[cip-dev] [RFC PATCH 4.19.y-cip 34/50] PCI: endpoint: Add support to handle multiple base for mapping outbound memory

Lad Prabhakar
2020-10-12T14:21:06Z

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commit d45e3c1a5979efd40dbbac9a5c3586f4fa41f734 upstream.

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>
[PL: manually applied changes to pcie-designware-ep.c]
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
.../pci/controller/dwc/pcie-designware-ep.c | 12 +-
drivers/pci/endpoint/pci-epc-mem.c | 199 ++++++++++++------
include/linux/pci-epc.h | 33 ++-
3 files changed, 168 insertions(+), 76 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 667763fd868f..471855feab03 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -434,11 +434,11 @@ 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;

@@ -495,7 +495,7 @@ 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);
+ epc->mem->window.page_size);
if (ret)
return ret;

@@ -511,7 +511,7 @@ 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);
}
@@ -586,7 +586,7 @@ 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,
+ 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");
@@ -594,7 +594,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
}

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 cdd1d3821249..80c46f3a4590 100644
--- 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 e5f6ca8c36a8..5adb881bbcd7 100644
--- 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);
--
2.17.1

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