[PATCH v4 3/6] PCI: endpoint: Add support to handle multiple base for mapping outbound memory

From: Lad Prabhakar
Date: Sat Feb 08 2020 - 13:37:14 EST


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 | 166 ++++++++++++++++-------
include/linux/pci-epc.h | 39 ++++--
5 files changed, 168 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);
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..b3eedee 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;
+ 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);
+ 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 +182,22 @@ 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 (mem->window.phys_base == phys_addr)
+ 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 +210,20 @@ 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
+ * @mem: array of address space of the endpoint controller
+ * @mem_windows: number of windows supported by device
* @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)

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);
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