On Wed, Apr 27, 2016 at 03:26:59PM +0100, Lorenzo Pieralisi wrote: > On Tue, Apr 26, 2016 at 09:39:16PM -0500, Bjorn Helgaas wrote: > > On Fri, Apr 15, 2016 at 07:06:40PM +0200, Tomasz Nowicki wrote: > > > Platforms that have memory mapped IO port (such as ARM64) need special > > > handling for PCI I/O resources. For host bridge's resource probing case > > > these resources need to be fixed up with pci_register_io_range/pci_remap_iospace etc. > > > > ia64 also has memory-mapped I/O port space. It would be ideal to find > > some way to handle ia64 and ARM64 similarly. At the very least, we > > have to make sure that this doesn't break ia64. The ia64 dense/sparse > > I/O spaces complicate things; I don't know if ARM64 has something > > similar or not. > > No it does not, and that's exactly the same problem we faced with > the DT generic version of of_pci_range_to_resource() which basically > relies on PCI_IOBASE to be defined to add code that creates IO port > resources out of the MMIO resource describing how IO port space is > mapped to MMIO (physical) address space. > > IIRC everything hinges on PCI_IOBASE definition to make sure that > of_pci_range_to_resource() *works*, which means that if PCI_IOBASE is > not defined (ie IA64) that code - acpi_pci_root_remap_iospace() in this > case - does nothing. > > So acpi_pci_root_remap_iospace() is of_pci_range_to_resource() ACPI > equivalent + the pci_remap_iospace() call (I have to dig into the > logs to check why Liviu did not add a call to pci_remap_iospace() > in of_pci_get_host_bridge_resources() - I want to do that actually). Because of_pci_get_host_bridge_resources() only gives you a list of resources, it doesn't allocate them. An arch or platform could add further filtering to that list before it gets requested (in our case it is done in pci-host-common.c) Best regards, Liviu > > The point here is: IO space (in DT and ACPI) handling is arch specific. > > For DT, by relying on PCI_IOBASE, we left that code in drivers/of and > it works (well, with some niggles - see the thread with Murali on IO > space on TI keystone) for ARM/ARM64. > > http://www.spinics.net/lists/linux-pci/msg49725.html > > What are we going to do with the ACPI version ? > > Do we want to add an arch specific call that takes the raw resource > describing IO space and creates an IO port resource (and the MMIO > equivalent - that's what add_io_space() does in IA64) and use that > in generic ACPI parsing code ? > > Or we just do what Tomasz does, which is basically the approach we took > for DT ? > > > > Furthermore, the same I/O resources need to be released after hotplug > > > removal so that it can be re-added back by the pci_remap_iospace > > > function during insertion. Therefore we implement new pci_unmap_iospace call > > > which unmaps I/O space as the symmetry to pci_remap_iospace. > > > > "Furthermore" is a hint that we should check to see if this can be > > split into two patches. > > > > We already have a pci_remap_iospace(), and you're adding > > pci_unmap_iospace(), which will be used for hotplug removal. So let's > > add pci_unmap_iospace() first in a patch by itself because that's > > potentially useful for other callers of pci_remap_iospace(), even if > > they don't need the acpi_pci_root_remap_iospace() stuff. > > I agree. > > Thanks, > Lorenzo > > > > Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx> > > > Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx> > > > Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx> > > > --- > > > drivers/acpi/pci_root.c | 33 +++++++++++++++++++++++++++++++++ > > > drivers/pci/pci.c | 24 ++++++++++++++++++++++++ > > > include/linux/pci.h | 1 + > > > 3 files changed, 58 insertions(+) > > > > > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > > > index d9a70c4..815b6ca 100644 > > > --- a/drivers/acpi/pci_root.c > > > +++ b/drivers/acpi/pci_root.c > > > @@ -742,6 +742,34 @@ next: > > > resource_list_add_tail(entry, resources); > > > } > > > } > > > +static void acpi_pci_root_remap_iospace(struct resource_entry *entry) > > > +{ > > > +#ifdef PCI_IOBASE > > > + struct resource *res = entry->res; > > > + resource_size_t cpu_addr = res->start; > > > + resource_size_t pci_addr = cpu_addr - entry->offset; > > > + resource_size_t length = resource_size(res); > > > + unsigned long port; > > > + > > > + if (pci_register_io_range(cpu_addr, length)) > > > + goto err; > > > + > > > + port = pci_address_to_pio(cpu_addr); > > > + if (port == (unsigned long)-1) > > > + goto err; > > > + > > > + res->start = port; > > > + res->end = port + length - 1; > > > + entry->offset = port - pci_addr; > > > + > > > + if (pci_remap_iospace(res, cpu_addr) < 0) > > > + goto err; > > > + pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res); > > > + return; > > > +err: > > > + res->flags |= IORESOURCE_DISABLED; > > > +#endif > > > +} > > > > > > int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info) > > > { > > > @@ -763,6 +791,9 @@ int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info) > > > "no IO and memory resources present in _CRS\n"); > > > else { > > > resource_list_for_each_entry_safe(entry, tmp, list) { > > > + if (entry->res->flags & IORESOURCE_IO) > > > + acpi_pci_root_remap_iospace(entry); > > > + > > > if (entry->res->flags & IORESOURCE_DISABLED) > > > resource_list_destroy_entry(entry); > > > else > > > @@ -834,6 +865,8 @@ static void acpi_pci_root_release_info(struct pci_host_bridge *bridge) > > > > > > resource_list_for_each_entry(entry, &bridge->windows) { > > > res = entry->res; > > > + if (res->flags & IORESOURCE_IO) > > > + pci_unmap_iospace(res); > > > if (res->parent && > > > (res->flags & (IORESOURCE_MEM | IORESOURCE_IO))) > > > release_resource(res); > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > index 89e9996..c0f8a4e 100644 > > > --- a/drivers/pci/pci.c > > > +++ b/drivers/pci/pci.c > > > @@ -26,6 +26,7 @@ > > > #include <linux/device.h> > > > #include <linux/pm_runtime.h> > > > #include <linux/pci_hotplug.h> > > > +#include <linux/vmalloc.h> > > > #include <asm/setup.h> > > > #include <linux/aer.h> > > > #include "pci.h" > > > @@ -3168,6 +3169,29 @@ int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > > > #endif > > > } > > > > > > +/** > > > + * pci_unmap_iospace - Unmap the memory mapped I/O space > > > + * @res: resource to be unmapped > > > + * > > > + * Unmap the CPU virtual address @res from virtual address space. > > > + * Only architectures that have memory mapped IO functions defined > > > + * (and the PCI_IOBASE value defined) should call this function. > > > + */ > > > +void pci_unmap_iospace(struct resource *res) > > > +{ > > > +#if defined(PCI_IOBASE) && defined(CONFIG_MMU) > > > + unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; > > > + > > > + unmap_kernel_range(vaddr, resource_size(res)); > > > +#else > > > + /* > > > + * This architecture does not have memory mapped I/O space, > > > + * so this function should never be called. > > > + */ > > > + WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); > > > +#endif > > > +} > > > + > > > static void __pci_set_master(struct pci_dev *dev, bool enable) > > > { > > > u16 old_cmd, cmd; > > > diff --git a/include/linux/pci.h b/include/linux/pci.h > > > index c28adb4..df1f33d 100644 > > > --- a/include/linux/pci.h > > > +++ b/include/linux/pci.h > > > @@ -1168,6 +1168,7 @@ int pci_register_io_range(phys_addr_t addr, resource_size_t size); > > > unsigned long pci_address_to_pio(phys_addr_t addr); > > > phys_addr_t pci_pio_to_address(unsigned long pio); > > > int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr); > > > +void pci_unmap_iospace(struct resource *res); > > > > > > static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar) > > > { > > > -- > > > 1.9.1 > > > > > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! 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