[PATCH 1/5] [v2][POWERPC] refactor dcr code
Benjamin Herrenschmidt
benh at kernel.crashing.org
Mon Mar 31 09:02:56 EST 2008
On Fri, 2008-03-28 at 09:23 -0700, Stephen Neuendorffer wrote:
> Previously, dcr support was configured at compile time to either using
> 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 slave device 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 interoducing overhead in existing usage.
>
> Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer at xilinx.com>
Looks good. Haven't had a chance to test it yet, but tentatively
Acked-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Initially, I thought about using function pointers but the if/else will
probably end up being more efficient. The only thing maybe to ponder
is whether we could avoid the dcr-generic.h file completely, and have
the generic wrappers be inline, though considering how slow DCRs are,
it may not be that useful in practice and less clean...
Cheers,
Ben.
> ---
> arch/powerpc/sysdev/dcr.c | 91 ++++++++++++++++++++++++++++++++-----
> include/asm-powerpc/dcr-generic.h | 49 ++++++++++++++++++++
> include/asm-powerpc/dcr-mmio.h | 20 +++++---
> include/asm-powerpc/dcr-native.h | 16 ++++---
> include/asm-powerpc/dcr.h | 36 ++++++++++++++-
> 5 files changed, 186 insertions(+), 26 deletions(-)
> create mode 100644 include/asm-powerpc/dcr-generic.h
>
> diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
> index 437e48d..d3de0ff 100644
> --- a/arch/powerpc/sysdev/dcr.c
> +++ b/arch/powerpc/sysdev/dcr.c
> @@ -23,6 +23,68 @@
> #include <asm/prom.h>
> #include <asm/dcr.h>
>
> +#if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
> +
> +bool dcr_map_ok_generic(dcr_host_t host)
> +{
> + if (host.type == INVALID)
> + return 0;
> + else if (host.type == NATIVE)
> + return dcr_map_ok_native(host.host.native);
> + else
> + return dcr_map_ok_mmio(host.host.mmio);
> +}
> +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;
> + const char *prop = of_get_property(dev, "dcr-access-method", NULL);
> +
> + if (!strcmp(prop, "native")) {
> + host.type = NATIVE;
> + host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
> + } else if (!strcmp(prop, "mmio")) {
> + host.type = MMIO;
> + host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
> + } else
> + host.type = INVALID;
> +
> + return host;
> +}
> +EXPORT_SYMBOL_GPL(dcr_map_generic);
> +
> +void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
> +{
> + if (host.type == NATIVE)
> + dcr_unmap_native(host.host.native, dcr_c);
> + else
> + dcr_unmap_mmio(host.host.mmio, dcr_c);
> +}
> +EXPORT_SYMBOL_GPL(dcr_unmap_generic);
> +
> +u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
> +{
> + if (host.type == NATIVE)
> + return dcr_read_native(host.host.native, dcr_n);
> + else
> + return dcr_read_mmio(host.host.mmio, dcr_n);
> +}
> +EXPORT_SYMBOL_GPL(dcr_read_generic);
> +
> +void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
> +{
> + if (host.type == NATIVE)
> + dcr_write_native(host.host.native, dcr_n, value);
> + else
> + dcr_write_mmio(host.host.mmio, dcr_n, value);
> +}
> +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;
> @@ -47,7 +109,7 @@ unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
> }
> EXPORT_SYMBOL_GPL(dcr_resource_len);
>
> -#ifndef CONFIG_PPC_DCR_NATIVE
> +#ifdef CONFIG_PPC_DCR_MMIO
>
> static struct device_node * find_dcr_parent(struct device_node * node)
> {
> @@ -101,18 +163,19 @@ u64 of_translate_dcr_address(struct device_node *dev,
> 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 +187,11 @@ 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 +199,11 @@ 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) */
> +
> diff --git a/include/asm-powerpc/dcr-generic.h b/include/asm-powerpc/dcr-generic.h
> new file mode 100644
> index 0000000..0ee74fb
> --- /dev/null
> +++ b/include/asm-powerpc/dcr-generic.h
> @@ -0,0 +1,49 @@
> +/*
> + * (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_GENERIC_H
> +#define _ASM_POWERPC_DCR_GENERIC_H
> +#ifdef __KERNEL__
> +#ifndef __ASSEMBLY__
> +
> +enum host_type_t {MMIO, NATIVE, INVALID};
> +
> +typedef struct {
> + enum host_type_t type;
> + union {
> + dcr_host_mmio_t mmio;
> + dcr_host_native_t native;
> + } host;
> +} dcr_host_t;
> +
> +extern bool dcr_map_ok_generic(dcr_host_t host);
> +
> +extern dcr_host_t dcr_map_generic(struct device_node *dev, unsigned int dcr_n,
> + unsigned int dcr_c);
> +extern void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c);
> +
> +extern u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n);
> +
> +extern void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value);
> +
> +#endif /* __ASSEMBLY__ */
> +#endif /* __KERNEL__ */
> +#endif /* _ASM_POWERPC_DCR_GENERIC_H */
> +
> +
> diff --git a/include/asm-powerpc/dcr-mmio.h b/include/asm-powerpc/dcr-mmio.h
> index 08532ff..acd491d 100644
> --- a/include/asm-powerpc/dcr-mmio.h
> +++ b/include/asm-powerpc/dcr-mmio.h
> @@ -27,20 +27,26 @@ typedef struct {
> void __iomem *token;
> unsigned int stride;
> unsigned int base;
> -} dcr_host_t;
> +} dcr_host_mmio_t;
>
> -#define DCR_MAP_OK(host) ((host).token != NULL)
> +static inline bool dcr_map_ok_mmio(dcr_host_mmio_t host)
> +{
> + return 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_c);
> +extern dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
> + unsigned int dcr_n,
> + unsigned int dcr_c);
> +extern void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c);
>
> -static inline u32 dcr_read(dcr_host_t host, unsigned int dcr_n)
> +static inline u32 dcr_read_mmio(dcr_host_mmio_t host, unsigned int dcr_n)
> {
> return in_be32(host.token + ((host.base + dcr_n) * host.stride));
> }
>
> -static inline void dcr_write(dcr_host_t host, unsigned int dcr_n, u32 value)
> +static inline void dcr_write_mmio(dcr_host_mmio_t host,
> + unsigned int dcr_n,
> + u32 value)
> {
> out_be32(host.token + ((host.base + dcr_n) * host.stride), value);
> }
> diff --git a/include/asm-powerpc/dcr-native.h b/include/asm-powerpc/dcr-native.h
> index be6c879..67832e5 100644
> --- a/include/asm-powerpc/dcr-native.h
> +++ b/include/asm-powerpc/dcr-native.h
> @@ -26,14 +26,18 @@
>
> typedef struct {
> unsigned int base;
> -} dcr_host_t;
> +} dcr_host_native_t;
>
> -#define DCR_MAP_OK(host) (1)
> +static inline bool dcr_map_ok_native(dcr_host_native_t host)
> +{
> + return 1;
> +}
>
> -#define dcr_map(dev, dcr_n, dcr_c) ((dcr_host_t){ .base = (dcr_n) })
> -#define dcr_unmap(host, dcr_c) do {} while (0)
> -#define dcr_read(host, dcr_n) mfdcr(dcr_n + host.base)
> -#define dcr_write(host, dcr_n, value) mtdcr(dcr_n + host.base, value)
> +#define dcr_map_native(dev, dcr_n, dcr_c) \
> + ((dcr_host_native_t){ .base = (dcr_n) })
> +#define dcr_unmap_native(host, dcr_c) do {} while (0)
> +#define dcr_read_native(host, dcr_n) mfdcr(dcr_n + host.base)
> +#define dcr_write_native(host, dcr_n, value) mtdcr(dcr_n + host.base, value)
>
> /* Device Control Registers */
> void __mtdcr(int reg, unsigned int val);
> diff --git a/include/asm-powerpc/dcr.h b/include/asm-powerpc/dcr.h
> index 9338d50..6b86322 100644
> --- a/include/asm-powerpc/dcr.h
> +++ b/include/asm-powerpc/dcr.h
> @@ -20,14 +20,47 @@
> #ifndef _ASM_POWERPC_DCR_H
> #define _ASM_POWERPC_DCR_H
> #ifdef __KERNEL__
> +#ifndef __ASSEMBLY__
> #ifdef CONFIG_PPC_DCR
>
> #ifdef CONFIG_PPC_DCR_NATIVE
> #include <asm/dcr-native.h>
> -#else
> +#endif
> +
> +#ifdef CONFIG_PPC_DCR_MMIO
> #include <asm/dcr-mmio.h>
> #endif
>
> +#if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
> +
> +#include <asm/dcr-generic.h>
> +
> +#define DCR_MAP_OK(host) dcr_map_ok_generic(host)
> +#define dcr_map(dev, dcr_n, dcr_c) dcr_map_generic(dev, dcr_n, dcr_c)
> +#define dcr_unmap(host, dcr_c) dcr_unmap_generic(host, dcr_c)
> +#define dcr_read(host, dcr_n) dcr_read_generic(host, dcr_n)
> +#define dcr_write(host, dcr_n, value) dcr_write_generic(host, dcr_n, value)
> +
> +#else
> +
> +#ifdef CONFIG_PPC_DCR_NATIVE
> +typedef dcr_host_native_t dcr_host_t;
> +#define DCR_MAP_OK(host) dcr_map_ok_native(host)
> +#define dcr_map(dev, dcr_n, dcr_c) dcr_map_native(dev, dcr_n, dcr_c)
> +#define dcr_unmap(host, dcr_c) dcr_unmap_native(host, dcr_c)
> +#define dcr_read(host, dcr_n) dcr_read_native(host, dcr_n)
> +#define dcr_write(host, dcr_n, value) dcr_write_native(host, dcr_n, value)
> +#else
> +typedef dcr_host_mmio_t dcr_host_t;
> +#define DCR_MAP_OK(host) dcr_map_ok_mmio(host)
> +#define dcr_map(dev, dcr_n, dcr_c) dcr_map_mmio(dev, dcr_n, dcr_c)
> +#define dcr_unmap(host, dcr_c) dcr_unmap_mmio(host, dcr_c)
> +#define dcr_read(host, dcr_n) dcr_read_mmio(host, dcr_n)
> +#define dcr_write(host, dcr_n, value) dcr_write_mmio(host, dcr_n, value)
> +#endif
> +
> +#endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
> +
> /*
> * On CONFIG_PPC_MERGE, we have additional helpers to read the DCR
> * base from the device-tree
> @@ -41,5 +74,6 @@ extern unsigned int dcr_resource_len(struct device_node *np,
> #endif /* CONFIG_PPC_MERGE */
>
> #endif /* CONFIG_PPC_DCR */
> +#endif /* __ASSEMBLY__ */
> #endif /* __KERNEL__ */
> #endif /* _ASM_POWERPC_DCR_H */
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