On Tue, Mar 19, 2024 at 09:58:29PM +0530, Manivannan Sadhasivam wrote: > 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. > > > > What do you mean by modifying caller's memory? Here, the memory for epc->windows > is being allocated and the pool is created for each window. windows[i].pool = gen_pool_create(ilog2(page_size), -1) 'windows' pass down from argument pci_epc_multi_mem_init( ..struct pci_epc_mem_window *windows, ) ^^^^^^^ windows[i].pool = gen_pool_create() actually change the caller's stack memory. > > > > + 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. > > > > It is not straightforward. First we need to free the memory for current > iteration and then all previous iterations, that too from different places. > Moving the code to free current iteration to the error label will look messy. All from current iteration. err_free_mem: iounmap(windows[i].virt_base); if (epc->windows[i]->pool) gen_pool_destroy(epc->windows[i]->pool) > > > > + 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]. > > > > First we are allocating the memory for 'struct pci_epc_mem_window' _pointers_ in > epc->windows. Then we need to allocate memory for each pointer in epc->windows > to actually store data. Otherwise, we will be referencing the nulll pointer. I think two layer pointer is totally unecessary. You can use one layer pointer 'struct pci_epc_mem_window *windows;' Code logic will become simple. Frank > > - Mani > > > > > > + 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> > > > > > -- > மணிவண்ணன் சதாசிவம்
