PCI: endpoint: Add support to handle multiple base for mapping outbound memory

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() initializes address space for endpoint
controller which support single window and pci_epc_multi_mem_init()
initializes multiple windows supported by endpoint controller.

Link: https://lore.kernel.org/r/1588854799-13710-6-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 1cdcbd102ce86830a424bd790bd653717b3eb578..a78902cbf2f0c54cb0470a1c6812427ad455409b 100644 (file)
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -412,11 +412,11 @@ 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);
+                                 epc->mem->window.page_size);
        if (ret)
                return ret;
 
@@ -459,9 +459,9 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
                return -EPERM;
        }
 
-       aligned_offset = msg_addr & (epc->mem->page_size - 1);
+       aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
        ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys,  msg_addr,
-                                 epc->mem->page_size);
+                                 epc->mem->window.page_size);
        if (ret)
                return ret;
 
@@ -477,7 +477,7 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
        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);
 }
@@ -610,15 +610,15 @@ 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);
+       ret = pci_epc_mem_init(epc, ep->phys_base, ep->addr_size,
+                              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);
+                                            epc->mem->window.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/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
index cdd1d38212492b892240a85107d07b869ded5e07..80c46f3a459090794e10e89d9a7441197a3842f0 100644 (file)
--- a/drivers/pci/endpoint/pci-epc-mem.c
+++ b/drivers/pci/endpoint/pci-epc-mem.c
@@ -23,7 +23,7 @@
 static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)
 {
        int order;
-       unsigned int page_shift = ilog2(mem->page_size);
+       unsigned int page_shift = ilog2(mem->window.page_size);
 
        size--;
        size >>= page_shift;
@@ -36,67 +36,95 @@ 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
+ * pci_epc_multi_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_multi_mem_init(struct pci_epc *epc,
+                          struct pci_epc_mem_window *windows,
+                          unsigned 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;
+       int pages;
+       int ret;
+       int i;
 
-       if (page_size < PAGE_SIZE)
-               page_size = PAGE_SIZE;
+       epc->num_windows = 0;
 
-       page_shift = ilog2(page_size);
-       pages = size >> page_shift;
-       bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
+       if (!windows || !num_windows)
+               return -EINVAL;
 
-       mem = kzalloc(sizeof(*mem), GFP_KERNEL);
-       if (!mem) {
-               ret = -ENOMEM;
-               goto err;
-       }
+       epc->windows = kcalloc(num_windows, sizeof(*epc->windows), GFP_KERNEL);
+       if (!epc->windows)
+               return -ENOMEM;
 
-       bitmap = kzalloc(bitmap_size, GFP_KERNEL);
-       if (!bitmap) {
-               ret = -ENOMEM;
-               goto err_mem;
-       }
+       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->bitmap = bitmap;
-       mem->phys_base = phys_base;
-       mem->page_size = page_size;
-       mem->pages = pages;
-       mem->size = size;
-       mutex_init(&mem->lock);
+               mem = kzalloc(sizeof(*mem), GFP_KERNEL);
+               if (!mem) {
+                       ret = -ENOMEM;
+                       i--;
+                       goto err_mem;
+               }
 
-       epc->mem = mem;
+               bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+               if (!bitmap) {
+                       ret = -ENOMEM;
+                       kfree(mem);
+                       i--;
+                       goto err_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;
+       }
+
+       epc->mem = epc->windows[0];
+       epc->num_windows = num_windows;
 
        return 0;
 
 err_mem:
-       kfree(mem);
+       for (; i >= 0; i--) {
+               mem = epc->windows[i];
+               kfree(mem->bitmap);
+               kfree(mem);
+       }
+       kfree(epc->windows);
 
-err:
-return ret;
+       return ret;
 }
-EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
+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)
 {
-       return __pci_epc_mem_init(epc, base, size, page_size);
+       struct pci_epc_mem_window mem_window;
+
+       mem_window.phys_base = base;
+       mem_window.size = size;
+       mem_window.page_size = page_size;
+
+       return pci_epc_multi_mem_init(epc, &mem_window, 1);
 }
 EXPORT_SYMBOL_GPL(pci_epc_mem_init);
 
@@ -109,11 +137,22 @@ 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->num_windows)
+               return;
+
+       for (i = 0; i < epc->num_windows; i++) {
+               mem = epc->windows[i];
+               kfree(mem->bitmap);
+               kfree(mem);
+       }
+       kfree(epc->windows);
+
+       epc->windows = NULL;
        epc->mem = NULL;
-       kfree(mem->bitmap);
-       kfree(mem);
+       epc->num_windows = 0;
 }
 EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
 
@@ -129,31 +168,60 @@ 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 = NULL;
-       struct pci_epc_mem *mem = epc->mem;
-       unsigned int page_shift = ilog2(mem->page_size);
+       struct pci_epc_mem *mem;
+       unsigned int page_shift;
+       size_t align_size;
+       int pageno;
        int order;
+       int i;
 
-       size = ALIGN(size, mem->page_size);
-       order = pci_epc_mem_get_order(mem, size);
-
-       mutex_lock(&mem->lock);
-       pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
-       if (pageno < 0)
-               goto ret;
+       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);
 
-       *phys_addr = mem->phys_base + ((phys_addr_t)pageno << page_shift);
-       virt_addr = ioremap(*phys_addr, size);
-       if (!virt_addr)
-               bitmap_release_region(mem->bitmap, pageno, order);
+               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);
+       }
 
-ret:
-       mutex_unlock(&mem->lock);
        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,
+                                                      phys_addr_t phys_addr)
+{
+       struct pci_epc_mem *mem;
+       int i;
+
+       for (i = 0; i < epc->num_windows; i++) {
+               mem = epc->windows[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
@@ -166,14 +234,23 @@ 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;
+       size_t page_size;
        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_size = mem->window.page_size;
+       page_shift = ilog2(page_size);
        iounmap(virt_addr);
-       pageno = (phys_addr - mem->phys_base) >> page_shift;
-       size = ALIGN(size, mem->page_size);
+       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);

diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 5bc1de65849e4dd18be926316f20def13ff39fb5..cc66bec8be9051e4c826d5430b43d859a0a82bd3 100644 (file)
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -65,20 +65,28 @@ struct pci_epc_ops {
        struct module *owner;
 };
 
+/**
+ * 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
  * @lock: mutex to protect bitmap
  */
 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;
        /* mutex to protect against concurrent access for memory allocation*/
        struct mutex    lock;
@@ -89,7 +97,11 @@ 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
+ * @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
  * @group: configfs group representing the PCI EPC device
  * @lock: mutex to protect pci_epc ops
@@ -100,7 +112,9 @@ struct pci_epc {
        struct device                   dev;
        struct list_head                pci_epf;
        const struct pci_epc_ops        *ops;
+       struct pci_epc_mem              **windows;
        struct pci_epc_mem              *mem;
+       unsigned int                    num_windows;
        u8                              max_functions;
        struct config_group             *group;
        /* mutex to protect against concurrent access of EP controller */
@@ -194,8 +208,9 @@ void pci_epc_put(struct pci_epc *epc);
 
 int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t base,
                     size_t size, size_t page_size);
-int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_addr, size_t size,
-                      size_t page_size);
+int pci_epc_multi_mem_init(struct pci_epc *epc,
+                          struct pci_epc_mem_window *window,
+                          unsigned 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);