On Tue, Mar 19, 2024 at 11:50:50AM -0400, Frank Li wrote: > On Sun, Mar 17, 2024 at 11:39:17AM +0530, Manivannan Sadhasivam wrote: > > As proposed during the last year 'PCI Endpoint Subsystem Open Items > > Discussion' of Linux Plumbers conference [1], let's migrate to Genalloc > > framework for managing the endpoint outbound window memory allocation. > > > > PCI Endpoint subsystem is using a custom memory allocator in pci-epc-mem > > driver from the start for managing the memory required to map the host > > address space (outbound) in endpoint. Even though it works well, it > > completely defeats the purpose of the 'Genalloc framework', a general > > purpose memory allocator framework created to avoid various custom memory > > allocators in the kernel. > > > > The migration to Genalloc framework is done is such a way that the existing > > API semantics are preserved. So that the callers of the EPC mem APIs do not > > need any modification (apart from the pcie-designware-epc driver that > > queries page size). > > > > Internally, the EPC mem driver now uses Genalloc framework's > > 'gen_pool_first_fit_order_align' algorithm that aligns the allocated memory > > based on the requested size as like the previous allocator. And the > > page size passed during pci_epc_mem_init() API is used as the minimum order > > for the memory allocations. > > > > During the migration, 'struct pci_epc_mem' is removed as it is seems > > redundant and the existing 'struct pci_epc_mem_window' in 'struct pci_epc' > > is now used to hold the address windows of the endpoint controller. > > > > [1] https://lpc.events/event/17/contributions/1419/ > > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> > > --- > > drivers/pci/controller/dwc/pcie-designware-ep.c | 14 +- > > drivers/pci/endpoint/pci-epc-mem.c | 182 +++++++++--------------- > > include/linux/pci-epc.h | 25 +--- > > 3 files changed, 81 insertions(+), 140 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c > > index 5befed2dc02b..37c612282eb6 100644 > > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c > > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c > > @@ -482,11 +482,11 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no, > > reg = ep_func->msi_cap + PCI_MSI_DATA_32; > > msg_data = dw_pcie_ep_readw_dbi(ep, func_no, reg); > > } > > - aligned_offset = msg_addr_lower & (epc->mem->window.page_size - 1); > > + aligned_offset = msg_addr_lower & (epc->windows[0]->page_size - 1); > > msg_addr = ((u64)msg_addr_upper) << 32 | > > (msg_addr_lower & ~aligned_offset); > > ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr, > > - epc->mem->window.page_size); > > + epc->windows[0]->page_size); > > if (ret) > > return ret; > > > > @@ -550,10 +550,10 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no, > > return -EPERM; > > } > > > > - aligned_offset = msg_addr & (epc->mem->window.page_size - 1); > > + aligned_offset = msg_addr & (epc->windows[0]->page_size - 1); > > msg_addr &= ~aligned_offset; > > ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr, > > - epc->mem->window.page_size); > > + epc->windows[0]->page_size); > > if (ret) > > return ret; > > > > @@ -572,7 +572,7 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep) > > dw_pcie_edma_remove(pci); > > > > pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem, > > - epc->mem->window.page_size); > > + epc->windows[0]->page_size); > > > > pci_epc_mem_exit(epc); > > > > @@ -742,7 +742,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > > } > > > > ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys, > > - epc->mem->window.page_size); > > + epc->windows[0]->page_size); > > if (!ep->msi_mem) { > > ret = -ENOMEM; > > dev_err(dev, "Failed to reserve memory for MSI/MSI-X\n"); > > @@ -770,7 +770,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep) > > > > err_free_epc_mem: > > pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem, > > - epc->mem->window.page_size); > > + epc->windows[0]->page_size); > > > > err_exit_epc_mem: > > pci_epc_mem_exit(epc); > > diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c > > index a9c028f58da1..f9e6e1a6aeaa 100644 > > --- a/drivers/pci/endpoint/pci-epc-mem.c > > +++ b/drivers/pci/endpoint/pci-epc-mem.c > > @@ -4,37 +4,18 @@ > > * > > * Copyright (C) 2017 Texas Instruments > > * Author: Kishon Vijay Abraham I <kishon@xxxxxx> > > + * > > + * Copyright (C) 2024 Linaro Ltd. > > + * Author: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> > > */ > > > > +#include <linux/genalloc.h> > > #include <linux/io.h> > > #include <linux/module.h> > > #include <linux/slab.h> > > > > #include <linux/pci-epc.h> > > > > -/** > > - * pci_epc_mem_get_order() - determine the allocation order of a memory size > > - * @mem: address space of the endpoint controller > > - * @size: the size for which to get the order > > - * > > - * Reimplement get_order() for mem->page_size since the generic get_order > > - * always gets order with a constant PAGE_SIZE. > > - */ > > -static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size) > > -{ > > - int order; > > - unsigned int page_shift = ilog2(mem->window.page_size); > > - > > - size--; > > - size >>= page_shift; > > -#if BITS_PER_LONG == 32 > > - order = fls(size); > > -#else > > - order = fls64(size); > > -#endif > > - return order; > > -} > > - > > /** > > * pci_epc_multi_mem_init() - initialize the pci_epc_mem structure > > * @epc: the EPC device that invoked pci_epc_mem_init > > @@ -48,17 +29,11 @@ int pci_epc_multi_mem_init(struct pci_epc *epc, > > struct pci_epc_mem_window *windows, > > unsigned int num_windows) > > { > > - struct pci_epc_mem *mem = NULL; > > - unsigned long *bitmap = NULL; > > - unsigned int page_shift; > > + struct pci_epc_mem_window *window = NULL; > > size_t page_size; > > - int bitmap_size; > > - int pages; > > int ret; > > int i; > > > > - epc->num_windows = 0; > > - > > if (!windows || !num_windows) > > return -EINVAL; > > > > @@ -70,45 +45,51 @@ int pci_epc_multi_mem_init(struct pci_epc *epc, > > page_size = windows[i].page_size; > > if (page_size < PAGE_SIZE) > > page_size = PAGE_SIZE; > > - page_shift = ilog2(page_size); > > - pages = windows[i].size >> page_shift; > > - bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); > > > > - mem = kzalloc(sizeof(*mem), GFP_KERNEL); > > - if (!mem) { > > + windows[i].pool = gen_pool_create(ilog2(page_size), -1); > > I think it is not good to modify caller's memory. This funciton suppose > pass down read-only information. And set to epc->windows[i]. I think it'd > better to use epc->windows[i].pool/windows. > > > + if (!windows[i].pool) { > > ret = -ENOMEM; > > - i--; > > - goto err_mem; > > + goto err_free_mem; > > + } > > + > > + gen_pool_set_algo(windows[i].pool, gen_pool_first_fit_order_align, > > + NULL); > > + > > + windows[i].virt_base = ioremap(windows[i].phys_base, windows[i].size); > > + ret = gen_pool_add_virt(windows[i].pool, (unsigned long)windows[i].virt_base, > > + windows[i].phys_base, windows[i].size, -1); > > + if (ret) { > > + iounmap(windows[i].virt_base); > > + gen_pool_destroy(epc->windows[i]->pool); > > I think move all free to err path will be easy to understand. > > > + goto err_free_mem; > > } > > > > - bitmap = kzalloc(bitmap_size, GFP_KERNEL); > > - if (!bitmap) { > > + window = kzalloc(sizeof(*window), GFP_KERNEL); > > According to below code > > epc->windows = kcalloc(num_windows, sizeof(*epc->windows), GFP_KERNEL); > if (!epc->windows) > return -ENOMEM; > > epc->windows already allocate whole num_windows * "struct pci_epc_mem_window". > I think you can direct use 'window = epc->windows + i', so needn't alloc > additional memory for epc->windows[i]. I just realize struct pci_epc_mem_window **windows in epc. But my comment should be valid also. pci_epc_mem_window *windows should be enough. Needn't two level pointer. > > > > + if (!window) { > > ret = -ENOMEM; > > - kfree(mem); > > - i--; > > - goto err_mem; > > + iounmap(windows[i].virt_base); > > + gen_pool_destroy(epc->windows[i]->pool); > > + goto err_free_mem; > > } > > > > - mem->window.phys_base = windows[i].phys_base; > > - mem->window.size = windows[i].size; > > - mem->window.page_size = page_size; > > - mem->bitmap = bitmap; > > - mem->pages = pages; > > - mutex_init(&mem->lock); > > - epc->windows[i] = mem; > > + window->phys_base = windows[i].phys_base; > > + window->size = windows[i].size; > > + window->page_size = page_size; > > + window->pool = windows[i].pool; > > + epc->windows[i] = window; > > } > > > > - epc->mem = epc->windows[0]; > > epc->num_windows = num_windows; > > > > return 0; > > > > -err_mem: > > - for (; i >= 0; i--) { > > - mem = epc->windows[i]; > > - kfree(mem->bitmap); > > - kfree(mem); > > +err_free_mem: > > + for (--i; i >= 0; i--) { > > + iounmap(windows[i].virt_base); > > + gen_pool_destroy(epc->windows[i]->pool); > > + kfree(epc->windows[i]); > > } > > + > > kfree(epc->windows); > > > > return ret; > > @@ -128,14 +109,15 @@ EXPORT_SYMBOL_GPL(pci_epc_multi_mem_init); > > int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t base, > > size_t size, size_t page_size) > > { > > - struct pci_epc_mem_window mem_window; > > + struct pci_epc_mem_window window; > > > > - mem_window.phys_base = base; > > - mem_window.size = size; > > - mem_window.page_size = page_size; > > + window.phys_base = base; > > + window.size = size; > > + window.page_size = page_size; > > > > - return pci_epc_multi_mem_init(epc, &mem_window, 1); > > + return pci_epc_multi_mem_init(epc, &window, 1); > > } > > + > > Remove extra empty line change > > > EXPORT_SYMBOL_GPL(pci_epc_mem_init); > > > > /** > > @@ -147,21 +129,20 @@ EXPORT_SYMBOL_GPL(pci_epc_mem_init); > > */ > > void pci_epc_mem_exit(struct pci_epc *epc) > > { > > - struct pci_epc_mem *mem; > > int i; > > > > if (!epc->num_windows) > > return; > > > > for (i = 0; i < epc->num_windows; i++) { > > - mem = epc->windows[i]; > > - kfree(mem->bitmap); > > - kfree(mem); > > + iounmap(epc->windows[i]->virt_base); > > + gen_pool_destroy(epc->windows[i]->pool); > > + kfree(epc->windows[i]); > > } > > + > > kfree(epc->windows); > > > > epc->windows = NULL; > > - epc->mem = NULL; > > epc->num_windows = 0; > > } > > EXPORT_SYMBOL_GPL(pci_epc_mem_exit); > > @@ -178,55 +159,42 @@ EXPORT_SYMBOL_GPL(pci_epc_mem_exit); > > void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc, > > phys_addr_t *phys_addr, size_t size) > > { > > + struct pci_epc_mem_window *window; > > void __iomem *virt_addr = NULL; > > - struct pci_epc_mem *mem; > > - unsigned int page_shift; > > + struct gen_pool *genpool; > > size_t align_size; > > - int pageno; > > - int order; > > int i; > > > > for (i = 0; i < epc->num_windows; i++) { > > - mem = epc->windows[i]; > > - mutex_lock(&mem->lock); > > - align_size = ALIGN(size, mem->window.page_size); > > - order = pci_epc_mem_get_order(mem, align_size); > > - > > - pageno = bitmap_find_free_region(mem->bitmap, mem->pages, > > - order); > > - if (pageno >= 0) { > > - page_shift = ilog2(mem->window.page_size); > > - *phys_addr = mem->window.phys_base + > > - ((phys_addr_t)pageno << page_shift); > > - virt_addr = ioremap(*phys_addr, align_size); > > - if (!virt_addr) { > > - bitmap_release_region(mem->bitmap, > > - pageno, order); > > - mutex_unlock(&mem->lock); > > - continue; > > - } > > - mutex_unlock(&mem->lock); > > - return virt_addr; > > - } > > - mutex_unlock(&mem->lock); > > + window = epc->windows[i]; > > + genpool = window->pool; > > + align_size = ALIGN(size, window->page_size); > > + > > + virt_addr = (void __iomem *)gen_pool_alloc(genpool, align_size); > > + if (!virt_addr) > > + continue; > > + > > + *phys_addr = gen_pool_virt_to_phys(genpool, (unsigned long)virt_addr); > > + > > + break; > > } > > > > return virt_addr; > > } > > EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr); > > > > -static struct pci_epc_mem *pci_epc_get_matching_window(struct pci_epc *epc, > > +static struct pci_epc_mem_window *pci_epc_get_matching_window(struct pci_epc *epc, > > phys_addr_t phys_addr) > > { > > - struct pci_epc_mem *mem; > > + struct pci_epc_mem_window *window; > > int i; > > > > for (i = 0; i < epc->num_windows; i++) { > > - mem = epc->windows[i]; > > + window = epc->windows[i]; > > > > - if (phys_addr >= mem->window.phys_base && > > - phys_addr < (mem->window.phys_base + mem->window.size)) > > - return mem; > > + if (phys_addr >= window->phys_base && > > + phys_addr < (window->phys_base + window->size)) > > + return window; > > } > > > > return NULL; > > @@ -244,27 +212,15 @@ static struct pci_epc_mem *pci_epc_get_matching_window(struct pci_epc *epc, > > 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; > > - size_t page_size; > > - int pageno; > > - int order; > > + struct pci_epc_mem_window *window; > > > > - mem = pci_epc_get_matching_window(epc, phys_addr); > > - if (!mem) { > > + window = pci_epc_get_matching_window(epc, phys_addr); > > + if (!window) { > > pr_err("failed to get matching window\n"); > > return; > > } > > > > - page_size = mem->window.page_size; > > - page_shift = ilog2(page_size); > > - iounmap(virt_addr); > > - pageno = (phys_addr - mem->window.phys_base) >> page_shift; > > - size = ALIGN(size, page_size); > > - order = pci_epc_mem_get_order(mem, size); > > - mutex_lock(&mem->lock); > > - bitmap_release_region(mem->bitmap, pageno, order); > > - mutex_unlock(&mem->lock); > > + gen_pool_free(window->pool, (unsigned long)virt_addr, size); > > } > > EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr); > > > > diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h > > index 40ea18f5aa02..37ea96ed3432 100644 > > --- a/include/linux/pci-epc.h > > +++ b/include/linux/pci-epc.h > > @@ -87,30 +87,19 @@ struct pci_epc_ops { > > /** > > * struct pci_epc_mem_window - address window of the endpoint controller > > * @phys_base: physical base address of the PCI address window > > + * @virt_base: virtual base address of the PCI address window > > + * @pool: memory pool descriptor > > * @size: the size of the PCI address window > > * @page_size: size of each page > > */ > > struct pci_epc_mem_window { > > phys_addr_t phys_base; > > + void __iomem *virt_base; > > + struct gen_pool *pool; > > size_t size; > > size_t page_size; > > }; > > > > -/** > > - * struct pci_epc_mem - address space of the endpoint controller > > - * @window: address window of the endpoint controller > > - * @bitmap: bitmap to manage the PCI address space > > - * @pages: number of bits representing the address region > > - * @lock: mutex to protect bitmap > > - */ > > -struct pci_epc_mem { > > - struct pci_epc_mem_window window; > > - unsigned long *bitmap; > > - int pages; > > - /* mutex to protect against concurrent access for memory allocation*/ > > - struct mutex lock; > > -}; > > - > > /** > > * struct pci_epc - represents the PCI EPC device > > * @dev: PCI EPC device > > @@ -118,9 +107,6 @@ struct pci_epc_mem { > > * @list_lock: Mutex for protecting pci_epf list > > * @ops: function pointers for performing endpoint operations > > * @windows: array of address space of the endpoint controller > > - * @mem: first window of the endpoint controller, which corresponds to > > - * default address space of the endpoint controller supporting > > - * single window. > > * @num_windows: number of windows supported by device > > * @max_functions: max number of functions that can be configured in this EPC > > * @max_vfs: Array indicating the maximum number of virtual functions that can > > @@ -134,8 +120,7 @@ struct pci_epc { > > struct list_head pci_epf; > > struct mutex list_lock; > > const struct pci_epc_ops *ops; > > - struct pci_epc_mem **windows; > > - struct pci_epc_mem *mem; > > + struct pci_epc_mem_window **windows; > > unsigned int num_windows; > > u8 max_functions; > > u8 *max_vfs; > > > > --- > > base-commit: 256833a66670ff28b7c1bddbd17973619e5281fd > > change-id: 20240317-pci-ep-genalloc-fa89f5e487e3 > > > > Best regards, > > -- > > Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> > >
