iop-adma: P+Q self test

Even though the intent is to extend dmatest with P+Q tests there is
still value in having an always-on sanity check to prevent an
unintentionally broken driver from registering.

This depends on raid6_pq.ko for verification, the side effect being that
PQ capable channels will fail to register when raid6 is disabled.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 181 insertions, 1 deletions

diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c
index 5a0f4fe2ee6..f4c59e59f6c 100644
--- a/drivers/dma/iop-adma.c
+++ b/drivers/dma/iop-adma.c
@@ -31,6 +31,7 @@
 #include <linux/platform_device.h>
 #include <linux/memory.h>
 #include <linux/ioport.h>
+#include <linux/raid/pq.h>
 
 #include <mach/adma.h>
 
@@ -1267,6 +1268,170 @@ out:
         return err;
 }
 
+#ifdef CONFIG_MD_RAID6_PQ
+static int __devinit
+iop_adma_pq_zero_sum_self_test(struct iop_adma_device *device)
+{
+        /* combined sources, software pq results, and extra hw pq results */
+        struct page *pq[IOP_ADMA_NUM_SRC_TEST+2+2];
+        /* ptr to the extra hw pq buffers defined above */
+        struct page **pq_hw = &pq[IOP_ADMA_NUM_SRC_TEST+2];
+        /* address conversion buffers (dma_map / page_address) */
+        void *pq_sw[IOP_ADMA_NUM_SRC_TEST+2];
+        dma_addr_t pq_src[IOP_ADMA_NUM_SRC_TEST];
+        dma_addr_t pq_dest[2];
+
+        int i;
+        struct dma_async_tx_descriptor *tx;
+        struct dma_chan *dma_chan;
+        dma_cookie_t cookie;
+        u32 zero_sum_result;
+        int err = 0;
+        struct device *dev;
+
+        dev_dbg(device->common.dev, "%s\n", __func__);
+
+        for (i = 0; i < ARRAY_SIZE(pq); i++) {
+                pq[i] = alloc_page(GFP_KERNEL);
+                if (!pq[i]) {
+                        while (i--)
+                                __free_page(pq[i]);
+                        return -ENOMEM;
+                }
+        }
+
+        /* Fill in src buffers */
+        for (i = 0; i < IOP_ADMA_NUM_SRC_TEST; i++) {
+                pq_sw[i] = page_address(pq[i]);
+                memset(pq_sw[i], 0x11111111 * (1<<i), PAGE_SIZE);
+        }
+        pq_sw[i] = page_address(pq[i]);
+        pq_sw[i+1] = page_address(pq[i+1]);
+
+        dma_chan = container_of(device->common.channels.next,
+                                struct dma_chan,
+                                device_node);
+        if (iop_adma_alloc_chan_resources(dma_chan) < 1) {
+                err = -ENODEV;
+                goto out;
+        }
+
+        dev = dma_chan->device->dev;
+
+        /* initialize the dests */
+        memset(page_address(pq_hw[0]), 0 , PAGE_SIZE);
+        memset(page_address(pq_hw[1]), 0 , PAGE_SIZE);
+
+        /* test pq */
+        pq_dest[0] = dma_map_page(dev, pq_hw[0], 0, PAGE_SIZE, DMA_FROM_DEVICE);
+        pq_dest[1] = dma_map_page(dev, pq_hw[1], 0, PAGE_SIZE, DMA_FROM_DEVICE);
+        for (i = 0; i < IOP_ADMA_NUM_SRC_TEST; i++)
+                pq_src[i] = dma_map_page(dev, pq[i], 0, PAGE_SIZE,
+                                         DMA_TO_DEVICE);
+
+        tx = iop_adma_prep_dma_pq(dma_chan, pq_dest, pq_src,
+                                  IOP_ADMA_NUM_SRC_TEST, (u8 *)raid6_gfexp,
+                                  PAGE_SIZE,
+                                  DMA_PREP_INTERRUPT |
+                                  DMA_CTRL_ACK);
+
+        cookie = iop_adma_tx_submit(tx);
+        iop_adma_issue_pending(dma_chan);
+        msleep(8);
+
+        if (iop_adma_is_complete(dma_chan, cookie, NULL, NULL) !=
+                DMA_SUCCESS) {
+                dev_err(dev, "Self-test pq timed out, disabling\n");
+                err = -ENODEV;
+                goto free_resources;
+        }
+
+        raid6_call.gen_syndrome(IOP_ADMA_NUM_SRC_TEST+2, PAGE_SIZE, pq_sw);
+
+        if (memcmp(pq_sw[IOP_ADMA_NUM_SRC_TEST],
+                   page_address(pq_hw[0]), PAGE_SIZE) != 0) {
+                dev_err(dev, "Self-test p failed compare, disabling\n");
+                err = -ENODEV;
+                goto free_resources;
+        }
+        if (memcmp(pq_sw[IOP_ADMA_NUM_SRC_TEST+1],
+                   page_address(pq_hw[1]), PAGE_SIZE) != 0) {
+                dev_err(dev, "Self-test q failed compare, disabling\n");
+                err = -ENODEV;
+                goto free_resources;
+        }
+
+        /* test correct zero sum using the software generated pq values */
+        for (i = 0; i < IOP_ADMA_NUM_SRC_TEST + 2; i++)
+                pq_src[i] = dma_map_page(dev, pq[i], 0, PAGE_SIZE,
+                                         DMA_TO_DEVICE);
+
+        zero_sum_result = ~0;
+        tx = iop_adma_prep_dma_pq_val(dma_chan, &pq_src[IOP_ADMA_NUM_SRC_TEST],
+                                      pq_src, IOP_ADMA_NUM_SRC_TEST,
+                                      raid6_gfexp, PAGE_SIZE, &zero_sum_result,
+                                      DMA_PREP_INTERRUPT|DMA_CTRL_ACK);
+
+        cookie = iop_adma_tx_submit(tx);
+        iop_adma_issue_pending(dma_chan);
+        msleep(8);
+
+        if (iop_adma_is_complete(dma_chan, cookie, NULL, NULL) !=
+                DMA_SUCCESS) {
+                dev_err(dev, "Self-test pq-zero-sum timed out, disabling\n");
+                err = -ENODEV;
+                goto free_resources;
+        }
+
+        if (zero_sum_result != 0) {
+                dev_err(dev, "Self-test pq-zero-sum failed to validate: %x\n",
+                        zero_sum_result);
+                err = -ENODEV;
+                goto free_resources;
+        }
+
+        /* test incorrect zero sum */
+        i = IOP_ADMA_NUM_SRC_TEST;
+        memset(pq_sw[i] + 100, 0, 100);
+        memset(pq_sw[i+1] + 200, 0, 200);
+        for (i = 0; i < IOP_ADMA_NUM_SRC_TEST + 2; i++)
+                pq_src[i] = dma_map_page(dev, pq[i], 0, PAGE_SIZE,
+                                         DMA_TO_DEVICE);
+
+        zero_sum_result = 0;
+        tx = iop_adma_prep_dma_pq_val(dma_chan, &pq_src[IOP_ADMA_NUM_SRC_TEST],
+                                      pq_src, IOP_ADMA_NUM_SRC_TEST,
+                                      raid6_gfexp, PAGE_SIZE, &zero_sum_result,
+                                      DMA_PREP_INTERRUPT|DMA_CTRL_ACK);
+
+        cookie = iop_adma_tx_submit(tx);
+        iop_adma_issue_pending(dma_chan);
+        msleep(8);
+
+        if (iop_adma_is_complete(dma_chan, cookie, NULL, NULL) !=
+                DMA_SUCCESS) {
+                dev_err(dev, "Self-test !pq-zero-sum timed out, disabling\n");
+                err = -ENODEV;
+                goto free_resources;
+        }
+
+        if (zero_sum_result != (SUM_CHECK_P_RESULT | SUM_CHECK_Q_RESULT)) {
+                dev_err(dev, "Self-test !pq-zero-sum failed to validate: %x\n",
+                        zero_sum_result);
+                err = -ENODEV;
+                goto free_resources;
+        }
+
+free_resources:
+        iop_adma_free_chan_resources(dma_chan);
+out:
+        i = ARRAY_SIZE(pq);
+        while (i--)
+                __free_page(pq[i]);
+        return err;
+}
+#endif
+
 static int __devexit iop_adma_remove(struct platform_device *dev)
 {
         struct iop_adma_device *device = platform_get_drvdata(dev);
@@ -1417,13 +1582,28 @@ static int __devinit iop_adma_probe(struct platform_device *pdev)
         }
 
         if (dma_has_cap(DMA_XOR, dma_dev->cap_mask) ||
-                dma_has_cap(DMA_MEMSET, dma_dev->cap_mask)) {
+            dma_has_cap(DMA_MEMSET, dma_dev->cap_mask)) {
                 ret = iop_adma_xor_val_self_test(adev);
                 dev_dbg(&pdev->dev, "xor self test returned %d\n", ret);
                 if (ret)
                         goto err_free_iop_chan;
         }
 
+        if (dma_has_cap(DMA_PQ, dma_dev->cap_mask) &&
+            dma_has_cap(DMA_PQ_VAL, dma_dev->cap_mask)) {
+                #ifdef CONFIG_MD_RAID6_PQ
+                ret = iop_adma_pq_zero_sum_self_test(adev);
+                dev_dbg(&pdev->dev, "pq self test returned %d\n", ret);
+                #else
+                /* can not test raid6, so do not publish capability */
+                dma_cap_clear(DMA_PQ, dma_dev->cap_mask);
+                dma_cap_clear(DMA_PQ_VAL, dma_dev->cap_mask);
+                ret = 0;
+                #endif
+                if (ret)
+                        goto err_free_iop_chan;
+        }
+
         dev_printk(KERN_INFO, &pdev->dev, "Intel(R) IOP: "
           "( %s%s%s%s%s%s%s%s%s%s)\n",
           dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "pq " : "",