Re: [PATCH v5 2/3] of/pci: Provide support for parsing PCI DT rangesproperty

From: Rob Herring
Date: Wed Apr 10 2013 - 14:26:14 EST

On 04/10/2013 02:29 AM, Andrew Murray wrote:
> This patch factors out common implementation patterns to reduce overall kernel
> code and provide a means for host bridge drivers to directly obtain struct
> resources from the DT's ranges property without relying on architecture specific
> DT handling. This will make it easier to write archiecture independent host bridge
> drivers and mitigate against further duplication of DT parsing code.
>
> This patch can be used in the following way:
>
> struct of_pci_range_parser parser;
> struct of_pci_range range;
>
> if (of_pci_range_parser(&parser, np))
> ; //no ranges property
>
> for_each_of_pci_range(&parser, &range) {
>
> /*
> directly access properties of the address range, e.g.:
> range.pci_space, range.pci_addr, range.cpu_addr,
> range.size, range.flags
>
> alternatively obtain a struct resource, e.g.:
> struct resource res;
> of_pci_range_to_resource(&range, np, &res);
> */
> }
>
> Additionally the implementation takes care of adjacent ranges and merges them
> into a single range (as was the case with powerpc and microblaze).
>
> Signed-off-by: Andrew Murray <Andrew.Murray@xxxxxxx>
> Signed-off-by: Liviu Dudau <Liviu.Dudau@xxxxxxx>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
> ---

A few minor things below, otherwise:

Reviewed-by: Rob Herring <rob.herring@xxxxxxxxxxx>

> drivers/of/address.c | 63 +++++++++++++++++++++++++
> drivers/of/of_pci.c | 112 ++++++++++++++++----------------------------
> include/linux/of_address.h | 42 ++++++++++++++++
> 3 files changed, 145 insertions(+), 72 deletions(-)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 04da786..e87f45e 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -227,6 +227,69 @@ int of_pci_address_to_resource(struct device_node *dev, int bar,
> return __of_address_to_resource(dev, addrp, size, flags, NULL, r);
> }
> EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
> +
> +int of_pci_range_parser(struct of_pci_range_parser *parser,
> + struct device_node *node)
> +{
> + const int na = 3, ns = 2;
> + int rlen;
> +
> + parser->node = node;
> + parser->pna = of_n_addr_cells(node);
> + parser->np = parser->pna + na + ns;
> +
> + parser->range = of_get_property(node, "ranges", &rlen);
> + if (parser->range == NULL)
> + return -ENOENT;
> +
> + parser->end = parser->range + rlen / sizeof(__be32);
> +
> + return 0;
> +}
> +
> +struct of_pci_range *of_pci_process_ranges(struct of_pci_range_parser *parser,
> + struct of_pci_range *range)
> +{
> + const int na = 3, ns = 2;
> +
> + if (!parser->range || parser->range + parser->np > parser->end)

Add a !range check

> + return NULL;
> +
> + range->pci_space = be32_to_cpup(parser->range);
> + range->flags = of_bus_pci_get_flags(parser->range);
> + range->pci_addr = of_read_number(parser->range + 1, ns);
> + range->cpu_addr = of_translate_address(parser->node,
> + parser->range + na);
> + range->size = of_read_number(parser->range + parser->pna + na, ns);
> +
> + parser->range += parser->np;
> +
> + /* Now consume following elements while they are contiguous */
> + while (parser->range + parser->np <= parser->end) {
> + u32 flags, pci_space;
> + u64 pci_addr, cpu_addr, size;
> +
> + pci_space = be32_to_cpup(parser->range);

This line doesn't do anything.

> + flags = of_bus_pci_get_flags(parser->range);
> + pci_addr = of_read_number(parser->range + 1, ns);
> + cpu_addr = of_translate_address(parser->node,
> + parser->range + na);
> + size = of_read_number(parser->range + parser->pna + na, ns);
> +
> + if (flags != range->flags)
> + break;
> + if (pci_addr != range->pci_addr + range->size ||
> + cpu_addr != range->cpu_addr + range->size)
> + break;
> +
> + range->size += size;
> + parser->range += parser->np;
> + }
> +
> + return range;
> +}
> +EXPORT_SYMBOL_GPL(of_pci_process_ranges);
> +
> #endif /* CONFIG_PCI */
>
> /*
> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> index 0611248..9680dc6 100644
> --- a/drivers/of/of_pci.c
> +++ b/drivers/of/of_pci.c
> @@ -82,67 +82,43 @@ EXPORT_SYMBOL_GPL(of_pci_find_child_device);
> void pci_process_bridge_OF_ranges(struct pci_controller *hose,
> struct device_node *dev, int primary)
> {
> - const u32 *ranges;
> - int rlen;
> - int pna = of_n_addr_cells(dev);
> - int np = pna + 5;
> int memno = 0, isa_hole = -1;
> - u32 pci_space;
> - unsigned long long pci_addr, cpu_addr, pci_next, cpu_next, size;
> unsigned long long isa_mb = 0;
> struct resource *res;
> + struct of_pci_range range;
> + struct of_pci_range_parser parser;
> + u32 res_type;
>
> pr_info("PCI host bridge %s %s ranges:\n",
> dev->full_name, primary ? "(primary)" : "");
>
> - /* Get ranges property */
> - ranges = of_get_property(dev, "ranges", &rlen);
> - if (ranges == NULL)
> + /* Check for ranges property */
> + if (of_pci_range_parser(&parser, dev))
> return;
>
> - /* Parse it */
> pr_debug("Parsing ranges property...\n");
> - while ((rlen -= np * 4) >= 0) {
> + for_each_of_pci_range(&parser, &range) {
> /* Read next ranges element */
> - pci_space = ranges[0];
> - pci_addr = of_read_number(ranges + 1, 2);
> - cpu_addr = of_translate_address(dev, ranges + 3);
> - size = of_read_number(ranges + pna + 3, 2);
> -
> - pr_debug("pci_space: 0x%08x pci_addr:0x%016llx ",
> - pci_space, pci_addr);
> - pr_debug("cpu_addr:0x%016llx size:0x%016llx\n",
> - cpu_addr, size);
> -
> - ranges += np;
> + pr_debug("pci_space: 0x%08x pci_addr: 0x%016llx ",
> + range.pci_space, range.pci_addr);
> + pr_debug("cpu_addr: 0x%016llx size: 0x%016llx\n",
> + range.cpu_addr, range.size);
>
> /* If we failed translation or got a zero-sized region
> * (some FW try to feed us with non sensical zero sized regions
> * such as power3 which look like some kind of attempt
> * at exposing the VGA memory hole)
> */
> - if (cpu_addr == OF_BAD_ADDR || size == 0)
> + if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
> continue;
>
> - /* Now consume following elements while they are contiguous */
> - for (; rlen >= np * sizeof(u32);
> - ranges += np, rlen -= np * 4) {
> - if (ranges[0] != pci_space)
> - break;
> - pci_next = of_read_number(ranges + 1, 2);
> - cpu_next = of_translate_address(dev, ranges + 3);
> - if (pci_next != pci_addr + size ||
> - cpu_next != cpu_addr + size)
> - break;
> - size += of_read_number(ranges + pna + 3, 2);
> - }
> -
> /* Act based on address space type */
> res = NULL;
> - switch ((pci_space >> 24) & 0x3) {
> - case 1: /* PCI IO space */
> + res_type = range.flags & IORESOURCE_TYPE_BITS;
> + if (res_type == IORESOURCE_IO) {
> pr_info(" IO 0x%016llx..0x%016llx -> 0x%016llx\n",
> - cpu_addr, cpu_addr + size - 1, pci_addr);
> + range.cpu_addr, range.cpu_addr + range.size - 1,
> + range.pci_addr);
>
> /* We support only one IO range */
> if (hose->pci_io_size) {
> @@ -151,11 +127,12 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
> }
> #if defined(CONFIG_PPC32) || defined(CONFIG_MICROBLAZE)
> /* On 32 bits, limit I/O space to 16MB */
> - if (size > 0x01000000)
> - size = 0x01000000;
> + if (range.size > 0x01000000)
> + range.size = 0x01000000;
>
> /* 32 bits needs to map IOs here */
> - hose->io_base_virt = ioremap(cpu_addr, size);
> + hose->io_base_virt = ioremap(range.cpu_addr,
> + range.size);
>
> /* Expect trouble if pci_addr is not 0 */
> if (primary)
> @@ -165,19 +142,18 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
> /* pci_io_size and io_base_phys always represent IO
> * space starting at 0 so we factor in pci_addr
> */
> - hose->pci_io_size = pci_addr + size;
> - hose->io_base_phys = cpu_addr - pci_addr;
> + hose->pci_io_size = range.pci_addr + range.size;
> + hose->io_base_phys = range.cpu_addr - range.pci_addr;
>
> /* Build resource */
> res = &hose->io_resource;
> - res->flags = IORESOURCE_IO;
> - res->start = pci_addr;
> - break;
> - case 2: /* PCI Memory space */
> - case 3: /* PCI 64 bits Memory space */
> + range.cpu_addr = range.pci_addr;
> + } else if (res_type == IORESOURCE_MEM) {
> pr_info(" MEM 0x%016llx..0x%016llx -> 0x%016llx %s\n",
> - cpu_addr, cpu_addr + size - 1, pci_addr,
> - (pci_space & 0x40000000) ? "Prefetch" : "");
> + range.cpu_addr, range.cpu_addr + range.size - 1,
> + range.pci_addr,
> + (range.pci_space & 0x40000000) ?
> + "Prefetch" : "");
>
> /* We support only 3 memory ranges */
> if (memno >= 3) {
> @@ -185,13 +161,13 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
> continue;
> }
> /* Handles ISA memory hole space here */
> - if (pci_addr == 0) {
> - isa_mb = cpu_addr;
> + if (range.pci_addr == 0) {
> + isa_mb = range.cpu_addr;
> isa_hole = memno;
> if (primary || isa_mem_base == 0)
> - isa_mem_base = cpu_addr;
> - hose->isa_mem_phys = cpu_addr;
> - hose->isa_mem_size = size;
> + isa_mem_base = range.cpu_addr;
> + hose->isa_mem_phys = range.cpu_addr;
> + hose->isa_mem_size = range.size;
> }
>
> /* We get the PCI/Mem offset from the first range or
> @@ -199,30 +175,22 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
> * hole. If they don't match, bugger.
> */
> if (memno == 0 ||
> - (isa_hole >= 0 && pci_addr != 0 &&
> + (isa_hole >= 0 && range.pci_addr != 0 &&
> hose->pci_mem_offset == isa_mb))
> - hose->pci_mem_offset = cpu_addr - pci_addr;
> - else if (pci_addr != 0 &&
> - hose->pci_mem_offset != cpu_addr - pci_addr) {
> + hose->pci_mem_offset = range.cpu_addr -
> + range.pci_addr;
> + else if (range.pci_addr != 0 &&
> + hose->pci_mem_offset != range.cpu_addr -
> + range.pci_addr) {
> pr_info(" \\--> Skipped (offset mismatch) !\n");
> continue;
> }
>
> /* Build resource */
> res = &hose->mem_resources[memno++];
> - res->flags = IORESOURCE_MEM;
> - if (pci_space & 0x40000000)
> - res->flags |= IORESOURCE_PREFETCH;
> - res->start = cpu_addr;
> - break;
> - }
> - if (res != NULL) {
> - res->name = dev->full_name;
> - res->end = res->start + size - 1;
> - res->parent = NULL;
> - res->sibling = NULL;
> - res->child = NULL;
> }
> + if (res != NULL)
> + of_pci_range_to_resource(&range, dev, res);
> }
>
> /* If there's an ISA hole and the pci_mem_offset is -not- matching
> diff --git a/include/linux/of_address.h b/include/linux/of_address.h
> index 0506eb5..c7003a3 100644
> --- a/include/linux/of_address.h
> +++ b/include/linux/of_address.h
> @@ -4,6 +4,32 @@
> #include <linux/errno.h>
> #include <linux/of.h>
>
> +struct of_pci_range_parser {
> + struct device_node *node;
> + const __be32 *range, *end;

Split these on to separate lines.

> + int np, pna;

ditto

> +};
> +
> +struct of_pci_range {
> + u32 pci_space;
> + u64 pci_addr;
> + u64 cpu_addr;
> + u64 size;
> + u32 flags;
> +};
> +
> +#define for_each_of_pci_range(parser, range) \
> + for (; of_pci_process_ranges(parser, range);)
> +
> +#define of_pci_range_to_resource(range, np, res) \

Why not a static inline here?

> + do { \
> + (res)->flags = (range)->flags; \
> + (res)->start = (range)->cpu_addr; \
> + (res)->end = (range)->cpu_addr + (range)->size - 1; \
> + (res)->parent = (res)->child = (res)->sibling = NULL; \
> + (res)->name = (np)->full_name; \
> + } while (0)
> +
> #ifdef CONFIG_OF_ADDRESS
> extern u64 of_translate_address(struct device_node *np, const __be32 *addr);
> extern bool of_can_translate_address(struct device_node *dev);
> @@ -27,6 +53,10 @@ static inline unsigned long pci_address_to_pio(phys_addr_t addr) { return -1; }
> #define pci_address_to_pio pci_address_to_pio
> #endif
>
> +int of_pci_range_parser(struct of_pci_range_parser *parser,
> + struct device_node *node);
> +struct of_pci_range *of_pci_process_ranges(struct of_pci_range_parser *parser,
> + struct of_pci_range *range);
> #else /* CONFIG_OF_ADDRESS */
> #ifndef of_address_to_resource
> static inline int of_address_to_resource(struct device_node *dev, int index,
> @@ -53,6 +83,18 @@ static inline const __be32 *of_get_address(struct device_node *dev, int index,
> {
> return NULL;
> }
> +
> +int of_pci_range_parser(struct of_pci_range_parser *parser,
> + struct device_noed *node)
> +{
> + return -1;
> +}
> +
> +struct of_pci_range *of_pci_process_ranges(struct of_pci_range_parser *parser,
> + struct of_pci_range *range)
> +{
> + return NULL;
> +}
> #endif /* CONFIG_OF_ADDRESS */
>
>
>

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