Messages in this thread | | | From | John Garry <> | Subject | Re: [PATCH v4 1/3] lib: logic_pio: Use logical PIO low-level accessors for !CONFIG_INDIRECT_PIO | Date | Thu, 13 Jun 2019 10:39:12 +0100 |
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On 13/06/2019 03:39, Bjorn Helgaas wrote: > On Tue, Jun 11, 2019 at 10:12:52PM +0800, John Garry wrote: >> Currently we only use logical PIO low-level accessors for when >> CONFIG_INDIRECT_PIO is enabled. >> >> Otherwise we just use inb/out et all directly. >>
Hi Bjorn,
thanks for checking this.
>> It is useful to now use logical PIO accessors for all cases, so we can add >> legality checks to accesses. Such a check would be for ensuring that the >> PCI IO port has been IO remapped prior to the access. > > IIUC, *this* patch doesn't actually add any
ok, fine. I suppose that the subsequent patches in the series describe the motivation.
additional checks, so no > need to mention that in this commit log. > > One thing this patch *does* do is "#define inb logic_inb" whenever > PCI_IOBASE is defined (we used to do that #define only when > CONFIG_INDIRECT_PIO was defined).
Yes, right.
> That's a pretty important change and needs to be very clear in the commit log.
ok
> > I'm not sure it's even safe, because CONFIG_INDIRECT_PIO depends on > ARM64, but PCI_IOBASE is defined on most arches via asm-generic/io.h, > so this potentially affects arches other than ARM64.
It would do. It would affect any arch which defines PCI_IOBASE and does not have arch-specific definition of inb et all.
> > If possible, split out the cleanup patches as below and make the patch > that does this PCI_IOBASE change as small as possible so we can > evaluate that change by itself. >
Fine
>> Using the logical PIO accesses will add a little processing overhead, but >> that's ok as IO port accesses are relatively slow anyway. >> >> Some changes are also made to stop spilling so many lines under >> CONFIG_INDIRECT_PIO. > > "Some changes are also made" is a good hint to me that this patch > might be able to be split up :) > >> Signed-off-by: John Garry <john.garry@huawei.com> >> --- >> include/linux/logic_pio.h | 7 ++-- >> lib/logic_pio.c | 83 ++++++++++++++++++++++++++++----------- >> 2 files changed, 63 insertions(+), 27 deletions(-) >> >> diff --git a/include/linux/logic_pio.h b/include/linux/logic_pio.h >> index cbd9d8495690..06d22b2ec99f 100644 >> --- a/include/linux/logic_pio.h >> +++ b/include/linux/logic_pio.h >> @@ -37,7 +37,7 @@ struct logic_pio_host_ops { >> size_t dwidth, unsigned int count); >> }; >> >> -#ifdef CONFIG_INDIRECT_PIO >> +#if defined(PCI_IOBASE) > > Why change the #ifdef style? I understand these are equivalent, but > unless there's a movement to change from "#ifdef X" to "#if defined(X)" > I wouldn't bother.
Not intentional. I can keep this style.
> >> u8 logic_inb(unsigned long addr); >> void logic_outb(u8 value, unsigned long addr); >> void logic_outw(u16 value, unsigned long addr); >> @@ -102,6 +102,7 @@ void logic_outsl(unsigned long addr, const void *buffer, unsigned int count); >> #define outsl logic_outsl >> #endif >> >> +#if defined(CONFIG_INDIRECT_PIO) >> /* >> * We reserve 0x4000 bytes for Indirect IO as so far this library is only >> * used by the HiSilicon LPC Host. If needed, we can reserve a wider IO >> @@ -109,10 +110,10 @@ void logic_outsl(unsigned long addr, const void *buffer, unsigned int count); >> */ >> #define PIO_INDIRECT_SIZE 0x4000 >> #define MMIO_UPPER_LIMIT (IO_SPACE_LIMIT - PIO_INDIRECT_SIZE) >> -#else >> +#else /* CONFIG_INDIRECT_PIO */ >> #define MMIO_UPPER_LIMIT IO_SPACE_LIMIT >> #endif /* CONFIG_INDIRECT_PIO */ >> - >> +#endif /* PCI_IOBASE */ >> struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode); >> unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode, >> resource_size_t hw_addr, resource_size_t size); >> diff --git a/lib/logic_pio.c b/lib/logic_pio.c >> index feea48fd1a0d..40d9428010e1 100644 >> --- a/lib/logic_pio.c >> +++ b/lib/logic_pio.c >> @@ -191,7 +191,8 @@ unsigned long logic_pio_trans_cpuaddr(resource_size_t addr) >> return ~0UL; >> } >> >> -#if defined(CONFIG_INDIRECT_PIO) && defined(PCI_IOBASE) >> +#if defined(PCI_IOBASE) >> +#if defined(CONFIG_INDIRECT_PIO) >> #define BUILD_LOGIC_IO(bw, type) \ >> type logic_in##bw(unsigned long addr) \ >> { \ >> @@ -200,11 +201,11 @@ type logic_in##bw(unsigned long addr) \ >> if (addr < MMIO_UPPER_LIMIT) { \ >> ret = read##bw(PCI_IOBASE + addr); \ >> } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \ >> - struct logic_pio_hwaddr *entry = find_io_range(addr); \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + size_t sz = sizeof(type); \ > > I don't mind changing "entry" to "range" and adding "sz". But that > could be done in a separate "no functional change" patch that is > trivial to review, which would make *this* patch smaller and easier to > review.
ok
> > Another "no functional change" simplification patch would be to > replace this: > > type ret = (type)~0; > > if (addr < MMIO_UPPER_LIMIT) { > ret = read##bw(...); > } else if (...) { > if (range && range->ops) > ret = range->ops->in(...); > else > WARN_ON_ONCE(); > } > return ret; > > with this: > > if (addr < MMIO_UPPER_LIMIT) > return read##bw(...); > > if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { > if (range && range->ops) > return range->ops->in(...); > else > WARN_ON_ONCE(); > } > > return (type)~0; > > Finally, I think the end result would be a little easier to read if > you restructured the #ifdefs like this: > > #ifdef PCI_IOBASE > #define BUILD_LOGIC_IO(...) > type logic_in##bw(...) > { > if (addr < MMIO_UPPER_LIMIT) > return read##bw(...); > > #ifdef CONFIG_INDIRECT_PIO
I get your idea, but I don't think that that we can have an ifdef in macros (BUILD_LOGIC_IO) like this.
> if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { > if (range && range->ops) > return range->ops->in(...); > else > WARN_ON_ONCE(); > } > #endif > > return (type)~0; > } > > That does mean a CONFIG_INDIRECT_PIO #ifdef in each in/out/ins/outs > builder, but it's more localized so I think it's easier to understand > that INDIRECT_PIO is just adding a new case to the default path.
I'll see what I can do to improve the flow. But any change would also depend on your idea in response to patch v2, to unify the 2 types of logic_inb.
> >> - if (entry && entry->ops) \ >> - ret = entry->ops->in(entry->hostdata, \ >> - addr, sizeof(type)); \ >> + if (range && range->ops) \ >> + ret = range->ops->in(range->hostdata, addr, sz);\ >> else \ >> WARN_ON_ONCE(1); \ >> } \ >> @@ -216,49 +217,83 @@ void logic_out##bw(type value, unsigned long addr) \ >> if (addr < MMIO_UPPER_LIMIT) { \ >> write##bw(value, PCI_IOBASE + addr); \
thanks again
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