[PATCH 06/13] openrisc: initial SMP support

Stafford Horne
2017-08-30T22:01:21Z

From: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>

This patch introduces the SMP support for the OpenRISC architecture.
The SMP architecture requires cores which have multicore features which
have been introduced a few years back including:

- New SPRS SPR_COREID SPR_NUMCORES
- Shadow SPRs
- Atomic Instructions
- Cache Coherency
- A wired in IPI controller

This patch adds all of the SMP specific changes to core infrastructure,
it looks big but it needs to go all together as its hard to split this
one up.

Boot loader spinning of second cpu is not supported yet, it's assumed
that Linux is booted straight after cpu reset.

The bulk of these changes are trivial changes to refactor to use per cpu
data structures throughout. The addition of the smp.c and changes in
time.c are the changes. Some specific notes:

MM changes
----------
The reason why this is created as an array, and not with DEFINE_PER_CPU
is that doing it this way, we'll save a load in the tlb-miss handler
(the load from __per_cpu_offset).

TLB Flush
---------
The SMP implementation of flush_tlb_* works by sending out a
function-call IPI to all the non-local cpus by using the generic
on_each_cpu() function.

Currently, all flush_tlb_* functions will result in a flush_tlb_all(),
which has always been the behaviour in the UP case.

CPU INFO
--------
This creates a per cpu cpuinfo struct and fills it out accordingly for
each activated cpu. show_cpuinfo is also updated to reflect new version
information in later versions of the spec.

SMP API
-------
This imitates the arm64 implementation by having a smp_cross_call
callback that can be set by set_smp_cross_call to initiate an IPI and a
handle_IPI function that is expected to be called from an IPI irqchip
driver.

Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
[shorne@gmail.com: added cpu stop, checkpatch fixes, wrote commit message]
Signed-off-by: Stafford Horne <shorne@gmail.com>
---
arch/openrisc/Kconfig | 17 ++-
arch/openrisc/include/asm/cpuinfo.h | 5 +-
arch/openrisc/include/asm/mmu_context.h | 2 +-
arch/openrisc/include/asm/pgtable.h | 2 +-
arch/openrisc/include/asm/serial.h | 2 +-
arch/openrisc/include/asm/smp.h | 26 ++++
arch/openrisc/include/asm/spr_defs.h | 14 ++
arch/openrisc/include/asm/tlbflush.h | 25 +++-
arch/openrisc/kernel/Makefile | 1 +
arch/openrisc/kernel/dma.c | 14 +-
arch/openrisc/kernel/head.S | 97 ++++++++++++-
arch/openrisc/kernel/setup.c | 155 +++++++++++++--------
arch/openrisc/kernel/smp.c | 234 ++++++++++++++++++++++++++++++++
arch/openrisc/kernel/time.c | 51 ++++---
arch/openrisc/lib/delay.c | 2 +-
arch/openrisc/mm/fault.c | 4 +-
arch/openrisc/mm/init.c | 2 +-
arch/openrisc/mm/tlb.c | 16 +--
18 files changed, 560 insertions(+), 109 deletions(-)
create mode 100644 arch/openrisc/include/asm/smp.h
create mode 100644 arch/openrisc/kernel/smp.c

diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index dd7e55e7e42d..b59e2ef84534 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -21,8 +21,10 @@ config OPENRISC
select HAVE_UID16
select GENERIC_ATOMIC64
select GENERIC_CLOCKEVENTS
+ select GENERIC_CLOCKEVENTS_BROADCAST
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
+ select GENERIC_SMP_IDLE_THREAD
select MODULES_USE_ELF_RELA
select HAVE_DEBUG_STACKOVERFLOW
select OR1K_PIC
@@ -107,8 +109,19 @@ config OPENRISC_HAVE_INST_DIV
endmenu

config NR_CPUS
- int
- default "1"
+ int "Maximum number of CPUs (2-32)"
+ range 2 32
+ depends on SMP
+ default "2"
+
+config SMP
+ bool "Symmetric Multi-Processing support"
+ help
+ This enables support for systems with more than one CPU. If you have
+ a system with only one CPU, say N. If you have a system with more
+ than one CPU, say Y.
+
+ If you don't know what to do here, say N.

source kernel/Kconfig.hz
source kernel/Kconfig.preempt
diff --git a/arch/openrisc/include/asm/cpuinfo.h b/arch/openrisc/include/asm/cpuinfo.h
index ec10679d6429..1bcf29072973 100644
--- a/arch/openrisc/include/asm/cpuinfo.h
+++ b/arch/openrisc/include/asm/cpuinfo.h
@@ -19,7 +19,7 @@
#ifndef __ASM_OPENRISC_CPUINFO_H
#define __ASM_OPENRISC_CPUINFO_H

-struct cpuinfo {
+struct cpuinfo_or1k {
u32 clock_frequency;

u32 icache_size;
@@ -31,6 +31,7 @@ struct cpuinfo {
u32 dcache_ways;
};

-extern struct cpuinfo cpuinfo;
+extern struct cpuinfo_or1k cpuinfo_or1k[NR_CPUS];
+extern void setup_cpuinfo(void);

#endif /* __ASM_OPENRISC_CPUINFO_H */
diff --git a/arch/openrisc/include/asm/mmu_context.h b/arch/openrisc/include/asm/mmu_context.h
index e94b814d2e3c..c380d8caf84f 100644
--- a/arch/openrisc/include/asm/mmu_context.h
+++ b/arch/openrisc/include/asm/mmu_context.h
@@ -34,7 +34,7 @@ extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
* registers like cr3 on the i386
*/

-extern volatile pgd_t *current_pgd; /* defined in arch/openrisc/mm/fault.c */
+extern volatile pgd_t *current_pgd[]; /* defined in arch/openrisc/mm/fault.c */

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h
index ff97374ca069..47eae2f78d2d 100644
--- a/arch/openrisc/include/asm/pgtable.h
+++ b/arch/openrisc/include/asm/pgtable.h
@@ -94,7 +94,7 @@ extern void paging_init(void);
* 64 MB of vmalloc area is comparable to what's available on other arches.
*/

-#define VMALLOC_START (PAGE_OFFSET-0x04000000)
+#define VMALLOC_START (PAGE_OFFSET-0x04000000UL)
#define VMALLOC_END (PAGE_OFFSET)
#define VMALLOC_VMADDR(x) ((unsigned long)(x))

diff --git a/arch/openrisc/include/asm/serial.h b/arch/openrisc/include/asm/serial.h
index 270a45241639..cb5932f5447a 100644
--- a/arch/openrisc/include/asm/serial.h
+++ b/arch/openrisc/include/asm/serial.h
@@ -29,7 +29,7 @@
* it needs to be correct to get the early console working.
*/

-#define BASE_BAUD (cpuinfo.clock_frequency/16)
+#define BASE_BAUD (cpuinfo_or1k[smp_processor_id()].clock_frequency/16)

#endif /* __KERNEL__ */

diff --git a/arch/openrisc/include/asm/smp.h b/arch/openrisc/include/asm/smp.h
new file mode 100644
index 000000000000..d25ca0952f52
--- /dev/null
+++ b/arch/openrisc/include/asm/smp.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#ifndef __ASM_OPENRISC_SMP_H
+#define __ASM_OPENRISC_SMP_H
+
+#include <asm/spr.h>
+#include <asm/spr_defs.h>
+
+#define raw_smp_processor_id() (current_thread_info()->cpu)
+#define hard_smp_processor_id() mfspr(SPR_COREID)
+
+extern void smp_init_cpus(void);
+
+extern void arch_send_call_function_single_ipi(int cpu);
+extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
+
+extern void set_smp_cross_call(void (*)(const struct cpumask *, unsigned int));
+extern void handle_IPI(int ipinr);
+
+#endif /* __ASM_OPENRISC_SMP_H */
diff --git a/arch/openrisc/include/asm/spr_defs.h b/arch/openrisc/include/asm/spr_defs.h
index 367dac70326a..154b5a1ee579 100644
--- a/arch/openrisc/include/asm/spr_defs.h
+++ b/arch/openrisc/include/asm/spr_defs.h
@@ -51,6 +51,11 @@
#define SPR_ICCFGR (SPRGROUP_SYS + 6)
#define SPR_DCFGR (SPRGROUP_SYS + 7)
#define SPR_PCCFGR (SPRGROUP_SYS + 8)
+#define SPR_VR2 (SPRGROUP_SYS + 9)
+#define SPR_AVR (SPRGROUP_SYS + 10)
+#define SPR_EVBAR (SPRGROUP_SYS + 11)
+#define SPR_AECR (SPRGROUP_SYS + 12)
+#define SPR_AESR (SPRGROUP_SYS + 13)
#define SPR_NPC (SPRGROUP_SYS + 16) /* CZ 21/06/01 */
#define SPR_SR (SPRGROUP_SYS + 17) /* CZ 21/06/01 */
#define SPR_PPC (SPRGROUP_SYS + 18) /* CZ 21/06/01 */
@@ -61,6 +66,8 @@
#define SPR_EEAR_LAST (SPRGROUP_SYS + 63)
#define SPR_ESR_BASE (SPRGROUP_SYS + 64)
#define SPR_ESR_LAST (SPRGROUP_SYS + 79)
+#define SPR_COREID (SPRGROUP_SYS + 128)
+#define SPR_NUMCORES (SPRGROUP_SYS + 129)
#define SPR_GPR_BASE (SPRGROUP_SYS + 1024)

/* Data MMU group */
@@ -135,12 +142,19 @@
#define SPR_VR_CFG 0x00ff0000 /* Processor configuration */
#define SPR_VR_RES 0x0000ffc0 /* Reserved */
#define SPR_VR_REV 0x0000003f /* Processor revision */
+#define SPR_VR_UVRP 0x00000040 /* Updated Version Registers Present */

#define SPR_VR_VER_OFF 24
#define SPR_VR_CFG_OFF 16
#define SPR_VR_REV_OFF 0

/*
+ * Bit definitions for the Version Register 2
+ */
+#define SPR_VR2_CPUID 0xff000000 /* Processor ID */
+#define SPR_VR2_VER 0x00ffffff /* Processor version */
+
+/*
* Bit definitions for the Unit Present Register
*
*/
diff --git a/arch/openrisc/include/asm/tlbflush.h b/arch/openrisc/include/asm/tlbflush.h
index 6a2accd6cb67..94227f0eaf6d 100644
--- a/arch/openrisc/include/asm/tlbflush.h
+++ b/arch/openrisc/include/asm/tlbflush.h
@@ -33,13 +33,26 @@
* - flush_tlb_page(vma, vmaddr) flushes one page
* - flush_tlb_range(mm, start, end) flushes a range of pages
*/
+extern void local_flush_tlb_all(void);
+extern void local_flush_tlb_mm(struct mm_struct *mm);
+extern void local_flush_tlb_page(struct vm_area_struct *vma,
+ unsigned long addr);
+extern void local_flush_tlb_range(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end);

-void flush_tlb_all(void);
-void flush_tlb_mm(struct mm_struct *mm);
-void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr);
-void flush_tlb_range(struct vm_area_struct *vma,
- unsigned long start,
- unsigned long end);
+#ifndef CONFIG_SMP
+#define flush_tlb_all local_flush_tlb_all
+#define flush_tlb_mm local_flush_tlb_mm
+#define flush_tlb_page local_flush_tlb_page
+#define flush_tlb_range local_flush_tlb_range
+#else
+extern void flush_tlb_all(void);
+extern void flush_tlb_mm(struct mm_struct *mm);
+extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr);
+extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end);
+#endif

static inline void flush_tlb(void)
{
diff --git a/arch/openrisc/kernel/Makefile b/arch/openrisc/kernel/Makefile
index ec6d9d37cefd..7d94643c878d 100644
--- a/arch/openrisc/kernel/Makefile
+++ b/arch/openrisc/kernel/Makefile
@@ -8,6 +8,7 @@ obj-y := setup.o or32_ksyms.o process.o dma.o \
traps.o time.o irq.o entry.o ptrace.o signal.o \
sys_call_table.o

+obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_OF) += prom.o

diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index b10369b7e31b..a945f00011b4 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -32,6 +32,7 @@ page_set_nocache(pte_t *pte, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
unsigned long cl;
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];

pte_val(*pte) |= _PAGE_CI;

@@ -42,7 +43,7 @@ page_set_nocache(pte_t *pte, unsigned long addr,
flush_tlb_page(NULL, addr);

/* Flush page out of dcache */
- for (cl = __pa(addr); cl < __pa(next); cl += cpuinfo.dcache_block_size)
+ for (cl = __pa(addr); cl < __pa(next); cl += cpuinfo->dcache_block_size)
mtspr(SPR_DCBFR, cl);

return 0;
@@ -140,6 +141,7 @@ or1k_map_page(struct device *dev, struct page *page,
{
unsigned long cl;
dma_addr_t addr = page_to_phys(page) + offset;
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];

if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
return addr;
@@ -148,13 +150,13 @@ or1k_map_page(struct device *dev, struct page *page,
case DMA_TO_DEVICE:
/* Flush the dcache for the requested range */
for (cl = addr; cl < addr + size;
- cl += cpuinfo.dcache_block_size)
+ cl += cpuinfo->dcache_block_size)
mtspr(SPR_DCBFR, cl);
break;
case DMA_FROM_DEVICE:
/* Invalidate the dcache for the requested range */
for (cl = addr; cl < addr + size;
- cl += cpuinfo.dcache_block_size)
+ cl += cpuinfo->dcache_block_size)
mtspr(SPR_DCBIR, cl);
break;
default:
@@ -213,9 +215,10 @@ or1k_sync_single_for_cpu(struct device *dev,
{
unsigned long cl;
dma_addr_t addr = dma_handle;
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];

/* Invalidate the dcache for the requested range */
- for (cl = addr; cl < addr + size; cl += cpuinfo.dcache_block_size)
+ for (cl = addr; cl < addr + size; cl += cpuinfo->dcache_block_size)
mtspr(SPR_DCBIR, cl);
}

@@ -226,9 +229,10 @@ or1k_sync_single_for_device(struct device *dev,
{
unsigned long cl;
dma_addr_t addr = dma_handle;
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];

/* Flush the dcache for the requested range */
- for (cl = addr; cl < addr + size; cl += cpuinfo.dcache_block_size)
+ for (cl = addr; cl < addr + size; cl += cpuinfo->dcache_block_size)
mtspr(SPR_DCBFR, cl);
}

diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S
index 1e49895408f4..a9972dc103f8 100644
--- a/arch/openrisc/kernel/head.S
+++ b/arch/openrisc/kernel/head.S
@@ -158,12 +158,38 @@

/* =========================================================[ macros ]=== */

-
+#ifdef CONFIG_SMP
#define GET_CURRENT_PGD(reg,t1) \
LOAD_SYMBOL_2_GPR(reg,current_pgd) ;\
+ l.mfspr t1,r0,SPR_COREID ;\
+ l.slli t1,t1,2 ;\
+ l.add reg,reg,t1 ;\
tophys (t1,reg) ;\
l.lwz reg,0(t1)
+#else
+#define GET_CURRENT_PGD(reg,t1) \
+ LOAD_SYMBOL_2_GPR(reg,current_pgd) ;\
+ tophys (t1,reg) ;\
+ l.lwz reg,0(t1)
+#endif

+/* Load r10 from current_thread_info_set - clobbers r1 and r30 */
+#ifdef CONFIG_SMP
+#define GET_CURRENT_THREAD_INFO \
+ LOAD_SYMBOL_2_GPR(r1,current_thread_info_set) ;\
+ tophys (r30,r1) ;\
+ l.mfspr r10,r0,SPR_COREID ;\
+ l.slli r10,r10,2 ;\
+ l.add r30,r30,r10 ;\
+ /* r10: current_thread_info */ ;\
+ l.lwz r10,0(r30)
+#else
+#define GET_CURRENT_THREAD_INFO \
+ LOAD_SYMBOL_2_GPR(r1,current_thread_info_set) ;\
+ tophys (r30,r1) ;\
+ /* r10: current_thread_info */ ;\
+ l.lwz r10,0(r30)
+#endif

/*
* DSCR: this is a common hook for handling exceptions. it will save
@@ -206,10 +232,7 @@
l.bnf 2f /* kernel_mode */ ;\
EXCEPTION_T_STORE_SP /* delay slot */ ;\
1: /* user_mode: */ ;\
- LOAD_SYMBOL_2_GPR(r1,current_thread_info_set) ;\
- tophys (r30,r1) ;\
- /* r10: current_thread_info */ ;\
- l.lwz r10,0(r30) ;\
+ GET_CURRENT_THREAD_INFO ;\
tophys (r30,r10) ;\
l.lwz r1,(TI_KSP)(r30) ;\
/* fall through */ ;\
@@ -530,6 +553,12 @@ _start:
CLEAR_GPR(r30)
CLEAR_GPR(r31)

+#ifdef CONFIG_SMP
+ l.mfspr r26,r0,SPR_COREID
+ l.sfeq r26,r0
+ l.bnf secondary_wait
+ l.nop
+#endif
/*
* set up initial ksp and current
*/
@@ -681,6 +710,64 @@ _flush_tlb:
l.jr r9
l.nop

+#ifdef CONFIG_SMP
+secondary_wait:
+ l.mfspr r25,r0,SPR_COREID
+ l.movhi r3,hi(secondary_release)
+ l.ori r3,r3,lo(secondary_release)
+ tophys(r4, r3)
+ l.lwz r3,0(r4)
+ l.sfeq r25,r3
+ l.bnf secondary_wait
+ l.nop
+ /* fall through to secondary_init */
+
+secondary_init:
+ /*
+ * set up initial ksp and current
+ */
+ LOAD_SYMBOL_2_GPR(r10, secondary_thread_info)
+ tophys (r30,r10)
+ l.lwz r10,0(r30)
+ l.addi r1,r10,THREAD_SIZE
+ tophys (r30,r10)
+ l.sw TI_KSP(r30),r1
+
+ l.jal _ic_enable
+ l.nop
+
+ l.jal _dc_enable
+ l.nop
+
+ l.jal _flush_tlb
+ l.nop
+
+ /*
+ * enable dmmu & immu
+ */
+ l.mfspr r30,r0,SPR_SR
+ l.movhi r28,hi(SPR_SR_DME | SPR_SR_IME)
+ l.ori r28,r28,lo(SPR_SR_DME | SPR_SR_IME)
+ l.or r30,r30,r28
+ /*
+ * This is a bit tricky, we need to switch over from physical addresses
+ * to virtual addresses on the fly.
+ * To do that, we first set up ESR with the IME and DME bits set.
+ * Then EPCR is set to secondary_start and then a l.rfe is issued to
+ * "jump" to that.
+ */
+ l.mtspr r0,r30,SPR_ESR_BASE
+ LOAD_SYMBOL_2_GPR(r30, secondary_start)
+ l.mtspr r0,r30,SPR_EPCR_BASE
+ l.rfe
+
+secondary_start:
+ LOAD_SYMBOL_2_GPR(r30, secondary_start_kernel)
+ l.jr r30
+ l.nop
+
+#endif
+
/* ========================================[ cache ]=== */

/* alignment here so we don't change memory offsets with
diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
index dbf5ee95a0d5..11c853e73d74 100644
--- a/arch/openrisc/kernel/setup.c
+++ b/arch/openrisc/kernel/setup.c
@@ -93,7 +93,7 @@ static void __init setup_memory(void)
memblock_dump_all();
}

-struct cpuinfo cpuinfo;
+struct cpuinfo_or1k cpuinfo_or1k[NR_CPUS];

static void print_cpuinfo(void)
{
@@ -101,12 +101,13 @@ static void print_cpuinfo(void)
unsigned long vr = mfspr(SPR_VR);
unsigned int version;
unsigned int revision;
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];

version = (vr & SPR_VR_VER) >> 24;
revision = (vr & SPR_VR_REV);

printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
- version, revision, cpuinfo.clock_frequency / 1000000);
+ version, revision, cpuinfo->clock_frequency / 1000000);

if (!(upr & SPR_UPR_UP)) {
printk(KERN_INFO
@@ -117,15 +118,15 @@ static void print_cpuinfo(void)
if (upr & SPR_UPR_DCP)
printk(KERN_INFO
"-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
- cpuinfo.dcache_size, cpuinfo.dcache_block_size,
- cpuinfo.dcache_ways);
+ cpuinfo->dcache_size, cpuinfo->dcache_block_size,
+ cpuinfo->dcache_ways);
else
printk(KERN_INFO "-- dcache disabled\n");
if (upr & SPR_UPR_ICP)
printk(KERN_INFO
"-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
- cpuinfo.icache_size, cpuinfo.icache_block_size,
- cpuinfo.icache_ways);
+ cpuinfo->icache_size, cpuinfo->icache_block_size,
+ cpuinfo->icache_ways);
else
printk(KERN_INFO "-- icache disabled\n");

@@ -153,32 +154,50 @@ static void print_cpuinfo(void)
printk(KERN_INFO "-- custom unit(s)\n");
}

+static struct device_node *setup_find_cpu_node(int cpu)
+{
+ u32 hwid;
+ struct device_node *cpun;
+ struct device_node *cpus = of_find_node_by_path("/cpus");
+
+ for_each_available_child_of_node(cpus, cpun) {
+ if (of_property_read_u32(cpun, "reg", &hwid))
+ continue;
+ if (hwid == cpu)
+ return cpun;
+ }
+
+ return NULL;
+}
+
void __init setup_cpuinfo(void)
{
struct device_node *cpu;
unsigned long iccfgr, dccfgr;
unsigned long cache_set_size;
+ int cpu_id = smp_processor_id();
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[cpu_id];

- cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
+ cpu = setup_find_cpu_node(cpu_id);
if (!cpu)
- panic("No compatible CPU found in device tree...\n");
+ panic("Couldn't find CPU%d in device tree...\n", cpu_id);

iccfgr = mfspr(SPR_ICCFGR);
- cpuinfo.icache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
+ cpuinfo->icache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
- cpuinfo.icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
- cpuinfo.icache_size =
- cache_set_size * cpuinfo.icache_ways * cpuinfo.icache_block_size;
+ cpuinfo->icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
+ cpuinfo->icache_size =
+ cache_set_size * cpuinfo->icache_ways * cpuinfo->icache_block_size;

dccfgr = mfspr(SPR_DCCFGR);
- cpuinfo.dcache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
+ cpuinfo->dcache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
- cpuinfo.dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
- cpuinfo.dcache_size =
- cache_set_size * cpuinfo.dcache_ways * cpuinfo.dcache_block_size;
+ cpuinfo->dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
+ cpuinfo->dcache_size =
+ cache_set_size * cpuinfo->dcache_ways * cpuinfo->dcache_block_size;

if (of_property_read_u32(cpu, "clock-frequency",
- &cpuinfo.clock_frequency)) {
+ &cpuinfo->clock_frequency)) {
printk(KERN_WARNING
"Device tree missing CPU 'clock-frequency' parameter."
"Assuming frequency 25MHZ"
@@ -251,8 +270,8 @@ void __init detect_unit_config(unsigned long upr, unsigned long mask,
void calibrate_delay(void)
{
const int *val;
- struct device_node *cpu = NULL;
- cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
+ struct device_node *cpu = setup_find_cpu_node(smp_processor_id());
+
val = of_get_property(cpu, "clock-frequency", NULL);
if (!val)
panic("no cpu 'clock-frequency' parameter in device tree");
@@ -268,6 +287,10 @@ void __init setup_arch(char **cmdline_p)

setup_cpuinfo();

+#ifdef CONFIG_SMP
+ smp_init_cpus();
+#endif
+
/* process 1's initial memory region is the kernel code/data */
init_mm.start_code = (unsigned long)_stext;
init_mm.end_code = (unsigned long)_etext;
@@ -302,48 +325,72 @@ void __init setup_arch(char **cmdline_p)

static int show_cpuinfo(struct seq_file *m, void *v)
{
- unsigned long vr;
- int version, revision;
+ unsigned int vr, cpucfgr;
+ unsigned int avr;
+ unsigned int version;
+ unsigned long n = (unsigned long) v - 1;
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[n];

vr = mfspr(SPR_VR);
- version = (vr & SPR_VR_VER) >> 24;
- revision = vr & SPR_VR_REV;
-
- seq_printf(m,
- "cpu\t\t: OpenRISC-%x\n"
- "revision\t: %d\n"
- "frequency\t: %ld\n"
- "dcache size\t: %d bytes\n"
- "dcache block size\t: %d bytes\n"
- "dcache ways\t: %d\n"
- "icache size\t: %d bytes\n"
- "icache block size\t: %d bytes\n"
- "icache ways\t: %d\n"
- "immu\t\t: %d entries, %lu ways\n"
- "dmmu\t\t: %d entries, %lu ways\n"
- "bogomips\t: %lu.%02lu\n",
- version,
- revision,
- loops_per_jiffy * HZ,
- cpuinfo.dcache_size,
- cpuinfo.dcache_block_size,
- cpuinfo.dcache_ways,
- cpuinfo.icache_size,
- cpuinfo.icache_block_size,
- cpuinfo.icache_ways,
- 1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
- 1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW),
- 1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
- 1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW),
- (loops_per_jiffy * HZ) / 500000,
- ((loops_per_jiffy * HZ) / 5000) % 100);
+ cpucfgr = mfspr(SPR_CPUCFGR);
+
+#ifdef CONFIG_SMP
+ seq_printf(m, "processor\t\t: %ld\n", n);
+#endif
+ if (vr & SPR_VR_UVRP) {
+ vr = mfspr(SPR_VR2);
+ version = vr & SPR_VR2_VER;
+ avr = mfspr(SPR_AVR);
+ seq_printf(m, "cpu architecture\t: "
+ "OpenRISC 1000 (%d.%d-rev%d)\n",
+ (avr >> 24) & 0xff,
+ (avr >> 16) & 0xff,
+ (avr >> 8) & 0xff);
+ seq_printf(m, "cpu implementation id\t: 0x%x\n",
+ (vr & SPR_VR2_CPUID) >> 24);
+ seq_printf(m, "cpu version\t\t: 0x%x\n", version);
+ } else {
+ version = (vr & SPR_VR_VER) >> 24;
+ seq_printf(m, "cpu\t\t\t: OpenRISC-%x\n", version);
+ seq_printf(m, "revision\t\t: %d\n", vr & SPR_VR_REV);
+ }
+ seq_printf(m, "frequency\t\t: %ld\n", loops_per_jiffy * HZ);
+ seq_printf(m, "dcache size\t\t: %d bytes\n", cpuinfo->dcache_size);
+ seq_printf(m, "dcache block size\t: %d bytes\n",
+ cpuinfo->dcache_block_size);
+ seq_printf(m, "dcache ways\t\t: %d\n", cpuinfo->dcache_ways);
+ seq_printf(m, "icache size\t\t: %d bytes\n", cpuinfo->icache_size);
+ seq_printf(m, "icache block size\t: %d bytes\n",
+ cpuinfo->icache_block_size);
+ seq_printf(m, "icache ways\t\t: %d\n", cpuinfo->icache_ways);
+ seq_printf(m, "immu\t\t\t: %d entries, %lu ways\n",
+ 1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
+ 1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
+ seq_printf(m, "dmmu\t\t\t: %d entries, %lu ways\n",
+ 1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
+ 1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));
+ seq_printf(m, "bogomips\t\t: %lu.%02lu\n",
+ (loops_per_jiffy * HZ) / 500000,
+ ((loops_per_jiffy * HZ) / 5000) % 100);
+
+ seq_puts(m, "features\t\t: ");
+ seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB32S ? "orbis32" : "");
+ seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB64S ? "orbis64" : "");
+ seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF32S ? "orfpx32" : "");
+ seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF64S ? "orfpx64" : "");
+ seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OV64S ? "orvdx64" : "");
+ seq_puts(m, "\n");
+
+ seq_puts(m, "\n");
+
return 0;
}

static void *c_start(struct seq_file *m, loff_t * pos)
{
- /* We only have one CPU... */
- return *pos < 1 ? (void *)1 : NULL;
+ unsigned long i = *pos;
+
+ return i < NR_CPUS ? (void *) (i + 1) : NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t * pos)
diff --git a/arch/openrisc/kernel/smp.c b/arch/openrisc/kernel/smp.c
new file mode 100644
index 000000000000..ae93b84062ff
--- /dev/null
+++ b/arch/openrisc/kernel/smp.c
@@ -0,0 +1,234 @@
+/*
+ * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
+ * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
+ *
+ * Based on arm64 and arc implementations
+ * Copyright (C) 2013 ARM Ltd.
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/cpu.h>
+#include <linux/sched.h>
+#include <linux/irq.h>
+#include <asm/cpuinfo.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+
+volatile unsigned long secondary_release = -1;
+struct thread_info *secondary_thread_info;
+
+enum ipi_msg_type {
+ IPI_RESCHEDULE,
+ IPI_CALL_FUNC,
+ IPI_CALL_FUNC_SINGLE,
+};
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static int boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ /*
+ * set synchronisation state between this boot processor
+ * and the secondary one
+ */
+ spin_lock(&boot_lock);
+
+ secondary_release = cpu;
+
+ /*
+ * now the secondary core is starting up let it run its
+ * calibrations, then wait for it to finish
+ */
+ spin_unlock(&boot_lock);
+
+ return 0;
+}
+
+void __init smp_prepare_boot_cpu(void)
+{
+}
+
+void __init smp_init_cpus(void)
+{
+ int i;
+
+ for (i = 0; i < NR_CPUS; i++)
+ set_cpu_possible(i, true);
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ int i;
+
+ /*
+ * Initialise the present map, which describes the set of CPUs
+ * actually populated at the present time.
+ */
+ for (i = 0; i < max_cpus; i++)
+ set_cpu_present(i, true);
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+static DECLARE_COMPLETION(cpu_running);
+
+int __cpu_up(unsigned int cpu, struct task_struct *idle)
+{
+ int ret;
+
+ secondary_thread_info = task_thread_info(idle);
+ current_pgd[cpu] = init_mm.pgd;
+
+ ret = boot_secondary(cpu, idle);
+ if (ret == 0) {
+ wait_for_completion_timeout(&cpu_running,
+ msecs_to_jiffies(1000));
+ if (!cpu_online(cpu))
+ ret = -EIO;
+ }
+
+ return ret;
+}
+
+extern void openrisc_clockevent_init(void);
+
+asmlinkage __init void secondary_start_kernel(void)
+{
+ struct mm_struct *mm = &init_mm;
+ unsigned int cpu = smp_processor_id();
+ /*
+ * All kernel threads share the same mm context; grab a
+ * reference and switch to it.
+ */
+ atomic_inc(&mm->mm_count);
+ current->active_mm = mm;
+ cpumask_set_cpu(cpu, mm_cpumask(mm));
+
+ pr_info("CPU%u: Booted secondary processor\n", cpu);
+
+ setup_cpuinfo();
+ openrisc_clockevent_init();
+
+ notify_cpu_starting(cpu);
+
+ /*
+ * OK, now it's safe to let the boot CPU continue
+ */
+ set_cpu_online(cpu, true);
+ complete(&cpu_running);
+
+ local_irq_enable();
+
+ /*
+ * OK, it's off to the idle thread for us
+ */
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+}
+
+void handle_IPI(int ipinr)
+{
+ unsigned int cpu = smp_processor_id();
+
+ switch (ipinr) {
+ case IPI_RESCHEDULE:
+ scheduler_ipi();
+ break;
+
+ case IPI_CALL_FUNC:
+ generic_smp_call_function_interrupt();
+ break;
+
+ case IPI_CALL_FUNC_SINGLE:
+ generic_smp_call_function_single_interrupt();
+ break;
+
+ default:
+ WARN(1, "CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr);
+ break;
+ }
+}
+
+static void (*smp_cross_call)(const struct cpumask *, unsigned int);
+
+void smp_send_reschedule(int cpu)
+{
+ smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
+}
+
+static void stop_this_cpu(void *dummy)
+{
+ /* Remove this CPU */
+ set_cpu_online(smp_processor_id(), false);
+
+ local_irq_disable();
+ /* CPU Doze */
+ if (mfspr(SPR_UPR) & SPR_UPR_PMP)
+ mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
+ /* If that didn't work, infinite loop */
+ while (1)
+ ;
+}
+
+void smp_send_stop(void)
+{
+ smp_call_function(stop_this_cpu, NULL, 0);
+}
+
+/* not supported, yet */
+int setup_profiling_timer(unsigned int multiplier)
+{
+ return -EINVAL;
+}
+
+void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
+{
+ smp_cross_call = fn;
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+ smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+ smp_cross_call(mask, IPI_CALL_FUNC);
+}
+
+/* TLB flush operations - Performed on each CPU*/
+static inline void ipi_flush_tlb_all(void *ignored)
+{
+ local_flush_tlb_all();
+}
+
+void flush_tlb_all(void)
+{
+ on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
+
+/*
+ * FIXME: implement proper functionality instead of flush_tlb_all.
+ * *But*, as things currently stands, the local_tlb_flush_* functions will
+ * all boil down to local_tlb_flush_all anyway.
+ */
+void flush_tlb_mm(struct mm_struct *mm)
+{
+ on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
+{
+ on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
+
+void flush_tlb_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
diff --git a/arch/openrisc/kernel/time.c b/arch/openrisc/kernel/time.c
index 687c11d048d7..ab04eaedbf8d 100644
--- a/arch/openrisc/kernel/time.c
+++ b/arch/openrisc/kernel/time.c
@@ -53,13 +53,32 @@ static int openrisc_timer_set_next_event(unsigned long delta,
* timers) we cannot enable the PERIODIC feature. The tick timer can run using
* one-shot events, so no problem.
*/
+DEFINE_PER_CPU(struct clock_event_device, clockevent_openrisc_timer);

-static struct clock_event_device clockevent_openrisc_timer = {
- .name = "openrisc_timer_clockevent",
- .features = CLOCK_EVT_FEAT_ONESHOT,
- .rating = 300,
- .set_next_event = openrisc_timer_set_next_event,
-};
+void openrisc_clockevent_init(void)
+{
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *evt =
+ &per_cpu(clockevent_openrisc_timer, cpu);
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[cpu];
+
+ mtspr(SPR_TTMR, SPR_TTMR_CR);
+
+#ifdef CONFIG_SMP
+ evt->broadcast = tick_broadcast;
+#endif
+ evt->name = "openrisc_timer_clockevent",
+ evt->features = CLOCK_EVT_FEAT_ONESHOT,
+ evt->rating = 300,
+ evt->set_next_event = openrisc_timer_set_next_event,
+
+ evt->cpumask = cpumask_of(cpu);
+
+ /* We only have 28 bits */
+ clockevents_config_and_register(evt, cpuinfo->clock_frequency,
+ 100, 0x0fffffff);
+
+}

static inline void timer_ack(void)
{
@@ -83,7 +102,9 @@ static inline void timer_ack(void)
irqreturn_t __irq_entry timer_interrupt(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
- struct clock_event_device *evt = &clockevent_openrisc_timer;
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *evt =
+ &per_cpu(clockevent_openrisc_timer, cpu);

timer_ack();

@@ -99,24 +120,12 @@ irqreturn_t __irq_entry timer_interrupt(struct pt_regs *regs)
return IRQ_HANDLED;
}

-static __init void openrisc_clockevent_init(void)
-{
- clockevent_openrisc_timer.cpumask = cpumask_of(0);
-
- /* We only have 28 bits */
- clockevents_config_and_register(&clockevent_openrisc_timer,
- cpuinfo.clock_frequency,
- 100, 0x0fffffff);
-
-}
-
/**
* Clocksource: Based on OpenRISC timer/counter
*
* This sets up the OpenRISC Tick Timer as a clock source. The tick timer
* is 32 bits wide and runs at the CPU clock frequency.
*/
-
static u64 openrisc_timer_read(struct clocksource *cs)
{
return (u64) mfspr(SPR_TTCR);
@@ -132,7 +141,9 @@ static struct clocksource openrisc_timer = {

static int __init openrisc_timer_init(void)
{
- if (clocksource_register_hz(&openrisc_timer, cpuinfo.clock_frequency))
+ struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];
+
+ if (clocksource_register_hz(&openrisc_timer, cpuinfo->clock_frequency))
panic("failed to register clocksource");

/* Enable the incrementer: 'continuous' mode with interrupt disabled */
diff --git a/arch/openrisc/lib/delay.c b/arch/openrisc/lib/delay.c
index 8b13fdf43ec6..a92bd621aa1f 100644
--- a/arch/openrisc/lib/delay.c
+++ b/arch/openrisc/lib/delay.c
@@ -25,7 +25,7 @@

int read_current_timer(unsigned long *timer_value)
{
- *timer_value = mfspr(SPR_TTCR);
+ *timer_value = get_cycles();
return 0;
}

diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
index e310ab499385..d0021dfae20a 100644
--- a/arch/openrisc/mm/fault.c
+++ b/arch/openrisc/mm/fault.c
@@ -33,7 +33,7 @@ unsigned long pte_errors; /* updated by do_page_fault() */
/* __PHX__ :: - check the vmalloc_fault in do_page_fault()
* - also look into include/asm-or32/mmu_context.h
*/
-volatile pgd_t *current_pgd;
+volatile pgd_t *current_pgd[NR_CPUS];

extern void die(char *, struct pt_regs *, long);

@@ -319,7 +319,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,

phx_mmu("vmalloc_fault");
*/
- pgd = (pgd_t *)current_pgd + offset;
+ pgd = (pgd_t *)current_pgd[smp_processor_id()] + offset;
pgd_k = init_mm.pgd + offset;

/* Since we're two-level, we don't need to do both
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index f67d82b9d22f..6972d5d6f23f 100644
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c
@@ -147,7 +147,7 @@ void __init paging_init(void)
* (even if it is most probably not used until the next
* switch_mm)
*/
- current_pgd = init_mm.pgd;
+ current_pgd[smp_processor_id()] = init_mm.pgd;

end = (unsigned long)__va(max_low_pfn * PAGE_SIZE);

diff --git a/arch/openrisc/mm/tlb.c b/arch/openrisc/mm/tlb.c
index 683bd4d31c7c..6c253a2e86bc 100644
--- a/arch/openrisc/mm/tlb.c
+++ b/arch/openrisc/mm/tlb.c
@@ -49,7 +49,7 @@
*
*/

-void flush_tlb_all(void)
+void local_flush_tlb_all(void)
{
int i;
unsigned long num_tlb_sets;
@@ -86,7 +86,7 @@ void flush_tlb_all(void)
#define flush_itlb_page_no_eir(addr) \
mtspr_off(SPR_ITLBMR_BASE(0), ITLB_OFFSET(addr), 0);

-void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
{
if (have_dtlbeir)
flush_dtlb_page_eir(addr);
@@ -99,8 +99,8 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
flush_itlb_page_no_eir(addr);
}

-void flush_tlb_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
+void local_flush_tlb_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
{
int addr;
bool dtlbeir;
@@ -129,13 +129,13 @@ void flush_tlb_range(struct vm_area_struct *vma,
* This should be changed to loop over over mm and call flush_tlb_range.
*/

-void flush_tlb_mm(struct mm_struct *mm)
+void local_flush_tlb_mm(struct mm_struct *mm)
{

/* Was seeing bugs with the mm struct passed to us. Scrapped most of
this function. */
/* Several architctures do this */
- flush_tlb_all();
+ local_flush_tlb_all();
}

/* called in schedule() just before actually doing the switch_to */
@@ -149,14 +149,14 @@ void switch_mm(struct mm_struct *prev, struct mm_struct *next,
* might be invalid at points where we still need to derefer
* the pgd.
*/
- current_pgd = next->pgd;
+ current_pgd[smp_processor_id()] = next->pgd;

/* We don't have context support implemented, so flush all
* entries belonging to previous map
*/

if (prev != next)
- flush_tlb_mm(prev);
+ local_flush_tlb_mm(prev);

}

--
2.13.5