[POWERPC] Refactor DCR code

Previously, DCR support was configured at compile time to either use
MMIO or native dcr instructions.  Although this works for most
platforms, it fails on FPGA platforms:

1) Systems may include more than one DCR bus.
2) Systems may be native DCR capable and still use memory mapped DCR interface.

This patch provides runtime support based on the device trees for the
case where CONFIG_PPC_DCR_MMIO and CONFIG_PPC_DCR_NATIVE are both
selected.  Previously, this was a poorly defined configuration, which
happened to provide NATIVE support.  The runtime selection is made
based on the dcr-controller having a 'dcr-access-method' attribute
in the device tree.  If only one of the above options is selected,
then the code uses #defines to select only the used code in order to
avoid introducing overhead in existing usage.

Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

1 files changed, 121 insertions, 33 deletions

diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
index 437e48d3ae33..5f39a79b0660 100644
--- a/arch/powerpc/sysdev/dcr.c
+++ b/arch/powerpc/sysdev/dcr.c
@@ -23,6 +23,105 @@
 #include <asm/prom.h>
 #include <asm/dcr.h>
 
+static struct device_node *find_dcr_parent(struct device_node *node)
+{
+        struct device_node *par, *tmp;
+        const u32 *p;
+
+        for (par = of_node_get(node); par;) {
+                if (of_get_property(par, "dcr-controller", NULL))
+                        break;
+                p = of_get_property(par, "dcr-parent", NULL);
+                tmp = par;
+                if (p == NULL)
+                        par = of_get_parent(par);
+                else
+                        par = of_find_node_by_phandle(*p);
+                of_node_put(tmp);
+        }
+        return par;
+}
+
+#if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
+
+bool dcr_map_ok_generic(dcr_host_t host)
+{
+        if (host.type == DCR_HOST_NATIVE)
+                return dcr_map_ok_native(host.host.native);
+        else if (host.type == DCR_HOST_MMIO)
+                return dcr_map_ok_mmio(host.host.mmio);
+        else
+                return 0;
+}
+EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
+
+dcr_host_t dcr_map_generic(struct device_node *dev,
+                           unsigned int dcr_n,
+                           unsigned int dcr_c)
+{
+        dcr_host_t host;
+        struct device_node *dp;
+        const char *prop;
+
+        host.type = DCR_HOST_INVALID;
+
+        dp = find_dcr_parent(dev);
+        if (dp == NULL)
+                return host;
+
+        prop = of_get_property(dp, "dcr-access-method", NULL);
+
+        pr_debug("dcr_map_generic(dcr-access-method = %s)\n", prop);
+
+        if (!strcmp(prop, "native")) {
+                host.type = DCR_HOST_NATIVE;
+                host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
+        } else if (!strcmp(prop, "mmio")) {
+                host.type = DCR_HOST_MMIO;
+                host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
+        }
+
+        of_node_put(dp);
+        return host;
+}
+EXPORT_SYMBOL_GPL(dcr_map_generic);
+
+void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
+{
+        if (host.type == DCR_HOST_NATIVE)
+                dcr_unmap_native(host.host.native, dcr_c);
+        else if (host.type == DCR_HOST_MMIO)
+                dcr_unmap_mmio(host.host.mmio, dcr_c);
+        else /* host.type == DCR_HOST_INVALID */
+                WARN_ON(true);
+}
+EXPORT_SYMBOL_GPL(dcr_unmap_generic);
+
+u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
+{
+        if (host.type == DCR_HOST_NATIVE)
+                return dcr_read_native(host.host.native, dcr_n);
+        else if (host.type == DCR_HOST_MMIO)
+                return dcr_read_mmio(host.host.mmio, dcr_n);
+        else /* host.type == DCR_HOST_INVALID */
+                WARN_ON(true);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(dcr_read_generic);
+
+void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
+{
+        if (host.type == DCR_HOST_NATIVE)
+                dcr_write_native(host.host.native, dcr_n, value);
+        else if (host.type == DCR_HOST_MMIO)
+                dcr_write_mmio(host.host.mmio, dcr_n, value);
+        else /* host.type == DCR_HOST_INVALID */
+                WARN_ON(true);
+}
+EXPORT_SYMBOL_GPL(dcr_write_generic);
+
+#endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
+
 unsigned int dcr_resource_start(struct device_node *np, unsigned int index)
 {
         unsigned int ds;
@@ -47,26 +146,7 @@ unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
 }
 EXPORT_SYMBOL_GPL(dcr_resource_len);
 
-#ifndef CONFIG_PPC_DCR_NATIVE
-
-static struct device_node * find_dcr_parent(struct device_node * node)
-{
-        struct device_node *par, *tmp;
-        const u32 *p;
-
-        for (par = of_node_get(node); par;) {
-                if (of_get_property(par, "dcr-controller", NULL))
-                        break;
-                p = of_get_property(par, "dcr-parent", NULL);
-                tmp = par;
-                if (p == NULL)
-                        par = of_get_parent(par);
-                else
-                        par = of_find_node_by_phandle(*p);
-                of_node_put(tmp);
-        }
-        return par;
-}
+#ifdef CONFIG_PPC_DCR_MMIO
 
 u64 of_translate_dcr_address(struct device_node *dev,
                              unsigned int dcr_n,
@@ -75,7 +155,7 @@ u64 of_translate_dcr_address(struct device_node *dev,
         struct device_node *dp;
         const u32 *p;
         unsigned int stride;
-        u64 ret;
+        u64 ret = OF_BAD_ADDR;
 
         dp = find_dcr_parent(dev);
         if (dp == NULL)
@@ -90,7 +170,7 @@ u64 of_translate_dcr_address(struct device_node *dev,
         if (p == NULL)
                 p = of_get_property(dp, "dcr-mmio-space", NULL);
         if (p == NULL)
-                return OF_BAD_ADDR;
+                goto done;
 
         /* Maybe could do some better range checking here */
         ret = of_translate_address(dp, p);
@@ -98,21 +178,25 @@ u64 of_translate_dcr_address(struct device_node *dev,
                 ret += (u64)(stride) * (u64)dcr_n;
         if (out_stride)
                 *out_stride = stride;
+
+ done:
+        of_node_put(dp);
         return ret;
 }
 
-dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
-                   unsigned int dcr_c)
+dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
+                             unsigned int dcr_n,
+                             unsigned int dcr_c)
 {
-        dcr_host_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
+        dcr_host_mmio_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
         u64 addr;
 
         pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
                  dev->full_name, dcr_n, dcr_c);
 
         addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
-        pr_debug("translates to addr: 0x%lx, stride: 0x%x\n",
-                 addr, ret.stride);
+        pr_debug("translates to addr: 0x%llx, stride: 0x%x\n",
+                 (unsigned long long) addr, ret.stride);
         if (addr == OF_BAD_ADDR)
                 return ret;
         pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
@@ -124,11 +208,11 @@ dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
         ret.token -= dcr_n * ret.stride;
         return ret;
 }
-EXPORT_SYMBOL_GPL(dcr_map);
+EXPORT_SYMBOL_GPL(dcr_map_mmio);
 
-void dcr_unmap(dcr_host_t host, unsigned int dcr_c)
+void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
 {
-        dcr_host_t h = host;
+        dcr_host_mmio_t h = host;
 
         if (h.token == NULL)
                 return;
@@ -136,7 +220,11 @@ void dcr_unmap(dcr_host_t host, unsigned int dcr_c)
         iounmap(h.token);
         h.token = NULL;
 }
-EXPORT_SYMBOL_GPL(dcr_unmap);
-#else   /* defined(CONFIG_PPC_DCR_NATIVE) */
+EXPORT_SYMBOL_GPL(dcr_unmap_mmio);
+
+#endif /* defined(CONFIG_PPC_DCR_MMIO) */
+
+#ifdef CONFIG_PPC_DCR_NATIVE
 DEFINE_SPINLOCK(dcr_ind_lock);
-#endif  /* !defined(CONFIG_PPC_DCR_NATIVE) */
+#endif  /* defined(CONFIG_PPC_DCR_NATIVE) */
+