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@xxxxxxxxxx>
---
arch/mips/Kconfig | 2 +-
arch/mips/include/asm/cpu-info.h | 4 +--
arch/mips/kernel/cps-vec.S | 53 ++++++++++++++++++++++++++++++++++++++--
arch/mips/kernel/smp-cps.c | 35 +++++++++++++++++++++++---
4 files changed, 85 insertions(+), 9 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 57a945e..3edb582 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2283,7 +2283,7 @@ 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
diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index e7dc785..aa526c3 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -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; })
diff --git a/arch/mips/kernel/cps-vec.S b/arch/mips/kernel/cps-vec.S
index 4849cbd..c28138d 100644
--- a/arch/mips/kernel/cps-vec.S
+++ b/arch/mips/kernel/cps-vec.S
@@ -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
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index afc727f..27f1c04 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -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);
--
2.7.0
