diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/endpoint/functions/pci-epf-test.c | 205 |
1 files changed, 202 insertions, 3 deletions
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index be04c6220265..737e15d9e5dc 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -8,6 +8,7 @@ #include <linux/crc32.h> #include <linux/delay.h> +#include <linux/dmaengine.h> #include <linux/io.h> #include <linux/module.h> #include <linux/slab.h> @@ -39,6 +40,8 @@ #define STATUS_SRC_ADDR_INVALID BIT(7) #define STATUS_DST_ADDR_INVALID BIT(8) +#define FLAG_USE_DMA BIT(0) + #define TIMER_RESOLUTION 1 static struct workqueue_struct *kpcitest_workqueue; @@ -48,6 +51,9 @@ struct pci_epf_test { struct pci_epf *epf; enum pci_barno test_reg_bar; struct delayed_work cmd_handler; + struct dma_chan *dma_chan; + struct completion transfer_complete; + bool dma_supported; const struct pci_epc_features *epc_features; }; @@ -61,6 +67,7 @@ struct pci_epf_test_reg { u32 checksum; u32 irq_type; u32 irq_number; + u32 flags; } __packed; static struct pci_epf_header test_header = { @@ -72,9 +79,121 @@ static struct pci_epf_header test_header = { static size_t bar_size[] = { 512, 512, 1024, 16384, 131072, 1048576 }; +static void pci_epf_test_dma_callback(void *param) +{ + struct pci_epf_test *epf_test = param; + + complete(&epf_test->transfer_complete); +} + +/** + * pci_epf_test_data_transfer() - Function that uses dmaengine API to transfer + * data between PCIe EP and remote PCIe RC + * @epf_test: the EPF test device that performs the data transfer operation + * @dma_dst: The destination address of the data transfer. It can be a physical + * address given by pci_epc_mem_alloc_addr or DMA mapping APIs. + * @dma_src: The source address of the data transfer. It can be a physical + * address given by pci_epc_mem_alloc_addr or DMA mapping APIs. + * @len: The size of the data transfer + * + * Function that uses dmaengine API to transfer data between PCIe EP and remote + * PCIe RC. The source and destination address can be a physical address given + * by pci_epc_mem_alloc_addr or the one obtained using DMA mapping APIs. + * + * The function returns '0' on success and negative value on failure. + */ +static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test, + dma_addr_t dma_dst, dma_addr_t dma_src, + size_t len) +{ + enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT; + struct dma_chan *chan = epf_test->dma_chan; + struct pci_epf *epf = epf_test->epf; + struct dma_async_tx_descriptor *tx; + struct device *dev = &epf->dev; + dma_cookie_t cookie; + int ret; + + if (IS_ERR_OR_NULL(chan)) { + dev_err(dev, "Invalid DMA memcpy channel\n"); + return -EINVAL; + } + + tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len, flags); + if (!tx) { + dev_err(dev, "Failed to prepare DMA memcpy\n"); + return -EIO; + } + + tx->callback = pci_epf_test_dma_callback; + tx->callback_param = epf_test; + cookie = tx->tx_submit(tx); + reinit_completion(&epf_test->transfer_complete); + + ret = dma_submit_error(cookie); + if (ret) { + dev_err(dev, "Failed to do DMA tx_submit %d\n", cookie); + return -EIO; + } + + dma_async_issue_pending(chan); + ret = wait_for_completion_interruptible(&epf_test->transfer_complete); + if (ret < 0) { + dmaengine_terminate_sync(chan); + dev_err(dev, "DMA wait_for_completion_timeout\n"); + return -ETIMEDOUT; + } + + return 0; +} + +/** + * pci_epf_test_init_dma_chan() - Function to initialize EPF test DMA channel + * @epf_test: the EPF test device that performs data transfer operation + * + * Function to initialize EPF test DMA channel. + */ +static int pci_epf_test_init_dma_chan(struct pci_epf_test *epf_test) +{ + struct pci_epf *epf = epf_test->epf; + struct device *dev = &epf->dev; + struct dma_chan *dma_chan; + dma_cap_mask_t mask; + int ret; + + dma_cap_zero(mask); + dma_cap_set(DMA_MEMCPY, mask); + + dma_chan = dma_request_chan_by_mask(&mask); + if (IS_ERR(dma_chan)) { + ret = PTR_ERR(dma_chan); + if (ret != -EPROBE_DEFER) + dev_err(dev, "Failed to get DMA channel\n"); + return ret; + } + init_completion(&epf_test->transfer_complete); + + epf_test->dma_chan = dma_chan; + + return 0; +} + +/** + * pci_epf_test_clean_dma_chan() - Function to cleanup EPF test DMA channel + * @epf: the EPF test device that performs data transfer operation + * + * Helper to cleanup EPF test DMA channel. + */ +static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test) +{ + dma_release_channel(epf_test->dma_chan); + epf_test->dma_chan = NULL; +} + static int pci_epf_test_copy(struct pci_epf_test *epf_test) { int ret; + bool use_dma; void __iomem *src_addr; void __iomem *dst_addr; phys_addr_t src_phys_addr; @@ -117,8 +236,23 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test) goto err_dst_addr; } - memcpy(dst_addr, src_addr, reg->size); + use_dma = !!(reg->flags & FLAG_USE_DMA); + if (use_dma) { + if (!epf_test->dma_supported) { + dev_err(dev, "Cannot transfer data using DMA\n"); + ret = -EINVAL; + goto err_map_addr; + } + ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr, + src_phys_addr, reg->size); + if (ret) + dev_err(dev, "Data transfer failed\n"); + } else { + memcpy(dst_addr, src_addr, reg->size); + } + +err_map_addr: pci_epc_unmap_addr(epc, epf->func_no, dst_phys_addr); err_dst_addr: @@ -140,10 +274,13 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test) void __iomem *src_addr; void *buf; u32 crc32; + bool use_dma; phys_addr_t phys_addr; + phys_addr_t dst_phys_addr; struct pci_epf *epf = epf_test->epf; struct device *dev = &epf->dev; struct pci_epc *epc = epf->epc; + struct device *dma_dev = epf->epc->dev.parent; enum pci_barno test_reg_bar = epf_test->test_reg_bar; struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar]; @@ -169,12 +306,38 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test) goto err_map_addr; } - memcpy_fromio(buf, src_addr, reg->size); + use_dma = !!(reg->flags & FLAG_USE_DMA); + if (use_dma) { + if (!epf_test->dma_supported) { + dev_err(dev, "Cannot transfer data using DMA\n"); + ret = -EINVAL; + goto err_dma_map; + } + + dst_phys_addr = dma_map_single(dma_dev, buf, reg->size, + DMA_FROM_DEVICE); + if (dma_mapping_error(dma_dev, dst_phys_addr)) { + dev_err(dev, "Failed to map destination buffer addr\n"); + ret = -ENOMEM; + goto err_dma_map; + } + + ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr, + phys_addr, reg->size); + if (ret) + dev_err(dev, "Data transfer failed\n"); + + dma_unmap_single(dma_dev, dst_phys_addr, reg->size, + DMA_FROM_DEVICE); + } else { + memcpy_fromio(buf, src_addr, reg->size); + } crc32 = crc32_le(~0, buf, reg->size); if (crc32 != reg->checksum) ret = -EIO; +err_dma_map: kfree(buf); err_map_addr: @@ -192,10 +355,13 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test) int ret; void __iomem *dst_addr; void *buf; + bool use_dma; phys_addr_t phys_addr; + phys_addr_t src_phys_addr; struct pci_epf *epf = epf_test->epf; struct device *dev = &epf->dev; struct pci_epc *epc = epf->epc; + struct device *dma_dev = epf->epc->dev.parent; enum pci_barno test_reg_bar = epf_test->test_reg_bar; struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar]; @@ -224,7 +390,32 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test) get_random_bytes(buf, reg->size); reg->checksum = crc32_le(~0, buf, reg->size); - memcpy_toio(dst_addr, buf, reg->size); + use_dma = !!(reg->flags & FLAG_USE_DMA); + if (use_dma) { + if (!epf_test->dma_supported) { + dev_err(dev, "Cannot transfer data using DMA\n"); + ret = -EINVAL; + goto err_map_addr; + } + + src_phys_addr = dma_map_single(dma_dev, buf, reg->size, + DMA_TO_DEVICE); + if (dma_mapping_error(dma_dev, src_phys_addr)) { + dev_err(dev, "Failed to map source buffer addr\n"); + ret = -ENOMEM; + goto err_dma_map; + } + + ret = pci_epf_test_data_transfer(epf_test, phys_addr, + src_phys_addr, reg->size); + if (ret) + dev_err(dev, "Data transfer failed\n"); + + dma_unmap_single(dma_dev, src_phys_addr, reg->size, + DMA_TO_DEVICE); + } else { + memcpy_toio(dst_addr, buf, reg->size); + } /* * wait 1ms inorder for the write to complete. Without this delay L3 @@ -232,6 +423,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test) */ usleep_range(1000, 2000); +err_dma_map: kfree(buf); err_map_addr: @@ -368,6 +560,7 @@ static void pci_epf_test_unbind(struct pci_epf *epf) int bar; cancel_delayed_work(&epf_test->cmd_handler); + pci_epf_test_clean_dma_chan(epf_test); pci_epc_stop(epc); for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) { epf_bar = &epf->bar[bar]; @@ -586,6 +779,12 @@ static int pci_epf_test_bind(struct pci_epf *epf) return ret; } + epf_test->dma_supported = true; + + ret = pci_epf_test_init_dma_chan(epf_test); + if (ret) + epf_test->dma_supported = false; + if (linkup_notifier) { epf->nb.notifier_call = pci_epf_test_notifier; pci_epc_register_notifier(epc, &epf->nb); |