linux-loongson/include/linux/of_address.h
Frank Li 4dbf0155df of: address: Add parent_bus_addr to struct of_pci_range
Add a new field called 'parent_bus_addr' to struct of_pci_range to use
when retrieving parent bus address information.

Refer to the diagram below to better understand that the bus fabric in
some systems (like i.MX8QXP) does not always use a 1:1 address map
between input and output.

Currently, many controller drivers use the cpu_addr_fixup() callback
that would often hardcode address translation directly in the code, e.g.,
"cpu_addr & CDNS_PLAT_CPU_TO_BUS_ADDR" or "cpu_addr + BUS_IATU_OFFSET",
etc., even though those translations *should* be described via DT.

However, the cpu_addr_fixup() can be eliminated if DT correctly reflects
hardware behavior and drivers use 'parent_bus_addr' in struct of_pci_range.

            ┌─────────┐                    ┌────────────┐
 ┌─────┐    │         │ IA: 0x8ff8_0000    │            │
 │ CPU ├───►│   ┌────►├─────────────────┐  │ PCI        │
 └─────┘    │   │     │ IA: 0x8ff0_0000 │  │            │
  CPU Addr  │   │  ┌─►├─────────────┐   │  │ Controller │
0x7ff8_0000─┼───┘  │  │             │   │  │            │
            │      │  │             │   │  │            │   PCI Addr
0x7ff0_0000─┼──────┘  │             │   └──► IOSpace   ─┼────────────►
            │         │             │      │            │    0
0x7000_0000─┼────────►├─────────┐   │      │            │
            └─────────┘         │   └──────► CfgSpace  ─┼────────────►
             BUS Fabric         │          │            │    0
                                │          │            │
                                └──────────► MemSpace  ─┼────────────►
                        IA: 0x8000_0000    │            │  0x8000_0000
                                           └────────────┘

bus@5f000000 {
        compatible = "simple-bus";
        #address-cells = <1>;
        #size-cells = <1>;
        ranges = <0x80000000 0x0 0x70000000 0x10000000>;

        pcie@5f010000 {
                compatible = "fsl,imx8q-pcie";
                reg = <0x5f010000 0x10000>, <0x8ff00000 0x80000>;
                reg-names = "dbi", "config";
                #address-cells = <3>;
                #size-cells = <2>;
                device_type = "pci";
                bus-range = <0x00 0xff>;
                ranges = <0x81000000 0 0x00000000 0x8ff80000 0 0x00010000>,
                         <0x82000000 0 0x80000000 0x80000000 0 0x0ff00000>;
	...
	};
};

In the diagram above, the 'parent_bus_addr' field in struct of_pci_range
can indicate internal address (IA) address information.

Link: https://lore.kernel.org/r/20241119-pci_fixup_addr-v8-1-c4bfa5193288@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
2025-01-18 15:04:23 -06:00

203 lines
5.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __OF_ADDRESS_H
#define __OF_ADDRESS_H
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/of.h>
#include <linux/io.h>
struct of_bus;
struct of_pci_range_parser {
struct device_node *node;
const struct of_bus *bus;
const __be32 *range;
const __be32 *end;
int na;
int ns;
int pna;
bool dma;
};
#define of_range_parser of_pci_range_parser
struct of_pci_range {
union {
u64 pci_addr;
u64 bus_addr;
};
u64 cpu_addr;
u64 parent_bus_addr;
u64 size;
u32 flags;
};
#define of_range of_pci_range
#define for_each_of_pci_range(parser, range) \
for (; of_pci_range_parser_one(parser, range);)
#define for_each_of_range for_each_of_pci_range
/*
* of_range_count - Get the number of "ranges" or "dma-ranges" entries
* @parser: Parser state initialized by of_range_parser_init()
*
* Returns the number of entries or 0 if none.
*
* Note that calling this within or after the for_each_of_range() iterator will
* be inaccurate giving the number of entries remaining.
*/
static inline int of_range_count(const struct of_range_parser *parser)
{
if (!parser || !parser->node || !parser->range || parser->range == parser->end)
return 0;
return (parser->end - parser->range) / (parser->na + parser->pna + parser->ns);
}
/* Translate a DMA address from device space to CPU space */
extern u64 of_translate_dma_address(struct device_node *dev,
const __be32 *in_addr);
extern const __be32 *of_translate_dma_region(struct device_node *dev, const __be32 *addr,
phys_addr_t *start, size_t *length);
#ifdef CONFIG_OF_ADDRESS
extern u64 of_translate_address(struct device_node *np, const __be32 *addr);
extern int of_address_to_resource(struct device_node *dev, int index,
struct resource *r);
extern void __iomem *of_iomap(struct device_node *device, int index);
void __iomem *of_io_request_and_map(struct device_node *device,
int index, const char *name);
/* Extract an address from a device, returns the region size and
* the address space flags too. The PCI version uses a BAR number
* instead of an absolute index
*/
extern const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no,
u64 *size, unsigned int *flags);
int of_property_read_reg(struct device_node *np, int idx, u64 *addr, u64 *size);
extern int of_pci_range_parser_init(struct of_pci_range_parser *parser,
struct device_node *node);
extern int of_pci_dma_range_parser_init(struct of_pci_range_parser *parser,
struct device_node *node);
extern struct of_pci_range *of_pci_range_parser_one(
struct of_pci_range_parser *parser,
struct of_pci_range *range);
extern int of_pci_address_to_resource(struct device_node *dev, int bar,
struct resource *r);
extern int of_pci_range_to_resource(const struct of_pci_range *range,
const struct device_node *np,
struct resource *res);
extern int of_range_to_resource(struct device_node *np, int index,
struct resource *res);
extern bool of_dma_is_coherent(struct device_node *np);
#else /* CONFIG_OF_ADDRESS */
static inline void __iomem *of_io_request_and_map(struct device_node *device,
int index, const char *name)
{
return IOMEM_ERR_PTR(-EINVAL);
}
static inline u64 of_translate_address(struct device_node *np,
const __be32 *addr)
{
return OF_BAD_ADDR;
}
static inline const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no,
u64 *size, unsigned int *flags)
{
return NULL;
}
static inline int of_property_read_reg(struct device_node *np, int idx, u64 *addr, u64 *size)
{
return -ENOSYS;
}
static inline int of_pci_range_parser_init(struct of_pci_range_parser *parser,
struct device_node *node)
{
return -ENOSYS;
}
static inline int of_pci_dma_range_parser_init(struct of_pci_range_parser *parser,
struct device_node *node)
{
return -ENOSYS;
}
static inline struct of_pci_range *of_pci_range_parser_one(
struct of_pci_range_parser *parser,
struct of_pci_range *range)
{
return NULL;
}
static inline int of_pci_address_to_resource(struct device_node *dev, int bar,
struct resource *r)
{
return -ENOSYS;
}
static inline int of_pci_range_to_resource(struct of_pci_range *range,
struct device_node *np,
struct resource *res)
{
return -ENOSYS;
}
static inline int of_range_to_resource(struct device_node *np, int index,
struct resource *res)
{
return -ENOSYS;
}
static inline bool of_dma_is_coherent(struct device_node *np)
{
return false;
}
#endif /* CONFIG_OF_ADDRESS */
#ifdef CONFIG_OF
extern int of_address_to_resource(struct device_node *dev, int index,
struct resource *r);
void __iomem *of_iomap(struct device_node *node, int index);
#else
static inline int of_address_to_resource(struct device_node *dev, int index,
struct resource *r)
{
return -EINVAL;
}
static inline void __iomem *of_iomap(struct device_node *device, int index)
{
return NULL;
}
#endif
#define of_range_parser_init of_pci_range_parser_init
static inline const __be32 *of_get_address(struct device_node *dev, int index,
u64 *size, unsigned int *flags)
{
return __of_get_address(dev, index, -1, size, flags);
}
static inline const __be32 *of_get_pci_address(struct device_node *dev, int bar_no,
u64 *size, unsigned int *flags)
{
return __of_get_address(dev, -1, bar_no, size, flags);
}
static inline int of_address_count(struct device_node *np)
{
struct resource res;
int count = 0;
while (of_address_to_resource(np, count, &res) == 0)
count++;
return count;
}
#endif /* __OF_ADDRESS_H */