Blackfin arch: SMP supporting patchset: Blackfin kernel and memory management code

Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like

In this patch, we provide SMP extend to Blackfin kernel and memory management code

Singed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 79 insertions, 35 deletions

diff --git a/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c
index eb2352320454..06de2ce67a9e 100644
--- a/arch/blackfin/kernel/time.c
+++ b/arch/blackfin/kernel/time.c
@@ -34,9 +34,11 @@
 #include <linux/interrupt.h>
 #include <linux/time.h>
 #include <linux/irq.h>
+#include <linux/delay.h>
 
 #include <asm/blackfin.h>
 #include <asm/time.h>
+#include <asm/gptimers.h>
 
 /* This is an NTP setting */
 #define TICK_SIZE (tick_nsec / 1000)
@@ -46,11 +48,14 @@ static unsigned long gettimeoffset(void);
 
 static struct irqaction bfin_timer_irq = {
         .name = "BFIN Timer Tick",
+#ifdef CONFIG_IRQ_PER_CPU
+        .flags = IRQF_DISABLED  | IRQF_PERCPU,
+#else
         .flags = IRQF_DISABLED
+#endif
 };
 
-static void
-time_sched_init(irq_handler_t timer_routine)
+void setup_core_timer(void)
 {
         u32 tcount;
 
@@ -71,12 +76,41 @@ time_sched_init(irq_handler_t timer_routine)
         CSYNC();
 
         bfin_write_TCNTL(7);
+}
+
+#ifdef CONFIG_TICK_SOURCE_SYSTMR0
+void setup_system_timer0(void)
+{
+        /* Power down the core timer, just to play safe. */
+        bfin_write_TCNTL(0);
+
+        disable_gptimers(TIMER0bit);
+        set_gptimer_status(0, TIMER_STATUS_TRUN0);
+        while (get_gptimer_status(0) & TIMER_STATUS_TRUN0)
+                udelay(10);
+
+        set_gptimer_config(0, 0x59); /* IRQ enable, periodic, PWM_OUT, SCLKed, OUT PAD disabled */
+        set_gptimer_period(TIMER0_id, get_sclk() / HZ);
+        set_gptimer_pwidth(TIMER0_id, 1);
+        SSYNC();
+        enable_gptimers(TIMER0bit);
+}
+#endif
 
+static void
+time_sched_init(irqreturn_t(*timer_routine) (int, void *))
+{
+#ifdef CONFIG_TICK_SOURCE_SYSTMR0
+        setup_system_timer0();
+#else
+        setup_core_timer();
+#endif
         bfin_timer_irq.handler = (irq_handler_t)timer_routine;
-        /* call setup_irq instead of request_irq because request_irq calls
-         * kmalloc which has not been initialized yet
-         */
+#ifdef CONFIG_TICK_SOURCE_SYSTMR0
+        setup_irq(IRQ_TIMER0, &bfin_timer_irq);
+#else
         setup_irq(IRQ_CORETMR, &bfin_timer_irq);
+#endif
 }
 
 /*
@@ -87,17 +121,23 @@ static unsigned long gettimeoffset(void)
         unsigned long offset;
         unsigned long clocks_per_jiffy;
 
+#ifdef CONFIG_TICK_SOURCE_SYSTMR0
+        clocks_per_jiffy =  bfin_read_TIMER0_PERIOD();
+        offset =  bfin_read_TIMER0_COUNTER() / \
+                (((clocks_per_jiffy + 1) * HZ) / USEC_PER_SEC);
+
+        if ((get_gptimer_status(0) & TIMER_STATUS_TIMIL0) && offset < (100000 / HZ / 2))
+                offset += (USEC_PER_SEC / HZ);
+#else
         clocks_per_jiffy = bfin_read_TPERIOD();
-        offset =
-            (clocks_per_jiffy -
-             bfin_read_TCOUNT()) / (((clocks_per_jiffy + 1) * HZ) /
-                                    USEC_PER_SEC);
+        offset = (clocks_per_jiffy - bfin_read_TCOUNT()) / \
+                (((clocks_per_jiffy + 1) * HZ)  / USEC_PER_SEC);
 
         /* Check if we just wrapped the counters and maybe missed a tick */
         if ((bfin_read_ILAT() & (1 << IRQ_CORETMR))
-            && (offset < (100000 / HZ / 2)))
+                && (offset < (100000 / HZ / 2)))
                 offset += (USEC_PER_SEC / HZ);
-
+#endif
         return offset;
 }
 
@@ -120,34 +160,38 @@ irqreturn_t timer_interrupt(int irq, void *dummy)
         static long last_rtc_update;
 
         write_seqlock(&xtime_lock);
-
-        do_timer(1);
-
-        profile_tick(CPU_PROFILING);
-
-        /*
-         * If we have an externally synchronized Linux clock, then update
-         * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
-         * called as close as possible to 500 ms before the new second starts.
-         */
-
-        if (ntp_synced() &&
-            xtime.tv_sec > last_rtc_update + 660 &&
-            (xtime.tv_nsec / NSEC_PER_USEC) >=
-            500000 - ((unsigned)TICK_SIZE) / 2
-            && (xtime.tv_nsec / NSEC_PER_USEC) <=
-            500000 + ((unsigned)TICK_SIZE) / 2) {
-                if (set_rtc_mmss(xtime.tv_sec) == 0)
-                        last_rtc_update = xtime.tv_sec;
-                else
-                        /* Do it again in 60s. */
-                        last_rtc_update = xtime.tv_sec - 600;
+#ifdef CONFIG_TICK_SOURCE_SYSTMR0
+        if (get_gptimer_status(0) & TIMER_STATUS_TIMIL0) {
+#endif
+                do_timer(1);
+
+
+                /*
+                 * If we have an externally synchronized Linux clock, then update
+                 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
+                 * called as close as possible to 500 ms before the new second starts.
+                 */
+
+                if (ntp_synced() &&
+                    xtime.tv_sec > last_rtc_update + 660 &&
+                    (xtime.tv_nsec / NSEC_PER_USEC) >=
+                    500000 - ((unsigned)TICK_SIZE) / 2
+                    && (xtime.tv_nsec / NSEC_PER_USEC) <=
+                    500000 + ((unsigned)TICK_SIZE) / 2) {
+                        if (set_rtc_mmss(xtime.tv_sec) == 0)
+                                last_rtc_update = xtime.tv_sec;
+                        else
+                                /* Do it again in 60s. */
+                                last_rtc_update = xtime.tv_sec - 600;
+                }
+#ifdef CONFIG_TICK_SOURCE_SYSTMR0
+                set_gptimer_status(0, TIMER_STATUS_TIMIL0);
         }
+#endif
         write_sequnlock(&xtime_lock);
 
-#ifndef CONFIG_SMP
         update_process_times(user_mode(get_irq_regs()));
-#endif
+        profile_tick(CPU_PROFILING);
 
         return IRQ_HANDLED;
 }