Subject: Re: [PATCH 3/5] [POWERPC] explicit dcr support

From: Benjamin Herrenschmidt <[email-masked]>
Date: Mon, 31 Mar 2008 09:04:07 +1100

On Fri, 2008-03-28 at 09:23 -0700, Stephen Neuendorffer wrote:
> Added literal mapping support if no device-tree support.  Added
> CONFIG_OF to guard device-tree parts, since literal support works for
> arch=ppc.
> 
> Signed-off-by: Stephen Neuendorffer <[email-masked]>

I'll let others decide whether they want to do that addition
to arch/ppc (which is really what it is) or not ... I'd rather
not myself considering that arch/ppc is scheduled to go away
soon now.

Cheers,
Ben.

> ---
>  arch/powerpc/sysdev/dcr.c         |   82 ++++++++++++++++++++++++++++---------
>  include/asm-powerpc/dcr-generic.h |    2 +
>  include/asm-powerpc/dcr-mmio.h    |   11 +++++
>  include/asm-powerpc/dcr-native.h  |    8 ++++
>  include/asm-powerpc/dcr.h         |   24 +++++++++++
>  5 files changed, 108 insertions(+), 19 deletions(-)
> 
> diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
> index d3de0ff..2ccae80 100644
> --- a/arch/powerpc/sysdev/dcr.c
> +++ b/arch/powerpc/sysdev/dcr.c
> @@ -20,9 +20,34 @@
>  #undef DEBUG
>  
>  #include <linux/kernel.h>
> +#include <linux/module.h>
>  #include <asm/prom.h>
>  #include <asm/dcr.h>
>  
> +#ifdef CONFIG_OF
> +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;
> +}
> +#endif /* CONFIG_OF */
> +
> +
> +/* Indirection layer for providing both NATIVE and MMIO support. */
> +
>  #if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
>  
>  bool dcr_map_ok_generic(dcr_host_t host)
> @@ -36,12 +61,24 @@ bool dcr_map_ok_generic(dcr_host_t host)
>  }
>  EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
>  
> +#ifdef CONFIG_OF
>  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);
> +	struct device_node *dp;
> +
> +	dp = find_dcr_parent(dev);
> +	if (dp == NULL) {
> +		host.type = INVALID;
> +		return host;
> +	}
> +
> +	const char *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 = NATIVE;
> @@ -56,6 +93,8 @@ dcr_host_t dcr_map_generic(struct device_node *dev,
>  }
>  EXPORT_SYMBOL_GPL(dcr_map_generic);
>  
> +#endif /* CONFIG_OF */
> +
>  void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
>  {
>  	if (host.type == NATIVE)
> @@ -85,9 +124,10 @@ EXPORT_SYMBOL_GPL(dcr_write_generic);
>  
>  #endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
>  
> +#ifdef CONFIG_OF
>  unsigned int dcr_resource_start(struct device_node *np, unsigned int index)
>  {
> -	unsigned int ds;
> +	int ds;
>  	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
>  
>  	if (dr == NULL || ds & 1 || index >= (ds / 8))
> @@ -99,7 +139,7 @@ EXPORT_SYMBOL_GPL(dcr_resource_start);
>  
>  unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
>  {
> -	unsigned int ds;
> +	int ds;
>  	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
>  
>  	if (dr == NULL || ds & 1 || index >= (ds / 8))
> @@ -109,26 +149,28 @@ unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
>  }
>  EXPORT_SYMBOL_GPL(dcr_resource_len);
>  
> +#endif /* CONFIG_OF */
> +
> +
> +
> +/* Support for MMIO */
>  #ifdef CONFIG_PPC_DCR_MMIO
>  
> -static struct device_node * find_dcr_parent(struct device_node * node)
> +dcr_host_mmio_t dcr_map_mmio_literal_mmio(resource_size_t mmio_start,
> +					  unsigned int stride,
> +					  unsigned int dcr_n,
> +					  unsigned int dcr_c)
>  {
> -	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;
> +	dcr_host_mmio_t host;
> +	host.stride = stride;
> +	host.token = ioremap(mmio_start, dcr_c * stride);
> +	host.token -= dcr_n * stride;
> +	host.base = dcr_n;
> +	return host;
>  }
> +EXPORT_SYMBOL_GPL(dcr_map_mmio_literal_mmio);
> +
> +#ifdef CONFIG_OF
>  
>  u64 of_translate_dcr_address(struct device_node *dev,
>  			     unsigned int dcr_n,
> @@ -189,6 +231,8 @@ dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
>  }
>  EXPORT_SYMBOL_GPL(dcr_map_mmio);
>  
> +#endif /* CONFIG_OF */
> +
>  void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
>  {
>  	dcr_host_mmio_t h = host;
> diff --git a/include/asm-powerpc/dcr-generic.h b/include/asm-powerpc/dcr-generic.h
> index 0ee74fb..8032795 100644
> --- a/include/asm-powerpc/dcr-generic.h
> +++ b/include/asm-powerpc/dcr-generic.h
> @@ -34,8 +34,10 @@ typedef struct {
>  
>  extern bool dcr_map_ok_generic(dcr_host_t host);
>  
> +#ifdef CONFIG_OF
>  extern dcr_host_t dcr_map_generic(struct device_node *dev, unsigned int dcr_n,
>  			  unsigned int dcr_c);
> +#endif
>  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);
> diff --git a/include/asm-powerpc/dcr-mmio.h b/include/asm-powerpc/dcr-mmio.h
> index acd491d..b12d291 100644
> --- a/include/asm-powerpc/dcr-mmio.h
> +++ b/include/asm-powerpc/dcr-mmio.h
> @@ -34,9 +34,18 @@ static inline bool dcr_map_ok_mmio(dcr_host_mmio_t host)
>  	return host.token != NULL;
>  }
>  
> +extern dcr_host_mmio_t dcr_map_mmio_literal_mmio(resource_size_t mmio_start,
> +						 unsigned int stride,
> +						 unsigned int dcr_n,
> +						 unsigned int dcr_c);
> +
> +
> +#ifdef CONFIG_OF
>  extern dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
>  				    unsigned int dcr_n,
>  				    unsigned int dcr_c);
> +#endif
> +
>  extern void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c);
>  
>  static inline u32 dcr_read_mmio(dcr_host_mmio_t host, unsigned int dcr_n)
> @@ -51,9 +60,11 @@ static inline void dcr_write_mmio(dcr_host_mmio_t host,
>  	out_be32(host.token + ((host.base + dcr_n) * host.stride), value);
>  }
>  
> +#ifdef CONFIG_OF
>  extern u64 of_translate_dcr_address(struct device_node *dev,
>  				    unsigned int dcr_n,
>  				    unsigned int *stride);
> +#endif
>  
>  #endif /* __KERNEL__ */
>  #endif /* _ASM_POWERPC_DCR_MMIO_H */
> diff --git a/include/asm-powerpc/dcr-native.h b/include/asm-powerpc/dcr-native.h
> index 67832e5..9b3e255 100644
> --- a/include/asm-powerpc/dcr-native.h
> +++ b/include/asm-powerpc/dcr-native.h
> @@ -33,6 +33,14 @@ static inline bool dcr_map_ok_native(dcr_host_native_t host)
>  	return 1;
>  }
>  
> +static inline
> +dcr_host_native_t dcr_map_native_literal_native(unsigned int dcr_n)
> +{
> +	dcr_host_native_t host;
> +	host.base = dcr_n;
> +	return host;
> +}
> +
>  #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)
> diff --git a/include/asm-powerpc/dcr.h b/include/asm-powerpc/dcr.h
> index 6b86322..dfd1c24 100644
> --- a/include/asm-powerpc/dcr.h
> +++ b/include/asm-powerpc/dcr.h
> @@ -35,6 +35,27 @@
>  
>  #include <asm/dcr-generic.h>
>  
> +static inline
> +dcr_host_t dcr_map_mmio_literal(resource_size_t mmio_start,
> +				unsigned int stride,
> +				unsigned int dcr_n,
> +				unsigned int dcr_c)
> +{
> +	dcr_host_t host;
> +	host.type = MMIO;
> +	host.host.mmio =
> +		dcr_map_mmio_literal_mmio(mmio_start, stride, dcr_n, dcr_c);
> +	return host;
> +}
> +static inline
> +dcr_host_t dcr_map_native_literal(unsigned int dcr_n)
> +{
> +	dcr_host_t host;
> +	host.type = NATIVE;
> +	host.host.native = dcr_map_native_literal_native(dcr_n);
> +	return host;
> +}
> +
>  #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)
> @@ -45,6 +66,7 @@
>  
>  #ifdef CONFIG_PPC_DCR_NATIVE
>  typedef dcr_host_native_t dcr_host_t;
> +#define dcr_map_native_literal(dcr_n) dcr_map_native_literal_native(dcr_n)
>  #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)
> @@ -52,6 +74,8 @@ typedef dcr_host_native_t dcr_host_t;
>  #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_mmio_literal(mmio_start, stride, dcr_n, dcr_c) \
> +	dcr_map_mmio_literal_mmio(mmio_start, stride, dcr_n, dcr_c)
>  #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)