linux/arch/mips/include/asm/mips-cps.h
Ilya Lipnitskiy 6decd1aad1 MIPS: add support for buggy MT7621S core detection
Most MT7621 SoCs have 2 cores, which is detected and supported properly
by CPS.

Unfortunately, MT7621 SoC has a less common S variant with only one core.
On MT7621S, GCR_CONFIG still reports 2 cores, which leads to hangs when
starting SMP. CPULAUNCH registers can be used in that case to detect the
absence of the second core and override the GCR_CONFIG PCORES field.

Rework a long-standing OpenWrt patch to override the value of
mips_cps_numcores on single-core MT7621 systems.

Tested on a dual-core MT7621 device (Ubiquiti ER-X) and a single-core
MT7621 device (Netgear R6220).

Original 4.14 OpenWrt patch:
Link: https://git.openwrt.org/?p=openwrt/openwrt.git;a=commitdiff;h=4cdbc90a376dd0555201c1434a2081e055e9ceb7
Current 5.10 OpenWrt patch:
Link: https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/ramips/patches-5.10/320-mt7621-core-detect-hack.patch;h=c63f0f4c1ec742e24d8480e80553863744b58f6a;hb=10267e17299806f9885d086147878f6c492cb904

Suggested-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2021-04-12 16:52:23 +02:00

258 lines
6.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2017 Imagination Technologies
* Author: Paul Burton <paul.burton@mips.com>
*/
#ifndef __MIPS_ASM_MIPS_CPS_H__
#define __MIPS_ASM_MIPS_CPS_H__
#include <linux/io.h>
#include <linux/types.h>
#include <asm/mips-boards/launch.h>
extern unsigned long __cps_access_bad_size(void)
__compiletime_error("Bad size for CPS accessor");
#define CPS_ACCESSOR_A(unit, off, name) \
static inline void *addr_##unit##_##name(void) \
{ \
return mips_##unit##_base + (off); \
}
#define CPS_ACCESSOR_R(unit, sz, name) \
static inline uint##sz##_t read_##unit##_##name(void) \
{ \
uint64_t val64; \
\
switch (sz) { \
case 32: \
return __raw_readl(addr_##unit##_##name()); \
\
case 64: \
if (mips_cm_is64) \
return __raw_readq(addr_##unit##_##name()); \
\
val64 = __raw_readl(addr_##unit##_##name() + 4); \
val64 <<= 32; \
val64 |= __raw_readl(addr_##unit##_##name()); \
return val64; \
\
default: \
return __cps_access_bad_size(); \
} \
}
#define CPS_ACCESSOR_W(unit, sz, name) \
static inline void write_##unit##_##name(uint##sz##_t val) \
{ \
switch (sz) { \
case 32: \
__raw_writel(val, addr_##unit##_##name()); \
break; \
\
case 64: \
if (mips_cm_is64) { \
__raw_writeq(val, addr_##unit##_##name()); \
break; \
} \
\
__raw_writel((uint64_t)val >> 32, \
addr_##unit##_##name() + 4); \
__raw_writel(val, addr_##unit##_##name()); \
break; \
\
default: \
__cps_access_bad_size(); \
break; \
} \
}
#define CPS_ACCESSOR_M(unit, sz, name) \
static inline void change_##unit##_##name(uint##sz##_t mask, \
uint##sz##_t val) \
{ \
uint##sz##_t reg_val = read_##unit##_##name(); \
reg_val &= ~mask; \
reg_val |= val; \
write_##unit##_##name(reg_val); \
} \
\
static inline void set_##unit##_##name(uint##sz##_t val) \
{ \
change_##unit##_##name(val, val); \
} \
\
static inline void clear_##unit##_##name(uint##sz##_t val) \
{ \
change_##unit##_##name(val, 0); \
}
#define CPS_ACCESSOR_RO(unit, sz, off, name) \
CPS_ACCESSOR_A(unit, off, name) \
CPS_ACCESSOR_R(unit, sz, name)
#define CPS_ACCESSOR_WO(unit, sz, off, name) \
CPS_ACCESSOR_A(unit, off, name) \
CPS_ACCESSOR_W(unit, sz, name)
#define CPS_ACCESSOR_RW(unit, sz, off, name) \
CPS_ACCESSOR_A(unit, off, name) \
CPS_ACCESSOR_R(unit, sz, name) \
CPS_ACCESSOR_W(unit, sz, name) \
CPS_ACCESSOR_M(unit, sz, name)
#include <asm/mips-cm.h>
#include <asm/mips-cpc.h>
#include <asm/mips-gic.h>
/**
* mips_cps_numclusters - return the number of clusters present in the system
*
* Returns the number of clusters in the system.
*/
static inline unsigned int mips_cps_numclusters(void)
{
unsigned int num_clusters;
if (mips_cm_revision() < CM_REV_CM3_5)
return 1;
num_clusters = read_gcr_config() & CM_GCR_CONFIG_NUM_CLUSTERS;
num_clusters >>= __ffs(CM_GCR_CONFIG_NUM_CLUSTERS);
return num_clusters;
}
/**
* mips_cps_cluster_config - return (GCR|CPC)_CONFIG from a cluster
* @cluster: the ID of the cluster whose config we want
*
* Read the value of GCR_CONFIG (or its CPC_CONFIG mirror) from a @cluster.
*
* Returns the value of GCR_CONFIG.
*/
static inline uint64_t mips_cps_cluster_config(unsigned int cluster)
{
uint64_t config;
if (mips_cm_revision() < CM_REV_CM3_5) {
/*
* Prior to CM 3.5 we don't have the notion of multiple
* clusters so we can trivially read the GCR_CONFIG register
* within this cluster.
*/
WARN_ON(cluster != 0);
config = read_gcr_config();
} else {
/*
* From CM 3.5 onwards we read the CPC_CONFIG mirror of
* GCR_CONFIG via the redirect region, since the CPC is always
* powered up allowing us not to need to power up the CM.
*/
mips_cm_lock_other(cluster, 0, 0, CM_GCR_Cx_OTHER_BLOCK_GLOBAL);
config = read_cpc_redir_config();
mips_cm_unlock_other();
}
return config;
}
/**
* mips_cps_numcores - return the number of cores present in a cluster
* @cluster: the ID of the cluster whose core count we want
*
* Returns the value of the PCORES field of the GCR_CONFIG register plus 1, or
* zero if no Coherence Manager is present.
*/
static inline unsigned int mips_cps_numcores(unsigned int cluster)
{
unsigned int ncores;
if (!mips_cm_present())
return 0;
/* Add one before masking to handle 0xff indicating no cores */
ncores = (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
if (IS_ENABLED(CONFIG_SOC_MT7621)) {
struct cpulaunch *launch;
/*
* Ralink MT7621S SoC is single core, but the GCR_CONFIG method
* always reports 2 cores. Check the second core's LAUNCH_FREADY
* flag to detect if the second core is missing. This method
* only works before the core has been started.
*/
launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
launch += 2; /* MT7621 has 2 VPEs per core */
if (!(launch->flags & LAUNCH_FREADY))
ncores = 1;
}
return ncores;
}
/**
* mips_cps_numiocu - return the number of IOCUs present in a cluster
* @cluster: the ID of the cluster whose IOCU count we want
*
* Returns the value of the NUMIOCU field of the GCR_CONFIG register, or zero
* if no Coherence Manager is present.
*/
static inline unsigned int mips_cps_numiocu(unsigned int cluster)
{
unsigned int num_iocu;
if (!mips_cm_present())
return 0;
num_iocu = mips_cps_cluster_config(cluster) & CM_GCR_CONFIG_NUMIOCU;
num_iocu >>= __ffs(CM_GCR_CONFIG_NUMIOCU);
return num_iocu;
}
/**
* mips_cps_numvps - return the number of VPs (threads) supported by a core
* @cluster: the ID of the cluster containing the core we want to examine
* @core: the ID of the core whose VP count we want
*
* Returns the number of Virtual Processors (VPs, ie. hardware threads) that
* are supported by the given @core in the given @cluster. If the core or the
* kernel do not support hardware mutlti-threading this returns 1.
*/
static inline unsigned int mips_cps_numvps(unsigned int cluster, unsigned int core)
{
unsigned int cfg;
if (!mips_cm_present())
return 1;
if ((!IS_ENABLED(CONFIG_MIPS_MT_SMP) || !cpu_has_mipsmt)
&& (!IS_ENABLED(CONFIG_CPU_MIPSR6) || !cpu_has_vp))
return 1;
mips_cm_lock_other(cluster, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL);
if (mips_cm_revision() < CM_REV_CM3_5) {
/*
* Prior to CM 3.5 we can only have one cluster & don't have
* CPC_Cx_CONFIG, so we read GCR_Cx_CONFIG.
*/
cfg = read_gcr_co_config();
} else {
/*
* From CM 3.5 onwards we read CPC_Cx_CONFIG because the CPC is
* always powered, which allows us to not worry about powering
* up the cluster's CM here.
*/
cfg = read_cpc_co_config();
}
mips_cm_unlock_other();
return (cfg + 1) & CM_GCR_Cx_CONFIG_PVPE;
}
#endif /* __MIPS_ASM_MIPS_CPS_H__ */