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MIPS: smp-cps: Support MIPSr6 Virtual Processors

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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: Paul 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: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Paul Burton 2016-02-03 03:15:33 +00:00 committed by Ralf Baechle
parent 87a70bcdb4
commit 5a3e7c02d8
4 changed files with 85 additions and 9 deletions
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2
arch/mips/Kconfig
View file

@ -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

4
arch/mips/include/asm/cpu-info.h
View file

@ -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; })

53
arch/mips/kernel/cps-vec.S
View file

@ -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

35
arch/mips/kernel/smp-cps.c
View file

@ -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);