From ed8775d3c3cd257fe2967ca4b2d52d69ced47425 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Fri, 11 Dec 2015 15:02:50 +0000 Subject: [PATCH] ramips: backport series of patches that ensure GCRs of other CPUs are accessed properly Signed-off-by: Nikolay Martynov SVN-Revision: 47838 --- ...ntoruce-core-other-locking-functions.patch | 140 ++++++++++++++++++ ...7-cm-use-core-other-locking-function.patch | 80 ++++++++++ ...-core-other-GCR-reflect-correct-core.patch | 49 ++++++ 3 files changed, 269 insertions(+) create mode 100644 target/linux/ramips/patches-4.3/0056-cm-intoruce-core-other-locking-functions.patch create mode 100644 target/linux/ramips/patches-4.3/0057-cm-use-core-other-locking-function.patch create mode 100644 target/linux/ramips/patches-4.3/0058-backport-ensure-core-other-GCR-reflect-correct-core.patch diff --git a/target/linux/ramips/patches-4.3/0056-cm-intoruce-core-other-locking-functions.patch b/target/linux/ramips/patches-4.3/0056-cm-intoruce-core-other-locking-functions.patch new file mode 100644 index 000000000000..e7c5a0b5aa75 --- /dev/null +++ b/target/linux/ramips/patches-4.3/0056-cm-intoruce-core-other-locking-functions.patch @@ -0,0 +1,140 @@ +commit 23d5de8efb9aed48074a72bf3d43841e1556ca42 +Author: Paul Burton +Date: Tue Sep 22 11:12:16 2015 -0700 + + MIPS: CM: Introduce core-other locking functions + + Introduce mips_cm_lock_other & mips_cm_unlock_other, mirroring the + existing CPC equivalents, in order to lock access from the current core + to another via the core-other GCR region. This hasn't been required in + the past but with CM3 the CPC starts using GCR_CL_OTHER rather than + CPC_CL_OTHER and this will be required for safety. + + [ralf@linux-mips.org: Fix merge conflict.] + + Signed-off-by: Paul Burton + Cc: linux-mips@linux-mips.org + Cc: linux-kernel@vger.kernel.org + Cc: James Hogan + Cc: Markos Chandras + Patchwork: https://patchwork.linux-mips.org/patch/11207/ + Signed-off-by: Ralf Baechle + +--- a/arch/mips/include/asm/mips-cm.h ++++ b/arch/mips/include/asm/mips-cm.h +@@ -334,6 +334,10 @@ BUILD_CM_Cx_R_(tcid_8_priority, 0x80) + /* GCR_Cx_OTHER register fields */ + #define CM_GCR_Cx_OTHER_CORENUM_SHF 16 + #define CM_GCR_Cx_OTHER_CORENUM_MSK (_ULCAST_(0xffff) << 16) ++#define CM3_GCR_Cx_OTHER_CORE_SHF 8 ++#define CM3_GCR_Cx_OTHER_CORE_MSK (_ULCAST_(0x3f) << 8) ++#define CM3_GCR_Cx_OTHER_VP_SHF 0 ++#define CM3_GCR_Cx_OTHER_VP_MSK (_ULCAST_(0x7) << 0) + + /* GCR_Cx_RESET_BASE register fields */ + #define CM_GCR_Cx_RESET_BASE_BEVEXCBASE_SHF 12 +@@ -444,4 +448,32 @@ static inline unsigned int mips_cm_vp_id + return (core * mips_cm_max_vp_width()) + vp; + } + ++#ifdef CONFIG_MIPS_CM ++ ++/** ++ * mips_cm_lock_other - lock access to another core ++ * @core: the other core to be accessed ++ * @vp: the VP within the other core to be accessed ++ * ++ * Call before operating upon a core via the 'other' register region in ++ * order to prevent the region being moved during access. Must be followed ++ * by a call to mips_cm_unlock_other. ++ */ ++extern void mips_cm_lock_other(unsigned int core, unsigned int vp); ++ ++/** ++ * mips_cm_unlock_other - unlock access to another core ++ * ++ * Call after operating upon another core via the 'other' register region. ++ * Must be called after mips_cm_lock_other. ++ */ ++extern void mips_cm_unlock_other(void); ++ ++#else /* !CONFIG_MIPS_CM */ ++ ++static inline void mips_cm_lock_other(unsigned int core) { } ++static inline void mips_cm_unlock_other(void) { } ++ ++#endif /* !CONFIG_MIPS_CM */ ++ + #endif /* __MIPS_ASM_MIPS_CM_H__ */ +--- a/arch/mips/kernel/mips-cm.c ++++ b/arch/mips/kernel/mips-cm.c +@@ -9,6 +9,8 @@ + */ + + #include ++#include ++#include + + #include + #include +@@ -136,6 +138,9 @@ static char *cm3_causes[32] = { + "0x19", "0x1a", "0x1b", "0x1c", "0x1d", "0x1e", "0x1f" + }; + ++static DEFINE_PER_CPU_ALIGNED(spinlock_t, cm_core_lock); ++static DEFINE_PER_CPU_ALIGNED(unsigned long, cm_core_lock_flags); ++ + phys_addr_t __mips_cm_phys_base(void) + { + u32 config3 = read_c0_config3(); +@@ -200,6 +205,7 @@ int mips_cm_probe(void) + { + phys_addr_t addr; + u32 base_reg; ++ unsigned cpu; + + /* + * No need to probe again if we have already been +@@ -247,9 +253,42 @@ int mips_cm_probe(void) + /* determine register width for this CM */ + mips_cm_is64 = config_enabled(CONFIG_64BIT) && (mips_cm_revision() >= CM_REV_CM3); + ++ for_each_possible_cpu(cpu) ++ spin_lock_init(&per_cpu(cm_core_lock, cpu)); ++ + return 0; + } + ++void mips_cm_lock_other(unsigned int core, unsigned int vp) ++{ ++ unsigned curr_core; ++ u32 val; ++ ++ preempt_disable(); ++ curr_core = current_cpu_data.core; ++ spin_lock_irqsave(&per_cpu(cm_core_lock, curr_core), ++ per_cpu(cm_core_lock_flags, curr_core)); ++ ++ if (mips_cm_revision() >= CM_REV_CM3) { ++ val = core << CM3_GCR_Cx_OTHER_CORE_SHF; ++ val |= vp << CM3_GCR_Cx_OTHER_VP_SHF; ++ } else { ++ BUG_ON(vp != 0); ++ val = core << CM_GCR_Cx_OTHER_CORENUM_SHF; ++ } ++ ++ write_gcr_cl_other(val); ++} ++ ++void mips_cm_unlock_other(void) ++{ ++ unsigned curr_core = current_cpu_data.core; ++ ++ spin_unlock_irqrestore(&per_cpu(cm_core_lock, curr_core), ++ per_cpu(cm_core_lock_flags, curr_core)); ++ preempt_enable(); ++} ++ + void mips_cm_error_report(void) + { + unsigned long revision = mips_cm_revision(); diff --git a/target/linux/ramips/patches-4.3/0057-cm-use-core-other-locking-function.patch b/target/linux/ramips/patches-4.3/0057-cm-use-core-other-locking-function.patch new file mode 100644 index 000000000000..2ac52f706ae9 --- /dev/null +++ b/target/linux/ramips/patches-4.3/0057-cm-use-core-other-locking-function.patch @@ -0,0 +1,80 @@ +commit 4ede31617056b7424eef28dce59dd6dbe81729c3 +Author: Paul Burton +Date: Tue Sep 22 11:12:17 2015 -0700 + + MIPS: CM: make use of mips_cm_{lock,unlock}_other + + Document that CPC core-other accesses must take place within the bounds + of the CM lock, and begin using the CM lock functions where we access + the GCRs of other cores. This is required because with CM3 the CPC began + using GCR_CL_OTHER instead of CPC_CL_OTHER. + + Signed-off-by: Paul Burton + Cc: linux-mips@linux-mips.org + Cc: Rusty Russell + Cc: Andrew Bresticker + Cc: Bjorn Helgaas + Cc: linux-kernel@vger.kernel.org + Cc: Niklas Cassel + Cc: Ezequiel Garcia + Cc: Markos Chandras + Patchwork: https://patchwork.linux-mips.org/patch/11208/ + Signed-off-by: Ralf Baechle + +--- a/arch/mips/include/asm/mips-cpc.h ++++ b/arch/mips/include/asm/mips-cpc.h +@@ -149,7 +149,8 @@ BUILD_CPC_Cx_RW(other, 0x10) + * core: the other core to be accessed + * + * Call before operating upon a core via the 'other' register region in +- * order to prevent the region being moved during access. Must be followed ++ * order to prevent the region being moved during access. Must be called ++ * within the bounds of a mips_cm_{lock,unlock}_other pair, and followed + * by a call to mips_cpc_unlock_other. + */ + extern void mips_cpc_lock_other(unsigned int core); +--- a/arch/mips/kernel/smp-cps.c ++++ b/arch/mips/kernel/smp-cps.c +@@ -37,8 +37,9 @@ static unsigned core_vpe_count(unsigned + if (!config_enabled(CONFIG_MIPS_MT_SMP) || !cpu_has_mipsmt) + return 1; + +- write_gcr_cl_other(core << CM_GCR_Cx_OTHER_CORENUM_SHF); ++ mips_cm_lock_other(core, 0); + cfg = read_gcr_co_config() & CM_GCR_Cx_CONFIG_PVPE_MSK; ++ mips_cm_unlock_other(); + return (cfg >> CM_GCR_Cx_CONFIG_PVPE_SHF) + 1; + } + +@@ -193,7 +194,7 @@ static void boot_core(unsigned core) + u32 access; + + /* Select the appropriate core */ +- write_gcr_cl_other(core << CM_GCR_Cx_OTHER_CORENUM_SHF); ++ mips_cm_lock_other(core, 0); + + /* Set its reset vector */ + write_gcr_co_reset_base(CKSEG1ADDR((unsigned long)mips_cps_core_entry)); +@@ -216,6 +217,8 @@ static void boot_core(unsigned core) + write_gcr_co_reset_release(0); + } + ++ mips_cm_unlock_other(); ++ + /* The core is now powered up */ + bitmap_set(core_power, core, 1); + } +--- a/arch/mips/kernel/smp-gic.c ++++ b/arch/mips/kernel/smp-gic.c +@@ -46,9 +46,11 @@ void gic_send_ipi_single(int cpu, unsign + + if (mips_cpc_present() && (core != current_cpu_data.core)) { + while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) { ++ mips_cm_lock_other(core, 0); + mips_cpc_lock_other(core); + write_cpc_co_cmd(CPC_Cx_CMD_PWRUP); + mips_cpc_unlock_other(); ++ mips_cm_unlock_other(); + } + } + diff --git a/target/linux/ramips/patches-4.3/0058-backport-ensure-core-other-GCR-reflect-correct-core.patch b/target/linux/ramips/patches-4.3/0058-backport-ensure-core-other-GCR-reflect-correct-core.patch new file mode 100644 index 000000000000..e8ed6abf7f65 --- /dev/null +++ b/target/linux/ramips/patches-4.3/0058-backport-ensure-core-other-GCR-reflect-correct-core.patch @@ -0,0 +1,49 @@ +commit 78a54c4d8e5a7915a4ec2ba0eb461fae50590683 +Author: Paul Burton +Date: Tue Sep 22 11:12:18 2015 -0700 + + MIPS: CM, CPC: Ensure core-other GCRs reflect the correct core + + Ensure the update to which core the core-other GCR regions reflect has + taken place before any core-other GCRs are accessed by placing a memory + barrier (sync instruction) between the write to the core-other registers + and any such GCR accesses. + + Signed-off-by: Paul Burton + Cc: linux-mips@linux-mips.org + Cc: Bjorn Helgaas + Cc: linux-kernel@vger.kernel.org + Cc: Markos Chandras + Patchwork: https://patchwork.linux-mips.org/patch/11209/ + Signed-off-by: Ralf Baechle + +--- a/arch/mips/kernel/mips-cm.c ++++ b/arch/mips/kernel/mips-cm.c +@@ -278,6 +278,12 @@ void mips_cm_lock_other(unsigned int cor + } + + write_gcr_cl_other(val); ++ ++ /* ++ * Ensure the core-other region reflects the appropriate core & ++ * VP before any accesses to it occur. ++ */ ++ mb(); + } + + void mips_cm_unlock_other(void) +--- a/arch/mips/kernel/mips-cpc.c ++++ b/arch/mips/kernel/mips-cpc.c +@@ -76,6 +76,12 @@ void mips_cpc_lock_other(unsigned int co + spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core), + per_cpu(cpc_core_lock_flags, curr_core)); + write_cpc_cl_other(core << CPC_Cx_OTHER_CORENUM_SHF); ++ ++ /* ++ * Ensure the core-other region reflects the appropriate core & ++ * VP before any accesses to it occur. ++ */ ++ mb(); + } + + void mips_cpc_unlock_other(void) -- 2.30.2