Re: [PATCH 2/5] pci: endpoint: add support to handle multiple base for mapping outbound memory
From: Kishon Vijay Abraham I
Date: Wed Nov 27 2019 - 00:15:50 EST
Hi Prabhakar,
On 07/11/19 1:06 AM, Lad Prabhakar wrote:
> From: "Lad, Prabhakar" <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> 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 multiple memory bases in
> endpoint framework. In case of multiple memory regions only chunk
> or complete region can be mapped and this window needs to be
> passed to the controller driver.
>
> Signed-off-by: Lad, Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Cc: <linux-rockchip@xxxxxxxxxxxxxxxxxxx>
> Cc: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> Cc: Heiko Stuebner <heiko@xxxxxxxxx>
> Cc: Tom Joseph <tjoseph@xxxxxxxxxxx>
> Cc: Jingoo Han <jingoohan1@xxxxxxxxx>
> Cc: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> ---
> .../pci/controller/dwc/pcie-designware-ep.c | 30 ++-
> drivers/pci/controller/pcie-cadence-ep.c | 11 +-
> drivers/pci/controller/pcie-rockchip-ep.c | 13 +-
> drivers/pci/endpoint/functions/pci-epf-test.c | 29 +--
> drivers/pci/endpoint/pci-epc-core.c | 7 +-
> drivers/pci/endpoint/pci-epc-mem.c | 189 ++++++++++++++----
> include/linux/pci-epc.h | 43 ++--
> 7 files changed, 234 insertions(+), 88 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 3dd2e2697294..8d23c20b9afd 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -195,7 +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,
> + phys_addr_t addr, int window,
> u64 pci_addr, size_t size)
> {
> int ret;
> @@ -367,6 +367,7 @@ 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 +391,11 @@ 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, window,
> + msg_addr, epc->mem[window]->page_size);
> if (ret)
> return ret;
>
> @@ -416,6 +417,7 @@ 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 +454,8 @@ 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, window,
> + msg_addr, epc->mem[window]->page_size);
> if (ret)
> return ret;
>
> @@ -466,10 +468,11 @@ 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);
> }
> @@ -499,9 +502,12 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> u32 reg;
> void *addr;
> u8 hdr_type;
> + int window;
> 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 +580,17 @@ 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;
> + ret = __pci_epc_mem_init(epc, &mem_window, 1, ep->page_size);
> if (ret < 0) {
> dev_err(dev, "Failed to initialize address space\n");
> return ret;
> }
>
> - ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
> - epc->mem->page_size);
> + msi_page_size = epc->mem[PCI_EPC_DEFAULT_WINDOW]->page_size;
> + ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys, &window,
> + 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-cadence-ep.c b/drivers/pci/controller/pcie-cadence-ep.c
> index def7820cb824..7991b38a5350 100644
> --- a/drivers/pci/controller/pcie-cadence-ep.c
> +++ b/drivers/pci/controller/pcie-cadence-ep.c
> @@ -172,7 +172,7 @@ static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
> }
>
> static int cdns_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, phys_addr_t addr,
> - u64 pci_addr, size_t size)
> + int window, u64 pci_addr, size_t size)
> {
> struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> struct cdns_pcie *pcie = &ep->pcie;
> @@ -434,12 +434,14 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct device_node *np = dev->of_node;
> + struct pci_epc_mem_window mem_window;
> struct cdns_pcie_ep *ep;
> struct cdns_pcie *pcie;
> struct pci_epc *epc;
> struct resource *res;
> int ret;
> int phy_count;
> + int window;
>
> ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
> if (!ep)
> @@ -502,15 +504,16 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
> 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);
> + ret = pci_epc_mem_init(epc, &mem_window, 1);
> if (ret < 0) {
> dev_err(dev, "failed to initialize the memory space\n");
> goto err_init;
> }
>
> ep->irq_cpu_addr = pci_epc_mem_alloc_addr(epc, &ep->irq_phys_addr,
> - SZ_128K);
> + &window, SZ_128K);
> if (!ep->irq_cpu_addr) {
> dev_err(dev, "failed to reserve memory space for MSI\n");
> ret = -ENOMEM;
> diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
> index d743b0a48988..d59e85c8d319 100644
> --- a/drivers/pci/controller/pcie-rockchip-ep.c
> +++ b/drivers/pci/controller/pcie-rockchip-ep.c
> @@ -256,8 +256,8 @@ static void rockchip_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
> }
>
> static int rockchip_pcie_ep_map_addr(struct pci_epc *epc, u8 fn,
> - phys_addr_t addr, u64 pci_addr,
> - size_t size)
> + phys_addr_t addr, int window,
> + u64 pci_addr, size_t size)
> {
> struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
> struct rockchip_pcie *pcie = &ep->rockchip;
> @@ -562,11 +562,13 @@ 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;
> struct pci_epc *epc;
> size_t max_regions;
> + int window;
> int err;
>
> ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
> @@ -614,15 +616,16 @@ 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);
> + 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;
> }
>
> ep->irq_cpu_addr = pci_epc_mem_alloc_addr(epc, &ep->irq_phys_addr,
> - SZ_128K);
> + &window, SZ_128K);
> if (!ep->irq_cpu_addr) {
> dev_err(dev, "failed to reserve memory space for MSI\n");
> err = -ENOMEM;
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 5d74f81ddfe4..475228011703 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -84,8 +84,10 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
> struct pci_epc *epc = epf->epc;
> enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
> + int window;
>
> - src_addr = pci_epc_mem_alloc_addr(epc, &src_phys_addr, reg->size);
> + src_addr = pci_epc_mem_alloc_addr(epc, &src_phys_addr,
> + &window, reg->size);
> if (!src_addr) {
> dev_err(dev, "Failed to allocate source address\n");
> reg->status = STATUS_SRC_ADDR_INVALID;
> @@ -93,15 +95,16 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
> goto err;
> }
>
> - ret = pci_epc_map_addr(epc, epf->func_no, src_phys_addr, reg->src_addr,
> - reg->size);
> + ret = pci_epc_map_addr(epc, epf->func_no, src_phys_addr, window,
> + reg->src_addr, reg->size);
> if (ret) {
> dev_err(dev, "Failed to map source address\n");
> reg->status = STATUS_SRC_ADDR_INVALID;
> goto err_src_addr;
> }
>
> - dst_addr = pci_epc_mem_alloc_addr(epc, &dst_phys_addr, reg->size);
> + dst_addr = pci_epc_mem_alloc_addr(epc, &dst_phys_addr,
> + &window, reg->size);
> if (!dst_addr) {
> dev_err(dev, "Failed to allocate destination address\n");
> reg->status = STATUS_DST_ADDR_INVALID;
> @@ -109,8 +112,8 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
> goto err_src_map_addr;
> }
>
> - ret = pci_epc_map_addr(epc, epf->func_no, dst_phys_addr, reg->dst_addr,
> - reg->size);
> + ret = pci_epc_map_addr(epc, epf->func_no, dst_phys_addr, window,
> + reg->dst_addr, reg->size);
> if (ret) {
> dev_err(dev, "Failed to map destination address\n");
> reg->status = STATUS_DST_ADDR_INVALID;
> @@ -146,8 +149,9 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
> struct pci_epc *epc = epf->epc;
> enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
> + int window;
>
> - src_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, reg->size);
> + src_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, &window, reg->size);
> if (!src_addr) {
> dev_err(dev, "Failed to allocate address\n");
> reg->status = STATUS_SRC_ADDR_INVALID;
> @@ -155,8 +159,8 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
> goto err;
> }
>
> - ret = pci_epc_map_addr(epc, epf->func_no, phys_addr, reg->src_addr,
> - reg->size);
> + ret = pci_epc_map_addr(epc, epf->func_no, phys_addr, window,
> + reg->src_addr, reg->size);
> if (ret) {
> dev_err(dev, "Failed to map address\n");
> reg->status = STATUS_SRC_ADDR_INVALID;
> @@ -193,13 +197,14 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
> void __iomem *dst_addr;
> void *buf;
> phys_addr_t phys_addr;
> + int window;
> struct pci_epf *epf = epf_test->epf;
> struct device *dev = &epf->dev;
> struct pci_epc *epc = epf->epc;
> enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
>
> - dst_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, reg->size);
> + dst_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, &window, reg->size);
> if (!dst_addr) {
> dev_err(dev, "Failed to allocate address\n");
> reg->status = STATUS_DST_ADDR_INVALID;
> @@ -207,8 +212,8 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
> goto err;
> }
>
> - ret = pci_epc_map_addr(epc, epf->func_no, phys_addr, reg->dst_addr,
> - reg->size);
> + ret = pci_epc_map_addr(epc, epf->func_no, phys_addr, window,
> + reg->dst_addr, reg->size);
> if (ret) {
> dev_err(dev, "Failed to map address\n");
> reg->status = STATUS_DST_ADDR_INVALID;
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index 2091508c1620..289c266c2d90 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -358,13 +358,15 @@ EXPORT_SYMBOL_GPL(pci_epc_unmap_addr);
> * @epc: the EPC device on which address is allocated
> * @func_no: the endpoint function number in the EPC device
> * @phys_addr: physical address of the local system
> + * @window: index to the window region where PCI address will be mapped
> * @pci_addr: PCI address to which the physical address should be mapped
> * @size: the size of the allocation
> *
> * Invoke to map CPU address with PCI address.
> */
> 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, int window,
> + u64 pci_addr, size_t size)
> {
> int ret;
> unsigned long flags;
> @@ -376,7 +378,8 @@ int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
> return 0;
>
> spin_lock_irqsave(&epc->lock, flags);
> - ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size);
> + ret = epc->ops->map_addr(epc, func_no, phys_addr,
> + window, pci_addr, size);
> spin_unlock_irqrestore(&epc->lock, flags);
>
> return ret;
> diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
> index d2b174ce15de..c955f2c97944 100644
> --- a/drivers/pci/endpoint/pci-epc-mem.c
> +++ b/drivers/pci/endpoint/pci-epc-mem.c
> @@ -39,56 +39,77 @@ 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
> + * @num_windows: number of windows device supports
struct pci_epc_mem_window is missing here.
> * @page_size: size of each page
> *
> * 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, 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;
>
> 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;
> - }
> + epc->mem = kcalloc(num_windows, sizeof(*mem), GFP_KERNEL);
> + if (!epc->mem)
> + return -EINVAL;
>
> - bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> - if (!bitmap) {
> - ret = -ENOMEM;
> - goto err_mem;
> - }
> + for (i = 0; i < num_windows; i++) {
> + pages = windows[i].phys_base >> page_shift;
> + bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
>
> - mem->bitmap = bitmap;
> - mem->phys_base = phys_base;
> - mem->page_size = page_size;
> - mem->pages = pages;
> - mem->size = size;
> + mem = kzalloc(sizeof(*mem), GFP_KERNEL);
> + if (!mem) {
> + ret = -ENOMEM;
> + goto err_mem;
> + }
>
> - epc->mem = 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;
> + mem->page_size = page_size;
> + mem->pages = pages;
> + mem->window.size = windows[i].size;
> + mem->window.map_size = 0;
> +
> + epc->mem[i] = mem;
> + }
> + epc->mem_windows = num_windows;
>
> return 0;
>
> err_mem:
> - kfree(mem);
> + for (; i >= 0; i--) {
> + kfree(mem->bitmap);
> + kfree(epc->mem[i]);
> + }
> + kfree(epc->mem);
>
> -err:
> -return ret;
> + return ret;
> }
> EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
>
> @@ -101,48 +122,126 @@ 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(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)
> +{
> + size_t window_least_size = 0;
> + int best_fit_window = -1;
> + struct pci_epc_mem *mem;
> + size_t actual_size;
> + int i;
> +
> + for (i = 0; i < epc->mem_windows; i++) {
> + mem = epc->mem[i];
> +
> + /* if chunk from this region is already used skip it */
> + if (mem->window.map_size)
> + continue;
> +
> + actual_size = ALIGN(size, mem->page_size);
> +
> + if (best_fit_window == -1) {
> + best_fit_window = i;
> + window_least_size = mem->window.size;
> + } else {
> + if (actual_size <= mem->window.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
> *
> * 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)
> {
> + 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) {
> + best_fit = pci_epc_find_best_fit_window(epc, size);
> + 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;
Assume I have two mem regions, first region is of size 128MB and the second
region is of size 4GB. If there is a allocation request for 4GB, will the
allocation succeed?
Thanks
Kishon