ARM: Delete ARM11MPCore (ARM11 ARMv6K SMP) support

This ARM11 SMP configuration was one of the first SMP configurations
the ARM kernel supported, but it has the downside of odd DMA handling,
odd cache tagging, and often (as of recent) completely broken cache
handling on the ARM RealView PB11MPCore test chips. To boot the
platform it was necessary to completely disable the cache.
When it comes to the EB 11MPCore it is unclear if this ever worked.

These reference designs are now the only ARMv6K SMP platforms.

As only reference designs of purely academic interest remain, and
since the special-cased DMA and PMU code is hard to maintain and
doesn't really work, it is not really worth our time.

Delete the ARM11MPCore support along with:

- The special DMA quirk CONFIG_DMA_CACHE_RWFO that is only used
  on ARMv6K SMP, and we are the last ARMV6K system leaving the
  building and the cache handling is awkward, so good-bye.

- The special PMU handling that was only used by ARM11MPCore.

The following is left behind:

- TIMER_OF_DECLARE(arm_twd_11mp, "arm,arm11mp-twd-timer", ...)
  in arch/arm/kernel/smp_twd.c, this is still in use by Marvell MMP3
  arch/arm/boot/dts/marvell/mmp3.dtsi

- IRQCHIP_DECLARE(arm11mp_gic, "arm,arm11mp-gic", ...)
  in drivers/irqchip/irq-gic.c, this is still in use by Marvell MMP3
  arch/arm/boot/dts/marvell/mmp3.dtsi

- A compatible for the arm11mpcore SCU, since this was mistakedly
  used for the Cortex-A9 version of RealView EB.

These are unfortunate but will need to be kept around for
compatibility. New Marvell-specific compatibles should however probably
be added.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://lore.kernel.org/r/20231207-drop-11mpcore-v2-1-560b396f3bf5@linaro.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 5 insertions, 19 deletions

diff --git a/arch/arm/mach-versatile/Kconfig b/arch/arm/mach-versatile/Kconfig
index b1519b4dc03a..e029270c2687 100644
--- a/arch/arm/mach-versatile/Kconfig
+++ b/arch/arm/mach-versatile/Kconfig
@@ -201,23 +201,6 @@ config REALVIEW_EB_A9MP
 	  Enable support for the Cortex-A9MPCore tile fitted to the
 	  Realview(R) Emulation Baseboard platform.
 
-config REALVIEW_EB_ARM11MP
-	bool "Support ARM11MPCore Tile"
-	depends on MACH_REALVIEW_EB && ARCH_MULTI_V6
-	select HAVE_SMP
-	help
-	  Enable support for the ARM11MPCore tile fitted to the Realview(R)
-	  Emulation Baseboard platform.
-
-config MACH_REALVIEW_PB11MP
-	bool "Support RealView(R) Platform Baseboard for ARM11MPCore"
-	depends on ARCH_MULTI_V6
-	select HAVE_SMP
-	help
-	  Include support for the ARM(R) RealView(R) Platform Baseboard for
-	  the ARM11MPCore.  This platform has an on-board ARM11MPCore and has
-	  support for PCI-E and Compact Flash.
-
 # ARMv6 CPU without K extensions, but does have the new exclusive ops
 config MACH_REALVIEW_PB1176
 	bool "Support RealView(R) Platform Baseboard for ARM1176JZF-S"
diff --git a/arch/arm/mach-versatile/platsmp-realview.c b/arch/arm/mach-versatile/platsmp-realview.c
index 5d363385c801..6965a1de727b 100644
--- a/arch/arm/mach-versatile/platsmp-realview.c
+++ b/arch/arm/mach-versatile/platsmp-realview.c
@@ -18,6 +18,11 @@
 #define REALVIEW_SYS_FLAGSSET_OFFSET	0x30
 
 static const struct of_device_id realview_scu_match[] = {
+	/*
+	 * The ARM11MP SCU compatible is only provided as fallback for
+	 * old RealView EB Cortex-A9 device trees that were using this
+	 * compatible by mistake.
+	 */
 	{ .compatible = "arm,arm11mp-scu", },
 	{ .compatible = "arm,cortex-a9-scu", },
 	{ .compatible = "arm,cortex-a5-scu", },
@@ -27,7 +32,6 @@ static const struct of_device_id realview_scu_match[] = {
 static const struct of_device_id realview_syscon_match[] = {
         { .compatible = "arm,core-module-integrator", },
         { .compatible = "arm,realview-eb-syscon", },
-        { .compatible = "arm,realview-pb11mp-syscon", },
         { .compatible = "arm,realview-pbx-syscon", },
         { },
 };
diff --git a/arch/arm/mach-versatile/realview.c b/arch/arm/mach-versatile/realview.c
index a3933e2373d5..36a6f6bc4fdd 100644
--- a/arch/arm/mach-versatile/realview.c
+++ b/arch/arm/mach-versatile/realview.c
@@ -9,7 +9,6 @@
 static const char *const realview_dt_platform_compat[] __initconst = {
 	"arm,realview-eb",
 	"arm,realview-pb1176",
-	"arm,realview-pb11mp",
 	"arm,realview-pba8",
 	"arm,realview-pbx",
 	NULL,