[PATCH 1/2] arm: vexpress: Remove obsolete RTSM DCSCB support
Rob Herring (Arm)
robh at kernel.org
Fri May 10 05:32:35 PDT 2024
The Arm Versatile DCSCB support is unused as the compatible
"arm,rtsm,dcscb" is unused in any .dts file. It was only ever
implemented on a s/w model (RTSM).
Signed-off-by: Rob Herring (Arm) <robh at kernel.org>
---
arch/arm/configs/vexpress_defconfig | 1 -
arch/arm/mach-versatile/Kconfig | 9 --
arch/arm/mach-versatile/Makefile | 3 -
arch/arm/mach-versatile/dcscb.c | 173 --------------------------
arch/arm/mach-versatile/dcscb_setup.S | 33 -----
5 files changed, 219 deletions(-)
delete mode 100644 arch/arm/mach-versatile/dcscb.c
delete mode 100644 arch/arm/mach-versatile/dcscb_setup.S
diff --git a/arch/arm/configs/vexpress_defconfig b/arch/arm/configs/vexpress_defconfig
index 96ad442089bd..cdb6065e04fd 100644
--- a/arch/arm/configs/vexpress_defconfig
+++ b/arch/arm/configs/vexpress_defconfig
@@ -14,7 +14,6 @@ CONFIG_CPUSETS=y
CONFIG_BLK_DEV_INITRD=y
CONFIG_PROFILING=y
CONFIG_ARCH_VEXPRESS=y
-CONFIG_ARCH_VEXPRESS_DCSCB=y
CONFIG_ARCH_VEXPRESS_TC2_PM=y
CONFIG_SMP=y
CONFIG_HAVE_ARM_ARCH_TIMER=y
diff --git a/arch/arm/mach-versatile/Kconfig b/arch/arm/mach-versatile/Kconfig
index e029270c2687..513618078440 100644
--- a/arch/arm/mach-versatile/Kconfig
+++ b/arch/arm/mach-versatile/Kconfig
@@ -278,15 +278,6 @@ config ARCH_VEXPRESS_CORTEX_A5_A9_ERRATA
build a working kernel, you must also enable relevant core
tile support or Flattened Device Tree based support options.
-config ARCH_VEXPRESS_DCSCB
- bool "Dual Cluster System Control Block (DCSCB) support"
- depends on MCPM
- select ARM_CCI400_PORT_CTRL
- help
- Support for the Dual Cluster System Configuration Block (DCSCB).
- This is needed to provide CPU and cluster power management
- on RTSM implementing big.LITTLE.
-
config ARCH_VEXPRESS_SPC
bool "Versatile Express Serial Power Controller (SPC)"
select PM_OPP
diff --git a/arch/arm/mach-versatile/Makefile b/arch/arm/mach-versatile/Makefile
index 27d712bcf1af..d819fb2fc450 100644
--- a/arch/arm/mach-versatile/Makefile
+++ b/arch/arm/mach-versatile/Makefile
@@ -16,9 +16,6 @@ obj-$(CONFIG_ARCH_REALVIEW) += realview.o
# vexpress
obj-$(CONFIG_ARCH_VEXPRESS) := v2m.o
-obj-$(CONFIG_ARCH_VEXPRESS_DCSCB) += dcscb.o dcscb_setup.o
-CFLAGS_dcscb.o += -march=armv7-a
-CFLAGS_REMOVE_dcscb.o = -pg
obj-$(CONFIG_ARCH_VEXPRESS_SPC) += spc.o
CFLAGS_REMOVE_spc.o = -pg
obj-$(CONFIG_ARCH_VEXPRESS_TC2_PM) += tc2_pm.o
diff --git a/arch/arm/mach-versatile/dcscb.c b/arch/arm/mach-versatile/dcscb.c
deleted file mode 100644
index d8797350996d..000000000000
--- a/arch/arm/mach-versatile/dcscb.c
+++ /dev/null
@@ -1,173 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * dcscb.c - Dual Cluster System Configuration Block
- *
- * Created by: Nicolas Pitre, May 2012
- * Copyright: (C) 2012-2013 Linaro Limited
- */
-
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/io.h>
-#include <linux/errno.h>
-#include <linux/of_address.h>
-#include <linux/vexpress.h>
-#include <linux/arm-cci.h>
-
-#include <asm/mcpm.h>
-#include <asm/proc-fns.h>
-#include <asm/cacheflush.h>
-#include <asm/cputype.h>
-#include <asm/cp15.h>
-
-#include "vexpress.h"
-
-#define RST_HOLD0 0x0
-#define RST_HOLD1 0x4
-#define SYS_SWRESET 0x8
-#define RST_STAT0 0xc
-#define RST_STAT1 0x10
-#define EAG_CFG_R 0x20
-#define EAG_CFG_W 0x24
-#define KFC_CFG_R 0x28
-#define KFC_CFG_W 0x2c
-#define DCS_CFG_R 0x30
-
-static void __iomem *dcscb_base;
-static int dcscb_allcpus_mask[2];
-
-static int dcscb_cpu_powerup(unsigned int cpu, unsigned int cluster)
-{
- unsigned int rst_hold, cpumask = (1 << cpu);
-
- pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
- if (cluster >= 2 || !(cpumask & dcscb_allcpus_mask[cluster]))
- return -EINVAL;
-
- rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
- rst_hold &= ~(cpumask | (cpumask << 4));
- writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
- return 0;
-}
-
-static int dcscb_cluster_powerup(unsigned int cluster)
-{
- unsigned int rst_hold;
-
- pr_debug("%s: cluster %u\n", __func__, cluster);
- if (cluster >= 2)
- return -EINVAL;
-
- /* remove cluster reset and add individual CPU's reset */
- rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
- rst_hold &= ~(1 << 8);
- rst_hold |= dcscb_allcpus_mask[cluster];
- writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
- return 0;
-}
-
-static void dcscb_cpu_powerdown_prepare(unsigned int cpu, unsigned int cluster)
-{
- unsigned int rst_hold;
-
- pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
- BUG_ON(cluster >= 2 || !((1 << cpu) & dcscb_allcpus_mask[cluster]));
-
- rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
- rst_hold |= (1 << cpu);
- writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
-}
-
-static void dcscb_cluster_powerdown_prepare(unsigned int cluster)
-{
- unsigned int rst_hold;
-
- pr_debug("%s: cluster %u\n", __func__, cluster);
- BUG_ON(cluster >= 2);
-
- rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
- rst_hold |= (1 << 8);
- writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
-}
-
-static void dcscb_cpu_cache_disable(void)
-{
- /* Disable and flush the local CPU cache. */
- v7_exit_coherency_flush(louis);
-}
-
-static void dcscb_cluster_cache_disable(void)
-{
- /* Flush all cache levels for this cluster. */
- v7_exit_coherency_flush(all);
-
- /*
- * A full outer cache flush could be needed at this point
- * on platforms with such a cache, depending on where the
- * outer cache sits. In some cases the notion of a "last
- * cluster standing" would need to be implemented if the
- * outer cache is shared across clusters. In any case, when
- * the outer cache needs flushing, there is no concurrent
- * access to the cache controller to worry about and no
- * special locking besides what is already provided by the
- * MCPM state machinery is needed.
- */
-
- /*
- * Disable cluster-level coherency by masking
- * incoming snoops and DVM messages:
- */
- cci_disable_port_by_cpu(read_cpuid_mpidr());
-}
-
-static const struct mcpm_platform_ops dcscb_power_ops = {
- .cpu_powerup = dcscb_cpu_powerup,
- .cluster_powerup = dcscb_cluster_powerup,
- .cpu_powerdown_prepare = dcscb_cpu_powerdown_prepare,
- .cluster_powerdown_prepare = dcscb_cluster_powerdown_prepare,
- .cpu_cache_disable = dcscb_cpu_cache_disable,
- .cluster_cache_disable = dcscb_cluster_cache_disable,
-};
-
-extern void dcscb_power_up_setup(unsigned int affinity_level);
-
-static int __init dcscb_init(void)
-{
- struct device_node *node;
- unsigned int cfg;
- int ret;
-
- if (!cci_probed())
- return -ENODEV;
-
- node = of_find_compatible_node(NULL, NULL, "arm,rtsm,dcscb");
- if (!node)
- return -ENODEV;
- dcscb_base = of_iomap(node, 0);
- of_node_put(node);
- if (!dcscb_base)
- return -EADDRNOTAVAIL;
- cfg = readl_relaxed(dcscb_base + DCS_CFG_R);
- dcscb_allcpus_mask[0] = (1 << (((cfg >> 16) >> (0 << 2)) & 0xf)) - 1;
- dcscb_allcpus_mask[1] = (1 << (((cfg >> 16) >> (1 << 2)) & 0xf)) - 1;
-
- ret = mcpm_platform_register(&dcscb_power_ops);
- if (!ret)
- ret = mcpm_sync_init(dcscb_power_up_setup);
- if (ret) {
- iounmap(dcscb_base);
- return ret;
- }
-
- pr_info("VExpress DCSCB support installed\n");
-
- /*
- * Future entries into the kernel can now go
- * through the cluster entry vectors.
- */
- vexpress_flags_set(__pa_symbol(mcpm_entry_point));
-
- return 0;
-}
-
-early_initcall(dcscb_init);
diff --git a/arch/arm/mach-versatile/dcscb_setup.S b/arch/arm/mach-versatile/dcscb_setup.S
deleted file mode 100644
index 92d1fd9d7f6a..000000000000
--- a/arch/arm/mach-versatile/dcscb_setup.S
+++ /dev/null
@@ -1,33 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Created by: Dave Martin, 2012-06-22
- * Copyright: (C) 2012-2013 Linaro Limited
- */
-
-#include <linux/linkage.h>
-
-
-ENTRY(dcscb_power_up_setup)
-
- cmp r0, #0 @ check affinity level
- beq 2f
-
-/*
- * Enable cluster-level coherency, in preparation for turning on the MMU.
- * The ACTLR SMP bit does not need to be set here, because cpu_resume()
- * already restores that.
- *
- * A15/A7 may not require explicit L2 invalidation on reset, dependent
- * on hardware integration decisions.
- * For now, this code assumes that L2 is either already invalidated,
- * or invalidation is not required.
- */
-
- b cci_enable_port_for_self
-
-2: @ Implementation-specific local CPU setup operations should go here,
- @ if any. In this case, there is nothing to do.
-
- bx lr
-
-ENDPROC(dcscb_power_up_setup)
--
2.43.0
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