pcie: endpoint: Introduce API to achieve PCIe data transfer

Introduce common API to achieve data transfer using memcpy
to/from outbound region of PCIe EP.

Signed-off-by: Abhishek Shah <abhishek.shah@broadcom.com>
This commit is contained in:
Abhishek Shah 2020-05-07 10:23:15 +05:30 committed by Andrew Boie
commit 3c2fa8cd51
3 changed files with 128 additions and 0 deletions

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@ -1 +1,3 @@
# SPDX-License-Identifier: Apache-2.0
zephyr_sources(pcie_ep_common.c)

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@ -0,0 +1,110 @@
/*
* SPDX-License-Identifier: Apache-2.0
*
* Copyright 2020 Broadcom
*
*/
#include <drivers/pcie/endpoint/pcie_ep.h>
#include <string.h>
#include <sys/util.h>
static int pcie_ep_mapped_copy(uint64_t mapped_addr, uintptr_t local_addr,
const uint32_t size,
const enum xfer_direction dir)
{
/*
* Make sure that address can be generated by core, this condition
* would not hit if proper pcie_ob_mem_type is passed by core
*/
if ((!IS_ENABLED(CONFIG_64BIT)) && (mapped_addr >> 32)) {
return -EINVAL;
}
if (dir == DEVICE_TO_HOST) {
memcpy(UINT_TO_POINTER(mapped_addr),
UINT_TO_POINTER(local_addr), size);
} else {
memcpy(UINT_TO_POINTER(local_addr),
UINT_TO_POINTER(mapped_addr), size);
}
return 0;
}
/*
* Helper API to achieve data transfer with memcpy operation
* through PCIe outbound memory
*/
int pcie_ep_xfer_data_memcpy(struct device *dev, uint64_t pcie_addr,
uintptr_t *local_addr, uint32_t size,
enum pcie_ob_mem_type ob_mem_type,
enum xfer_direction dir)
{
uint64_t mapped_addr;
int mapped_size, ret;
uint32_t xfer_size, unmapped_size;
mapped_size = pcie_ep_map_addr(dev, pcie_addr, &mapped_addr,
size, ob_mem_type);
/* Check if outbound memory mapping succeeded */
if (mapped_size < 0) {
return mapped_size;
}
ret = pcie_ep_mapped_copy(mapped_addr, (uintptr_t)local_addr,
mapped_size, dir);
pcie_ep_unmap_addr(dev, mapped_addr);
/* Check if mapped_copy succeeded */
if (ret < 0) {
return ret;
}
/* Check if we achieved data transfer for given size */
if (mapped_size == size) {
return 0;
}
/*
* In normal case, we are done with data transfer by now,
* but some PCIe address translation hardware requires us to
* align Host address to be mapped to the translation window size.
* So, even though translation window size is good enough for
* size of Host buffer, we may not be able to map entire Host buffer
* to given outbound window in one time, and we may need to map
* ramaining size and complete remaining data transfer
*/
xfer_size = mapped_size; /* save already tranferred data size */
unmapped_size = size - mapped_size;
mapped_size = pcie_ep_map_addr(dev, pcie_addr + xfer_size,
&mapped_addr, unmapped_size,
ob_mem_type);
/* Check if outbound memory mapping succeeded */
if (mapped_size < 0) {
return mapped_size;
}
ret = pcie_ep_mapped_copy(mapped_addr,
((uintptr_t)local_addr) + xfer_size,
mapped_size, dir);
pcie_ep_unmap_addr(dev, mapped_addr);
/* Check if mapped_copy succeeded */
if (ret < 0) {
return ret;
}
/* In second attempt, we must have completed data transfer */
if (mapped_size != unmapped_size) {
return -EIO;
}
return 0;
}

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@ -30,6 +30,11 @@ enum pci_ep_irq_type {
PCIE_EP_IRQ_MSIX, /**< Raise MSIX interrupt */
};
enum xfer_direction {
HOST_TO_DEVICE, /**< Read from Host */
DEVICE_TO_HOST, /**< Write to Host */
};
struct pcie_ep_driver_api {
int (*conf_read)(struct device *dev, uint32_t offset, uint32_t *data);
void (*conf_write)(struct device *dev, uint32_t offset, uint32_t data);
@ -160,4 +165,15 @@ static inline int pcie_ep_raise_irq(struct device *dev,
return api->raise_irq(dev, irq_type, irq_num);
}
/**
* @brief Data transfer using memcpy
*
* @details Helper API to achieve data transfer with memcpy
* through PCIe outbound memory
*/
int pcie_ep_xfer_data_memcpy(struct device *dev, uint64_t pcie_addr,
uintptr_t *local_addr, uint32_t size,
enum pcie_ob_mem_type ob_mem_type,
enum xfer_direction dir);
#endif /* ZEPHYR_INCLUDE_DRIVERS_PCIE_EP_H_ */