> -----Original Message----- > From: Dan Williams <[email protected]> > Sent: Wednesday, 1 April 2020 7:49 PM > To: Alastair D'Silva <[email protected]> > Cc: Aneesh Kumar K . V <[email protected]>; Oliver O'Halloran > <[email protected]>; Benjamin Herrenschmidt > <[email protected]>; Paul Mackerras <[email protected]>; Michael > Ellerman <[email protected]>; Frederic Barrat <[email protected]>; > Andrew Donnellan <[email protected]>; Arnd Bergmann > <[email protected]>; Greg Kroah-Hartman <[email protected]>; > Vishal Verma <[email protected]>; Dave Jiang > <[email protected]>; Ira Weiny <[email protected]>; Andrew Morton > <[email protected]>; Mauro Carvalho Chehab > <[email protected]>; David S. Miller <[email protected]>; > Rob Herring <[email protected]>; Anton Blanchard <[email protected]>; > Krzysztof Kozlowski <[email protected]>; Mahesh Salgaonkar > <[email protected]>; Madhavan Srinivasan > <[email protected]>; Cédric Le Goater <[email protected]>; Anju T > Sudhakar <[email protected]>; Hari Bathini > <[email protected]>; Thomas Gleixner <[email protected]>; Greg > Kurz <[email protected]>; Nicholas Piggin <[email protected]>; Masahiro > Yamada <[email protected]>; Alexey Kardashevskiy > <[email protected]>; Linux Kernel Mailing List <[email protected]>; > linuxppc-dev <[email protected]>; linux-nvdimm <linux- > [email protected]>; Linux MM <[email protected]> > Subject: Re: [PATCH v4 07/25] ocxl: Add functions to map/unmap LPC > memory > > On Sun, Mar 29, 2020 at 10:23 PM Alastair D'Silva <[email protected]> > wrote: > > > > Add functions to map/unmap LPC memory > > > > "map memory" is an overloaded term. I'm guessing this patch has nothing to > do with mapping memory in the MMU. Is it updating hardware resource > decoders to start claiming address space that was allocated previously? >
It's similar to MMIO - these calls end up setting up a BAR which places the LPC memory into a physical memory range addressable by the kernel. > > Signed-off-by: Alastair D'Silva <[email protected]> > > Acked-by: Frederic Barrat <[email protected]> > > --- > > drivers/misc/ocxl/core.c | 51 +++++++++++++++++++++++++++++++ > > drivers/misc/ocxl/ocxl_internal.h | 3 ++ > > include/misc/ocxl.h | 21 +++++++++++++ > > 3 files changed, 75 insertions(+) > > > > diff --git a/drivers/misc/ocxl/core.c b/drivers/misc/ocxl/core.c index > > 2531c6cf19a0..75ff14e3882a 100644 > > --- a/drivers/misc/ocxl/core.c > > +++ b/drivers/misc/ocxl/core.c > > @@ -210,6 +210,56 @@ static void unmap_mmio_areas(struct ocxl_afu > *afu) > > release_fn_bar(afu->fn, afu->config.global_mmio_bar); } > > > > +int ocxl_afu_map_lpc_mem(struct ocxl_afu *afu) { > > + struct pci_dev *dev = to_pci_dev(afu->fn->dev.parent); > > + > > + if ((afu->config.lpc_mem_size + afu- > >config.special_purpose_mem_size) == 0) > > + return 0; > > + > > + afu->lpc_base_addr = ocxl_link_lpc_map(afu->fn->link, dev); > > + if (afu->lpc_base_addr == 0) > > + return -EINVAL; > > + > > + if (afu->config.lpc_mem_size > 0) { > > + afu->lpc_res.start = afu->lpc_base_addr + afu- > >config.lpc_mem_offset; > > + afu->lpc_res.end = afu->lpc_res.start + > > afu->config.lpc_mem_size > - 1; > > + } > > + > > + if (afu->config.special_purpose_mem_size > 0) { > > + afu->special_purpose_res.start = afu->lpc_base_addr + > > + > > afu->config.special_purpose_mem_offset; > > + afu->special_purpose_res.end = > > afu->special_purpose_res.start + > > + > > afu->config.special_purpose_mem_size - 1; > > + } > > + > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(ocxl_afu_map_lpc_mem); > > + > > +struct resource *ocxl_afu_lpc_mem(struct ocxl_afu *afu) { > > + return &afu->lpc_res; > > +} > > +EXPORT_SYMBOL_GPL(ocxl_afu_lpc_mem); > > + > > +static void unmap_lpc_mem(struct ocxl_afu *afu) { > > + struct pci_dev *dev = to_pci_dev(afu->fn->dev.parent); > > + > > + if (afu->lpc_res.start || afu->special_purpose_res.start) { > > + void *link = afu->fn->link; > > + > > + // only release the link when the the last consumer calls > > release > > + ocxl_link_lpc_release(link, dev); > > + > > + afu->lpc_res.start = 0; > > + afu->lpc_res.end = 0; > > + afu->special_purpose_res.start = 0; > > + afu->special_purpose_res.end = 0; > > + } > > +} > > + > > static int configure_afu(struct ocxl_afu *afu, u8 afu_idx, struct > > pci_dev *dev) { > > int rc; > > @@ -251,6 +301,7 @@ static int configure_afu(struct ocxl_afu *afu, u8 > > afu_idx, struct pci_dev *dev) > > > > static void deconfigure_afu(struct ocxl_afu *afu) { > > + unmap_lpc_mem(afu); > > unmap_mmio_areas(afu); > > reclaim_afu_pasid(afu); > > reclaim_afu_actag(afu); > > diff --git a/drivers/misc/ocxl/ocxl_internal.h > > b/drivers/misc/ocxl/ocxl_internal.h > > index 2d7575225bd7..7b975a89db7b 100644 > > --- a/drivers/misc/ocxl/ocxl_internal.h > > +++ b/drivers/misc/ocxl/ocxl_internal.h > > @@ -52,6 +52,9 @@ struct ocxl_afu { > > void __iomem *global_mmio_ptr; > > u64 pp_mmio_start; > > void *private; > > + u64 lpc_base_addr; /* Covers both LPC & special purpose memory */ > > + struct resource lpc_res; > > + struct resource special_purpose_res; > > }; > > > > enum ocxl_context_status { > > diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h index > > 357ef1aadbc0..d8b0b4d46bfb 100644 > > --- a/include/misc/ocxl.h > > +++ b/include/misc/ocxl.h > > @@ -203,6 +203,27 @@ int ocxl_irq_set_handler(struct ocxl_context > > *ctx, int irq_id, > > > > // AFU Metadata > > > > +/** > > + * ocxl_afu_map_lpc_mem() - Map the LPC system & special purpose > > +memory for an AFU > > + * Do not call this during device discovery, as there may me multiple > > s/me/be/ > > > > + * devices on a link, and the memory is mapped for the whole link, > > +not > > + * just one device. It should only be called after all devices have > > + * registered their memory on the link. > > + * > > + * @afu: The AFU that has the LPC memory to map > > + * > > + * Returns 0 on success, negative on failure */ int > > +ocxl_afu_map_lpc_mem(struct ocxl_afu *afu); > > + > > +/** > > + * ocxl_afu_lpc_mem() - Get the physical address range of LPC memory > > +for an AFU > > + * @afu: The AFU associated with the LPC memory > > + * > > + * Returns a pointer to the resource struct for the physical address > > +range */ struct resource *ocxl_afu_lpc_mem(struct ocxl_afu *afu); > > + > > /** > > * ocxl_afu_config() - Get a pointer to the config for an AFU > > * @afu: a pointer to the AFU to get the config for > > -- > > 2.24.1 > > -- Alastair D'Silva mob: 0423 762 819 skype: alastair_dsilva msn: [email protected] blog: http://alastair.d-silva.org Twitter: @EvilDeece _______________________________________________ Linux-nvdimm mailing list -- [email protected] To unsubscribe send an email to [email protected]
