diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-26 20:43:09 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-26 20:43:09 +0300 |
commit | ecf0aa5317b0ad6bb015128a5b763c954fd58708 (patch) | |
tree | 2bf6f0eb2ad2922bc644b72be2a75ac0df6e4403 /arch/arm/mach-versatile/dcscb.c | |
parent | a0439cf4eca05fe562f19ece4b6761852d911adb (diff) | |
parent | 1a23accae82d780b5d5de6254d32c270aeb7f664 (diff) |
Merge tag 'arm-multiplatform-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARMv4T/v5 multiplatform support from Arnd Bergmann:
"This series has been 12 years in the making, it mostly finishes the
work that was started with the founding of Linaro to clean up platform
support in the kernel.
The largest change here is a cleanup of the omap1 platform, which is
the final ARM machine type to get converted to the common-clk
subsystem. All the omap1 specific drivers are now made independent of
the mach/*.h headers to allow the platform to be part of a generic
ARMv4/v5 multiplatform kernel.
The last bit that enables this support is still missing here while we
wait for some last dependencies to make it into the mainline kernel
through other subsystems.
The s3c24xx, ixp4xx, iop32x, ep93xx and dove platforms were all almost
at the point of allowing multiplatform kernels, this work gets
completed here along with a few additional cleanup. At the same time,
the s3c24xx and s3c64xx are now deprecated and expected to get removed
in the future.
The PXA and OMAP1 bits are in a separate branch because of
dependencies. Once both branches are merged, only the three Intel
StrongARM platforms (RiscPC, Footbridge/NetWinder and StrongARM1100)
need separate kernels, and there are no plans to include these"
* tag 'arm-multiplatform-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (61 commits)
ARM: ixp4xx: Consolidate Kconfig fixing issue
ARM: versatile: Add missing of_node_put in dcscb_init
ARM: config: Refresh IXP4xx config after multiplatform
ARM: omap1: add back omap_set_dma_priority() stub
ARM: omap: fix missing declaration warnings
ARM: omap: fix address space warnings from sparse
ARM: spear: remove include/mach/ subdirectory
ARM: davinci: remove include/mach/ subdirectory
ARM: omap2: remove include/mach/ subdirectory
integrator: remove empty ap_init_early()
ARM: s3c: fix include path
MAINTAINERS: omap1: Add Janusz as an additional maintainer
ARM: omap1: htc_herald: fix typos in comments
ARM: OMAP1: fix typos in comments
ARM: OMAP1: clock: Remove noop code
ARM: OMAP1: clock: Remove unused code
ARM: OMAP1: clock: Fix UART rate reporting algorithm
ARM: OMAP1: clock: Fix early UART rate issues
ARM: OMAP1: Prepare for conversion of OMAP1 clocks to CCF
ARM: omap1: fix build with no SoC selected
...
Diffstat (limited to 'arch/arm/mach-versatile/dcscb.c')
-rw-r--r-- | arch/arm/mach-versatile/dcscb.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/arm/mach-versatile/dcscb.c b/arch/arm/mach-versatile/dcscb.c new file mode 100644 index 000000000000..d8797350996d --- /dev/null +++ b/arch/arm/mach-versatile/dcscb.c @@ -0,0 +1,173 @@ +// 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); |