Re: [PATCH 2/5] pci: endpoint: add support to handle multiple base for mapping outbound memory
From: Lad, Prabhakar
Date: Wed Nov 27 2019 - 16:22:01 EST
Hi Kishon,
Thank you for the review.
On Wed, Nov 27, 2019 at 5:15 AM Kishon Vijay Abraham I <kishon@xxxxxx> wrote:
>
> 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.
oops my bad will fix that.
> > * @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?
>
yes it would succeed, the pci_epc_find_best_fit_window() would get the
corresponding window.
Cheers,
--Prabhakar Lad