[PATCH] powerpc: New DCR access methods
Benjamin Herrenschmidt
benh at kernel.crashing.org
Wed Oct 11 15:42:53 EST 2006
Ѕubject: powerpc: generic DCR access
This patch adds new dcr_map/dcr_read/dcr_write accessors for DCRs that
can be used by drivers to transparently address either native DCRs or
memory mapped DCRs. The implementation for memory mapped DCRs is done
after the binding being currently worked on for SLOF and the Axon
chipset. This patch enables it for the cell native platform
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
Arnd: This will replace powerpc-generic-dcr.diff, though don't put it in
your tree just yet. I'll have other axon related patches including a new
one porting emac over and a new infrastructure for probing OF devices
in the upcoming few days. I'm posting this one early to get comments from
4xx folks.
Eugene: As you can see, the overhead for 4xx is nil. I have a patch hacking
the MAL driver to use those instead of mfdcr/mtdcr. I did it to quicky test
I didn't do anything stupid and it still builds with an ebony_defconfig with
ARCH=ppc. I'll send it separately.
Index: linux-cell/include/asm-powerpc/dcr.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-cell/include/asm-powerpc/dcr.h 2006-10-11 15:28:41.000000000 +1000
@@ -0,0 +1,40 @@
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ * <benh at kernel.crashing.org>
+ *
+ * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _ASM_POWERPC_DCR_H
+#define _ASM_POWERPC_DCR_H
+#ifdef __KERNEL__
+
+#ifdef CONFIG_PPC_DCR_NATIVE
+#include <asm/dcr-native.h>
+#else
+#include <asm/dcr-mmio.h>
+#endif
+
+/*
+ * On CONFIG_PPC_MERGE, we have additional helpers to read the DCR
+ * base from the device-tree
+ */
+#ifdef CONFIG_PPC_MERGE
+extern int dcr_resource_start(struct device_node *np, unsigned int index);
+extern int dcr_resource_len(struct device_node *np, unsigned int index);
+#endif /* CONFIG_PPC_MERGE */
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_DCR_H */
Index: linux-cell/arch/powerpc/Kconfig
===================================================================
--- linux-cell.orig/arch/powerpc/Kconfig 2006-10-11 15:27:03.000000000 +1000
+++ linux-cell/arch/powerpc/Kconfig 2006-10-11 15:29:31.000000000 +1000
@@ -160,9 +160,11 @@ config PPC_86xx
config 40x
bool "AMCC 40x"
+ select PPC_DCR_NATIVE
config 44x
bool "AMCC 44x"
+ select PPC_DCR_NATIVE
config 8xx
bool "Freescale 8xx"
@@ -208,6 +210,19 @@ config PPC_FPU
bool
default y if PPC64
+config PPC_DCR_NATIVE
+ bool
+ default n
+
+config PPC_DCR_MMIO
+ bool
+ default n
+
+config PPC_DCR
+ bool
+ depends on PPC_DCR_NATIVE || PPC_DCR_MMIO
+ default y
+
config BOOKE
bool
depends on E200 || E500
@@ -445,6 +460,7 @@ config PPC_CELL
config PPC_CELL_NATIVE
bool
select PPC_CELL
+ select PPC_DCR_MMIO
default n
config PPC_IBM_CELL_BLADE
Index: linux-cell/include/asm-powerpc/dcr-mmio.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-cell/include/asm-powerpc/dcr-mmio.h 2006-10-11 15:34:02.000000000 +1000
@@ -0,0 +1,51 @@
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ * <benh at kernel.crashing.org>
+ *
+ * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _ASM_POWERPC_DCR_MMIO_H
+#define _ASM_POWERPC_DCR_MMIO_H
+#ifdef __KERNEL__
+
+#include <asm/io.h>
+
+typedef struct { void __iomem *token; unsigned int stride; } dcr_host_t;
+
+#define DCR_MAP_OK(host) ((host).token != NULL)
+
+extern dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
+ unsigned int dcr_c);
+extern void dcr_unmap(dcr_host_t host, unsigned int dcr_n, unsigned int dcr_c);
+
+static inline u32 dcr_read(dcr_host_t host, unsigned int dcr_n)
+{
+ return in_be32(host.token + dcr_n * host.stride);
+}
+
+static inline void dcr_write(dcr_host_t host, unsigned int dcr_n, u32 value)
+{
+ out_be32(host.token + dcr_n * host.stride, value);
+}
+
+extern u64 of_translate_dcr_address(struct device_node *dev,
+ unsigned int dcr_n,
+ unsigned int *stride);
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_DCR_MMIO_H */
+
+
Index: linux-cell/include/asm-powerpc/dcr-native.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-cell/include/asm-powerpc/dcr-native.h 2006-10-11 15:28:41.000000000 +1000
@@ -0,0 +1,39 @@
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ * <benh at kernel.crashing.org>
+ *
+ * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _ASM_POWERPC_DCR_NATIVE_H
+#define _ASM_POWERPC_DCR_NATIVE_H
+#ifdef __KERNEL__
+
+#include <asm/reg.h>
+
+typedef struct {} dcr_host_t;
+
+#define DCR_MAP_OK(host) (1)
+
+#define dcr_map(dev, dcr_n, dcr_c) {}
+#define dcr_unmap(host, dcr_n, dcr_c) {}
+#define dcr_read(host, dcr_n) mfdcr(dcr_n)
+#define dcr_write(host, dcr_n, value) mtdcr(dcr_n, value)
+
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_DCR_NATIVE_H */
+
+
Index: linux-cell/arch/ppc/Kconfig
===================================================================
--- linux-cell.orig/arch/ppc/Kconfig 2006-10-11 15:27:03.000000000 +1000
+++ linux-cell/arch/ppc/Kconfig 2006-10-11 15:28:41.000000000 +1000
@@ -77,9 +77,11 @@ config 6xx
config 40x
bool "40x"
+ select PPC_DCR_NATIVE
config 44x
bool "44x"
+ select PPC_DCR_NATIVE
config 8xx
bool "8xx"
@@ -95,6 +97,15 @@ endchoice
config PPC_FPU
bool
+config PPC_DCR_NATIVE
+ bool
+ default n
+
+config PPC_DCR
+ bool
+ depends on PPC_DCR_NATIVE
+ default y
+
config BOOKE
bool
depends on E200 || E500
Index: linux-cell/arch/powerpc/kernel/Makefile
===================================================================
--- linux-cell.orig/arch/powerpc/kernel/Makefile 2006-10-11 15:27:03.000000000 +1000
+++ linux-cell/arch/powerpc/kernel/Makefile 2006-10-11 15:28:41.000000000 +1000
@@ -60,6 +60,8 @@ obj-$(CONFIG_BOOTX_TEXT) += btext.o
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_PPC_UDBG_16550) += legacy_serial.o udbg_16550.o
+obj-$(CONFIG_PPC_DCR) += dcr.o
+
module-$(CONFIG_PPC64) += module_64.o
obj-$(CONFIG_MODULES) += $(module-y)
Index: linux-cell/arch/powerpc/kernel/dcr.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-cell/arch/powerpc/kernel/dcr.c 2006-10-11 15:35:34.000000000 +1000
@@ -0,0 +1,120 @@
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ * <benh at kernel.crashing.org>
+ *
+ * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <asm/prom.h>
+#include <asm/dcr.h>
+
+int dcr_resource_start(struct device_node *np, unsigned int index)
+{
+ unsigned int ds;
+ const u32 *dr = get_property(np, "dcr-reg", &ds);
+
+ if (dr == NULL || ds & 1 || index >= (ds / 8))
+ return -EINVAL;
+
+ return dr[index * 2];
+}
+
+int dcr_resource_len(struct device_node *np, unsigned int index)
+{
+ unsigned int ds;
+ const u32 *dr = get_property(np, "dcr-reg", &ds);
+
+ if (dr == NULL || ds & 1 || index >= (ds / 8))
+ return -EINVAL;
+
+ return dr[index * 2 + 1];
+}
+
+#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 (get_property(par, "dcr-controller", NULL))
+ break;
+ p = 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;
+}
+
+u64 of_translate_dcr_address(struct device_node *dev,
+ unsigned int dcr_n,
+ unsigned int *stride)
+{
+ struct device_node *dp;
+ const u32 *p;
+ u64 ret;
+
+ dp = find_dcr_parent(dev);
+ if (dp == NULL)
+ return OF_BAD_ADDR;
+
+ /* Stride is not properly defined yet, default to 0x10 for Axon */
+ p = get_property(dp, "dcr-mmio-stride", NULL);
+ *stride = (p == NULL) ? 0x10 : *p;
+
+ p = get_property(dp, "dcr-mmio-range", NULL);
+ if (p == NULL)
+ return OF_BAD_ADDR;
+
+ /* Maybe could do some better range checking here */
+ ret = of_translate_address(dp, p);
+ if (ret != OF_BAD_ADDR)
+ ret += *stride * dcr_n;
+ return ret;
+}
+
+dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
+ unsigned int dcr_c)
+{
+ dcr_host_t ret = { .token = NULL, .stride = 0 };
+ u64 addr;
+
+ addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
+ if (addr == OF_BAD_ADDR)
+ return ret;
+ ret.token = ioremap(addr, dcr_c * ret.stride);
+ if (ret.token == NULL)
+ return ret;
+ ret.token -= dcr_n * ret.stride;
+ return ret;
+}
+
+void dcr_unmap(dcr_host_t host, unsigned int dcr_n, unsigned int dcr_c)
+{
+ dcr_host_t h = host;
+
+ if (h.token == NULL)
+ return;
+ h.token -= dcr_n * h.stride;
+ iounmap(h.token);
+ h.token = NULL;
+}
+
+#endif /* !defined(CONFIG_PPC_DCR_NATIVE) */
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