From 889a4c7b33607bf03c04b8f2d5607fd4274f47f3 Mon Sep 17 00:00:00 2001 From: "Steven J. Hill" Date: Mon, 9 Apr 2012 10:58:39 -0500 Subject: [PATCH] MIPS: SMTC: Support for Multi-threaded FPUs Signed-off-by: Steven J. Hill Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/3603/ Signed-off-by: Ralf Baechle --- arch/mips/include/asm/mipsmtregs.h | 13 +++++ arch/mips/include/asm/smtc.h | 6 +++ arch/mips/kernel/smp.c | 4 +- arch/mips/kernel/smtc.c | 76 ++++++++++++++++++++++++++---- 4 files changed, 90 insertions(+), 9 deletions(-) diff --git a/arch/mips/include/asm/mipsmtregs.h b/arch/mips/include/asm/mipsmtregs.h index e71ff4c317f2..5b3cb8553e9a 100644 --- a/arch/mips/include/asm/mipsmtregs.h +++ b/arch/mips/include/asm/mipsmtregs.h @@ -28,6 +28,9 @@ #define read_c0_vpeconf0() __read_32bit_c0_register($1, 2) #define write_c0_vpeconf0(val) __write_32bit_c0_register($1, 2, val) +#define read_c0_vpeconf1() __read_32bit_c0_register($1, 3) +#define write_c0_vpeconf1(val) __write_32bit_c0_register($1, 3, val) + #define read_c0_tcstatus() __read_32bit_c0_register($2, 1) #define write_c0_tcstatus(val) __write_32bit_c0_register($2, 1, val) @@ -124,6 +127,14 @@ #define VPECONF0_XTC_SHIFT 21 #define VPECONF0_XTC (_ULCAST_(0xff) << VPECONF0_XTC_SHIFT) +/* VPEConf1 fields (per VPE) */ +#define VPECONF1_NCP1_SHIFT 0 +#define VPECONF1_NCP1 (_ULCAST_(0xff) << VPECONF1_NCP1_SHIFT) +#define VPECONF1_NCP2_SHIFT 10 +#define VPECONF1_NCP2 (_ULCAST_(0xff) << VPECONF1_NCP2_SHIFT) +#define VPECONF1_NCX_SHIFT 20 +#define VPECONF1_NCX (_ULCAST_(0xff) << VPECONF1_NCX_SHIFT) + /* TCStatus fields (per TC) */ #define TCSTATUS_TASID (_ULCAST_(0xff)) #define TCSTATUS_IXMT_SHIFT 10 @@ -350,6 +361,8 @@ do { \ #define write_vpe_c0_vpecontrol(val) mttc0(1, 1, val) #define read_vpe_c0_vpeconf0() mftc0(1, 2) #define write_vpe_c0_vpeconf0(val) mttc0(1, 2, val) +#define read_vpe_c0_vpeconf1() mftc0(1, 3) +#define write_vpe_c0_vpeconf1(val) mttc0(1, 3, val) #define read_vpe_c0_count() mftc0(9, 0) #define write_vpe_c0_count(val) mttc0(9, 0, val) #define read_vpe_c0_status() mftc0(12, 0) diff --git a/arch/mips/include/asm/smtc.h b/arch/mips/include/asm/smtc.h index c9736fc06325..8935426a56ab 100644 --- a/arch/mips/include/asm/smtc.h +++ b/arch/mips/include/asm/smtc.h @@ -33,6 +33,12 @@ typedef long asiduse; #endif #endif +/* + * VPE Management information + */ + +#define MAX_SMTC_VPES MAX_SMTC_TLBS /* FIXME: May not always be true. */ + extern asiduse smtc_live_asid[MAX_SMTC_TLBS][MAX_SMTC_ASIDS]; struct mm_struct; diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 1268392f1d27..31637d8c8738 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -102,7 +102,9 @@ asmlinkage __cpuinit void start_secondary(void) #ifdef CONFIG_MIPS_MT_SMTC /* Only do cpu_probe for first TC of CPU */ - if ((read_c0_tcbind() & TCBIND_CURTC) == 0) + if ((read_c0_tcbind() & TCBIND_CURTC) != 0) + __cpu_name[smp_processor_id()] = __cpu_name[0]; + else #endif /* CONFIG_MIPS_MT_SMTC */ cpu_probe(); cpu_report(); diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c index 15b5f3cfd20c..1d47843d3cc0 100644 --- a/arch/mips/kernel/smtc.c +++ b/arch/mips/kernel/smtc.c @@ -86,6 +86,13 @@ struct smtc_ipi_q IPIQ[NR_CPUS]; static struct smtc_ipi_q freeIPIq; +/* + * Number of FPU contexts for each VPE + */ + +static int smtc_nconf1[MAX_SMTC_VPES]; + + /* Forward declarations */ void ipi_decode(struct smtc_ipi *); @@ -174,9 +181,9 @@ static int __init tintq(char *str) __setup("tintq=", tintq); -static int imstuckcount[2][8]; +static int imstuckcount[MAX_SMTC_VPES][8]; /* vpemask represents IM/IE bits of per-VPE Status registers, low-to-high */ -static int vpemask[2][8] = { +static int vpemask[MAX_SMTC_VPES][8] = { {0, 0, 1, 0, 0, 0, 0, 1}, {0, 0, 0, 0, 0, 0, 0, 1} }; @@ -331,6 +338,22 @@ int __init smtc_build_cpu_map(int start_cpu_slot) static void smtc_tc_setup(int vpe, int tc, int cpu) { + static int cp1contexts[MAX_SMTC_VPES]; + + /* + * Make a local copy of the available FPU contexts in order + * to keep track of TCs that can have one. + */ + if (tc == 1) + { + /* + * FIXME: Multi-core SMTC hasn't been tested and the + * maximum number of VPEs may change. + */ + cp1contexts[0] = smtc_nconf1[0] - 1; + cp1contexts[1] = smtc_nconf1[1]; + } + settc(tc); write_tc_c0_tchalt(TCHALT_H); mips_ihb(); @@ -343,22 +366,29 @@ static void smtc_tc_setup(int vpe, int tc, int cpu) * an active IPI queue. */ write_tc_c0_tccontext((sizeof(struct smtc_ipi_q) * cpu) << 16); - /* Bind tc to vpe */ + + /* Bind TC to VPE. */ write_tc_c0_tcbind(vpe); + /* In general, all TCs should have the same cpu_data indications. */ memcpy(&cpu_data[cpu], &cpu_data[0], sizeof(struct cpuinfo_mips)); - /* For 34Kf, start with TC/CPU 0 as sole owner of single FPU context */ - if (cpu_data[0].cputype == CPU_34K || - cpu_data[0].cputype == CPU_1004K) + + /* Check to see if there is a FPU context available for this TC. */ + if (!cp1contexts[vpe]) cpu_data[cpu].options &= ~MIPS_CPU_FPU; + else + cp1contexts[vpe]--; + + /* Store the TC and VPE into the cpu_data structure. */ cpu_data[cpu].vpe_id = vpe; cpu_data[cpu].tc_id = tc; - /* Multi-core SMTC hasn't been tested, but be prepared */ + + /* FIXME: Multi-core SMTC hasn't been tested, but be prepared. */ cpu_data[cpu].core = (read_vpe_c0_ebase() >> 1) & 0xff; } /* - * Tweak to get Count registes in as close a sync as possible. The + * Tweak to get Count registers synced as closely as possible. The * value seems good for 34K-class cores. */ @@ -466,6 +496,24 @@ void smtc_prepare_cpus(int cpus) smtc_configure_tlb(); for (tc = 0, vpe = 0 ; (vpe < nvpe) && (tc < ntc) ; vpe++) { + /* Get number of CP1 contexts for each VPE. */ + if (tc == 0) + { + /* + * Do not call settc() for TC0 or the FPU context + * value will be incorrect. Besides, we know that + * we are TC0 anyway. + */ + smtc_nconf1[0] = ((read_vpe_c0_vpeconf1() & + VPECONF1_NCP1) >> VPECONF1_NCP1_SHIFT); + if (nvpe == 2) + { + settc(1); + smtc_nconf1[1] = ((read_vpe_c0_vpeconf1() & + VPECONF1_NCP1) >> VPECONF1_NCP1_SHIFT); + settc(0); + } + } if (tcpervpe[vpe] == 0) continue; if (vpe != 0) @@ -479,6 +527,18 @@ void smtc_prepare_cpus(int cpus) */ if (tc != 0) { smtc_tc_setup(vpe, tc, cpu); + if (vpe != 0) { + /* + * Set MVP bit (possibly again). Do it + * here to catch CPUs that have no TCs + * bound to the VPE at reset. In that + * case, a TC must be bound to the VPE + * before we can set VPEControl[MVP] + */ + write_vpe_c0_vpeconf0( + read_vpe_c0_vpeconf0() | + VPECONF0_MVP); + } cpu++; } printk(" %d", tc); -- 2.39.2