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]. > + 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> >
