (Flattened Device Tree)")
 	/* Maintainer: Barry Song <baohua.song@csr.com> */
 	.smp            = smp_ops(sirfsoc_smp_ops),
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.map_io         = sirfsoc_map_io,
 	.init_late	= sirfsoc_init_late,
 	.dt_compat      = marco_dt_match,
diff --git a/arch/arm/mach-prima2/l2x0.c b/arch/arm/mach-prima2/l2x0.c
deleted file mode 100644
index 09f68f046830..000000000000
--- a/arch/arm/mach-prima2/l2x0.c
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * l2 cache initialization for CSR SiRFprimaII
- *
- * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
- *
- * Licensed under GPLv2 or later.
- */
-
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <asm/hardware/cache-l2x0.h>
-
-static int __init sirfsoc_l2x0_init(void)
-{
-	return l2x0_of_init(0, ~0);
-}
-early_initcall(sirfsoc_l2x0_init);
-- 
1.8.3.1

[PATCH 09/16] ARM: l2c: convert vexpress to generic l2c initialisation

[Russell King]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-vexpress/v2m.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
index 4f8b8cb17ff5..b2fea70d412d 100644
--- a/arch/arm/mach-vexpress/v2m.c
+++ b/arch/arm/mach-vexpress/v2m.c
@@ -432,7 +432,6 @@ static const struct of_device_id v2m_dt_bus_match[] __initconst = {
 
 static void __init v2m_dt_init(void)
 {
-	l2x0_of_init(0x00400000, 0xfe0fffff);
 	of_platform_populate(NULL, v2m_dt_bus_match, NULL, NULL);
 }
 
@@ -443,6 +442,8 @@ static const char * const v2m_dt_match[] __initconst = {
 
 DT_MACHINE_START(VEXPRESS_DT, "ARM-Versatile Express")
 	.dt_compat	= v2m_dt_match,
+	.l2c_aux_val	= 0x00400000,
+	.l2c_aux_mask	= 0xfe0fffff,
 	.smp		= smp_ops(vexpress_smp_ops),
 	.smp_init	= smp_init_ops(vexpress_smp_init_ops),
 	.map_io		= v2m_dt_map_io,
-- 
1.8.3.1

[PATCH 10/16] ARM: l2c: convert mvebu to generic l2c initialisation

[Russell King]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-mvebu/board-v7.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-mvebu/board-v7.c b/arch/arm/mach-mvebu/board-v7.c
index c6bd79f64744..48169caa56ea 100644
--- a/arch/arm/mach-mvebu/board-v7.c
+++ b/arch/arm/mach-mvebu/board-v7.c
@@ -59,9 +59,6 @@ static void __init mvebu_timer_and_clk_init(void)
 	clocksource_of_init();
 	coherency_init();
 	BUG_ON(mvebu_mbus_dt_init());
-#ifdef CONFIG_CACHE_L2X0
-	l2x0_of_init(0, ~0);
-#endif
 
 	if (of_machine_is_compatible("marvell,armada375"))
 		hook_fault_code(16 + 6, armada_375_external_abort_wa, SIGBUS, 0,
@@ -109,6 +106,8 @@ static const char * const armada_370_xp_dt_compat[] = {
 };
 
 DT_MACHINE_START(ARMADA_370_XP_DT, "Marvell Armada 370/XP (Device Tree)")
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.smp		= smp_ops(armada_xp_smp_ops),
 	.init_machine	= mvebu_dt_init,
 	.init_time	= mvebu_timer_and_clk_init,
@@ -122,6 +121,8 @@ static const char * const armada_375_dt_compat[] = {
 };
 
 DT_MACHINE_START(ARMADA_375_DT, "Marvell Armada 375 (Device Tree)")
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.init_time	= mvebu_timer_and_clk_init,
 	.restart	= mvebu_restart,
 	.dt_compat	= armada_375_dt_compat,
@@ -134,6 +135,8 @@ static const char * const armada_38x_dt_compat[] = {
 };
 
 DT_MACHINE_START(ARMADA_38X_DT, "Marvell Armada 380/385 (Device Tree)")
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.init_time	= mvebu_timer_and_clk_init,
 	.restart	= mvebu_restart,
 	.dt_compat	= armada_38x_dt_compat,
-- 
1.8.3.1

[PATCH 11/16] ARM: l2c: convert bcm_5301x to generic l2c initialisation

[Russell King]

This also allows us to eliminate the .init_machine function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-bcm/bcm_5301x.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-bcm/bcm_5301x.c b/arch/arm/mach-bcm/bcm_5301x.c
index 6bc9c31b1b0b..e9bcbdbce555 100644
--- a/arch/arm/mach-bcm/bcm_5301x.c
+++ b/arch/arm/mach-bcm/bcm_5301x.c
@@ -43,19 +43,14 @@ static void __init bcm5301x_init_early(void)
 			"imprecise external abort");
 }
 
-static void __init bcm5301x_dt_init(void)
-{
-	l2x0_of_init(0, ~0);
-	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
-}
-
 static const char __initconst *bcm5301x_dt_compat[] = {
 	"brcm,bcm4708",
 	NULL,
 };
 
 DT_MACHINE_START(BCM5301X, "BCM5301X")
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.init_early	= bcm5301x_init_early,
-	.init_machine	= bcm5301x_dt_init,
 	.dt_compat	= bcm5301x_dt_compat,
 MACHINE_END
-- 
1.8.3.1

[PATCH 12/16] ARM: l2c: convert imx vf610 to generic l2c initialisation

[Russell King]

Since the .init_irq method only calls irqchip_init, we can remove that
too.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-imx/mach-vf610.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-imx/mach-vf610.c b/arch/arm/mach-imx/mach-vf610.c
index 6288a9690e78..c44602758120 100644
--- a/arch/arm/mach-imx/mach-vf610.c
+++ b/arch/arm/mach-imx/mach-vf610.c
@@ -20,19 +20,14 @@ static void __init vf610_init_machine(void)
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 }
 
-static void __init vf610_init_irq(void)
-{
-	l2x0_of_init(0, ~0);
-	irqchip_init();
-}
-
 static const char *vf610_dt_compat[] __initconst = {
 	"fsl,vf610",
 	NULL,
 };
 
 DT_MACHINE_START(VYBRID_VF610, "Freescale Vybrid VF610 (Device Tree)")
-	.init_irq	= vf610_init_irq,
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.init_machine   = vf610_init_machine,
 	.dt_compat	= vf610_dt_compat,
 	.restart	= mxc_restart,
-- 
1.8.3.1

[PATCH 13/16] ARM: l2c: convert sti to generic l2c initialisation

[Russell King]

We can remove the .init_machine as it becomes the generic version.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-sti/board-dt.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mach-sti/board-dt.c b/arch/arm/mach-sti/board-dt.c
index cf716ae10726..4924d2214be6 100644
--- a/arch/arm/mach-sti/board-dt.c
+++ b/arch/arm/mach-sti/board-dt.c
@@ -14,19 +14,6 @@
 
 #include "smp.h"
 
-void __init stih41x_l2x0_init(void)
-{
-	l2x0_of_init(L2C_AUX_CTRL_SHARED_OVERRIDE |
-		     L310_AUX_CTRL_DATA_PREFETCH |
-		     L310_AUX_CTRL_INSTR_PREFETCH, 0xc00f0fff);
-}
-
-static void __init stih41x_machine_init(void)
-{
-	stih41x_l2x0_init();
-	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
-}
-
 static const char *stih41x_dt_match[] __initdata = {
 	"st,stih415",
 	"st,stih416",
@@ -34,7 +21,10 @@ static const char *stih41x_dt_match[] __initdata = {
 };
 
 DT_MACHINE_START(STM, "STiH415/416 SoC with Flattened Device Tree")
-	.init_machine	= stih41x_machine_init,
-	.smp		= smp_ops(sti_smp_ops),
 	.dt_compat	= stih41x_dt_match,
+	.l2c_aux_val	= L2C_AUX_CTRL_SHARED_OVERRIDE |
+			  L310_AUX_CTRL_DATA_PREFETCH |
+			  L310_AUX_CTRL_INSTR_PREFETCH,
+	.l2c_aux_mask	= 0xc00f0fff,
+	.smp		= smp_ops(sti_smp_ops),
 MACHINE_END
-- 
1.8.3.1

[PATCH 14/16] ARM: l2c: convert exynos to generic l2c initialisation (and thereby fix it)

[Russell King]

exynos was unconditionally calling the L2 cache initialisation from an
early_initcall.  This breaks multiplatform kernels.  Thankfully,
converting to generic l2c initialisation fixes this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-exynos/exynos.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
index fbfc29df3299..a763c0862da9 100644
--- a/arch/arm/mach-exynos/exynos.c
+++ b/arch/arm/mach-exynos/exynos.c
@@ -316,12 +316,6 @@ static int __init exynos_core_init(void)
 }
 core_initcall(exynos_core_init);
 
-static int __init exynos4_l2x0_cache_init(void)
-{
-	return l2x0_of_init(0x3c400001, 0xc20fffff);
-}
-early_initcall(exynos4_l2x0_cache_init);
-
 static void __init exynos_dt_machine_init(void)
 {
 	struct device_node *i2c_np;
@@ -387,6 +381,8 @@ static void __init exynos_reserve(void)
 DT_MACHINE_START(EXYNOS_DT, "SAMSUNG EXYNOS (Flattened Device Tree)")
 	/* Maintainer: Thomas Abraham <thomas.abraham@linaro.org> */
 	/* Maintainer: Kukjin Kim <kgene.kim@samsung.com> */
+	.l2c_aux_val	= 0x3c400001,
+	.l2c_aux_mask	= 0xc20fffff,
 	.smp		= smp_ops(exynos_smp_ops),
 	.map_io		= exynos_init_io,
 	.init_early	= exynos_firmware_init,
-- 
1.8.3.1

[PATCH 15/16] ARM: l2c: convert socfpga to generic l2c initialisation

[Russell King]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-socfpga/socfpga.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
index 9bbb8177f247..adbf38314ca8 100644
--- a/arch/arm/mach-socfpga/socfpga.c
+++ b/arch/arm/mach-socfpga/socfpga.c
@@ -98,22 +98,17 @@ static void socfpga_cyclone5_restart(enum reboot_mode mode, const char *cmd)
 	writel(temp, rst_manager_base_addr + SOCFPGA_RSTMGR_CTRL);
 }
 
-static void __init socfpga_cyclone5_init(void)
-{
-	l2x0_of_init(0, ~0);
-	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
-}
-
 static const char *altera_dt_match[] = {
 	"altr,socfpga",
 	NULL
 };
 
 DT_MACHINE_START(SOCFPGA, "Altera SOCFPGA")
+	.l2c_aux_val	= 0,
+	.l2c_aux_mask	= ~0,
 	.smp		= smp_ops(socfpga_smp_ops),
 	.map_io		= socfpga_map_io,
 	.init_irq	= socfpga_init_irq,
-	.init_machine	= socfpga_cyclone5_init,
 	.restart	= socfpga_cyclone5_restart,
 	.dt_compat	= altera_dt_match,
 MACHINE_END
-- 
1.8.3.1

[PATCH 16/16] ARM: l2c: convert berlin to generic l2c initialisation

[Russell King]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-berlin/berlin.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/arch/arm/mach-berlin/berlin.c b/arch/arm/mach-berlin/berlin.c
index 6709d2a6bec8..ac181c6797ee 100644
--- a/arch/arm/mach-berlin/berlin.c
+++ b/arch/arm/mach-berlin/berlin.c
@@ -18,16 +18,6 @@
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/mach/arch.h>
 
-static void __init berlin_init_machine(void)
-{
-	/*
-	 * with DT probing for L2CCs, berlin_init_machine can be removed.
-	 * Note: 88DE3005 (Armada 1500-mini) uses pl310 l2cc
-	 */
-	l2x0_of_init(0x30c00000, 0xfeffffff);
-	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
-}
-
 static const char * const berlin_dt_compat[] = {
 	"marvell,berlin",
 	NULL,
@@ -35,5 +25,10 @@ static const char * const berlin_dt_compat[] = {
 
 DT_MACHINE_START(BERLIN_DT, "Marvell Berlin")
 	.dt_compat	= berlin_dt_compat,
-	.init_machine	= berlin_init_machine,
+	/*
+	 * with DT probing for L2CCs, berlin_init_machine can be removed.
+	 * Note: 88DE3005 (Armada 1500-mini) uses pl310 l2cc
+	 */
+	.l2c_aux_val	= 0x30c00000,
+	.l2c_aux_mask	= 0xfeffffff,
 MACHINE_END
-- 
1.8.3.1

[PATCH 00/16] Another 16 L2C patches

[Stephen Warren]

On 04/28/2014 10:56 AM, Russell King - ARM Linux wrote:
> So, in response to Matt Porter's complaint about breaking prima2, here's
> another 16 patches which changes the way the L2 cache is initialised on
> many platforms.  This series moves towards a situation where the generic
> code initialises the L2 cache itself, with as little help as possible
> from board specific code.
> 
> A number of platforms are left alone because they're more complex -
> these should still eventually be converted.
> 
> At some point in the near future, I will see about sorting out their
> ordering wrt the previous patch set.  For the time being, they apply
> on top of the existing l2c changes.

Are "the existing l2c changes" in next-20140428? If not, is there a git
branch I can pull to test the whole thing, rather than tracking down and
applying "the existing l2c changes" first?

[PATCH 00/16] Another 16 L2C patches

[Stephen Warren]

On 04/28/2014 11:12 AM, Stephen Warren wrote:
> On 04/28/2014 10:56 AM, Russell King - ARM Linux wrote:
>> So, in response to Matt Porter's complaint about breaking prima2, here's
>> another 16 patches which changes the way the L2 cache is initialised on
>> many platforms.  This series moves towards a situation where the generic
>> code initialises the L2 cache itself, with as little help as possible
>> from board specific code.
>>
>> A number of platforms are left alone because they're more complex -
>> these should still eventually be converted.
>>
>> At some point in the near future, I will see about sorting out their
>> ordering wrt the previous patch set.  For the time being, they apply
>> on top of the existing l2c changes.
> 
> Are "the existing l2c changes" in next-20140428? If not, is there a git
> branch I can pull to test the whole thing, rather than tracking down and
> applying "the existing l2c changes" first?

I guess they must be in linux-next, since this series applies cleanly on
top of it.

So, patches 2/16 ("ARM: l2c: add platform independent core L2 cache
initialisation") and 7/16 ("ARM: l2c: convert tegra to generic l2c
initialisation"),

Tested-by: Stephen Warren <swarren@nvidia.com>

(On an NVIDIA Tegra20 Seaboard/Springbank board, on top of next-20140428)

I do see one error in dmesg during boot, but it doesn't appear to
negatively affect operation in brief testing, and is present in
linux-next without this series anyway. Is this message a problem?

> [    0.000000] L2C: platform modifies aux control register: 0x02080000 -> 0x3e480001
> [    0.000000] L2C: DT/platform modifies aux control register: 0x02080000 -> 0x3e480001
> [    0.000000] L2C-310 errata 727915 769419 enabled
> [    0.000000] L2C-310 enabling early BRESP for Cortex-A9
> [    0.000000] L2C-310: enabling full line of zeros but not enabled in Cortex-A9
                          ^^^^^^ this is logged at error level
> [    0.000000] L2C-310 ID prefetch enabled, offset 1 lines
> [    0.000000] L2C-310 dynamic clock gating disabled, standby mode disabled
> [    0.000000] L2C-310 cache controller enabled, 8 ways, 1024 kB
> [    0.000000] L2C-310: CACHE_ID 0x410000c4, AUX_CTRL 0x7e480001

[PATCH 07/16] ARM: l2c: convert tegra to generic l2c initialisation

[Stephen Warren]

On 04/28/2014 10:58 AM, Russell King wrote:

> diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c

>  DT_MACHINE_START(TEGRA_DT, "NVIDIA Tegra SoC (Flattened Device Tree)")
> -	.map_io		= tegra_map_common_io,
>  	.smp		= smp_ops(tegra_smp_ops),
> +	.l2c_aux_val	= 0x3c400001,
> +	.l2c_aux_mask	= 0xc20fc3fe,
> +	.map_io		= tegra_map_common_io,

I'm not sure why .map_io was moved. Was it to sort the entries in order
of execution? If so, I assume that .smp should be moved too?

[PATCH 08/16] ARM: l2c: convert prima2 to generic l2c initialisation

[Matt Porter]

On Mon, Apr 28, 2014 at 05:58:27PM +0100, Russell King wrote:
> Along with this change, we can delete l2x0.c from prima2.
> 
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> ---
>  arch/arm/mach-prima2/Makefile |  1 -
>  arch/arm/mach-prima2/common.c |  6 ++++++
>  arch/arm/mach-prima2/l2x0.c   | 17 -----------------
>  3 files changed, 6 insertions(+), 18 deletions(-)
>  delete mode 100644 arch/arm/mach-prima2/l2x0.c

I can confirm that this approach fixes the boot failure on bcm281xx and
bcm21664 against the previous set of l2c patches in -next.

Tested-by: Matt Porter <mporter@linaro.org>

Thanks,
Matt

[PATCH 00/16] Another 16 L2C patches

[Russell King - ARM Linux]

On Mon, Apr 28, 2014 at 11:27:09AM -0600, Stephen Warren wrote:
> On 04/28/2014 11:12 AM, Stephen Warren wrote:
> > On 04/28/2014 10:56 AM, Russell King - ARM Linux wrote:
> >> So, in response to Matt Porter's complaint about breaking prima2, here's
> >> another 16 patches which changes the way the L2 cache is initialised on
> >> many platforms.  This series moves towards a situation where the generic
> >> code initialises the L2 cache itself, with as little help as possible
> >> from board specific code.
> >>
> >> A number of platforms are left alone because they're more complex -
> >> these should still eventually be converted.
> >>
> >> At some point in the near future, I will see about sorting out their
> >> ordering wrt the previous patch set.  For the time being, they apply
> >> on top of the existing l2c changes.
> > 
> > Are "the existing l2c changes" in next-20140428? If not, is there a git
> > branch I can pull to test the whole thing, rather than tracking down and
> > applying "the existing l2c changes" first?
> 
> I guess they must be in linux-next, since this series applies cleanly on
> top of it.
> 
> So, patches 2/16 ("ARM: l2c: add platform independent core L2 cache
> initialisation") and 7/16 ("ARM: l2c: convert tegra to generic l2c
> initialisation"),
> 
> Tested-by: Stephen Warren <swarren@nvidia.com>
> 
> (On an NVIDIA Tegra20 Seaboard/Springbank board, on top of next-20140428)
> 
> I do see one error in dmesg during boot, but it doesn't appear to
> negatively affect operation in brief testing, and is present in
> linux-next without this series anyway. Is this message a problem?
> 
> > [    0.000000] L2C: platform modifies aux control register: 0x02080000 -> 0x3e480001
> > [    0.000000] L2C: DT/platform modifies aux control register: 0x02080000 -> 0x3e480001
> > [    0.000000] L2C-310 errata 727915 769419 enabled
> > [    0.000000] L2C-310 enabling early BRESP for Cortex-A9
> > [    0.000000] L2C-310: enabling full line of zeros but not enabled in Cortex-A9
>                           ^^^^^^ this is logged at error level

Correct, it's an error because on Tegra you explicitly set bit 0 in the
auxiliary control register, which is pointless unless the feature is
also enabled in the Cortex-A9 control register as well.

Rather than trying to track down everyone who does this, and then end
up in a long discussion about it, I'm just going to make the kernel
print an error message as a result, it's just wrong to set random bits
in device control registers without first properly understanding what
they're doing.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

[PATCH 07/16] ARM: l2c: convert tegra to generic l2c initialisation

[Russell King - ARM Linux]

On Mon, Apr 28, 2014 at 11:28:00AM -0600, Stephen Warren wrote:
> On 04/28/2014 10:58 AM, Russell King wrote:
> 
> > diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c
> 
> >  DT_MACHINE_START(TEGRA_DT, "NVIDIA Tegra SoC (Flattened Device Tree)")
> > -	.map_io		= tegra_map_common_io,
> >  	.smp		= smp_ops(tegra_smp_ops),
> > +	.l2c_aux_val	= 0x3c400001,
> > +	.l2c_aux_mask	= 0xc20fc3fe,
> > +	.map_io		= tegra_map_common_io,
> 
> I'm not sure why .map_io was moved. Was it to sort the entries in order
> of execution? If so, I assume that .smp should be moved too?

I moved it quite simply because I keep entries in order:

        unsigned                l2c_aux_val;    /* L2 cache aux value   */
        unsigned                l2c_aux_mask;   /* L2 cache aux mask    */
        void                    (*l2c_write_sec)(unsigned long, unsigned);
        struct smp_operations   *smp;           /* SMP operations       */
        bool                    (*smp_init)(void);
        void                    (*fixup)(struct tag *, char **,
                                         struct meminfo *);
        void                    (*init_meminfo)(void);
        void                    (*reserve)(void);/* reserve mem blocks  */
        void                    (*map_io)(void);/* IO mapping function  */
        void                    (*init_early)(void);

And the order of declaration in there (for the functions after "smp")
is the order in which they are called during kernel initialisation.
Platforms randomising their declarations is... silly.  And yes, I'll
move those l2c ones before .smp.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

[PATCH 02/16] ARM: l2c: add platform independent core L2 cache initialisation

[Rob Herring]

On Mon, Apr 28, 2014 at 11:57 AM, Russell King
<rmk+kernel@arm.linux.org.uk> wrote:
> Add a hook into the core ARM code to perform L2 cache initialisation
> in a platform independent manner.  Platforms still get to indicate
> their auxiliary control register values and mask, but the
> initialisation call will now be made from generic code.
>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[...]

> diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
> index 9723d17b8f38..2c4257604513 100644
> --- a/arch/arm/kernel/irq.c
> +++ b/arch/arm/kernel/irq.c
> @@ -37,6 +37,7 @@
>  #include <linux/proc_fs.h>
>  #include <linux/export.h>
>
> +#include <asm/hardware/cache-l2x0.h>
>  #include <asm/exception.h>
>  #include <asm/mach/arch.h>
>  #include <asm/mach/irq.h>
> @@ -115,10 +116,21 @@ EXPORT_SYMBOL_GPL(set_irq_flags);
>
>  void __init init_IRQ(void)
>  {
> +       int ret;
> +
>         if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
>                 irqchip_init();
>         else
>                 machine_desc->init_irq();
> +
> +       if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
> +           (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
> +               outer_cache.write_sec = machine_desc->l2c_write_sec;
> +               ret = l2x0_of_init(machine_desc->l2c_aux_val,
> +                                  machine_desc->l2c_aux_mask);

This function should be a nop if there is no DT node matching, so we
don't really need to trigger calling it based on machine_desc values.
If we do that, then we can have aux_mask and aux_val values of 0 for
both also mean don't do any aux ctrl setup. That would help minimize
the machine_desc for many platforms.

Rob

[PATCH 15/16] ARM: l2c: convert socfpga to generic l2c initialisation

[Dinh Nguyen]

On Mon, 2014-04-28 at 17:59 +0100, Russell King wrote:
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> ---
>  arch/arm/mach-socfpga/socfpga.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
> index 9bbb8177f247..adbf38314ca8 100644
> --- a/arch/arm/mach-socfpga/socfpga.c
> +++ b/arch/arm/mach-socfpga/socfpga.c
> @@ -98,22 +98,17 @@ static void socfpga_cyclone5_restart(enum reboot_mode mode, const char *cmd)
>  	writel(temp, rst_manager_base_addr + SOCFPGA_RSTMGR_CTRL);
>  }
>  
> -static void __init socfpga_cyclone5_init(void)
> -{
> -	l2x0_of_init(0, ~0);
> -	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
> -}
> -
>  static const char *altera_dt_match[] = {
>  	"altr,socfpga",
>  	NULL
>  };
>  
>  DT_MACHINE_START(SOCFPGA, "Altera SOCFPGA")
> +	.l2c_aux_val	= 0,
> +	.l2c_aux_mask	= ~0,
>  	.smp		= smp_ops(socfpga_smp_ops),
>  	.map_io		= socfpga_map_io,
>  	.init_irq	= socfpga_init_irq,
> -	.init_machine	= socfpga_cyclone5_init,
>  	.restart	= socfpga_cyclone5_restart,
>  	.dt_compat	= altera_dt_match,
>  MACHINE_END

Thanks so much for doing this.

Tested-by: Dinh Nguyen <dinguyen@altera.com>

Dinh

[PATCH 00/16] Another 16 L2C patches

[Stephen Warren]

(Dropping most people from CC since this sub-thread is a Tegra-specific
discussion)

On 04/28/2014 11:39 AM, Russell King - ARM Linux wrote:
> On Mon, Apr 28, 2014 at 11:27:09AM -0600, Stephen Warren wrote:
...
>> I do see one error in dmesg during boot, but it doesn't appear to
>> negatively affect operation in brief testing, and is present in
>> linux-next without this series anyway. Is this message a problem?
>>
>>> [    0.000000] L2C: platform modifies aux control register: 0x02080000 -> 0x3e480001
>>> [    0.000000] L2C: DT/platform modifies aux control register: 0x02080000 -> 0x3e480001
>>> [    0.000000] L2C-310 errata 727915 769419 enabled
>>> [    0.000000] L2C-310 enabling early BRESP for Cortex-A9
>>> [    0.000000] L2C-310: enabling full line of zeros but not enabled in Cortex-A9
>>                           ^^^^^^ this is logged at error level
> 
> Correct, it's an error because on Tegra you explicitly set bit 0 in the
> auxiliary control register, which is pointless unless the feature is
> also enabled in the Cortex-A9 control register as well.

Please forgive my almost complete lack of knowledge re: cache
controllers. Is the correct fix for this:

a) To remove bit 0 from the aux_val passed to l2x0_of_init()

b) To set some BIT(3) in the Cortex-A9 auxcr, so this feature is enabled
there too.

And if (b), I assume that's something that the bootloader should be
doing, not the kernel?

Thanks.

[PATCH 00/16] Another 16 L2C patches

[Russell King - ARM Linux]

On Mon, Apr 28, 2014 at 12:08:11PM -0600, Stephen Warren wrote:
> (Dropping most people from CC since this sub-thread is a Tegra-specific
> discussion)
> 
> On 04/28/2014 11:39 AM, Russell King - ARM Linux wrote:
> > On Mon, Apr 28, 2014 at 11:27:09AM -0600, Stephen Warren wrote:
> ...
> >> I do see one error in dmesg during boot, but it doesn't appear to
> >> negatively affect operation in brief testing, and is present in
> >> linux-next without this series anyway. Is this message a problem?
> >>
> >>> [    0.000000] L2C: platform modifies aux control register: 0x02080000 -> 0x3e480001
> >>> [    0.000000] L2C: DT/platform modifies aux control register: 0x02080000 -> 0x3e480001
> >>> [    0.000000] L2C-310 errata 727915 769419 enabled
> >>> [    0.000000] L2C-310 enabling early BRESP for Cortex-A9
> >>> [    0.000000] L2C-310: enabling full line of zeros but not enabled in Cortex-A9
> >>                           ^^^^^^ this is logged at error level
> > 
> > Correct, it's an error because on Tegra you explicitly set bit 0 in the
> > auxiliary control register, which is pointless unless the feature is
> > also enabled in the Cortex-A9 control register as well.
> 
> Please forgive my almost complete lack of knowledge re: cache
> controllers. Is the correct fix for this:
> 
> a) To remove bit 0 from the aux_val passed to l2x0_of_init()
> 
> b) To set some BIT(3) in the Cortex-A9 auxcr, so this feature is enabled
> there too.
> 
> And if (b), I assume that's something that the bootloader should be
> doing, not the kernel?

See "Full line of zero write."

http://infocenter.arm.com/help/topic/com.arm.doc.ddi0246h/CJACBHHB.html#CJADBCJJ

which makes it (a).  The reverse steps are required when disabling the L2
cache controller.

If we decide that we encounter a platform which needs this feature
disabled, the correct way to deal with that is to add a L2C-310
specific property to DT, and not to try to crowbar it in via the L2C
aux control register masks (which should never have been exposed to
platforms using DT.)

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[PATCH 08/16] ARM: l2c: convert prima2 to generic l2c initialisation

[Russell King - ARM Linux]

On Mon, Apr 28, 2014 at 01:34:35PM -0400, Matt Porter wrote:
> On Mon, Apr 28, 2014 at 05:58:27PM +0100, Russell King wrote:
> > Along with this change, we can delete l2x0.c from prima2.
> > 
> > Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> > ---
> >  arch/arm/mach-prima2/Makefile |  1 -
> >  arch/arm/mach-prima2/common.c |  6 ++++++
> >  arch/arm/mach-prima2/l2x0.c   | 17 -----------------
> >  3 files changed, 6 insertions(+), 18 deletions(-)
> >  delete mode 100644 arch/arm/mach-prima2/l2x0.c
> 
> I can confirm that this approach fixes the boot failure on bcm281xx and
> bcm21664 against the previous set of l2c patches in -next.
> 
> Tested-by: Matt Porter <mporter@linaro.org>

Great, rather than taking that tested-by, I'll rework the patches such
that we avoid the breakage through the patch series.

The resulting patch series is now around 100 patches long...

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[PATCH 02/16] ARM: l2c: add platform independent core L2 cache initialisation

[Russell King - ARM Linux]

On Mon, Apr 28, 2014 at 12:54:58PM -0500, Rob Herring wrote:
> This function should be a nop if there is no DT node matching, so we
> don't really need to trigger calling it based on machine_desc values.
> If we do that, then we can have aux_mask and aux_val values of 0 for
> both also mean don't do any aux ctrl setup. That would help minimize
> the machine_desc for many platforms.

Calling it with both set to zero results in the auxiliary control register
being cleared to zero.  We don't want that to happen.

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[PATCH 00/16] Another 16 L2C patches

[Stephen Warren]

On 04/28/2014 12:19 PM, Russell King - ARM Linux wrote:
> On Mon, Apr 28, 2014 at 12:08:11PM -0600, Stephen Warren wrote:
>> (Dropping most people from CC since this sub-thread is a Tegra-specific
>> discussion)
>>
>> On 04/28/2014 11:39 AM, Russell King - ARM Linux wrote:
>>> On Mon, Apr 28, 2014 at 11:27:09AM -0600, Stephen Warren wrote:
>> ...
>>>> I do see one error in dmesg during boot, but it doesn't appear to
>>>> negatively affect operation in brief testing, and is present in
>>>> linux-next without this series anyway. Is this message a problem?
>>>>
>>>>> [    0.000000] L2C: platform modifies aux control register: 0x02080000 -> 0x3e480001
>>>>> [    0.000000] L2C: DT/platform modifies aux control register: 0x02080000 -> 0x3e480001
>>>>> [    0.000000] L2C-310 errata 727915 769419 enabled
>>>>> [    0.000000] L2C-310 enabling early BRESP for Cortex-A9
>>>>> [    0.000000] L2C-310: enabling full line of zeros but not enabled in Cortex-A9
>>>>                           ^^^^^^ this is logged at error level
>>>
>>> Correct, it's an error because on Tegra you explicitly set bit 0 in the
>>> auxiliary control register, which is pointless unless the feature is
>>> also enabled in the Cortex-A9 control register as well.
>>
>> Please forgive my almost complete lack of knowledge re: cache
>> controllers. Is the correct fix for this:
>>
>> a) To remove bit 0 from the aux_val passed to l2x0_of_init()
>>
>> b) To set some BIT(3) in the Cortex-A9 auxcr, so this feature is enabled
>> there too.
>>
>> And if (b), I assume that's something that the bootloader should be
>> doing, not the kernel?
> 
> See "Full line of zero write."
> 
> http://infocenter.arm.com/help/topic/com.arm.doc.ddi0246h/CJACBHHB.html#CJADBCJJ
> 
> which makes it (a).  The reverse steps are required when disabling the L2
> cache controller.

Do you say that simply because to make use of this feature, it also
needs to be enabled in the A9 but no code in the kernel is currently
doing that? Or, because enabling the feature stops the cache controller
from supporting strongly ordered writes?

It seems like the condition this error message detects is benign; the
cache controller is prepared to receive these transactions, but the A9
will never send them. Nothing can go wrong in this case, I believe,
although admittedly it's a pointless configuration.

Equally, given the required enable sequence in that document, won't this
error always get printed if BIT(0) is sent in aux_val; before the bit is
enabled in the cache controller, the associated bit in the A9 /should/
be disabled. It seems like the test in the kernel should simply check if
BIT(0) is set in aux_val and ignore the value in the A9 completely, if
you want to ban people from enabling this feature via aux_val. Or, are
there some platforms where something outside (before) the kernel enables
the feature in the A9 even before the kernel cache init code runs, and
you want to avoid printing the error in that case?

> If we decide that we encounter a platform which needs this feature
> disabled, the correct way to deal with that is to add a L2C-310

I assume /disabled/enabled/ there?

> specific property to DT, and not to try to crowbar it in via the L2C
> aux control register masks (which should never have been exposed to
> platforms using DT.)

[PATCH 02/16] ARM: l2c: add platform independent core L2 cache initialisation

[Rob Herring]

On Mon, Apr 28, 2014 at 1:23 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Mon, Apr 28, 2014 at 12:54:58PM -0500, Rob Herring wrote:
>> This function should be a nop if there is no DT node matching, so we
>> don't really need to trigger calling it based on machine_desc values.
>> If we do that, then we can have aux_mask and aux_val values of 0 for
>> both also mean don't do any aux ctrl setup. That would help minimize
>> the machine_desc for many platforms.
>
> Calling it with both set to zero results in the auxiliary control register
> being cleared to zero.  We don't want that to happen.

Right, but we can make the core L2 init code only write aux ctrl if
(aux_val && ~aux_mask). Then you don't have to add the values on a
bunch of platforms.

Rob

[PATCH 00/16] Another 16 L2C patches

[Heiko Stübner]

Am Montag, 28. April 2014, 17:56:31 schrieb Russell King - ARM Linux:
> So, in response to Matt Porter's complaint about breaking prima2, here's
> another 16 patches which changes the way the L2 cache is initialised on
> many platforms.  This series moves towards a situation where the generic
> code initialises the L2 cache itself, with as little help as possible
> from board specific code.

Patches 2/16 ("ARM: l2c: add platform independent core L2 cache
initialisation") and 3/16 ("ARM: l2c:  convert rockchip to generic l2c 
initialisation") applied on a linux-next from 20140428,

Tested-by: Heiko Stuebner <heiko@sntech.de>

[PATCH 00/16] Another 16 L2C patches

[Russell King - ARM Linux]

On Mon, Apr 28, 2014 at 12:40:16PM -0600, Stephen Warren wrote:
> Do you say that simply because to make use of this feature, it also
> needs to be enabled in the A9 but no code in the kernel is currently
> doing that? Or, because enabling the feature stops the cache controller
> from supporting strongly ordered writes?
> 
> It seems like the condition this error message detects is benign; the
> cache controller is prepared to receive these transactions, but the A9
> will never send them. Nothing can go wrong in this case, I believe,
> although admittedly it's a pointless configuration.

Yes, it's benign, but it's an unnecessary difference between platforms
which stands in the way of trying to clean this crap up.

This is what I've been moaning about for a while: totally pointless
differences between platforms which then stand in the way of future
cleanups, because it's impossible to tell whether a difference is there
because it's required or because (speaking plainly) the maintainer
didn't have any clue what they were doing when the wrote the code.

The L2 cache code has suffered a lot from cargo cult programming, and
other sloppiness - so yes, while it's benign, we can now also have a
benign warning to encourage people not to do this kind of stuff.

> Equally, given the required enable sequence in that document, won't this
> error always get printed if BIT(0) is sent in aux_val; before the bit is
> enabled in the cache controller, the associated bit in the A9 /should/
> be disabled.

The point here is that if we are going to enable various Cortex-A9
optimisations, the way it _should_ be done is that the L2 cache code makes
that decision based on the revision of the parts found, and the only
control which platforms should ever have is one to say "this feature is
broken on platform X, please don't enable it" which that done via DT,
and not via random values passed via an initialisation interface.

So, what this error is all about is:

- the platform maintainer decided to set bit 0 which enables a cortex-a9
  specific feature, which is useless given that the enable bit in
  cortex-a9 is disabled.

- the platform maintainer is setting bits without thinking.

- platform maintainers copy code from other platforms without thinking
  (just look at all the crap uses of L2X0_AUX_CTRL_MASK which is only
  suitable for L2C-210, but gets used on everything.)

So once one person does it, it ends up propagating to other platforms,
and the problem just spreads.

> It seems like the test in the kernel should simply check if
> BIT(0) is set in aux_val and ignore the value in the A9 completely, if
> you want to ban people from enabling this feature via aux_val. Or, are
> there some platforms where something outside (before) the kernel enables
> the feature in the A9 even before the kernel cache init code runs, and
> you want to avoid printing the error in that case?

You're asking questions I have no answer to - and this is the whole
problem here.  Platform maintainers go off in their own tiny worlds,
with blinkers on, doing their own crap without really knowing what the
hell they're doing.

I've *no* clue whether there's a platform which gets this wrong and
enables the FLZ bit in the CA9 control register.  Given the kind of
crap that we have in the kernel - with platforms just deciding to set
bit 0 of the L2 cache auxiliary control register without taking any
time to think, I have no reason to doubt that someone hasn't tried
crap like that, and I have no doubt that it _could_ have worked for
someone sufficiently to get into the kernel.

This is the whole problem: I have no idea what kind of bollocks platform
maintainers do in their spare time.

Frankly, this is another in the long list of arm-soc failures: this
is something that should have been fixed a /long/ time ago - it's
far more important than getting rid of silly timex.h header files,
and the problem is more pervasive.  Instead, it was left, and left and
left, and the problem has grown bigger and bigger.

So no, I'm not offering any sympathy here to anyone, partly because of
the shere amount of effort that the L2 cache series has taken to get
this far - and it's now soo big that it in itself is starting to become
unmanageable.  And with many platform maintainers not really taking an
interest in it when it has been posted, I'm at the point where I just
don't give a that much of a damn about their platform code unless they
take an interest and help do some testing.

> > If we decide that we encounter a platform which needs this feature
> > disabled, the correct way to deal with that is to add a L2C-310
> 
> I assume /disabled/enabled/ there?

No, I meant what I said.  Enable the optimistions by default.  If someone
whinges, we'll fix it, but *only* if it causes a failure.  Any other
solution is total madness, and doesn't get much in the way of interest.

It's easy to ignore a plea for help.  It's impossible to ignore if it
causes a problem.

> > specific property to DT, and not to try to crowbar it in via the L2C
> > aux control register masks (which should never have been exposed to
> > platforms using DT.)

We're only at this point _because_ I've forced people to take an interest
in this code.  I know most platform maintainers would rather not think
about it, as evidenced by the wide-spread cargo-cult programming that has
been going on here.  The only way to get this sorted is to ram this kind
of thing down people's throats.  Yes, it's not a nice way to do it, but
it's the only way.

Also, remember that I don't have these huge board farms that Olof and
Kevin have - in comparison I'm a pauper when it comes to platforms I
can directly test.  This makes my job that much harder, especially when
platform maintainers are uncooperative, and is why I resort to pushing
such stuff into linux-next to _force_ the issue, after I've completed
what testing I can do here, and given it a run through Olof's build
system.

Olof's system is useless for remote debugging though, so it is of little
value other than seeing how many platforms succeed or fail.

-- 
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improving, and getting towards what was expected from it.

[PATCH 02/16] ARM: l2c: add platform independent core L2 cache initialisation

[Russell King - ARM Linux]

On Mon, Apr 28, 2014 at 01:50:33PM -0500, Rob Herring wrote:
> On Mon, Apr 28, 2014 at 1:23 PM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> > On Mon, Apr 28, 2014 at 12:54:58PM -0500, Rob Herring wrote:
> >> This function should be a nop if there is no DT node matching, so we
> >> don't really need to trigger calling it based on machine_desc values.
> >> If we do that, then we can have aux_mask and aux_val values of 0 for
> >> both also mean don't do any aux ctrl setup. That would help minimize
> >> the machine_desc for many platforms.
> >
> > Calling it with both set to zero results in the auxiliary control register
> > being cleared to zero.  We don't want that to happen.
> 
> Right, but we can make the core L2 init code only write aux ctrl if
> (aux_val && ~aux_mask). Then you don't have to add the values on a
> bunch of platforms.

I would rather add them right now rather than introduce new logic which
_could_ potentially change the behaviour for an existing platform.  Maybe
that's an improvement to come after this series is merged, but I'm already
up to almost 100 patches in this series right now, and I'll be damned if
I'm going to change the behaviour of this stuff even more as part of a
single series.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.