Commit 5a3e7c02 authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle
Browse files

MIPS: smp-cps: Support MIPSr6 Virtual Processors 



Introduce support for bringing up Virtual Processors in MIPSr6 systems
as CPUs, much like their VPE parallel from the now-deprecated MT ASE.
The existing mips_cps_boot_vpes function fits the MIPSr6 architecture
pretty well - it can now simply write the mask of running VPs to the
VC_RUN register, rather than looping through each & starting or stopping
as appropriate as is done for VPEs from the MT ASE. Thus the VP support
is in general an extension & simplification of the existing MT ASE VPE
(aka SMVP) support.

Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12339/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 87a70bcd

arch/mips/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -2282,7 +2282,7 @@ config MIPS_CMP 


config MIPS_CPS

	bool "MIPS Coherent Processing System support"

	depends on SYS_SUPPORTS_MIPS_CPS && !CPU_MIPSR6

	depends on SYS_SUPPORTS_MIPS_CPS

	select MIPS_CM

	select MIPS_CPC

	select MIPS_CPS_PM if HOTPLUG_CPU

arch/mips/include/asm/cpu-info.h

+2 −2
Original line number Diff line number Diff line
@@ -68,7 +68,7 @@ struct cpuinfo_mips { 
#ifdef CONFIG_64BIT

	int			vmbits; /* Virtual memory size in bits */

#endif

#ifdef CONFIG_MIPS_MT_SMP

#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_CPU_MIPSR6)

	/*

	 * There is not necessarily a 1:1 mapping of VPE num to CPU number

	 * in particular on multi-core systems.
@@ -125,7 +125,7 @@ struct proc_cpuinfo_notifier_args { 
	unsigned long n;

};



#ifdef CONFIG_MIPS_MT_SMP

#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_CPU_MIPSR6)

# define cpu_vpe_id(cpuinfo)	((cpuinfo)->vpe_id)

#else

# define cpu_vpe_id(cpuinfo)	({ (void)cpuinfo; 0; })

arch/mips/kernel/cps-vec.S

+51 −2
Original line number Diff line number Diff line
@@ -18,9 +18,12 @@ 
#include <asm/mipsmtregs.h>

#include <asm/pm.h>



#define GCR_CPC_BASE_OFS	0x0088

#define GCR_CL_COHERENCE_OFS	0x2008

#define GCR_CL_ID_OFS		0x2028



#define CPC_CL_VC_RUN_OFS	0x2028



.extern mips_cm_base



.set noreorder
@@ -60,6 +63,26 @@ 
	 nop

	.endm



	/*

	 * Set dest to non-zero if the core supports MIPSr6 multithreading

	 * (ie. VPs), else zero. If MIPSr6 multithreading is not supported then

	 * branch to nomt.

	 */

	.macro	has_vp	dest, nomt

	mfc0	\dest, CP0_CONFIG, 1

	bgez	\dest, \nomt

	 mfc0	\dest, CP0_CONFIG, 2

	bgez	\dest, \nomt

	 mfc0	\dest, CP0_CONFIG, 3

	bgez	\dest, \nomt

	 mfc0	\dest, CP0_CONFIG, 4

	bgez	\dest, \nomt

	 mfc0	\dest, CP0_CONFIG, 5

	andi	\dest, \dest, MIPS_CONF5_VP

	beqz	\dest, \nomt

	 nop

	.endm



	/* Calculate an uncached address for the CM GCRs */

	.macro	cmgcrb	dest

	.set	push
@@ -296,7 +319,17 @@ LEAF(mips_cps_get_bootcfg) 


	/* Calculate this VPEs ID. If the core doesn't support MT use 0 */

	li	t9, 0

#ifdef CONFIG_MIPS_MT_SMP

#if defined(CONFIG_CPU_MIPSR6)

	has_vp	ta2, 1f



	/*

	 * Assume non-contiguous numbering. Perhaps some day we'll need

	 * to handle contiguous VP numbering, but no such systems yet

	 * exist.

	 */

	mfc0	t9, $3, 1

	andi	t9, t9, 0xff

#elif defined(CONFIG_MIPS_MT_SMP)

	has_mt	ta2, 1f



	/* Find the number of VPEs present in the core */
@@ -332,7 +365,23 @@ LEAF(mips_cps_boot_vpes) 
	PTR_L	ta2, COREBOOTCFG_VPEMASK(a0)

	PTR_L	ta3, COREBOOTCFG_VPECONFIG(a0)



#ifdef CONFIG_MIPS_MT

#if defined(CONFIG_CPU_MIPSR6)



	has_vp	t0, 5f



	/* Find base address of CPC */

	cmgcrb	t3

	PTR_L	t1, GCR_CPC_BASE_OFS(t3)

	PTR_LI	t2, ~0x7fff

	and	t1, t1, t2

	PTR_LI	t2, UNCAC_BASE

	PTR_ADD	t1, t1, t2



	/* Set VC_RUN to the VPE mask */

	PTR_S	ta2, CPC_CL_VC_RUN_OFS(t1)

	ehb



#elif defined(CONFIG_MIPS_MT)



	.set	push

	.set	mt

arch/mips/kernel/smp-cps.c

+31 −4
Original line number Diff line number Diff line
@@ -35,7 +35,8 @@ static unsigned core_vpe_count(unsigned core) 
{

	unsigned cfg;



	if (!config_enabled(CONFIG_MIPS_MT_SMP) || !cpu_has_mipsmt)

	if ((!config_enabled(CONFIG_MIPS_MT_SMP) || !cpu_has_mipsmt)

		&& (!config_enabled(CONFIG_CPU_MIPSR6) || !cpu_has_vp))

		return 1;



	mips_cm_lock_other(core, 0);
@@ -47,11 +48,12 @@ static unsigned core_vpe_count(unsigned core) 
static void __init cps_smp_setup(void)

{

	unsigned int ncores, nvpes, core_vpes;

	unsigned long core_entry;

	int c, v;



	/* Detect & record VPE topology */

	ncores = mips_cm_numcores();

	pr_info("VPE topology ");

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

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

		core_vpes = core_vpe_count(c);

		pr_cont("%c%u", c ? ',' : '{', core_vpes);
@@ -62,7 +64,7 @@ static void __init cps_smp_setup(void) 


		for (v = 0; v < min_t(int, core_vpes, NR_CPUS - nvpes); v++) {

			cpu_data[nvpes + v].core = c;

#ifdef CONFIG_MIPS_MT_SMP

#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_CPU_MIPSR6)

			cpu_data[nvpes + v].vpe_id = v;

#endif

		}
@@ -91,6 +93,11 @@ static void __init cps_smp_setup(void) 
	/* Make core 0 coherent with everything */

	write_gcr_cl_coherence(0xff);



	if (mips_cm_revision() >= CM_REV_CM3) {

		core_entry = CKSEG1ADDR((unsigned long)mips_cps_core_entry);

		write_gcr_bev_base(core_entry);

	}



#ifdef CONFIG_MIPS_MT_FPAFF

	/* If we have an FPU, enroll ourselves in the FPU-full mask */

	if (cpu_has_fpu)
@@ -213,6 +220,18 @@ static void boot_core(unsigned core) 
	if (mips_cpc_present()) {

		/* Reset the core */

		mips_cpc_lock_other(core);



		if (mips_cm_revision() >= CM_REV_CM3) {

			/* Run VP0 following the reset */

			write_cpc_co_vp_run(0x1);



			/*

			 * Ensure that the VP_RUN register is written before the

			 * core leaves reset.

			 */

			wmb();

		}



		write_cpc_co_cmd(CPC_Cx_CMD_RESET);



		timeout = 100;
@@ -262,6 +281,7 @@ static void cps_boot_secondary(int cpu, struct task_struct *idle) 
	unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]);

	struct core_boot_config *core_cfg = &mips_cps_core_bootcfg[core];

	struct vpe_boot_config *vpe_cfg = &core_cfg->vpe_config[vpe_id];

	unsigned long core_entry;

	unsigned int remote;

	int err;
@@ -279,6 +299,13 @@ static void cps_boot_secondary(int cpu, struct task_struct *idle) 
		goto out;

	}



	if (cpu_has_vp) {

		mips_cm_lock_other(core, vpe_id);

		core_entry = CKSEG1ADDR((unsigned long)mips_cps_core_entry);

		write_gcr_co_reset_base(core_entry);

		mips_cm_unlock_other();

	}



	if (core != current_cpu_data.core) {

		/* Boot a VPE on another powered up core */

		for (remote = 0; remote < NR_CPUS; remote++) {
@@ -296,7 +323,7 @@ static void cps_boot_secondary(int cpu, struct task_struct *idle) 
		goto out;

	}



	BUG_ON(!cpu_has_mipsmt);

	BUG_ON(!cpu_has_mipsmt && !cpu_has_vp);



	/* Boot a VPE on this core */

	mips_cps_boot_vpes(core_cfg, vpe_id);

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