PCI: endpoint: functions/pci-epf-test: Print throughput information

Print throughput information in KB/s after every completed transfer,
including information on whether DMA is used or not.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Alan Mikhak <alan.mikhak@sifive.com>

drivers/pci/endpoint/functions/pci-epf-test.c

@@ -190,6 +190,36 @@ static void pci_epf_test_clean_dma_chan(struct pci_epf_test *epf_test)
 	epf_test->dma_chan = NULL;
 }
 
+static void pci_epf_test_print_rate(const char *ops, u64 size,
+				    struct timespec64 *start,
+				    struct timespec64 *end, bool dma)
+{
+	struct timespec64 ts;
+	u64 rate, ns;
+
+	ts = timespec64_sub(*end, *start);
+
+	/* convert both size (stored in 'rate') and time in terms of 'ns' */
+	ns = timespec64_to_ns(&ts);
+	rate = size * NSEC_PER_SEC;
+
+	/* Divide both size (stored in 'rate') and ns by a common factor */
+	while (ns > UINT_MAX) {
+		rate >>= 1;
+		ns >>= 1;
+	}
+
+	if (!ns)
+		return;
+
+	/* calculate the rate */
+	do_div(rate, (uint32_t)ns);
+
+	pr_info("\n%s => Size: %llu bytes\t DMA: %s\t Time: %llu.%09u seconds\t"
+		"Rate: %llu KB/s\n", ops, size, dma ? "YES" : "NO",
+		(u64)ts.tv_sec, (u32)ts.tv_nsec, rate / 1024);
+}
+
 static int pci_epf_test_copy(struct pci_epf_test *epf_test)
 {
 	int ret;
@@ -198,6 +228,7 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
 	void __iomem *dst_addr;
 	phys_addr_t src_phys_addr;
 	phys_addr_t dst_phys_addr;
+	struct timespec64 start, end;
 	struct pci_epf *epf = epf_test->epf;
 	struct device *dev = &epf->dev;
 	struct pci_epc *epc = epf->epc;
@@ -236,6 +267,7 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
 		goto err_dst_addr;
 	}
 
+	ktime_get_ts64(&start);
 	use_dma = !!(reg->flags & FLAG_USE_DMA);
 	if (use_dma) {
 		if (!epf_test->dma_supported) {
@@ -251,6 +283,8 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
 	} else {
 		memcpy(dst_addr, src_addr, reg->size);
 	}
+	ktime_get_ts64(&end);
+	pci_epf_test_print_rate("COPY", reg->size, &start, &end, use_dma);
 
 err_map_addr:
 	pci_epc_unmap_addr(epc, epf->func_no, dst_phys_addr);
@@ -277,6 +311,7 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
 	bool use_dma;
 	phys_addr_t phys_addr;
 	phys_addr_t dst_phys_addr;
+	struct timespec64 start, end;
 	struct pci_epf *epf = epf_test->epf;
 	struct device *dev = &epf->dev;
 	struct pci_epc *epc = epf->epc;
@@ -322,17 +357,23 @@ static int pci_epf_test_read(struct pci_epf_test *epf_test)
 			goto err_dma_map;
 		}
 
+		ktime_get_ts64(&start);
 		ret = pci_epf_test_data_transfer(epf_test, dst_phys_addr,
 						 phys_addr, reg->size);
 		if (ret)
 			dev_err(dev, "Data transfer failed\n");
+		ktime_get_ts64(&end);
 
 		dma_unmap_single(dma_dev, dst_phys_addr, reg->size,
 				 DMA_FROM_DEVICE);
 	} else {
+		ktime_get_ts64(&start);
 		memcpy_fromio(buf, src_addr, reg->size);
+		ktime_get_ts64(&end);
 	}
 
+	pci_epf_test_print_rate("READ", reg->size, &start, &end, use_dma);
+
 	crc32 = crc32_le(~0, buf, reg->size);
 	if (crc32 != reg->checksum)
 		ret = -EIO;
@@ -358,6 +399,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
 	bool use_dma;
 	phys_addr_t phys_addr;
 	phys_addr_t src_phys_addr;
+	struct timespec64 start, end;
 	struct pci_epf *epf = epf_test->epf;
 	struct device *dev = &epf->dev;
 	struct pci_epc *epc = epf->epc;
@@ -406,17 +448,23 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test)
 			goto err_dma_map;
 		}
 
+		ktime_get_ts64(&start);
 		ret = pci_epf_test_data_transfer(epf_test, phys_addr,
 						 src_phys_addr, reg->size);
 		if (ret)
 			dev_err(dev, "Data transfer failed\n");
+		ktime_get_ts64(&end);
 
 		dma_unmap_single(dma_dev, src_phys_addr, reg->size,
 				 DMA_TO_DEVICE);
 	} else {
+		ktime_get_ts64(&start);
 		memcpy_toio(dst_addr, buf, reg->size);
+		ktime_get_ts64(&end);
 	}
 
+	pci_epf_test_print_rate("WRITE", reg->size, &start, &end, use_dma);
+
 	/*
 	 * wait 1ms inorder for the write to complete. Without this delay L3
 	 * error in observed in the host system.