[PATCH] powerpc: Experimental support for new G5 Macs (#2)

This adds some very basic support for the new machines, including the
Quad G5 (tested), and other new dual core based machines and iMac G5
iSight (untested). This is still experimental !  There is no thermal
control yet, there is no proper handing of MSIs, etc.. but it
boots, I have all 4 cores up on my machine. Compared to the previous
version of this patch, this one adds DART IOMMU support for the U4
chipset and thus should work fine on setups with more than 2Gb of RAM.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 168 insertions, 151 deletions

diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 862f1e985c19..df01bb8feb16 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -361,7 +361,6 @@ static void __init psurge_dual_sync_tb(int cpu_nr)
         set_dec(tb_ticks_per_jiffy);
         /* XXX fixme */
         set_tb(0, 0);
-        last_jiffy_stamp(cpu_nr) = 0;
 
         if (cpu_nr > 0) {
                 mb();
@@ -429,15 +428,62 @@ struct smp_ops_t psurge_smp_ops = {
 };
 #endif /* CONFIG_PPC32 - actually powersurge support */
 
+/*
+ * Core 99 and later support
+ */
+
+static void (*pmac_tb_freeze)(int freeze);
+static unsigned long timebase;
+static int tb_req;
+
+static void smp_core99_give_timebase(void)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+
+        while(!tb_req)
+                barrier();
+        tb_req = 0;
+        (*pmac_tb_freeze)(1);
+        mb();
+        timebase = get_tb();
+        mb();
+        while (timebase)
+                barrier();
+        mb();
+        (*pmac_tb_freeze)(0);
+        mb();
+
+        local_irq_restore(flags);
+}
+
+
+static void __devinit smp_core99_take_timebase(void)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+
+        tb_req = 1;
+        mb();
+        while (!timebase)
+                barrier();
+        mb();
+        set_tb(timebase >> 32, timebase & 0xffffffff);
+        timebase = 0;
+        mb();
+        set_dec(tb_ticks_per_jiffy/2);
+
+        local_irq_restore(flags);
+}
+
 #ifdef CONFIG_PPC64
 /*
  * G5s enable/disable the timebase via an i2c-connected clock chip.
  */
 static struct device_node *pmac_tb_clock_chip_host;
 static u8 pmac_tb_pulsar_addr;
-static void (*pmac_tb_freeze)(int freeze);
-static DEFINE_SPINLOCK(timebase_lock);
-static unsigned long timebase;
 
 static void smp_core99_cypress_tb_freeze(int freeze)
 {
@@ -447,7 +493,8 @@ static void smp_core99_cypress_tb_freeze(int freeze)
         /* Strangely, the device-tree says address is 0xd2, but darwin
          * accesses 0xd0 ...
          */
-        pmac_low_i2c_setmode(pmac_tb_clock_chip_host, pmac_low_i2c_mode_combined);
+        pmac_low_i2c_setmode(pmac_tb_clock_chip_host,
+                             pmac_low_i2c_mode_combined);
         rc = pmac_low_i2c_xfer(pmac_tb_clock_chip_host,
                                0xd0 | pmac_low_i2c_read,
                                0x81, &data, 1);
@@ -475,7 +522,8 @@ static void smp_core99_pulsar_tb_freeze(int freeze)
         u8 data;
         int rc;
 
-        pmac_low_i2c_setmode(pmac_tb_clock_chip_host, pmac_low_i2c_mode_combined);
+        pmac_low_i2c_setmode(pmac_tb_clock_chip_host,
+                             pmac_low_i2c_mode_combined);
         rc = pmac_low_i2c_xfer(pmac_tb_clock_chip_host,
                                pmac_tb_pulsar_addr | pmac_low_i2c_read,
                                0x2e, &data, 1);
@@ -496,54 +544,14 @@ static void smp_core99_pulsar_tb_freeze(int freeze)
         }
 }
 
-
-static void smp_core99_give_timebase(void)
-{
-        /* Open i2c bus for synchronous access */
-        if (pmac_low_i2c_open(pmac_tb_clock_chip_host, 0))
-                panic("Can't open i2c for TB sync !\n");
-
-        spin_lock(&timebase_lock);
-        (*pmac_tb_freeze)(1);
-        mb();
-        timebase = get_tb();
-        spin_unlock(&timebase_lock);
-
-        while (timebase)
-                barrier();
-
-        spin_lock(&timebase_lock);
-        (*pmac_tb_freeze)(0);
-        spin_unlock(&timebase_lock);
-
-        /* Close i2c bus */
-        pmac_low_i2c_close(pmac_tb_clock_chip_host);
-}
-
-
-static void __devinit smp_core99_take_timebase(void)
-{
-        while (!timebase)
-                barrier();
-        spin_lock(&timebase_lock);
-        set_tb(timebase >> 32, timebase & 0xffffffff);
-        timebase = 0;
-        spin_unlock(&timebase_lock);
-}
-
-static void __init smp_core99_setup(int ncpus)
+static void __init smp_core99_setup_i2c_hwsync(int ncpus)
 {
         struct device_node *cc = NULL;  
         struct device_node *p;
+        const char *name = NULL;
         u32 *reg;
         int ok;
 
-        /* HW sync only on these platforms */
-        if (!machine_is_compatible("PowerMac7,2") &&
-            !machine_is_compatible("PowerMac7,3") &&
-            !machine_is_compatible("RackMac3,1"))
-                return;
-
         /* Look for the clock chip */
         while ((cc = of_find_node_by_name(cc, "i2c-hwclock")) != NULL) {
                 p = of_get_parent(cc);
@@ -561,114 +569,64 @@ static void __init smp_core99_setup(int ncpus)
                         if (device_is_compatible(cc, "pulsar-legacy-slewing")) {
                                 pmac_tb_freeze = smp_core99_pulsar_tb_freeze;
                                 pmac_tb_pulsar_addr = 0xd2;
-                                printk(KERN_INFO "Timebase clock is Pulsar chip\n");
+                                name = "Pulsar";
                         } else if (device_is_compatible(cc, "cy28508")) {
                                 pmac_tb_freeze = smp_core99_cypress_tb_freeze;
-                                printk(KERN_INFO "Timebase clock is Cypress chip\n");
+                                name = "Cypress";
                         }
                         break;
                 case 0xd4:
                         pmac_tb_freeze = smp_core99_pulsar_tb_freeze;
                         pmac_tb_pulsar_addr = 0xd4;
-                        printk(KERN_INFO "Timebase clock is Pulsar chip\n");
+                        name = "Pulsar";
                         break;
                 }
-                if (pmac_tb_freeze != NULL) {
-                        pmac_tb_clock_chip_host = of_get_parent(cc);
-                        of_node_put(cc);
+                if (pmac_tb_freeze != NULL)
                         break;
-                }
         }
-        if (pmac_tb_freeze == NULL) {
-                smp_ops->give_timebase = smp_generic_give_timebase;
-                smp_ops->take_timebase = smp_generic_take_timebase;
+        if (pmac_tb_freeze != NULL) {
+                struct device_node *p = of_get_parent(cc);
+                of_node_put(cc);
+                while(p && strcmp(p->type, "i2c")) {
+                        cc = of_get_parent(p);
+                        of_node_put(p);
+                        p = cc;
+                }
+                if (p == NULL)
+                        goto no_i2c_sync;
+                /* Open i2c bus for synchronous access */
+                if (pmac_low_i2c_open(p, 0)) {
+                        printk(KERN_ERR "Failed top open i2c bus %s for clock"
+                               " sync, fallback to software sync !\n",
+                               p->full_name);
+                        of_node_put(p);
+                        goto no_i2c_sync;
+                }
+                pmac_tb_clock_chip_host = p;
+                printk(KERN_INFO "Processor timebase sync using %s i2c clock\n",
+                       name);
+                return;
         }
+ no_i2c_sync:
+        pmac_tb_freeze = NULL;
 }
 
-/* nothing to do here, caches are already set up by service processor */
-static inline void __devinit core99_init_caches(int cpu)
-{
-}
+#endif /* CONFIG_PPC64 */
 
-#else /* CONFIG_PPC64 */
 
 /*
- * SMP G4 powermacs use a GPIO to enable/disable the timebase.
+ * SMP G4 and newer G5 use a GPIO to enable/disable the timebase.
  */
 
 static unsigned int core99_tb_gpio;     /* Timebase freeze GPIO */
 
-static unsigned int pri_tb_hi, pri_tb_lo;
-static unsigned int pri_tb_stamp;
-
-/* not __init, called in sleep/wakeup code */
-void smp_core99_give_timebase(void)
+static void smp_core99_gpio_tb_freeze(int freeze)
 {
-        unsigned long flags;
-        unsigned int t;
-
-        /* wait for the secondary to be in take_timebase */
-        for (t = 100000; t > 0 && !sec_tb_reset; --t)
-                udelay(10);
-        if (!sec_tb_reset) {
-                printk(KERN_WARNING "Timeout waiting sync on second CPU\n");
-                return;
-        }
-
-        /* freeze the timebase and read it */
-        /* disable interrupts so the timebase is disabled for the
-           shortest possible time */
-        local_irq_save(flags);
-        pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, core99_tb_gpio, 4);
+        if (freeze)
+                pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, core99_tb_gpio, 4);
+        else
+                pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, core99_tb_gpio, 0);
         pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, core99_tb_gpio, 0);
-        mb();
-        pri_tb_hi = get_tbu();
-        pri_tb_lo = get_tbl();
-        pri_tb_stamp = last_jiffy_stamp(smp_processor_id());
-        mb();
-
-        /* tell the secondary we're ready */
-        sec_tb_reset = 2;
-        mb();
-
-        /* wait for the secondary to have taken it */
-        /* note: can't use udelay here, since it needs the timebase running */
-        for (t = 10000000; t > 0 && sec_tb_reset; --t)
-                barrier();
-        if (sec_tb_reset)
-                /* XXX BUG_ON here? */
-                printk(KERN_WARNING "Timeout waiting sync(2) on second CPU\n");
-
-        /* Now, restart the timebase by leaving the GPIO to an open collector */
-        pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, core99_tb_gpio, 0);
-        pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, core99_tb_gpio, 0);
-        local_irq_restore(flags);
-}
-
-/* not __init, called in sleep/wakeup code */
-void smp_core99_take_timebase(void)
-{
-        unsigned long flags;
-
-        /* tell the primary we're here */
-        sec_tb_reset = 1;
-        mb();
-
-        /* wait for the primary to set pri_tb_hi/lo */
-        while (sec_tb_reset < 2)
-                mb();
-
-        /* set our stuff the same as the primary */
-        local_irq_save(flags);
-        set_dec(1);
-        set_tb(pri_tb_hi, pri_tb_lo);
-        last_jiffy_stamp(smp_processor_id()) = pri_tb_stamp;
-        mb();
-
-        /* tell the primary we're done */
-        sec_tb_reset = 0;
-        mb();
-        local_irq_restore(flags);
 }
 
 /* L2 and L3 cache settings to pass from CPU0 to CPU1 on G4 cpus */
@@ -677,6 +635,7 @@ volatile static long int core99_l3_cache;
 
 static void __devinit core99_init_caches(int cpu)
 {
+#ifndef CONFIG_PPC64
         if (!cpu_has_feature(CPU_FTR_L2CR))
                 return;
 
@@ -702,30 +661,80 @@ static void __devinit core99_init_caches(int cpu)
                 _set_L3CR(core99_l3_cache);
                 printk("CPU%d: L3CR set to %lx\n", cpu, core99_l3_cache);
         }
+#endif /* !CONFIG_PPC64 */
 }
 
 static void __init smp_core99_setup(int ncpus)
 {
-        struct device_node *cpu;
-        u32 *tbprop = NULL;
-        int i;
+#ifdef CONFIG_PPC64
 
-        core99_tb_gpio = KL_GPIO_TB_ENABLE;     /* default value */
-        cpu = of_find_node_by_type(NULL, "cpu");
-        if (cpu != NULL) {
-                tbprop = (u32 *)get_property(cpu, "timebase-enable", NULL);
-                if (tbprop)
-                        core99_tb_gpio = *tbprop;
-                of_node_put(cpu);
+        /* i2c based HW sync on some G5s */
+        if (machine_is_compatible("PowerMac7,2") ||
+            machine_is_compatible("PowerMac7,3") ||
+            machine_is_compatible("RackMac3,1"))
+                smp_core99_setup_i2c_hwsync(ncpus);
+
+        /* GPIO based HW sync on recent G5s */
+        if (pmac_tb_freeze == NULL) {
+                struct device_node *np =
+                        of_find_node_by_name(NULL, "timebase-enable");
+                u32 *reg = (u32 *)get_property(np, "reg", NULL);
+
+                if (np && reg && !strcmp(np->type, "gpio")) {
+                        core99_tb_gpio = *reg;
+                        if (core99_tb_gpio < 0x50)
+                                core99_tb_gpio += 0x50;
+                        pmac_tb_freeze = smp_core99_gpio_tb_freeze;
+                        printk(KERN_INFO "Processor timebase sync using"
+                               " GPIO 0x%02x\n", core99_tb_gpio);
+                }
         }
 
-        /* XXX should get this from reg properties */
-        for (i = 1; i < ncpus; ++i)
-                smp_hw_index[i] = i;
-        powersave_nap = 0;
-}
+#else /* CONFIG_PPC64 */
+
+        /* GPIO based HW sync on ppc32 Core99 */
+        if (pmac_tb_freeze == NULL && !machine_is_compatible("MacRISC4")) {
+                struct device_node *cpu;
+                u32 *tbprop = NULL;
+
+                core99_tb_gpio = KL_GPIO_TB_ENABLE;     /* default value */
+                cpu = of_find_node_by_type(NULL, "cpu");
+                if (cpu != NULL) {
+                        tbprop = (u32 *)get_property(cpu, "timebase-enable",
+                                                     NULL);
+                        if (tbprop)
+                                core99_tb_gpio = *tbprop;
+                        of_node_put(cpu);
+                }
+                pmac_tb_freeze = smp_core99_gpio_tb_freeze;
+                printk(KERN_INFO "Processor timebase sync using"
+                       " GPIO 0x%02x\n", core99_tb_gpio);
+        }
+
+#endif /* CONFIG_PPC64 */
+
+        /* No timebase sync, fallback to software */
+        if (pmac_tb_freeze == NULL) {
+                smp_ops->give_timebase = smp_generic_give_timebase;
+                smp_ops->take_timebase = smp_generic_take_timebase;
+                printk(KERN_INFO "Processor timebase sync using software\n");
+        }
+
+#ifndef CONFIG_PPC64
+        {
+                int i;
+
+                /* XXX should get this from reg properties */
+                for (i = 1; i < ncpus; ++i)
+                        smp_hw_index[i] = i;
+        }
 #endif
 
+        /* 32 bits SMP can't NAP */
+        if (!machine_is_compatible("MacRISC4"))
+                powersave_nap = 0;
+}
+
 static int __init smp_core99_probe(void)
 {
         struct device_node *cpus;
@@ -803,17 +812,25 @@ static void __devinit smp_core99_setup_cpu(int cpu_nr)
         mpic_setup_this_cpu();
 
         if (cpu_nr == 0) {
-#ifdef CONFIG_POWER4
+#ifdef CONFIG_PPC64
                 extern void g5_phy_disable_cpu1(void);
 
+                /* Close i2c bus if it was used for tb sync */
+                if (pmac_tb_clock_chip_host) {
+                        pmac_low_i2c_close(pmac_tb_clock_chip_host);
+                        pmac_tb_clock_chip_host = NULL;
+                }
+
                 /* If we didn't start the second CPU, we must take
                  * it off the bus
                  */
                 if (machine_is_compatible("MacRISC4") &&
                     num_online_cpus() < 2)              
                         g5_phy_disable_cpu1();
-#endif /* CONFIG_POWER4 */
-                if (ppc_md.progress) ppc_md.progress("core99_setup_cpu 0 done", 0x349);
+#endif /* CONFIG_PPC64 */
+
+                if (ppc_md.progress)
+                        ppc_md.progress("core99_setup_cpu 0 done", 0x349);
         }
 }