RE: [PATCH v5 4/7] PCI: endpoint: Add support to handle multiple base for mapping outbound memory
From: Yoshihiro Shimoda
Date: Tue Mar 17 2020 - 04:12:04 EST
Hi Prabhakar-san,
Thank you for the patch!
> From: Lad Prabhakar, Sent: Saturday, February 29, 2020 12:41 AM
>
> R-Car PCIe controller has support to map multiple memory regions for
> mapping the outbound memory in local system also the controller limits
> single allocation for each region (that is, once a chunk is used from the
> region it cannot be used to allocate a new one). This features inspires to
> add support for handling multiple memory bases in endpoint framework.
>
> With this patch pci_epc_mem_init() now accepts multiple regions, also
> page_size for each memory region is passed during initialization so as
> to handle single allocation for each region by setting the page_size to
> window_size.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> ---
> drivers/pci/controller/cadence/pcie-cadence-ep.c | 7 +-
> drivers/pci/controller/dwc/pcie-designware-ep.c | 29 ++--
> drivers/pci/controller/pcie-rockchip-ep.c | 7 +-
> drivers/pci/endpoint/pci-epc-mem.c | 167 ++++++++++++++++-------
I could not apply this patch on the latest pci.git / next branch.
So, you need to rebase.
> include/linux/pci-epc.h | 39 ++++--
> 5 files changed, 169 insertions(+), 80 deletions(-)
>
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
> index 1c173da..90e32438 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
> +++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
> @@ -401,6 +401,7 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
> struct device *dev = ep->pcie.dev;
> struct platform_device *pdev = to_platform_device(dev);
> struct device_node *np = dev->of_node;
> + struct pci_epc_mem_window mem_window;
> struct cdns_pcie *pcie = &ep->pcie;
> struct resource *res;
> struct pci_epc *epc;
> @@ -449,8 +450,10 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
> if (of_property_read_u8(np, "max-functions", &epc->max_functions) < 0)
> epc->max_functions = 1;
>
> - ret = pci_epc_mem_init(epc, pcie->mem_res->start,
> - resource_size(pcie->mem_res));
> + mem_window.phys_base = pcie->mem_res->start;
> + mem_window.size = resource_size(pcie->mem_res);
> + mem_window.page_size = PAGE_SIZE;
> + ret = pci_epc_mem_init(epc, &mem_window, 1);
I'm not sure my idea is acceptable or not but,
I think we can have compatible API for single window like below.
- In this patch, pci_epc_mem_init() and __pci_epc_mem_init() become the same behavior.
So, for example, pci_epc_mem_init() is for simple, and __pci_epc_mem_init() is multiple windows.
-- In this case, pci_epc_mem_init() should have page_size argument.
- The original "mem" in the pci_epc can be the default window instead of
PCI_EPC_DEFAULT_WINDOW.
> if (ret < 0) {
> dev_err(dev, "failed to initialize the memory space\n");
> goto err_init;
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index cfeccd7..b150ef3 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -195,8 +195,7 @@ static void dw_pcie_ep_unmap_addr(struct pci_epc *epc, u8 func_no,
> }
>
> static int dw_pcie_ep_map_addr(struct pci_epc *epc, u8 func_no,
> - phys_addr_t addr,
> - u64 pci_addr, size_t size)
> + phys_addr_t addr, u64 pci_addr, size_t size)
> {
> int ret;
> struct dw_pcie_ep *ep = epc_get_drvdata(epc);
> @@ -367,6 +366,7 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
> unsigned int aligned_offset;
> u16 msg_ctrl, msg_data;
> u32 msg_addr_lower, msg_addr_upper, reg;
> + int window = PCI_EPC_DEFAULT_WINDOW;
> u64 msg_addr;
> bool has_upper;
> int ret;
> @@ -390,11 +390,11 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
> reg = ep->msi_cap + PCI_MSI_DATA_32;
> msg_data = dw_pcie_readw_dbi(pci, reg);
> }
> - aligned_offset = msg_addr_lower & (epc->mem->page_size - 1);
> + aligned_offset = msg_addr_lower & (epc->mem[window]->page_size - 1);
> msg_addr = ((u64)msg_addr_upper) << 32 |
> (msg_addr_lower & ~aligned_offset);
> - ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys, msg_addr,
> - epc->mem->page_size);
> + ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys,
> + msg_addr, epc->mem[window]->page_size);
> if (ret)
> return ret;
>
> @@ -416,6 +416,7 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
> u32 reg, msg_data, vec_ctrl;
> u64 tbl_addr, msg_addr, reg_u64;
> void __iomem *msix_tbl;
> + int window = PCI_EPC_DEFAULT_WINDOW;
> int ret;
>
> reg = ep->msix_cap + PCI_MSIX_TABLE;
> @@ -452,8 +453,8 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
> return -EPERM;
> }
>
> - ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys, msg_addr,
> - epc->mem->page_size);
> + ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys,
> + msg_addr, epc->mem[window]->page_size);
> if (ret)
> return ret;
>
> @@ -466,10 +467,11 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
>
> void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
> {
> + int window = PCI_EPC_DEFAULT_WINDOW;
> struct pci_epc *epc = ep->epc;
>
> pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
> - epc->mem->page_size);
> + epc->mem[window]->page_size);
>
> pci_epc_mem_exit(epc);
> }
> @@ -502,6 +504,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> unsigned int nbars;
> unsigned int offset;
> struct pci_epc *epc;
> + size_t msi_page_size;
> + struct pci_epc_mem_window mem_window;
> struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> struct device *dev = pci->dev;
> struct device_node *np = dev->of_node;
> @@ -574,15 +578,18 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> if (ret < 0)
> epc->max_functions = 1;
>
> - ret = __pci_epc_mem_init(epc, ep->phys_base, ep->addr_size,
> - ep->page_size);
> + mem_window.phys_base = ep->phys_base;
> + mem_window.size = ep->addr_size;
> + mem_window.page_size = ep->page_size;
> + ret = __pci_epc_mem_init(epc, &mem_window, 1);
> if (ret < 0) {
> dev_err(dev, "Failed to initialize address space\n");
> return ret;
> }
>
> + msi_page_size = epc->mem[PCI_EPC_DEFAULT_WINDOW]->page_size;
> ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
> - epc->mem->page_size);
> + msi_page_size);
> if (!ep->msi_mem) {
> dev_err(dev, "Failed to reserve memory for MSI/MSI-X\n");
> return -ENOMEM;
> diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
> index d743b0a..5a97390 100644
> --- a/drivers/pci/controller/pcie-rockchip-ep.c
> +++ b/drivers/pci/controller/pcie-rockchip-ep.c
> @@ -562,6 +562,7 @@ static const struct of_device_id rockchip_pcie_ep_of_match[] = {
>
> static int rockchip_pcie_ep_probe(struct platform_device *pdev)
> {
> + struct pci_epc_mem_window mem_window;
> struct device *dev = &pdev->dev;
> struct rockchip_pcie_ep *ep;
> struct rockchip_pcie *rockchip;
> @@ -614,8 +615,10 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
> /* Only enable function 0 by default */
> rockchip_pcie_write(rockchip, BIT(0), PCIE_CORE_PHY_FUNC_CFG);
>
> - err = pci_epc_mem_init(epc, rockchip->mem_res->start,
> - resource_size(rockchip->mem_res));
> + mem_window.phys_base = rockchip->mem_res->start;
> + mem_window.size = resource_size(rockchip->mem_res);
> + mem_window.page_size = PAGE_SIZE;
> + err = pci_epc_mem_init(epc, &mem_window, 1);
> if (err < 0) {
> dev_err(dev, "failed to initialize the memory space\n");
> goto err_uninit_port;
> diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
> index d2b174c..6c21957 100644
> --- a/drivers/pci/endpoint/pci-epc-mem.c
> +++ b/drivers/pci/endpoint/pci-epc-mem.c
> @@ -38,57 +38,76 @@ static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)
> /**
> * __pci_epc_mem_init() - initialize the pci_epc_mem structure
> * @epc: the EPC device that invoked pci_epc_mem_init
> - * @phys_base: the physical address of the base
> - * @size: the size of the address space
> - * @page_size: size of each page
> + * @windows: pointer to windows supported by the device
> + * @num_windows: number of windows device supports
> *
> * Invoke to initialize the pci_epc_mem structure used by the
> * endpoint functions to allocate mapped PCI address.
> */
> -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)
> {
> - 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;
> + size_t page_size;
> int bitmap_size;
> -
> - if (page_size < PAGE_SIZE)
> - page_size = PAGE_SIZE;
> -
> - page_shift = ilog2(page_size);
> - pages = size >> page_shift;
> - bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
> -
> - mem = kzalloc(sizeof(*mem), GFP_KERNEL);
> - if (!mem) {
> - ret = -ENOMEM;
> - goto err;
> - }
> -
> - bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> - if (!bitmap) {
> - ret = -ENOMEM;
> - goto err_mem;
> + int pages;
> + int ret;
> + int i;
> +
> + epc->mem_windows = 0;
> +
> + if (!windows)
> + return -EINVAL;
> +
> + if (num_windows <= 0)
> + return -EINVAL;
> +
> + epc->mem = kcalloc(num_windows, sizeof(*mem), GFP_KERNEL);
> + if (!epc->mem)
> + return -EINVAL;
> +
> + for (i = 0; i < num_windows; i++) {
> + 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) {
> + ret = -ENOMEM;
> + goto err_mem;
> + }
> +
> + bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> + if (!bitmap) {
> + ret = -ENOMEM;
> + goto err_mem;
> + }
> +
> + mem->bitmap = bitmap;
> + mem->window.phys_base = windows[i].phys_base;
I could not understand why the window member is needed.
I think original members (just phys_base and size) are enough.
Also, this function doesn't store the page_size to mem->window.page_size.
> + mem->page_size = page_size;
> + mem->pages = pages;
> + mem->window.size = windows[i].size;
> + epc->mem[i] = mem;
> }
> -
> - mem->bitmap = bitmap;
> - mem->phys_base = phys_base;
> - mem->page_size = page_size;
> - mem->pages = pages;
> - mem->size = size;
> -
> - epc->mem = mem;
> + epc->mem_windows = num_windows;
>
> return 0;
>
> err_mem:
> - kfree(mem);
> + for (; i >= 0; i--) {
> + mem = epc->mem[i];
> + kfree(mem->bitmap);
If bitmap cannot be allocated, the epc->mem[i] is NULL.
So, freeing mem->bitmap anyway is not good.
> + kfree(mem);
> + }
> + kfree(epc->mem);
>
> -err:
> -return ret;
> + return ret;
> }
> EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
>
> @@ -101,11 +120,21 @@ EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
> */
> 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;
> +
> + for (i = 0; i <= epc->mem_windows; i++) {
> + mem = epc->mem[i];
> + kfree(mem->bitmap);
> + kfree(mem);
> + }
> + kfree(epc->mem);
>
> epc->mem = NULL;
> - kfree(mem->bitmap);
> - kfree(mem);
> + epc->mem_windows = 0;
> }
> EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
>
> @@ -121,20 +150,30 @@ 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)
> {
> - int pageno;
> - void __iomem *virt_addr;
> - struct pci_epc_mem *mem = epc->mem;
> - unsigned int page_shift = ilog2(mem->page_size);
> + void __iomem *virt_addr = NULL;
> + struct pci_epc_mem *mem;
> + unsigned int page_shift;
> + int pageno = -EINVAL;
> int order;
> + int i;
>
> - size = ALIGN(size, mem->page_size);
> - order = pci_epc_mem_get_order(mem, size);
> + for (i = 0; i < epc->mem_windows; i++) {
> + mem = epc->mem[i];
> + size = ALIGN(size, mem->page_size);
> + order = pci_epc_mem_get_order(mem, size);
> +
> + pageno = bitmap_find_free_region(mem->bitmap, mem->pages,
> + order);
> + if (pageno >= 0)
> + break;
> + }
>
> - pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
> if (pageno < 0)
> return NULL;
>
> - *phys_addr = mem->phys_base + ((phys_addr_t)pageno << page_shift);
> + page_shift = ilog2(mem->page_size);
> + *phys_addr = mem->window.phys_base +
> + ((phys_addr_t)pageno << page_shift);
> virt_addr = ioremap(*phys_addr, size);
> if (!virt_addr)
> bitmap_release_region(mem->bitmap, pageno, order);
> @@ -143,6 +182,23 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
> }
> EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
>
> +struct pci_epc_mem *pci_epc_get_matching_window(struct pci_epc *epc,
> + phys_addr_t phys_addr)
> +{
> + struct pci_epc_mem *mem;
> + int i;
> +
> + for (i = 0; i < epc->mem_windows; i++) {
> + mem = epc->mem[i];
> +
> + if (phys_addr >= mem->window.phys_base &&
> + phys_addr < (mem->window.phys_base + mem->window.size))
> + return mem;
> + }
> +
> + return NULL;
> +}
> +
> /**
> * pci_epc_mem_free_addr() - free the allocated memory address
> * @epc: the EPC device on which memory was allocated
> @@ -155,13 +211,20 @@ 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 pageno;
> - struct pci_epc_mem *mem = epc->mem;
> - unsigned int page_shift = ilog2(mem->page_size);
> int order;
>
> + mem = pci_epc_get_matching_window(epc, phys_addr);
> + if (!mem) {
> + pr_err("failed to get matching window\n");
> + return;
> + }
> +
> + 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);
> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> index 56f1846..dde42e5 100644
> --- a/include/linux/pci-epc.h
> +++ b/include/linux/pci-epc.h
> @@ -64,17 +64,29 @@ struct pci_epc_ops {
> struct module *owner;
> };
>
> +#define PCI_EPC_DEFAULT_WINDOW 0
> +
> +/**
> + * struct pci_epc_mem_window - address window of the endpoint controller
> + * @phys_base: physical base address of the PCI address window
> + * @size: the size of the PCI address window
> + * @page_size: size of each page
> + */
> +struct pci_epc_mem_window {
> + phys_addr_t phys_base;
> + size_t size;
> + size_t page_size;
> +};
> +
> /**
> * struct pci_epc_mem - address space of the endpoint controller
> - * @phys_base: physical base address of the PCI address space
> - * @size: the size of the PCI address space
> + * @window: address window of the endpoint controller
> * @bitmap: bitmap to manage the PCI address space
> - * @pages: number of bits representing the address region
> * @page_size: size of each page
> + * @pages: number of bits representing the address region
> */
> struct pci_epc_mem {
> - phys_addr_t phys_base;
> - size_t size;
> + struct pci_epc_mem_window window;
> unsigned long *bitmap;
> size_t page_size;
> int pages;
> @@ -85,7 +97,8 @@ 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
If my idea is acceptable, this should be "default address space ...".
> + * @mem: array of address space of the endpoint controller
And, this should be difference name.
> + * @mem_windows: number of windows supported by device
Perhaps, num_windows?
> * @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 +107,8 @@ 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;
> + unsigned int mem_windows;
> u8 max_functions;
> struct config_group *group;
> /* spinlock to protect against concurrent access of EP controller */
> @@ -128,8 +142,8 @@ struct pci_epc_features {
> #define devm_pci_epc_create(dev, ops) \
> __devm_pci_epc_create((dev), (ops), THIS_MODULE)
>
> -#define pci_epc_mem_init(epc, phys_addr, size) \
> - __pci_epc_mem_init((epc), (phys_addr), (size), PAGE_SIZE)
> +#define pci_epc_mem_init(epc, windows, num_windows) \
> + __pci_epc_mem_init((epc), windows, num_windows)
As I mentioned above, pci_epc_mem_init() and __ pci_epc_mem_init() are the same behavior.
> static inline void epc_set_drvdata(struct pci_epc *epc, void *data)
> {
> @@ -159,8 +173,7 @@ int pci_epc_set_bar(struct pci_epc *epc, u8 func_no,
> void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no,
> struct pci_epf_bar *epf_bar);
> int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
> - phys_addr_t phys_addr,
> - u64 pci_addr, size_t size);
> + phys_addr_t phys_addr, u64 pci_addr, size_t size);
Perhaps, this is not needed to change?
Best regards,
Yoshihiro Shimoda
> void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no,
> phys_addr_t phys_addr);
> int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts);
> @@ -178,8 +191,8 @@ unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
> struct pci_epc *pci_epc_get(const char *epc_name);
> void pci_epc_put(struct pci_epc *epc);
>
> -int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_addr, size_t size,
> - size_t page_size);
> +int __pci_epc_mem_init(struct pci_epc *epc, struct pci_epc_mem_window *window,
> + int num_windows);
> void pci_epc_mem_exit(struct pci_epc *epc);
> void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
> phys_addr_t *phys_addr, size_t size);
> --
> 2.7.4