[POWERPC] cell: add low-level performance monitoring code

Add routines for accessing the registers and counters in the performance
monitoring unit.

Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

4 files changed, 392 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/cell/Makefile b/arch/powerpc/platforms/cell/Makefile
index c89cdd67383b..412649b3529c 100644
--- a/arch/powerpc/platforms/cell/Makefile
+++ b/arch/powerpc/platforms/cell/Makefile
@@ -1,5 +1,6 @@
 obj-$(CONFIG_PPC_CELL_NATIVE)           += interrupt.o iommu.o setup.o \
-                                           cbe_regs.o spider-pic.o pervasive.o
+                                           cbe_regs.o spider-pic.o pervasive.o \
+                                           pmu.o
 obj-$(CONFIG_CBE_RAS)                   += ras.o
 
 ifeq ($(CONFIG_SMP),y)
diff --git a/arch/powerpc/platforms/cell/cbe_regs.h b/arch/powerpc/platforms/cell/cbe_regs.h
index d352f110ef9c..91083f51a0cb 100644
--- a/arch/powerpc/platforms/cell/cbe_regs.h
+++ b/arch/powerpc/platforms/cell/cbe_regs.h
@@ -35,6 +35,11 @@
  *
  */
 
+/* Macros for the pm_control register. */
+#define CBE_PM_16BIT_CTR(ctr)                   (1 << (24 - ((ctr) & (NR_PHYS_CTRS - 1))))
+#define CBE_PM_ENABLE_PERF_MON                  0x80000000
+
+
 union spe_reg {
         u64 val;
         u8 spe[8];
diff --git a/arch/powerpc/platforms/cell/pmu.c b/arch/powerpc/platforms/cell/pmu.c
new file mode 100644
index 000000000000..30d17ce236a7
--- /dev/null
+++ b/arch/powerpc/platforms/cell/pmu.c
@@ -0,0 +1,328 @@
+/*
+ * Cell Broadband Engine Performance Monitor
+ *
+ * (C) Copyright IBM Corporation 2001,2006
+ *
+ * Author:
+ *    David Erb (djerb@us.ibm.com)
+ *    Kevin Corry (kevcorry@us.ibm.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/types.h>
+#include <asm/io.h>
+#include <asm/machdep.h>
+#include <asm/reg.h>
+#include <asm/spu.h>
+
+#include "cbe_regs.h"
+#include "interrupt.h"
+#include "pmu.h"
+
+/*
+ * When writing to write-only mmio addresses, save a shadow copy. All of the
+ * registers are 32-bit, but stored in the upper-half of a 64-bit field in
+ * pmd_regs.
+ */
+
+#define WRITE_WO_MMIO(reg, x)                                   \
+        do {                                                    \
+                u32 _x = (x);                                   \
+                struct cbe_pmd_regs __iomem *pmd_regs;          \
+                struct cbe_pmd_shadow_regs *shadow_regs;        \
+                pmd_regs = cbe_get_cpu_pmd_regs(cpu);           \
+                shadow_regs = cbe_get_cpu_pmd_shadow_regs(cpu); \
+                out_be64(&(pmd_regs->reg), (((u64)_x) << 32));  \
+                shadow_regs->reg = _x;                          \
+        } while (0)
+
+#define READ_SHADOW_REG(val, reg)                               \
+        do {                                                    \
+                struct cbe_pmd_shadow_regs *shadow_regs;        \
+                shadow_regs = cbe_get_cpu_pmd_shadow_regs(cpu); \
+                (val) = shadow_regs->reg;                       \
+        } while (0)
+
+#define READ_MMIO_UPPER32(val, reg)                             \
+        do {                                                    \
+                struct cbe_pmd_regs __iomem *pmd_regs;          \
+                pmd_regs = cbe_get_cpu_pmd_regs(cpu);           \
+                (val) = (u32)(in_be64(&pmd_regs->reg) >> 32);   \
+        } while (0)
+
+/*
+ * Physical counter registers.
+ * Each physical counter can act as one 32-bit counter or two 16-bit counters.
+ */
+
+u32 cbe_read_phys_ctr(u32 cpu, u32 phys_ctr)
+{
+        u32 val_in_latch, val = 0;
+
+        if (phys_ctr < NR_PHYS_CTRS) {
+                READ_SHADOW_REG(val_in_latch, counter_value_in_latch);
+
+                /* Read the latch or the actual counter, whichever is newer. */
+                if (val_in_latch & (1 << phys_ctr)) {
+                        READ_SHADOW_REG(val, pm_ctr[phys_ctr]);
+                } else {
+                        READ_MMIO_UPPER32(val, pm_ctr[phys_ctr]);
+                }
+        }
+
+        return val;
+}
+
+void cbe_write_phys_ctr(u32 cpu, u32 phys_ctr, u32 val)
+{
+        struct cbe_pmd_shadow_regs *shadow_regs;
+        u32 pm_ctrl;
+
+        if (phys_ctr < NR_PHYS_CTRS) {
+                /* Writing to a counter only writes to a hardware latch.
+                 * The new value is not propagated to the actual counter
+                 * until the performance monitor is enabled.
+                 */
+                WRITE_WO_MMIO(pm_ctr[phys_ctr], val);
+
+                pm_ctrl = cbe_read_pm(cpu, pm_control);
+                if (pm_ctrl & CBE_PM_ENABLE_PERF_MON) {
+                        /* The counters are already active, so we need to
+                         * rewrite the pm_control register to "re-enable"
+                         * the PMU.
+                         */
+                        cbe_write_pm(cpu, pm_control, pm_ctrl);
+                } else {
+                        shadow_regs = cbe_get_cpu_pmd_shadow_regs(cpu);
+                        shadow_regs->counter_value_in_latch |= (1 << phys_ctr);
+                }
+        }
+}
+
+/*
+ * "Logical" counter registers.
+ * These will read/write 16-bits or 32-bits depending on the
+ * current size of the counter. Counters 4 - 7 are always 16-bit.
+ */
+
+u32 cbe_read_ctr(u32 cpu, u32 ctr)
+{
+        u32 val;
+        u32 phys_ctr = ctr & (NR_PHYS_CTRS - 1);
+
+        val = cbe_read_phys_ctr(cpu, phys_ctr);
+
+        if (cbe_get_ctr_size(cpu, phys_ctr) == 16)
+                val = (ctr < NR_PHYS_CTRS) ? (val >> 16) : (val & 0xffff);
+
+        return val;
+}
+
+void cbe_write_ctr(u32 cpu, u32 ctr, u32 val)
+{
+        u32 phys_ctr;
+        u32 phys_val;
+
+        phys_ctr = ctr & (NR_PHYS_CTRS - 1);
+
+        if (cbe_get_ctr_size(cpu, phys_ctr) == 16) {
+                phys_val = cbe_read_phys_ctr(cpu, phys_ctr);
+
+                if (ctr < NR_PHYS_CTRS)
+                        val = (val << 16) | (phys_val & 0xffff);
+                else
+                        val = (val & 0xffff) | (phys_val & 0xffff0000);
+        }
+
+        cbe_write_phys_ctr(cpu, phys_ctr, val);
+}
+
+/*
+ * Counter-control registers.
+ * Each "logical" counter has a corresponding control register.
+ */
+
+u32 cbe_read_pm07_control(u32 cpu, u32 ctr)
+{
+        u32 pm07_control = 0;
+
+        if (ctr < NR_CTRS)
+                READ_SHADOW_REG(pm07_control, pm07_control[ctr]);
+
+        return pm07_control;
+}
+
+void cbe_write_pm07_control(u32 cpu, u32 ctr, u32 val)
+{
+        if (ctr < NR_CTRS)
+                WRITE_WO_MMIO(pm07_control[ctr], val);
+}
+
+/*
+ * Other PMU control registers. Most of these are write-only.
+ */
+
+u32 cbe_read_pm(u32 cpu, enum pm_reg_name reg)
+{
+        u32 val = 0;
+
+        switch (reg) {
+        case group_control:
+                READ_SHADOW_REG(val, group_control);
+                break;
+
+        case debug_bus_control:
+                READ_SHADOW_REG(val, debug_bus_control);
+                break;
+
+        case trace_address:
+                READ_MMIO_UPPER32(val, trace_address);
+                break;
+
+        case ext_tr_timer:
+                READ_SHADOW_REG(val, ext_tr_timer);
+                break;
+
+        case pm_status:
+                READ_MMIO_UPPER32(val, pm_status);
+                break;
+
+        case pm_control:
+                READ_SHADOW_REG(val, pm_control);
+                break;
+
+        case pm_interval:
+                READ_SHADOW_REG(val, pm_interval);
+                break;
+
+        case pm_start_stop:
+                READ_SHADOW_REG(val, pm_start_stop);
+                break;
+        }
+
+        return val;
+}
+
+void cbe_write_pm(u32 cpu, enum pm_reg_name reg, u32 val)
+{
+        switch (reg) {
+        case group_control:
+                WRITE_WO_MMIO(group_control, val);
+                break;
+
+        case debug_bus_control:
+                WRITE_WO_MMIO(debug_bus_control, val);
+                break;
+
+        case trace_address:
+                WRITE_WO_MMIO(trace_address, val);
+                break;
+
+        case ext_tr_timer:
+                WRITE_WO_MMIO(ext_tr_timer, val);
+                break;
+
+        case pm_status:
+                WRITE_WO_MMIO(pm_status, val);
+                break;
+
+        case pm_control:
+                WRITE_WO_MMIO(pm_control, val);
+                break;
+
+        case pm_interval:
+                WRITE_WO_MMIO(pm_interval, val);
+                break;
+
+        case pm_start_stop:
+                WRITE_WO_MMIO(pm_start_stop, val);
+                break;
+        }
+}
+
+/*
+ * Get/set the size of a physical counter to either 16 or 32 bits.
+ */
+
+u32 cbe_get_ctr_size(u32 cpu, u32 phys_ctr)
+{
+        u32 pm_ctrl, size = 0;
+
+        if (phys_ctr < NR_PHYS_CTRS) {
+                pm_ctrl = cbe_read_pm(cpu, pm_control);
+                size = (pm_ctrl & CBE_PM_16BIT_CTR(phys_ctr)) ? 16 : 32;
+        }
+
+        return size;
+}
+
+void cbe_set_ctr_size(u32 cpu, u32 phys_ctr, u32 ctr_size)
+{
+        u32 pm_ctrl;
+
+        if (phys_ctr < NR_PHYS_CTRS) {
+                pm_ctrl = cbe_read_pm(cpu, pm_control);
+                switch (ctr_size) {
+                case 16:
+                        pm_ctrl |= CBE_PM_16BIT_CTR(phys_ctr);
+                        break;
+
+                case 32:
+                        pm_ctrl &= ~CBE_PM_16BIT_CTR(phys_ctr);
+                        break;
+                }
+                cbe_write_pm(cpu, pm_control, pm_ctrl);
+        }
+}
+
+/*
+ * Enable/disable the entire performance monitoring unit.
+ * When we enable the PMU, all pending writes to counters get committed.
+ */
+
+void cbe_enable_pm(u32 cpu)
+{
+        struct cbe_pmd_shadow_regs *shadow_regs;
+        u32 pm_ctrl;
+
+        shadow_regs = cbe_get_cpu_pmd_shadow_regs(cpu);
+        shadow_regs->counter_value_in_latch = 0;
+
+        pm_ctrl = cbe_read_pm(cpu, pm_control) | CBE_PM_ENABLE_PERF_MON;
+        cbe_write_pm(cpu, pm_control, pm_ctrl);
+}
+
+void cbe_disable_pm(u32 cpu)
+{
+        u32 pm_ctrl;
+        pm_ctrl = cbe_read_pm(cpu, pm_control) & ~CBE_PM_ENABLE_PERF_MON;
+        cbe_write_pm(cpu, pm_control, pm_ctrl);
+}
+
+/*
+ * Reading from the trace_buffer.
+ * The trace buffer is two 64-bit registers. Reading from
+ * the second half automatically increments the trace_address.
+ */
+
+void cbe_read_trace_buffer(u32 cpu, u64 *buf)
+{
+        struct cbe_pmd_regs __iomem *pmd_regs = cbe_get_cpu_pmd_regs(cpu);
+
+        *buf++ = in_be64(&pmd_regs->trace_buffer_0_63);
+        *buf++ = in_be64(&pmd_regs->trace_buffer_64_127);
+}
+
diff --git a/arch/powerpc/platforms/cell/pmu.h b/arch/powerpc/platforms/cell/pmu.h
new file mode 100644
index 000000000000..eb1e8e0af910
--- /dev/null
+++ b/arch/powerpc/platforms/cell/pmu.h
@@ -0,0 +1,57 @@
+/*
+ * Cell Broadband Engine Performance Monitor
+ *
+ * (C) Copyright IBM Corporation 2001,2006
+ *
+ * Author:
+ *   David Erb (djerb@us.ibm.com)
+ *   Kevin Corry (kevcorry@us.ibm.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __PERFMON_H__
+#define __PERFMON_H__
+
+enum pm_reg_name {
+        group_control,
+        debug_bus_control,
+        trace_address,
+        ext_tr_timer,
+        pm_status,
+        pm_control,
+        pm_interval,
+        pm_start_stop,
+};
+
+extern u32  cbe_read_phys_ctr(u32 cpu, u32 phys_ctr);
+extern void cbe_write_phys_ctr(u32 cpu, u32 phys_ctr, u32 val);
+extern u32  cbe_read_ctr(u32 cpu, u32 ctr);
+extern void cbe_write_ctr(u32 cpu, u32 ctr, u32 val);
+
+extern u32  cbe_read_pm07_control(u32 cpu, u32 ctr);
+extern void cbe_write_pm07_control(u32 cpu, u32 ctr, u32 val);
+extern u32  cbe_read_pm (u32 cpu, enum pm_reg_name reg);
+extern void cbe_write_pm (u32 cpu, enum pm_reg_name reg, u32 val);
+
+extern u32  cbe_get_ctr_size(u32 cpu, u32 phys_ctr);
+extern void cbe_set_ctr_size(u32 cpu, u32 phys_ctr, u32 ctr_size);
+
+extern void cbe_enable_pm(u32 cpu);
+extern void cbe_disable_pm(u32 cpu);
+
+extern void cbe_read_trace_buffer(u32 cpu, u64 *buf);
+
+#endif