subject:"\[PATCH v4 3\/7\] of\/address\: Introduce of_dma_get_max_cpu

Re: [PATCH v4 3/7] of/address: Introduce of_dma_get_max_cpu_address()

2020-10-22 Thread Nicolas Saenz Julienne

On Thu, 2020-10-22 at 14:23 +0200, Ard Biesheuvel wrote:
> > +/**
> > + * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA
> > + * @np: The node to start searching from or NULL to start from the root
> > + *
> > + * Gets the highest CPU physical address that is addressable by all DMA 
> > masters
> > + * in the sub-tree pointed by np, or the whole tree if NULL is passed. If 
> > no
> > + * DMA constrained device is found, it returns PHYS_ADDR_MAX.
> > + */
> > +phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
> > +{
> > +   phys_addr_t max_cpu_addr = PHYS_ADDR_MAX;
> > +   struct of_range_parser parser;
> > +   phys_addr_t subtree_max_addr;
> > +   struct device_node *child;
> > +   struct of_range range;
> > +   const __be32 *ranges;
> > +   u64 cpu_end = 0;
> > +   int len;
> > +
> > +   if (!np)
> > +   np = of_root;
> > +
> > +   ranges = of_get_property(np, "dma-ranges", );
> > +   if (ranges && len) {
> > +   of_dma_range_parser_init(, np);
> > +   for_each_of_range(, )
> > +   if (range.cpu_addr + range.size > cpu_end)
> > +   cpu_end = range.cpu_addr + range.size;
> 
> 
> Shouldn't this be 'range.cpu_addr + range.size - 1' ?

Yes, I agree. In that case arm64's counterpart should be:

zone_dma_bits = max(32U, fls64(of_dma_get_max_cpu_address(NULL)));

I'll update it.

Regards,
Nicolas



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Re: [PATCH v4 3/7] of/address: Introduce of_dma_get_max_cpu_address()

2020-10-22 Thread Ard Biesheuvel

On Wed, 21 Oct 2020 at 14:35, Nicolas Saenz Julienne
 wrote:
>
> Introduce of_dma_get_max_cpu_address(), which provides the highest CPU
> physical address addressable by all DMA masters in the system. It's
> specially useful for setting memory zones sizes at early boot time.
>
> Signed-off-by: Nicolas Saenz Julienne 
>
> ---
>
> Changes since v3:
>  - use u64 with cpu_end
>
> Changes since v2:
>  - Use PHYS_ADDR_MAX
>  - return phys_dma_t
>  - Rename function
>  - Correct subject
>  - Add support to start parsing from an arbitrary device node in order
>for the function to work with unit tests
>
>  drivers/of/address.c | 42 ++
>  include/linux/of.h   |  7 +++
>  2 files changed, 49 insertions(+)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index eb9ab4f1e80b..47dfe5881e18 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -1024,6 +1024,48 @@ int of_dma_get_range(struct device_node *np, const 
> struct bus_dma_region **map)
>  }
>  #endif /* CONFIG_HAS_DMA */
>
> +/**
> + * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA
> + * @np: The node to start searching from or NULL to start from the root
> + *
> + * Gets the highest CPU physical address that is addressable by all DMA 
> masters
> + * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no
> + * DMA constrained device is found, it returns PHYS_ADDR_MAX.
> + */
> +phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
> +{
> +   phys_addr_t max_cpu_addr = PHYS_ADDR_MAX;
> +   struct of_range_parser parser;
> +   phys_addr_t subtree_max_addr;
> +   struct device_node *child;
> +   struct of_range range;
> +   const __be32 *ranges;
> +   u64 cpu_end = 0;
> +   int len;
> +
> +   if (!np)
> +   np = of_root;
> +
> +   ranges = of_get_property(np, "dma-ranges", );
> +   if (ranges && len) {
> +   of_dma_range_parser_init(, np);
> +   for_each_of_range(, )
> +   if (range.cpu_addr + range.size > cpu_end)
> +   cpu_end = range.cpu_addr + range.size;

Shouldn't this be 'range.cpu_addr + range.size - 1' ?

> +
> +   if (max_cpu_addr > cpu_end)
> +   max_cpu_addr = cpu_end;
> +   }
> +
> +   for_each_available_child_of_node(np, child) {
> +   subtree_max_addr = of_dma_get_max_cpu_address(child);
> +   if (max_cpu_addr > subtree_max_addr)
> +   max_cpu_addr = subtree_max_addr;
> +   }
> +
> +   return max_cpu_addr;
> +}
> +
>  /**
>   * of_dma_is_coherent - Check if device is coherent
>   * @np:device node
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 481ec0467285..db8db8f2c967 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -558,6 +558,8 @@ int of_map_id(struct device_node *np, u32 id,
>const char *map_name, const char *map_mask_name,
>struct device_node **target, u32 *id_out);
>
> +phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
> +
>  #else /* CONFIG_OF */
>
>  static inline void of_core_init(void)
> @@ -995,6 +997,11 @@ static inline int of_map_id(struct device_node *np, u32 
> id,
> return -EINVAL;
>  }
>
> +static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np)
> +{
> +   return PHYS_ADDR_MAX;
> +}
> +
>  #define of_match_ptr(_ptr) NULL
>  #define of_match_node(_matches, _node) NULL
>  #endif /* CONFIG_OF */
> --
> 2.28.0
>
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[PATCH v4 3/7] of/address: Introduce of_dma_get_max_cpu_address()

2020-10-21 Thread Nicolas Saenz Julienne

Introduce of_dma_get_max_cpu_address(), which provides the highest CPU
physical address addressable by all DMA masters in the system. It's
specially useful for setting memory zones sizes at early boot time.

Signed-off-by: Nicolas Saenz Julienne 

---

Changes since v3:
 - use u64 with cpu_end

Changes since v2:
 - Use PHYS_ADDR_MAX
 - return phys_dma_t
 - Rename function
 - Correct subject
 - Add support to start parsing from an arbitrary device node in order
   for the function to work with unit tests

 drivers/of/address.c | 42 ++
 include/linux/of.h   |  7 +++
 2 files changed, 49 insertions(+)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index eb9ab4f1e80b..47dfe5881e18 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -1024,6 +1024,48 @@ int of_dma_get_range(struct device_node *np, const 
struct bus_dma_region **map)
 }
 #endif /* CONFIG_HAS_DMA */
 
+/**
+ * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA
+ * @np: The node to start searching from or NULL to start from the root
+ *
+ * Gets the highest CPU physical address that is addressable by all DMA masters
+ * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no
+ * DMA constrained device is found, it returns PHYS_ADDR_MAX.
+ */
+phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
+{
+   phys_addr_t max_cpu_addr = PHYS_ADDR_MAX;
+   struct of_range_parser parser;
+   phys_addr_t subtree_max_addr;
+   struct device_node *child;
+   struct of_range range;
+   const __be32 *ranges;
+   u64 cpu_end = 0;
+   int len;
+
+   if (!np)
+   np = of_root;
+
+   ranges = of_get_property(np, "dma-ranges", );
+   if (ranges && len) {
+   of_dma_range_parser_init(, np);
+   for_each_of_range(, )
+   if (range.cpu_addr + range.size > cpu_end)
+   cpu_end = range.cpu_addr + range.size;
+
+   if (max_cpu_addr > cpu_end)
+   max_cpu_addr = cpu_end;
+   }
+
+   for_each_available_child_of_node(np, child) {
+   subtree_max_addr = of_dma_get_max_cpu_address(child);
+   if (max_cpu_addr > subtree_max_addr)
+   max_cpu_addr = subtree_max_addr;
+   }
+
+   return max_cpu_addr;
+}
+
 /**
  * of_dma_is_coherent - Check if device is coherent
  * @np:device node
diff --git a/include/linux/of.h b/include/linux/of.h
index 481ec0467285..db8db8f2c967 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -558,6 +558,8 @@ int of_map_id(struct device_node *np, u32 id,
   const char *map_name, const char *map_mask_name,
   struct device_node **target, u32 *id_out);
 
+phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
+
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
@@ -995,6 +997,11 @@ static inline int of_map_id(struct device_node *np, u32 id,
return -EINVAL;
 }
 
+static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np)
+{
+   return PHYS_ADDR_MAX;
+}
+
 #define of_match_ptr(_ptr) NULL
 #define of_match_node(_matches, _node) NULL
 #endif /* CONFIG_OF */
-- 
2.28.0

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Re: [PATCH v4 3/7] of/address: Introduce of_dma_get_max_cpu_address()

Re: [PATCH v4 3/7] of/address: Introduce of_dma_get_max_cpu_address()

[PATCH v4 3/7] of/address: Introduce of_dma_get_max_cpu_address()

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