Commit 3c9b4166 authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle
Browse files

MIPS: CPS: Cluster support for topology functions 



Modify the functions we use to read information about the topology of
the system (the number of cores, VPs & IOCUs that it contains) in order
to take into account multiple clusters, and provide a new function to
determine the number of clusters in the system.

Users of these functions are modified only such that they continue to
build successfully - having them actually handle multiple clusters is
left to further patches.

Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17016/
Patchwork: https://patchwork.linux-mips.org/patch/17218/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent e83f7e02

arch/mips/Kconfig

+1 −2
Original line number Diff line number Diff line
@@ -2365,7 +2365,6 @@ config MIPS_CPS 
	bool "MIPS Coherent Processing System support"

	depends on SYS_SUPPORTS_MIPS_CPS

	select MIPS_CM

	select MIPS_CPC

	select MIPS_CPS_PM if HOTPLUG_CPU

	select SMP

	select SYNC_R4K if (CEVT_R4K || CSRC_R4K)
@@ -2382,11 +2381,11 @@ config MIPS_CPS 


config MIPS_CPS_PM

	depends on MIPS_CPS

	select MIPS_CPC

	bool



config MIPS_CM

	bool

	select MIPS_CPC



config MIPS_CPC

	bool

arch/mips/include/asm/mips-cm.h

+0 −30
Original line number Diff line number Diff line
@@ -328,36 +328,6 @@ GCR_CX_ACCESSOR_RW(32, 0x030, reset_ext_base) 
#define CM_GCR_Cx_RESET_EXT_BASE_BEVEXCPA	GENMASK(7, 1)

#define CM_GCR_Cx_RESET_EXT_BASE_PRESENT	BIT(0)



/**

 * mips_cm_numcores - return the number of cores present in the system

 *

 * 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 mips_cm_numcores(void)

{

	if (!mips_cm_present())

		return 0;



	return ((read_gcr_config() & CM_GCR_CONFIG_PCORES)

		>> __ffs(CM_GCR_CONFIG_PCORES)) + 1;

}



/**

 * mips_cm_numiocu - return the number of IOCUs present in the system

 *

 * Returns the value of the NUMIOCU field of the GCR_CONFIG register, or zero

 * if no Coherence Manager is present.

 */

static inline unsigned mips_cm_numiocu(void)

{

	if (!mips_cm_present())

		return 0;



	return (read_gcr_config() & CM_GCR_CONFIG_NUMIOCU)

		>> __ffs(CM_GCR_CONFIG_NUMIOCU);

}



/**

 * mips_cm_l2sync - perform an L2-only sync operation

 *

arch/mips/include/asm/mips-cps.h

+128 −0
Original line number Diff line number Diff line
@@ -108,4 +108,132 @@ static inline void clear_##unit##_##name(uint##sz##_t val) \ 
#include <asm/mips-cm.h>

#include <asm/mips-cpc.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)

{

	if (!mips_cm_present())

		return 0;



	/* Add one before masking to handle 0xff indicating no cores */

	return (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;

}



/**

 * 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__ */

arch/mips/kernel/smp-cps.c

+3 −12
Original line number Diff line number Diff line
@@ -42,19 +42,10 @@ early_param("nothreads", setup_nothreads); 


static unsigned core_vpe_count(unsigned core)

{

	unsigned cfg;



	if (threads_disabled)

		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(0, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL);

	cfg = read_gcr_co_config() & CM_GCR_Cx_CONFIG_PVPE;

	mips_cm_unlock_other();

	return cfg + 1;

	return mips_cps_numvps(0, core);

}



static void __init cps_smp_setup(void)
@@ -64,7 +55,7 @@ static void __init cps_smp_setup(void) 
	int c, v;



	/* Detect & record VPE topology */

	ncores = mips_cm_numcores();

	ncores = mips_cps_numcores(0);

	pr_info("%s topology ", cpu_has_mips_r6 ? "VP" : "VPE");

	for (c = nvpes = 0; c < ncores; c++) {

		core_vpes = core_vpe_count(c);
@@ -138,7 +129,7 @@ static void __init cps_prepare_cpus(unsigned int max_cpus) 
	}



	/* Warn the user if the CCA prevents multi-core */

	ncores = mips_cm_numcores();

	ncores = mips_cps_numcores(0);

	if ((cca_unsuitable || cpu_has_dc_aliases) && ncores > 1) {

		pr_warn("Using only one core due to %s%s%s\n",

			cca_unsuitable ? "unsuitable CCA" : "",

arch/mips/mti-malta/malta-setup.c

+1 −1
Original line number Diff line number Diff line
@@ -128,7 +128,7 @@ static int __init plat_enable_iocoherency(void) 
				 BONITO_PCIMEMBASECFG_MEMBASE1_CACHED);

			pr_info("Enabled Bonito IOBC coherency\n");

		}

	} else if (mips_cm_numiocu() != 0) {

	} else if (mips_cps_numiocu(0) != 0) {

		/* Nothing special needs to be done to enable coherency */

		pr_info("CMP IOCU detected\n");

		cfg = __raw_readl((u32 *)CKSEG1ADDR(ROCIT_CONFIG_GEN0));

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