[POWERPC] Support for DCR based MPIC

This patch implements support for DCR based MPIC implementations. Such
implementations have the MPIC_USES_DCR flag set and don't use the phys_addr
argument of mpic_alloc (they require a valid dcr mapping in the device node)

This version of the patch can use a little bif of cleanup still (I can
probably consolidate rb->dbase/doff, at least once I'm sure on how the
hardware is actually supposed to work vs. possible simulator issues) and
it should be possible to build a DCR-only version of the driver. I need
to cleanup a bit the CONFIG_* handling for that and probably introduce
CONFIG_MPIC_MMIO and CONFIG_MPIC_DCR.

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

1 files changed, 100 insertions, 36 deletions

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index ba4833f57d47..909306ca04f4 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -147,33 +147,51 @@ static u32 mpic_infos[][MPIC_IDX_END] = {
  */
 
 
-static inline u32 _mpic_read(unsigned int be, volatile u32 __iomem *base,
-                            unsigned int reg)
+static inline u32 _mpic_read(enum mpic_reg_type type,
+                             struct mpic_reg_bank *rb,
+                             unsigned int reg)
 {
-        if (be)
-                return in_be32(base + (reg >> 2));
-        else
-                return in_le32(base + (reg >> 2));
+        switch(type) {
+#ifdef CONFIG_PPC_DCR
+        case mpic_access_dcr:
+                return dcr_read(rb->dhost,
+                                rb->dbase + reg + rb->doff);
+#endif
+        case mpic_access_mmio_be:
+                return in_be32(rb->base + (reg >> 2));
+        case mpic_access_mmio_le:
+        default:
+                return in_le32(rb->base + (reg >> 2));
+        }
 }
 
-static inline void _mpic_write(unsigned int be, volatile u32 __iomem *base,
-                              unsigned int reg, u32 value)
+static inline void _mpic_write(enum mpic_reg_type type,
+                               struct mpic_reg_bank *rb,
+                               unsigned int reg, u32 value)
 {
-        if (be)
-                out_be32(base + (reg >> 2), value);
-        else
-                out_le32(base + (reg >> 2), value);
+        switch(type) {
+#ifdef CONFIG_PPC_DCR
+        case mpic_access_dcr:
+                return dcr_write(rb->dhost,
+                                 rb->dbase + reg + rb->doff, value);
+#endif
+        case mpic_access_mmio_be:
+                return out_be32(rb->base + (reg >> 2), value);
+        case mpic_access_mmio_le:
+        default:
+                return out_le32(rb->base + (reg >> 2), value);
+        }
 }
 
 static inline u32 _mpic_ipi_read(struct mpic *mpic, unsigned int ipi)
 {
-        unsigned int be = (mpic->flags & MPIC_BIG_ENDIAN) != 0;
+        enum mpic_reg_type type = mpic->reg_type;
         unsigned int offset = MPIC_INFO(GREG_IPI_VECTOR_PRI_0) +
                               (ipi * MPIC_INFO(GREG_IPI_STRIDE));
 
-        if (mpic->flags & MPIC_BROKEN_IPI)
-                be = !be;
-        return _mpic_read(be, mpic->gregs, offset);
+        if ((mpic->flags & MPIC_BROKEN_IPI) && type == mpic_access_mmio_le)
+                type = mpic_access_mmio_be;
+        return _mpic_read(type, &mpic->gregs, offset);
 }
 
 static inline void _mpic_ipi_write(struct mpic *mpic, unsigned int ipi, u32 value)
@@ -181,7 +199,7 @@ static inline void _mpic_ipi_write(struct mpic *mpic, unsigned int ipi, u32 valu
         unsigned int offset = MPIC_INFO(GREG_IPI_VECTOR_PRI_0) +
                               (ipi * MPIC_INFO(GREG_IPI_STRIDE));
 
-        _mpic_write(mpic->flags & MPIC_BIG_ENDIAN, mpic->gregs, offset, value);
+        _mpic_write(mpic->reg_type, &mpic->gregs, offset, value);
 }
 
 static inline u32 _mpic_cpu_read(struct mpic *mpic, unsigned int reg)
@@ -190,8 +208,7 @@ static inline u32 _mpic_cpu_read(struct mpic *mpic, unsigned int reg)
 
         if (mpic->flags & MPIC_PRIMARY)
                 cpu = hard_smp_processor_id();
-        return _mpic_read(mpic->flags & MPIC_BIG_ENDIAN,
-                          mpic->cpuregs[cpu], reg);
+        return _mpic_read(mpic->reg_type, &mpic->cpuregs[cpu], reg);
 }
 
 static inline void _mpic_cpu_write(struct mpic *mpic, unsigned int reg, u32 value)
@@ -201,7 +218,7 @@ static inline void _mpic_cpu_write(struct mpic *mpic, unsigned int reg, u32 valu
         if (mpic->flags & MPIC_PRIMARY)
                 cpu = hard_smp_processor_id();
 
-        _mpic_write(mpic->flags & MPIC_BIG_ENDIAN, mpic->cpuregs[cpu], reg, value);
+        _mpic_write(mpic->reg_type, &mpic->cpuregs[cpu], reg, value);
 }
 
 static inline u32 _mpic_irq_read(struct mpic *mpic, unsigned int src_no, unsigned int reg)
@@ -209,7 +226,7 @@ static inline u32 _mpic_irq_read(struct mpic *mpic, unsigned int src_no, unsigne
         unsigned int    isu = src_no >> mpic->isu_shift;
         unsigned int    idx = src_no & mpic->isu_mask;
 
-        return _mpic_read(mpic->flags & MPIC_BIG_ENDIAN, mpic->isus[isu],
+        return _mpic_read(mpic->reg_type, &mpic->isus[isu],
                           reg + (idx * MPIC_INFO(IRQ_STRIDE)));
 }
 
@@ -219,12 +236,12 @@ static inline void _mpic_irq_write(struct mpic *mpic, unsigned int src_no,
         unsigned int    isu = src_no >> mpic->isu_shift;
         unsigned int    idx = src_no & mpic->isu_mask;
 
-        _mpic_write(mpic->flags & MPIC_BIG_ENDIAN, mpic->isus[isu],
+        _mpic_write(mpic->reg_type, &mpic->isus[isu],
                     reg + (idx * MPIC_INFO(IRQ_STRIDE)), value);
 }
 
-#define mpic_read(b,r)          _mpic_read(mpic->flags & MPIC_BIG_ENDIAN,(b),(r))
-#define mpic_write(b,r,v)       _mpic_write(mpic->flags & MPIC_BIG_ENDIAN,(b),(r),(v))
+#define mpic_read(b,r)          _mpic_read(mpic->reg_type,&(b),(r))
+#define mpic_write(b,r,v)       _mpic_write(mpic->reg_type,&(b),(r),(v))
 #define mpic_ipi_read(i)        _mpic_ipi_read(mpic,(i))
 #define mpic_ipi_write(i,v)     _mpic_ipi_write(mpic,(i),(v))
 #define mpic_cpu_read(i)        _mpic_cpu_read(mpic,(i))
@@ -238,6 +255,38 @@ static inline void _mpic_irq_write(struct mpic *mpic, unsigned int src_no,
  */
 
 
+static void _mpic_map_mmio(struct mpic *mpic, unsigned long phys_addr,
+                           struct mpic_reg_bank *rb, unsigned int offset,
+                           unsigned int size)
+{
+        rb->base = ioremap(phys_addr + offset, size);
+        BUG_ON(rb->base == NULL);
+}
+
+#ifdef CONFIG_PPC_DCR
+static void _mpic_map_dcr(struct mpic *mpic, struct mpic_reg_bank *rb,
+                          unsigned int offset, unsigned int size)
+{
+        rb->dbase = mpic->dcr_base;
+        rb->doff = offset;
+        rb->dhost = dcr_map(mpic->of_node, rb->dbase + rb->doff, size);
+        BUG_ON(!DCR_MAP_OK(rb->dhost));
+}
+
+static inline void mpic_map(struct mpic *mpic, unsigned long phys_addr,
+                            struct mpic_reg_bank *rb, unsigned int offset,
+                            unsigned int size)
+{
+        if (mpic->flags & MPIC_USES_DCR)
+                _mpic_map_dcr(mpic, rb, offset, size);
+        else
+                _mpic_map_mmio(mpic, phys_addr, rb, offset, size);
+}
+#else /* CONFIG_PPC_DCR */
+#define mpic_map(m,p,b,o,s)     _mpic_map_mmio(m,p,b,o,s)
+#endif /* !CONFIG_PPC_DCR */
+
+
 
 /* Check if we have one of those nice broken MPICs with a flipped endian on
  * reads from IPI registers
@@ -883,6 +932,7 @@ struct mpic * __init mpic_alloc(struct device_node *node,
         if (flags & MPIC_PRIMARY)
                 mpic->hc_ht_irq.set_affinity = mpic_set_affinity;
 #endif /* CONFIG_MPIC_BROKEN_U3 */
+
 #ifdef CONFIG_SMP
         mpic->hc_ipi = mpic_ipi_chip;
         mpic->hc_ipi.typename = name;
@@ -897,11 +947,26 @@ struct mpic * __init mpic_alloc(struct device_node *node,
         mpic->hw_set = mpic_infos[MPIC_GET_REGSET(flags)];
 #endif
 
+        /* default register type */
+        mpic->reg_type = (flags & MPIC_BIG_ENDIAN) ?
+                mpic_access_mmio_be : mpic_access_mmio_le;
+
+#ifdef CONFIG_PPC_DCR
+        if (mpic->flags & MPIC_USES_DCR) {
+                const u32 *dbasep;
+                BUG_ON(mpic->of_node == NULL);
+                dbasep = get_property(mpic->of_node, "dcr-reg", NULL);
+                BUG_ON(dbasep == NULL);
+                mpic->dcr_base = *dbasep;
+                mpic->reg_type = mpic_access_dcr;
+        }
+#else
+        BUG_ON (mpic->flags & MPIC_USES_DCR);
+#endif /* CONFIG_PPC_DCR */
+
         /* Map the global registers */
-        mpic->gregs = ioremap(phys_addr + MPIC_INFO(GREG_BASE), 0x1000);
-        mpic->tmregs = mpic->gregs +
-                       ((MPIC_INFO(TIMER_BASE) - MPIC_INFO(GREG_BASE)) >> 2);
-        BUG_ON(mpic->gregs == NULL);
+        mpic_map(mpic, phys_addr, &mpic->gregs, MPIC_INFO(GREG_BASE), 0x1000);
+        mpic_map(mpic, phys_addr, &mpic->tmregs, MPIC_INFO(TIMER_BASE), 0x1000);
 
         /* Reset */
         if (flags & MPIC_WANTS_RESET) {
@@ -926,17 +991,16 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 
         /* Map the per-CPU registers */
         for (i = 0; i < mpic->num_cpus; i++) {
-                mpic->cpuregs[i] = ioremap(phys_addr + MPIC_INFO(CPU_BASE) +
-                                           i * MPIC_INFO(CPU_STRIDE), 0x1000);
-                BUG_ON(mpic->cpuregs[i] == NULL);
+                mpic_map(mpic, phys_addr, &mpic->cpuregs[i],
+                         MPIC_INFO(CPU_BASE) + i * MPIC_INFO(CPU_STRIDE),
+                         0x1000);
         }
 
         /* Initialize main ISU if none provided */
         if (mpic->isu_size == 0) {
                 mpic->isu_size = mpic->num_sources;
-                mpic->isus[0] = ioremap(phys_addr + MPIC_INFO(IRQ_BASE),
-                                        MPIC_INFO(IRQ_STRIDE) * mpic->isu_size);
-                BUG_ON(mpic->isus[0] == NULL);
+                mpic_map(mpic, phys_addr, &mpic->isus[0],
+                         MPIC_INFO(IRQ_BASE), MPIC_INFO(IRQ_STRIDE) * mpic->isu_size);
         }
         mpic->isu_shift = 1 + __ilog2(mpic->isu_size - 1);
         mpic->isu_mask = (1 << mpic->isu_shift) - 1;
@@ -979,8 +1043,8 @@ void __init mpic_assign_isu(struct mpic *mpic, unsigned int isu_num,
 
         BUG_ON(isu_num >= MPIC_MAX_ISU);
 
-        mpic->isus[isu_num] = ioremap(phys_addr,
-                                      MPIC_INFO(IRQ_STRIDE) * mpic->isu_size);
+        mpic_map(mpic, phys_addr, &mpic->isus[isu_num], 0,
+                 MPIC_INFO(IRQ_STRIDE) * mpic->isu_size);
         if ((isu_first + mpic->isu_size) > mpic->num_sources)
                 mpic->num_sources = isu_first + mpic->isu_size;
 }