From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 33E3D16D9CB; Fri, 5 Apr 2024 14:10:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712326239; cv=none; b=gfN3ocnI9+HaNB6mEvDJ/CdsW+6Oa9kOQPhZyrvmKQxsZT0ZQNl4DBZ2/v8/DcPdzgu0YSadaWfhohEfhkaheVDBK6B+Df2nJnCC3aBX4UFZ+tBFgWoaObxnRmCcczAq6vslbWYcCLd5VSK25gfLq3q/ouzVXtUz0PVvL5LsRnY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712326239; c=relaxed/simple; bh=6sWHundRt9py16+WBy2EBbLSt7kiYgIblwW8lz5k9UQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Sl3vN0RAWG/ck3lGWM6k4F6hfBjiwDUJHXzt2ESrXXX+z43CTQ4m3aG4EyAKk0mewUtv6i5Yk99SfEqUO01KPvtAeFsff5nLtCHiS4ekCHeTlD4mjr/50j8ckcgFOoAROuwqmFkyqboTwvczGH4BprGRVp0U5TPItpykUbVLdvc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dYdJQTbt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dYdJQTbt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3AA58C433F1; Fri, 5 Apr 2024 14:10:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712326238; bh=6sWHundRt9py16+WBy2EBbLSt7kiYgIblwW8lz5k9UQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dYdJQTbtmhmWreOZBZxN5qpqdpgmCopUqgcBuklqrBbo5uG0iFj7oZ6yuSIu4poaP zpLnsBxPrV2yt/Cy8HvriOLxu2BwiIYeo5v9ydu+f0mHpU3NOIfat83RzJfGVlDACg KYn8lzCRW8DiUDkxhPU5Qi7chMeocdoo2ZCOpEUauLLCSGB1EaLI0SXQId+jvZAop8 8F1IqCN/EeunEHMy3tgkz0C0j0SZbbF2XeHPaCfohtieEKQcUMfqdYJEsReseBiP3z CYZp4mBuJbGV8jd6O1LEQmoKqam3aymIGiiKYdcj97Clhe9uESVQ53lNzUxxFiqRcs UG7GkaAKDpw6Q== Date: Fri, 5 Apr 2024 16:10:30 +0200 From: Niklas Cassel To: Damien Le Moal Cc: Manivannan Sadhasivam , Lorenzo Pieralisi , Kishon Vijay Abraham I , Shawn Lin , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Bjorn Helgaas , Heiko Stuebner , linux-pci@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Rick Wertenbroek , Wilfred Mallawa Subject: Re: [PATCH v2 03/18] PCI: endpoint: Introduce pci_epc_mem_map()/unmap() Message-ID: References: <20240330041928.1555578-1-dlemoal@kernel.org> <20240330041928.1555578-4-dlemoal@kernel.org> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240330041928.1555578-4-dlemoal@kernel.org> On Sat, Mar 30, 2024 at 01:19:13PM +0900, Damien Le Moal wrote: > Introduce the function pci_epc_mem_map() to facilitate controller memory > address allocation and mapping to a RC PCI address region in endpoint > function drivers. > > This function first uses pci_epc_map_align() to determine the controller > memory address alignment (offset and size) constraints. The result of > this function is used to allocate a controller physical memory region > using pci_epc_mem_alloc_addr() and map it to the RC PCI address > space with pci_epc_map_addr(). Since pci_epc_map_align() may indicate > that a mapping can be smaller than the requested size, pci_epc_mem_map() > may only partially map the RC PCI address region specified and return > a smaller size for the effective mapping. > > The counterpart of pci_epc_mem_map() to unmap and free the controller > memory address region is pci_epc_mem_unmap(). > > Both functions operate using struct pci_epc_map data structure which is > extended to contain the physical and virtual addresses of the allocated > controller memory. Endpoint function drivers can use struct pci_epc_map > to implement read/write accesses within the mapped RC PCI address region > using the ->virt_addr and ->size fields. > > This commit contains contributions from Rick Wertenbroek > . > > Signed-off-by: Damien Le Moal > --- > drivers/pci/endpoint/pci-epc-core.c | 68 +++++++++++++++++++++++++++++ > include/linux/pci-epc.h | 6 +++ > 2 files changed, 74 insertions(+) > > diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c > index 37758ca91d7f..0095b54bdf9e 100644 > --- a/drivers/pci/endpoint/pci-epc-core.c > +++ b/drivers/pci/endpoint/pci-epc-core.c > @@ -530,6 +530,74 @@ int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > } > EXPORT_SYMBOL_GPL(pci_epc_map_addr); > > +/** > + * pci_epc_mem_map() - allocate and map CPU address to PCI address > + * @epc: the EPC device on which the CPU address is to be allocated and mapped > + * @func_no: the physical endpoint function number in the EPC device > + * @vfunc_no: the virtual endpoint function number in the physical function > + * @pci_addr: PCI address to which the CPU address should be mapped > + * @size: the number of bytes to map starting from @pci_addr > + * @map: where to return the mapping information > + * > + * Allocate a controller physical address region and map it to a RC PCI address > + * region, taking into account the controller physical address mapping > + * constraints (if any). Returns the effective size of the mapping, which may > + * be less than @size, or a negative error code in case of error. > + */ > +ssize_t pci_epc_mem_map(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > + u64 pci_addr, size_t size, struct pci_epc_map *map) > +{ > + int ret; > + > + ret = pci_epc_map_align(epc, func_no, vfunc_no, pci_addr, size, map); > + if (ret) > + return ret; > + > + map->virt_base = pci_epc_mem_alloc_addr(epc, &map->phys_base, > + map->map_size); > + if (!map->virt_base) > + return -ENOMEM; > + > + map->phys_addr = map->phys_base + map->map_ofst; > + map->virt_addr = map->virt_base + map->map_ofst; > + > + ret = pci_epc_map_addr(epc, func_no, vfunc_no, map->phys_base, > + map->map_pci_addr, map->map_size); > + if (ret) { > + pci_epc_mem_free_addr(epc, map->phys_base, map->virt_base, > + map->map_size); > + return ret; > + } > + > + return map->pci_size; map->pci_size is of type size_t. pci_epc_mem_map returns a type of ssize_t. This means that on ILP32 you will truncate the result, and will only be able to map a region of max size 2GB. Could we perhaps change this function to return an int instead? (0 on success). The mapped size can still be accessed in map->pci_size. Kind regards, Niklas > +} > +EXPORT_SYMBOL_GPL(pci_epc_mem_map); > + > +/** > + * pci_epc_mem_unmap() - unmap from PCI address and free a CPU address region > + * @epc: the EPC device on which the CPU address is allocated and mapped > + * @func_no: the physical endpoint function number in the EPC device > + * @vfunc_no: the virtual endpoint function number in the physical function > + * @map: the mapping information > + * > + * Allocate and map local CPU address to a PCI address, accounting for the > + * controller local CPU address alignment constraints. > + */ > +void pci_epc_mem_unmap(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > + struct pci_epc_map *map) > +{ > + if (!pci_epc_function_is_valid(epc, func_no, vfunc_no)) > + return; > + > + if (!map || !map->pci_size) > + return; > + > + pci_epc_unmap_addr(epc, func_no, vfunc_no, map->phys_base); > + pci_epc_mem_free_addr(epc, map->phys_base, map->virt_base, > + map->map_size); > +} > +EXPORT_SYMBOL_GPL(pci_epc_mem_unmap); > + > /** > * pci_epc_clear_bar() - reset the BAR > * @epc: the EPC device for which the BAR has to be cleared > diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h > index 8cfb4aaf2628..86397a500b54 100644 > --- a/include/linux/pci-epc.h > +++ b/include/linux/pci-epc.h > @@ -304,4 +304,10 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc, > phys_addr_t *phys_addr, size_t size); > void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr, > void __iomem *virt_addr, size_t size); > + > +ssize_t pci_epc_mem_map(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > + u64 pci_addr, size_t size, struct pci_epc_map *map); > +void pci_epc_mem_unmap(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > + struct pci_epc_map *map); > + > #endif /* __LINUX_PCI_EPC_H */ > -- > 2.44.0 >