On Tue, Nov 01, 2016 at 09:28:45PM +0800, zhichang.yuan wrote:
> Currently if the range property is not specified of_translate_one
> returns an error. There are some special devices that work on a
> range of I/O ports where it's is not correct to specify a range
> property as the cpu addresses are used by special accessors.
> Here we add a new exception in of_translate_one to return
> the cpu address if the range property is not there. The exception
> checks if the parent bus is ISA and if the special accessors are
> defined.
Using "()" after function names helps distinguish them from text.
s/it's is/it's/
I haven't been paying attention, so I missed the context. But "as the
cpu addresses are used by special accessors" doesn't really make sense
to me. In general, *most* acccessors use CPU addresses, i.e.,
resource addresses. Accessors don't use bus addresses because we may
have multiple instances of a bus, and we may reuse bus address ranges
on the different instances.
In the patch, I see a check for "parent bus is ISA"
("of_bus_isa_match(parent)"), but I don't see the check for whether
the special accessors are defined, so I can't quite connect the dots.
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Signed-off-by: zhichang.yuan <yuanzhichang@xxxxxxxxxxxxx>
> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/io.h | 7 +++++++
> arch/arm64/kernel/extio.c | 24 +++++++++++++++++++++++
> drivers/of/address.c | 47 +++++++++++++++++++++++++++++++++++++++++++--
> drivers/pci/pci.c | 6 +++---
> include/linux/of_address.h | 17 ++++++++++++++++
> 5 files changed, 96 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
> index 136735d..e480199 100644
> --- a/arch/arm64/include/asm/io.h
> +++ b/arch/arm64/include/asm/io.h
> @@ -175,6 +175,13 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)
> #define outsl outsl
>
> DECLARE_EXTIO(l, u32)
> +
> +
> +#define indirect_io_ison indirect_io_ison
> +extern int indirect_io_ison(void);
This makes it look like "ison" is some new word I'm not familiar with.
"indirect_io_is_on()" or even "indirect_io_enabled()" would be more
readable.
> +
> +#define chk_indirect_range chk_indirect_range
> +extern int chk_indirect_range(u64 taddr);
> #endif
>
>
> diff --git a/arch/arm64/kernel/extio.c b/arch/arm64/kernel/extio.c
> index 80cafd5..55df8dc 100644
> --- a/arch/arm64/kernel/extio.c
> +++ b/arch/arm64/kernel/extio.c
> @@ -19,6 +19,30 @@
>
> struct extio_ops *arm64_extio_ops;
>
> +/**
> + * indirect_io_ison - check whether indirectIO can work well. This function only call
> + * before the target I/O address was obtained.
> + *
> + * Returns 1 when indirectIO can work.
> + */
> +int indirect_io_ison()
> +{
> + return arm64_extio_ops ? 1 : 0;
> +}
> +
> +/**
> + * check_indirect_io - check whether the input taddr is for indirectIO.
Comment name ("check_indirect_io") doesn't match actual function name
("chk_indirect_range").
One of my pet peeves: "check" is completely worthless as part of a
function name because it doesn't help the reader figure out the sense
of the result. What does a "true" result mean? Name it something
like "address_is_indirect()" so it reads naturally when the caller
does something like "if (address_is_indirect())"
> + * @taddr: the io address to be checked.
> + *
> + * Returns 1 when taddr is in the range; otherwise return 0.
> + */
> +int chk_indirect_range(u64 taddr)
> +{
> + if (arm64_extio_ops->start > taddr || arm64_extio_ops->end < taddr)
> + return 0;
> +
> + return 1;
> +}
>
> BUILD_EXTIO(b, u8)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 02b2903..0bee822 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -479,6 +479,39 @@ static int of_empty_ranges_quirk(struct device_node *np)
> return false;
> }
>
> +
> +/*
> + * Check whether the current device being translating use indirectIO.
What does "the current device" mean? I assume you're talking about
"any device on 'bus'"? And apparently the caller is inquiring about a
particular address, too?
> + * return 1 if the check is past, or 0 represents fail checking.
This doesn't really make sense. I assume you mean something like
"return 1 if 'address' uses indirectIO; 0 otherwise"?
> + */
> +static int of_isa_indirect_io(struct device_node *parent,
> + struct of_bus *bus, __be32 *addr,
> + int na, u64 *presult)
> +{
> + unsigned int flags;
> + unsigned int rlen;
> +
> + /* whether support indirectIO */
> + if (!indirect_io_ison())
> + return 0;
> +
> + if (!of_bus_isa_match(parent))
> + return 0;
> +
> + flags = bus->get_flags(addr);
> + if (!(flags & IORESOURCE_IO))
> + return 0;
> +
> + /* there is ranges property, apply the normal translation directly. */
> + if (of_get_property(parent, "ranges", &rlen))
> + return 0;
> +
> + *presult = of_read_number(addr + 1, na - 1);
> +
> + return chk_indirect_range(*presult);
> +}
> +
> static int of_translate_one(struct device_node *parent, struct of_bus *bus,
> struct of_bus *pbus, __be32 *addr,
> int na, int ns, int pna, const char *rprop)
> @@ -532,7 +565,7 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
> }
> memcpy(addr, ranges + na, 4 * pna);
>
> - finish:
> +finish:
> of_dump_addr("parent translation for:", addr, pna);
> pr_debug("with offset: %llx\n", (unsigned long long)offset);
>
> @@ -595,6 +628,15 @@ static u64 __of_translate_address(struct device_node *dev,
> result = of_read_number(addr, na);
> break;
> }
> + /*
> + * For indirectIO device which has no ranges property, get
> + * the address from reg directly.
> + */
> + if (of_isa_indirect_io(dev, bus, addr, na, &result)) {
> + pr_info("isa indirectIO matched(%s)..addr = 0x%llx\n",
> + of_node_full_name(dev), result);
> + break;
> + }
>
> /* Get new parent bus and counts */
> pbus = of_match_bus(parent);
> @@ -688,8 +730,9 @@ static int __of_address_to_resource(struct device_node *dev,
> if (taddr == OF_BAD_ADDR)
> return -EINVAL;
> memset(r, 0, sizeof(struct resource));
> - if (flags & IORESOURCE_IO) {
> + if (flags & IORESOURCE_IO && taddr >= PCIBIOS_MIN_IO) {
> unsigned long port;
> +
> port = pci_address_to_pio(taddr);
> if (port == (unsigned long)-1)
> return -EINVAL;
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index ba34907..1a08511 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3263,7 +3263,7 @@ int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
>
> #ifdef PCI_IOBASE
> struct io_range *range;
> - resource_size_t allocated_size = 0;
> + resource_size_t allocated_size = PCIBIOS_MIN_IO;
I don't understand what's going on here. PCIBIOS_MIN_IO is an
*address*, so you're setting a *size* to an address. Maybe this just
needs an explanation. The connection to the rest of this patch isn't
obvious. If it could be split to a separate patch, so much the
better; then you'd have a nice place to describe it.
> /* check if the range hasn't been previously recorded */
> spin_lock(&io_range_lock);
> @@ -3312,7 +3312,7 @@ phys_addr_t pci_pio_to_address(unsigned long pio)
>
> #ifdef PCI_IOBASE
> struct io_range *range;
> - resource_size_t allocated_size = 0;
> + resource_size_t allocated_size = PCIBIOS_MIN_IO;
>
> if (pio > IO_SPACE_LIMIT)
> return address;
> @@ -3335,7 +3335,7 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address)
> {
> #ifdef PCI_IOBASE
> struct io_range *res;
> - resource_size_t offset = 0;
> + resource_size_t offset = PCIBIOS_MIN_IO;
> unsigned long addr = -1;
>
> spin_lock(&io_range_lock);
> diff --git a/include/linux/of_address.h b/include/linux/of_address.h
> index 3786473..0ba7e21 100644
> --- a/include/linux/of_address.h
> +++ b/include/linux/of_address.h
> @@ -24,6 +24,23 @@ struct of_pci_range {
> #define for_each_of_pci_range(parser, range) \
> for (; of_pci_range_parser_one(parser, range);)
>
> +
> +#ifndef indirect_io_ison
> +#define indirect_io_ison indirect_io_ison
> +static inline int indirect_io_ison(void)
> +{
> + return 0;
> +}
> +#endif
> +
> +#ifndef chk_indirect_range
> +#define chk_indirect_range chk_indirect_range
> +static inline int chk_indirect_range(u64 taddr)
> +{
> + return 0;
> +}
> +#endif
> +
> /* Translate a DMA address from device space to CPU space */
> extern u64 of_translate_dma_address(struct device_node *dev,
> const __be32 *in_addr);
> --
> 1.9.1
>
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