From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Lad, Prabhakar" Subject: Re: [v2 2/6] pci: endpoint: add support to handle features of outbound memory Date: Mon, 16 Dec 2019 08:21:31 +0000 Message-ID: References: <20191213084748.11210-3-prabhakar.mahadev-lad.rj@bp.renesas.com> <20191213195727.GA170874@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20191213195727.GA170874@google.com> Sender: linux-kernel-owner@vger.kernel.org To: Bjorn Helgaas Cc: Rob Herring , Mark Rutland , Geert Uytterhoeven , Magnus Damm , Kishon Vijay Abraham I , Marek Vasut , Yoshihiro Shimoda , linux-pci , Catalin Marinas , Will Deacon , Lorenzo Pieralisi , Arnd Bergmann , Greg Kroah-Hartman , Andrew Murray , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , LKML , LAK List-Id: linux-rockchip.vger.kernel.org Hi Bjorn, thank you for the review. On Fri, Dec 13, 2019 at 9:06 PM Bjorn Helgaas wrote: > > On Fri, Dec 13, 2019 at 08:47:44AM +0000, Lad Prabhakar wrote: > > From: "Lad, Prabhakar" > > > > rcar pcie controller has support to map multiple memory regions > > for mapping the outbound memory in local system, this feature > > inspires to add support for handling such features in endpoint > > framework. similar features exists on other controllers where > > outbound regions can be specifically used for low/high priority > > transactions, and regions can be flagged and used for allocation > > of large/small memory allocations. > > This patch adds support to handle such features, where the > > properties described for outbound regions are used whenever a > > request to memory is made. > > For this and the other patches, please: > > - start sentences with a capital letter > - leave a blank line between paragraphs > - wrap commit log text to use the whole 80 character line (I wrap to > 75 characters to account for "git log" indenting by 4 spaces) > - check your signed-off-by: it shows your name as "Lad, Prabhakar", > while your email From: line shows "Lad Prabhakar". Choose one :) > sure will fix it next version. > > diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c > > index 2bf8bd1..4b610cd 100644 > > --- a/drivers/pci/endpoint/pci-epc-mem.c > > +++ b/drivers/pci/endpoint/pci-epc-mem.c > > > -int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size, > > - size_t page_size) > > +int __pci_epc_mem_init(struct pci_epc *epc, struct pci_epc_mem_window *windows, > > + int num_windows, size_t page_size) > > { > > - int ret; > > - struct pci_epc_mem *mem; > > - unsigned long *bitmap; > > + struct pci_epc_mem *mem = NULL; > > + unsigned long *bitmap = NULL; > > unsigned int page_shift; > > - int pages; > > int bitmap_size; > > + int pages; > > + int ret; > > + int i; > > + > > + epc->mem_windows = 0; > > + > > + if (!windows) > > + return -EINVAL; > > + > > + if (num_windows <= 0) > > + return -EINVAL; > > Why is num_windows signed? > > > void pci_epc_mem_exit(struct pci_epc *epc) > > { > > - struct pci_epc_mem *mem = epc->mem; > > + struct pci_epc_mem *mem; > > + int i; > > + > > + if (!epc->mem_windows) > > + return; > > If you fix the loop below, why do you even need to test this? > yes makes sense will drop this check. > > + for (i = 0; i <= epc->mem_windows; i--) { > > Huh? "<="? "i--"? Surely you mean > > for (i = 0; i < epc->mem_windows; i++) { > oops my bad, will fix it. > > + mem = epc->mem[i]; > > + kfree(mem->bitmap); > > + kfree(epc->mem[i]); > > + } > > + kfree(epc->mem); > > > > epc->mem = NULL; > > - kfree(mem->bitmap); > > - kfree(mem); > > + epc->mem_windows = 0; > > } > > EXPORT_SYMBOL_GPL(pci_epc_mem_exit); > > > > +static int pci_epc_find_best_fit_window(struct pci_epc *epc, size_t size, > > + u32 flags) > > Can this just return a struct pci_epc_mem *, so the caller doesn't > have to lookup epc->mem[i] again? > yes makes sense will change it to return struct pci_epc_mem * > > +{ > > + size_t window_least_size = 0; > > + int best_fit_window = -1; > > + struct pci_epc_mem *mem; > > + size_t actual_size; > > + size_t avail_size; > > + u32 win_flags; > > + int i; > > + > > + for (i = 0; i < epc->mem_windows; i++) { > > + mem = epc->mem[i]; > > + win_flags = mem->window.flags; > > + > > + actual_size = ALIGN(size, mem->page_size); > > + avail_size = mem->window.size - mem->window.map_size; > > + > > + if (win_flags == 0x0) { > > + if (best_fit_window == -1) { > > + if (actual_size <= avail_size) { > > + best_fit_window = i; > > + window_least_size = mem->window.size; > > + } > > + } else { > > + if (actual_size <= avail_size && > > + mem->window.size < window_least_size) { > > + best_fit_window = i; > > + window_least_size = mem->window.size; > > + } > > + } > > + } else { > > + if (mem->window.map_size && > > + (win_flags | PCI_EPC_WINDOW_FLAG_NON_MULTI_ALLOC)) > > + continue; > > + > > + if (!(win_flags | flags)) > > + continue; > > + > > + if (best_fit_window == -1) { > > + if (actual_size <= avail_size) { > > + best_fit_window = i; > > + window_least_size = mem->window.size; > > + } > > + } else { > > + if (actual_size <= avail_size && > > + mem->window.size < window_least_size) { > > + best_fit_window = i; > > + window_least_size = mem->window.size; > > + } > > + } > > + } > > + } > > + > > + return best_fit_window; > > +} > > + > > /** > > * pci_epc_mem_alloc_addr() - allocate memory address from EPC addr space > > * @epc: the EPC device on which memory has to be allocated > > * @phys_addr: populate the allocated physical address here > > + * @window: populate the window here which will be used to map PCI address > > * @size: the size of the address space that has to be allocated > > + * @flags: look for window as requested in flags > > * > > * Invoke to allocate memory address from the EPC address space. This > > * is usually done to map the remote RC address into the local system. > > */ > > void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc, > > - phys_addr_t *phys_addr, size_t size) > > + phys_addr_t *phys_addr, > > + int *window, size_t size, uint32_t flags) > > { > > + int best_fit = PCI_EPC_DEFAULT_WINDOW; > > + void __iomem *virt_addr = NULL; > > + struct pci_epc_mem *mem; > > + unsigned int page_shift; > > int pageno; > > - void __iomem *virt_addr; > > - struct pci_epc_mem *mem = epc->mem; > > - unsigned int page_shift = ilog2(mem->page_size); > > int order; > > > > + if (epc->mem_windows <= 0) > > + return NULL; > > + > > + if (epc->mem_windows > 1) { > > Why bother testing epc->mem_windows here? Just make sure > pci_epc_find_best_fit_window() returns the correct thing for > "mem_windows == 0" and "mem_windows == 1", and remove both the tests > above. > will fix that. > > + best_fit = pci_epc_find_best_fit_window(epc, size, flags); > > + if (best_fit < 0) > > + return NULL; > > + } > > + > > + mem = epc->mem[best_fit]; > > size = ALIGN(size, mem->page_size); > > + if (size > (mem->window.size - mem->window.map_size)) > > + return NULL; > > + page_shift = ilog2(mem->page_size); > > order = pci_epc_mem_get_order(mem, size); > > > > pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order); > > if (pageno < 0) > > return NULL; > > > > - *phys_addr = mem->phys_base + (pageno << page_shift); > > + *phys_addr = mem->window.phys_base + (pageno << page_shift); > > virt_addr = ioremap(*phys_addr, size); > > - if (!virt_addr) > > + if (!virt_addr) { > > bitmap_release_region(mem->bitmap, pageno, order); > > + } else { > > + mem->window.map_size += size; > > + *window = best_fit; > > + } > > > > return virt_addr; > > } > > EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr); > > > > +static int pci_epc_get_matching_window(struct pci_epc *epc, > > + phys_addr_t phys_addr) > > Return struct pci_epc_mem * again? > yes makes sense. > > +{ > > + struct pci_epc_mem *mem; > > + int i; > > + > > + for (i = 0; i < epc->mem_windows; i++) { > > + mem = epc->mem[i]; > > + > > + if (mem->window.phys_base == phys_addr) > > + return i; > > + } > > + > > + return -EINVAL; > > +} > > + > > /** > > * pci_epc_mem_free_addr() - free the allocated memory address > > * @epc: the EPC device on which memory was allocated > > @@ -155,16 +281,26 @@ EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr); > > void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr, > > void __iomem *virt_addr, size_t size) > > { > > + struct pci_epc_mem *mem; > > + unsigned int page_shift; > > + int window = 0; > > int pageno; > > - struct pci_epc_mem *mem = epc->mem; > > - unsigned int page_shift = ilog2(mem->page_size); > > int order; > > > > + if (epc->mem_windows > 1) { > > Same here (unnecessary test). > will drop it. > > + window = pci_epc_get_matching_window(epc, phys_addr); > > + if (window < 0) > > + return; > > + } > > + > > + mem = epc->mem[window]; > > + page_shift = ilog2(mem->page_size); > > iounmap(virt_addr); > > - pageno = (phys_addr - mem->phys_base) >> page_shift; > > + pageno = (phys_addr - mem->window.phys_base) >> page_shift; > > size = ALIGN(size, mem->page_size); > > order = pci_epc_mem_get_order(mem, size); > > bitmap_release_region(mem->bitmap, pageno, order); > > + mem->window.map_size -= size; > > } > > EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr); > > > @@ -85,7 +126,8 @@ struct pci_epc_mem { > > * @dev: PCI EPC device > > * @pci_epf: list of endpoint functions present in this EPC device > > * @ops: function pointers for performing endpoint operations > > - * @mem: address space of the endpoint controller > > + * @mem: array of address space of the endpoint controller > > + * @mem_windows: number of windows supported by device > > * @max_functions: max number of functions that can be configured in this EPC > > * @group: configfs group representing the PCI EPC device > > * @lock: spinlock to protect pci_epc ops > > @@ -94,7 +136,8 @@ struct pci_epc { > > struct device dev; > > struct list_head pci_epf; > > const struct pci_epc_ops *ops; > > - struct pci_epc_mem *mem; > > + struct pci_epc_mem **mem; > > + int mem_windows; > > Can't this be unsigned int and then there's no need to check > "mem_windows < 0"? > yes will change it unsigned int. Cheers, --Prabhakar > > u8 max_functions; > > struct config_group *group; > > /* spinlock to protect against concurrent access of EP controller */