Hi Cov > -----Original Message----- > From: linux-pci-owner@xxxxxxxxxxxxxxx [mailto:linux-pci- > owner@xxxxxxxxxxxxxxx] On Behalf Of Christopher Covington > Sent: 03 June 2016 16:15 > To: Tomasz Nowicki; helgaas@xxxxxxxxxx; arnd@xxxxxxxx; > will.deacon@xxxxxxx; catalin.marinas@xxxxxxx; rafael@xxxxxxxxxx; > hanjun.guo@xxxxxxxxxx; Lorenzo.Pieralisi@xxxxxxx; okaya@xxxxxxxxxxxxxx; > jchandra@xxxxxxxxxxxx > Cc: jcm@xxxxxxxxxx; linaro-acpi@xxxxxxxxxxxxxxxx; linux- > pci@xxxxxxxxxxxxxxx; dhdang@xxxxxxx; Liviu.Dudau@xxxxxxx; > ddaney@xxxxxxxxxxxxxxxxxx; jeremy.linton@xxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; > robert.richter@xxxxxxxxxxxxxxxxxx; Suravee.Suthikulpanit@xxxxxxx; > msalter@xxxxxxxxxx; Wangyijing; mw@xxxxxxxxxxxx; > andrea.gallo@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > liudongdong (C); Gabriele Paoloni > Subject: Re: [RFC PATCH 1/3] pci, acpi: Match PCI config space > accessors against platfrom specific ECAM quirks. > > Hi Tomasz, > > Thanks for your work on this. > > On 06/02/2016 04:41 AM, Tomasz Nowicki wrote: > > Some platforms may not be fully compliant with generic set of PCI > config > > accessors. For these cases we implement the way to overwrite > accessors > > set. Algorithm traverses available quirk list, matches against > > <oem_id, oem_rev, domain, bus number> tuple and returns corresponding > > PCI config ops. oem_id and oem_rev come from MCFG table standard > header. > > All quirks can be defined using DECLARE_ACPI_MCFG_FIXUP() macro and > > kept self contained. Example: > > > > /* Custom PCI config ops */ > > static struct pci_generic_ecam_ops foo_pci_ops = { > > .bus_shift = 24, > > .pci_ops = { > > .map_bus = pci_ecam_map_bus, > > .read = foo_ecam_config_read, > > .write = foo_ecam_config_write, > > } > > }; > > > > DECLARE_ACPI_MCFG_FIXUP(&foo_pci_ops, <oem_id_str>, <oem_rev>, > <domain_nr>, <bus_nr>); > > > > Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx> > > --- > > drivers/acpi/pci_mcfg.c | 32 > ++++++++++++++++++++++++++++++++ > > include/asm-generic/vmlinux.lds.h | 7 +++++++ > > include/linux/pci-acpi.h | 19 +++++++++++++++++++ > > 3 files changed, 58 insertions(+) > > > > diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c > > index 1847f74..f3d4570 100644 > > --- a/drivers/acpi/pci_mcfg.c > > +++ b/drivers/acpi/pci_mcfg.c > > @@ -22,11 +22,43 @@ > > #include <linux/kernel.h> > > #include <linux/pci.h> > > #include <linux/pci-acpi.h> > > +#include <linux/pci-ecam.h> > > > > /* Root pointer to the mapped MCFG table */ > > static struct acpi_table_mcfg *mcfg_table; > > static int mcfg_entries; > > > > +extern struct pci_cfg_fixup __start_acpi_mcfg_fixups[]; > > +extern struct pci_cfg_fixup __end_acpi_mcfg_fixups[]; > > + > > +struct pci_ecam_ops *pci_mcfg_get_ops(struct acpi_pci_root *root) > > +{ > > + int bus_num = root->secondary.start; > > + int domain = root->segment; > > + struct pci_cfg_fixup *f; > > + > > + if (!mcfg_table) > > + return &pci_generic_ecam_ops; > > + > > + /* > > + * Match against platform specific quirks and return > corresponding > > + * CAM ops. > > + * > > + * First match against PCI topology <domain:bus> then use OEM ID > and > > + * OEM revision from MCFG table standard header. > > + */ > > + for (f = __start_acpi_mcfg_fixups; f < __end_acpi_mcfg_fixups; > f++) { > > + if ((f->domain == domain || f->domain == > PCI_MCFG_DOMAIN_ANY) && > > + (f->bus_num == bus_num || f->bus_num == > PCI_MCFG_BUS_ANY) && > > + (!strncmp(f->oem_id, mcfg_table->header.oem_id, > > + ACPI_OEM_ID_SIZE)) && > > + (f->oem_revision == mcfg_table->header.oem_revision)) > > Is this more likely to be updated between quirky and fixed platforms > than oem_table_id? What do folks think about using oem_table_id instead > of, or in addition to, oem_revision? >From my understanding we need to stick to this mechanism as (otherwise) there are platforms out in the field that would need a FW update. So I don't think that using oem_table_id "instead" is possible; about "in addition" I think it is doable, but I do not see the advantage much. I mean that if a platform gets fixed the oem revision should change too, Right? Thanks Gab > > In case these details are helpful, here was my simple prototype of an > MCFG based approach: > > https://codeaurora.org/cgit/quic/server/kernel/commit/?h=cov/4.7-rc1- > testing&id=c5d8bc49a198fd8f61f82c7d8f169564d6176b07 > https://codeaurora.org/cgit/quic/server/kernel/commit/?h=cov/4.7-rc1- > testing&id=50bfe77ccd1639e6ce8c7c4fcca187d50e0bead4 > > Thanks, > Cov > > -- > Qualcomm Innovation Center, Inc. > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > a Linux Foundation Collaborative Project > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
