{"id":294984,"date":"2024-12-15T04:05:30","date_gmt":"2024-12-14T20:05:30","guid":{"rendered":"https:\/\/lrxjmw.cn\/srjxlnhzsyds.html"},"modified":"2024-12-15T04:05:30","modified_gmt":"2024-12-14T20:05:30","slug":"srjxlnhzsyds","status":"publish","type":"post","link":"https:\/\/lrxjmw.cn\/srjxlnhzsyds.html","title":{"rendered":"\u6df1\u5165\u89e3\u6790Linux\u5185\u6838\u4e2d\u4f7f\u7528DMA\u5b9e\u73b0\u5185\u5b58\u6570\u636e\u4f20\u9012\u7684\u5b8c\u6574\u6307\u5357"},"content":{"rendered":"<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4e00\uff0c\u7b80\u4ecb<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u672c\u6587\u4e3b\u8981\u4ecb\u7ecd\u5728\u5185\u6838\u4e2d\u7b80\u5355\u4f7f\u7528DMA\u5b9e\u73b0\u663e\u5b58\u6570\u636e\u4f20\u9012\u3002\u56e0\u4e3a\u672c\u7bc7\u6587\u7ae0\u4e2d\u6ca1\u6709\u4ecb\u7ecd\u4e0e\u6846\u67b6\u76f8\u5173\u7684\u7a0b\u5e8f\uff0c\u53ea\u662f\u4f7f\u7528\u5b57\u7b26\u8bbe\u5907\u6765\u64cd\u4f5cDMA\uff0c\u540c\u65f6\u4e5f\u6ca1\u6709\u5177\u8c61\u7684\u5c42\u6b21\uff0c\u56e0\u800c\u672c\u6587\u4e2d\u4ee3\u7801\u5256\u6790\u90e8\u4efd\u5c31\u76f8\u5bf9\u7b80\u5355\u3002\u4f46\u6211\u8fd8\u662f\u4f1a\u5c06\u6587\u7ae0\u5206\u4e3a\u4e24\u90e8\u4efd\uff0c\u7b2c\u4e00\u90e8\u4efd\u6211\u5c06\u4ecb\u7ecd\u4e0eDMA\u76f8\u5173\u7684\u77e5\u8bc6\u3002\u800c\u7b2c\u4e8c\u90e8\u4efd\u8bb2\u89e3\u5728\u5185\u6838\u4e2d\u600e\u6837\u901a\u8fc7\u4ee3\u7801\u5b9e\u73b0DMA\u7684\u6570\u636e\u4f20\u9012\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><a style='color:#0000CC;font-size:16px' href='https:\/\/lrxjmw.cn\/' target='_blank'>Linux<\/a>\u5185\u6838\uff1alinux-2.6.22.6<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u6240\u7528\u5f00\u53d1\u677f\uff1aJZ2440V3\uff08S3C2440A\uff09<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u7b2c\u4e00\u90e8\u4efd\uff1aDMA\u76f8\u5173\u77e5\u8bc6<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u5728\u4ecb\u7ecdDMA\u4e4b\u524d\u6211\u60f3\u95ee\u4f60\u4eec\uff1a\u6211\u4eec\u4e3a\u4f55\u8981\u5f15\u5165DMA\uff0cDMA\u5bf9\u6211\u4eec\u6709\u54ea\u4e9b\u7528\u5904\u90a3\uff1f<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u7b54\uff1a\u8ba1\u7b97\u673a\u7cfb\u7edf\u4e2d\u5404\u7c7b\u5e38\u7528\u7684\u6570\u636e\u8f93\u5165\/\u8f93\u51fa\u65b9\u5f0f\u6709\u67e5\u8be2\u65b9\u6cd5(\u5305\u62ec\u65e0\u6761\u4ef6\u53ca\u6761\u4ef6\u4f20\u9001\u5f62\u5f0f)\u548c\u4e2d\u65ad\u65b9\u6cd5\uff0c\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8eCPU\u4e0e\u6162\u901f\u53ca\u4e2d\u901f\u5916\u8bbe\u4e4b\u95f4\u7684\u6570\u636e\u4ea4\u6362\u3002\u4f46\u5f53\u9ad8\u901f\u5916\u8bbe\u8981\u4e0e\u7cfb\u7edf\u663e\u5b58\u6216\u5219\u8981\u5728\u7cfb\u7edf\u663e\u5b58\u7684\u4e0d\u540c\u533a\u57df\u4e4b\u95f4\u8fdb\u884c\u5927\u91cf\u6570\u636e\u7684\u5feb\u901f\u4f20\u9001\u65f6\uff0c\u5c31\u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u9650\u5236\u4e86\u6570\u636e\u4f20\u9001\u7684\u901f\u5ea6\u3002\u76f4\u63a5\u50a8\u5b58\u5668\u5b58\u53d6(DMA)\u5c31\u662f\u4e3a\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u63d0\u51fa\u7684\uff0c\u91c7\u7528DMA\u5f62\u5f0f\uff0c\u5728\u4e00\u5b9a\u65f6\u95f4\u6bb5\u5185\uff0c\u7531DMA\u63a7\u5236\u5668\u4ee3\u66ffCPU\uff0c\u83b7\u5f97\u603b\u7ebf\u63a7\u5236\u6743\uff0c\u6765\u5b9e\u73b0\u663e\u5b58\u4e0e\u5916\u8bbe\u6216\u5219\u663e\u5b58\u7684\u4e0d\u540c\u533a\u57df\u4e4b\u95f4\u5927\u91cf\u6570\u636e\u7684\u5feb\u901f\u4f20\u9001\u3002\u540c\u65f6\u5f88\u91cd\u8981\u7684\u4e00\u70b9\u662f\u5f53DMA\u4f20\u8f93\u6570\u636e\u65f6\uff0c\u5e76\u4e0d\u5360\u7528CPU\u8d44\u6e90\uff0c\u5728\u8fd9\u4e2a\u65f6\u4fafCPU\u53ef\u4ee5\u7a7a\u51fa\u624b\u6765\u505a\u5176\u4ed6\u7684\u4e8b\u60c5\u3002\u8fd9\u6837\u6211\u4eec\u65e2\u53ef\u4ee5\u505a\u5927\u91cf\u6570\u636e\u7684\u9ad8\u901f\u4f20\u8f93\u53c8\u53ef\u4ee5\u8ba9CPU\u6709\u65f6\u95f4\u548c\u8d44\u6e90\u53bb\u505a\u5176\u4ed6\u7684\u4e8b\u60c5\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u91cc\u9762\u4ecb\u7ecd\u4e86\u54ea\u4e9b\u662fDMA\uff0c\u4e5f\u4ecb\u7ecd\u4e86DMA\u7684\u91cd\u8981\u6027\u3002\u8fd9\u4e48\u6211\u4eec\u5c31\u8981\u77a7\u77a7\u6211\u4eec\u82af\u7247\u4e2d\u7684DMA\u4e86\u3002\u5728S3C2440A\u4e2d\uff0c\u6211\u4eec\u96c6\u6210\u4e86DMA\u6a21\u5757\uff0c\u53ef\u4ee5\u62ff\u6765\u4f20\u9012\u9ad8\u901f\u4f20\u8f93\u6570\u636e\u3002\u65e2\u7136\u662f\u6570\u636e\u4f20\u8f93\u8fd9\u4e48\u6211\u53c8\u8981\u95ee\u4e86\uff0c\u6211\u4eec\u6653\u5f97\u6570\u636e\u4f20\u8f93\u4e09\u8981\u7d20\uff1a\u6e90\uff0c\u76ee\u7684\uff0c\u5bbd\u5ea6\u3002\u8fd9\u662f\u6211\u4eec\u6570\u636e\u4f20\u8f93\u65f6\u8981\u6653\u5f97\u7684\u3002\u8fd9\u4e48\u5728S3C2440A\u4e2d\uff0c\u6e90\uff0c\u76ee\u7684\uff0c\u5bbd\u5ea6\u662f\u5982\u4f55\u8868\u793a\u7684\u90a3\uff1f<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u57282440\u4e2d\u6211\u4eec\u7684\u6e90\u4e0e\u76ee\u7684\u5730\u9009\u62e9\u6709\u56db\u79cd\u60c5\u51b5\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>2440\u4e2d\u6e90\u4e0e\u76ee\u7684\u5c31\u662f\u901a\u8baf\u7684\u53cc\u65b9\uff0c\u800c\u8fd9\u53cc\u65b9\u662f\u901a\u8fc7\u6073\u6c42DMA\u4f20\u9012\u4fe1\u606f\u7684\uff0c\u6240\u4ee5\u6211\u4eec\u5c06\u524d\u9762\u90a3\u4e9b\u5411DMA\u53d1\u9001\u6073\u6c42\u7684\uff08\u4e0d\u7ba1\u662f\u6e90\u8fd8\u662f\u76ee\u7684\uff09\u79f0\u4e3a\u6073\u6c42\u6e90\u3002\u5979\u4eec\u6073\u6c42DMA\u6765\u4f20\u8f93\u6570\u636e\u3002\u800c\u57282440\u4e2d\u6709\u56db\u6761\u901a\u9053\u6765\u8bbe\u7f6e\u4e0d\u540c\u7684\u6073\u6c42\u6e90\uff0c\u5979\u4eec\u4e3a\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_0.jpg' alt='linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1_linux\u7f51\u7edc\u5185\u6838_linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48' \/><\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4ecb\u7ecd\u5b8c\u7f18\u7531\u4e0e\u76ee\u7684\uff0c\u6211\u4eec\u539f\u672c\u662f\u8981\u4ecb\u7ecd\u6570\u636e\u4f20\u8f93\u5bbd\u5ea6\u7684\u3002\u5e76\u4e14\u6211\u60f3\u8fd8\u662f\u5148\u4ecb\u7ecd\u6570\u636e\u4f20\u8f93\u65b9\u6cd5\u6bd4\u8f83\u597d\u3002\u4ecb\u7ecd\u5b8c\u6570\u636e\u4f20\u8f93\u65b9\u6cd5\u6211\u4eec\u4e86\u89e3\u4e86\u6570\u636e\u662f\u4ee5\u54ea\u4e9b\u6837\u7684\u5f62\u5f0f\u4f20\u8f93\u7684\u3002\u8fd9\u6837\u6211\u4eec\u81ea\u7136\u5c31\u6653\u5f97\u8981\u4f20\u8f93\u7684\u6570\u636e\u5bbd\u5ea6\u4e86\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>DMA\u6a21\u5f0f\u4ecb\u7ecd\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>DMAservicemode\uff1asingleservice\uff06Wholeservice\u3002\u524d\u4e00\u6a21\u5f0f\u4e0b\uff0c\u4e00\u6b21DMA\u6073\u6c42\u5b8c\u6210\u4e00\u9879\u539f\u5b50\u64cd\u4f5c\uff0c\u800c\u4e14transfercount\u7684\u503c\u51cf1\u3002\u540e\u4e00\u6a21\u5f0f\u4e0b\uff0c\u4e00\u6b21DMA\u6073\u6c42\u5b8c\u6210\u4e00\u6279\u539f\u5b50\u64cd\u4f5c\uff0c\u76f4\u81f3transfercount\u7b49\u4e8e0\u8868\u793a\u5b8c\u6210\u4e00\u6b21\u6574\u4f53\u670d\u52a1\u3002\u5177\u4f53\u5bf9\u5e94DCON[27]\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>DMADREQ\/DACKPROTOCOL\uff1aDMA\u6073\u6c42\u548c\u5e94\u7b54\u7684\u5408\u540c\u6709\u4e24\u79cd\uff0cDemondmode\u548cHandshakemode\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4e8c\u8005\u5bf9Request\u548cAck\u7684\u65f6\u5e8f\u5b9a\u4e49\u6709\u6240\u4e0d\u540c\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_1.jpg' alt='linux\u7f51\u7edc\u5185\u6838_linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48_linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1' \/><\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4e0b\u8fb9\u6211\u4eec\u6765\u4ecb\u7ecdDMA\u4e2d\u6570\u636e\u4f20\u8f93\u7684\u683c\u5f0f\uff0c\u6ce8\u610f\uff0c\u8fd9\u513f\u8bf4\u7684\u662f\u4f20\u8f93\u683c\u5f0f\uff0c\u800c\u4e0d\u662f\u4f20\u8f93\u7684\u5927\u5c0f\u3002\u5728DMA\u4e2d\u6709\u4e24\u79cd\u4f20\u8f93\u683c\u5f0f\uff0c\u5355\u5143\u4f20\u8f93\u548cburst4\u4f20\u8f93\uff0c\u76f8\u5bf9\u4e8e\u5355\u5143\u4f20\u8f93\u7684\u6bcf\u6b21\u8bfb\u5199\u4e00\u4e2a\u5355\u5143\uff0cburst4\u53ef\u4ee5\u4e00\u6b21\u5b8c\u6210\u56db\u4e2a\u5355\u5143\u7684\u8bfb\u5199\u3002\u800c\u8fd9\u513f\u7684\u5355\u5143\u5c31\u662f\u6211\u4eec\u8bf4\u7684\u6570\u636e\u7684\u5927\u5c0f\u6709\uff1a\u5b57\u8282\uff0c\u534a\u5b57\uff0c\u5b57\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_2.jpg' alt='linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48_linux\u7f51\u7edc\u5185\u6838_linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1' \/><\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u6709\u4e86\u524d\u9762\u7684\u77e5\u8bc6\u6211\u4eec\u5c31\u53ef\u4ee5\u4ecb\u7ecd\u603b\u7684\u6570\u636e\u7684\u4f20\u8f93\u5927\u5c0f\u4e86\uff1aDSZxTSZxTC\uff0c\u5176\u4e2dDSZ\u5c31\u662f\u524d\u9762\u8bf4\u7684\u6570\u636e\u7684\u5927\u5c0f\uff0cTSZ\u662f\u4f20\u8f93\u7684\u683c\u5f0f\uff0c\u800cTC\u662f\u4f20\u8f93\u7684\u6b21\u6570\u3002\u5979\u4eec\u7684\u4e58\u79ef\u5c31\u662f\u6574\u4e2a\u6570\u636e\u7684\u5927\u5c0f\u4e86\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4ecb\u7ecd\u4e86\u6570\u636e\u4f20\u8f93\u7684\u4e09\u8981\u7d20\uff0c\u6211\u60f3\u4f60\u4eec\u53c8\u8981\u95ee\u4e86\uff1a\u65e2\u7136\u6709\u4e86\u6570\u636e\u4f20\u8f93\u7684\u4e09\u8981\u7d20linux\u7cfb\u7edf\uff0c\u8fd9\u4e48\u6211\u4eec\u7684\u6570\u636e\u662f\u600e\u6837\u4f20\u8f93\u7684\uff1f<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u5728\u6211\u4eec\u7684S3C2440\u4e2d\u4ed6\u662f\u4f7f\u7528\u4e09\u6001\u7684\u6709\u9650\u72b6\u6001\u673a\uff08FSM\uff09\u6765\u5b9e\u73b0\u6570\u636e\u7684\u4f20\u8f93\u7684\u3002\u5176\u5b9e\u662f\u4f7f\u7528\u7684\u6709\u9650\u72b6\u6001\u673a\uff0c\u4f462440\u4e2d\u8fd8\u6709\u4e24\u79cd\u4f20\u8f93\u6a21\u5f0f\uff1a\u5355\u670d\u52a1\u6a21\u5f0f\u548c\u5168\u670d\u52a1\u6a21\u5f0f\u3002\u6211\u4e0b\u8fb9\u7528\u4e00\u5e45\u56fe\u6765\u5c55\u793a\u4e09\u6001\u7684\u6709\u9650\u72b6\u6001\u673a\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u5728\u72b6\u60011\u65f6\uff0cDMA\u7b49\u5f85DMA\u6073\u6c42\uff0c\u6b64\u65f6DMAACK\u548cINTREQ\u4e3a0\u3002\u5f53DMA\u6536\u5230DMA\u6073\u6c42\u65f6\uff0c\u4ed6\u8df3\u8f6c\u5230\u72b6\u60012\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u5728\u72b6\u60012\u65f6\uff0cDMAACK\u4e3a1\uff0cINTREQ\u8fd8\u4e3a0\uff0c\u6b64\u65f6CURR_TC\u4eceDCON[19:0]\u4ece\u52a0\u8f7d\u8ba1\u6570\u503c\u3002\u5728\u5979\u4eec\u5b8c\u6210\u540e\u4ed6\u8df3\u5230\u72b6\u60013\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u5728\u72b6\u60013\u65f6\uff0c\u5f15\u5165\u5b50\u72b6\u6001\u673a\u62ff\u6765\u5904\u7406\u4e00\u6b21\u539f\u5b50\u64cd\u4f5c<strong>linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1<\/strong>\uff0c\u5373\u5b8c\u6210\u4e00\u6b21\u6570\u636e\u4ece\u6e90\u8bfb\u51fa\u4e4b\u540e\u8bb2\u5230\u76ee\u7684\u4e2d\u3002\u800c\u5728\u8fd9\u65f6\u6211\u4eec\u5c31\u8981\u5206\u5355\u670d\u52a1\u6a21\u5f0f\u548c\u5168\u670d\u52a1\u6a21\u5f0f\u6765\u8ba8\u8bba\u4e86\u3002\u5728\u5355\u670d\u52a1\u6a21\u5f0f\u4e2d\uff0c\u5b50\u6709\u9650\u72b6\u6001\u673a\u5b8c\u6210\u4e00\u6b21\u539f\u5b50\u64cd\u4f5c\u540eCURR_TC-1\uff0c\u4e3b\u6709\u9650\u72b6\u6001\u673a\u5c06DMAACK\u8bbe\u4e3a0\uff0c\u4e4b\u540e\u8c03\u56de\u5230\u72b6\u60011\uff0c\u4e4b\u540e\u7b49\u5f85\u4e0b\u4e00\u6b21\u7684DMA\u6073\u6c42\u3002\u800c\u5728\u5168\u670d\u52a1\u6a21\u5f0f\u65f6\uff0c\u5b50\u6709\u9650\u72b6\u6001\u673a\u5c06\u4ecd\u7136\u8fd0\u884c\u76f4\u81f3CURR_TC\u4e3a0\uff0c\u4e4b\u540e\u4ed6\u518d\u5c06INTREQ\u8bbe\u4e3a1\u800c\u5c06DMAACK\u8bbe\u4e3a0\uff0c\u4e4b\u540e\u8c03\u56de\u5230\u72b6\u60011\uff0c\u4e4b\u540e\u7b49\u5f85\u4e0b\u4e00\u6b21\u7684DMA\u6073\u6c42\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u524d\u9762\u6211\u4eec\u4ecb\u7ecd\u4e86DMA\u662f\u600e\u6837\u4f20\u8f93\u6570\u636e\u7684\uff0c\u540c\u65f6\u4e5f\u8bb2\u4e86\u6570\u636e\u4f20\u8f93\u7684\u4e09\u8981\u7d20\u3002\u8fd9\u4e48\u6211\u4eec\u4e0b\u8fb9\u5c31\u8981\u8bb2\u4e00\u4e0b\u57282440\u4e2dDMA\u7684\u914d\u7f6e\u6b65\u9aa4\u548c\u8981\u70b9\u4e86\uff08\u4e3b\u8981\u9488\u5bf9\u5bc4\u5b58\u5668\uff09\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>1.\u6570\u636e\u4ece\u54ea\u513f\u6765\uff0c\u5230\u90a3\u91cc\u53bb\uff1f<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4f7f\u7528DMA\u9996\u5148\u6211\u4eec\u8981\u6653\u5f97\u6570\u636e\u7684\u6d41\u5411\uff0cDISRCx\u5bc4\u5b58\u5668\u662fDMA\u521d\u59cb\u6e90\u5bc4\u5b58\u5668\uff0c\u50a8\u5b58\u4e86\u6570\u636e\u7684\u6e90\u5730\u5740\u3002DIDSTx\u662fDMA\u7684\u521d\u59cb\u76ee\u7684\u5bc4\u5b58\u5668\uff0c\u50a8\u5b58\u6570\u636e\u7684\u76ee\u7684\u5730\u5740\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>2.\u6570\u636e\u8d70\u7684\u54ea\u4e9b\u603b\u7ebf\uff1f\u5730\u5740\u662f\u5426\u662f\u56fa\u5b9a\u7684\uff1f<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u6211\u4eec\u8fd8\u8981\u6653\u5f97\u6e90\u4e0e\u76ee\u7684\u6570\u636e\u50a8\u5b58\u8bbe\u5907\u5728\u54ea\u4e9b\u603b\u7ebf\u4e0a\uff08AHB\u7cfb\u7edf\u603b\u7ebf\uff0c\u901a\u5e38\u662f\u9ad8\u901f\u7684\u8bf8\u5982\u663e\u5b58\uff0cAPB\u5916\u56f4\u603b\u7ebf\uff0c\u4f4e\u901f\u7684\u4f8b\u5982SD\uff0cUART\uff1b\u5177\u4f53\u8d70\u54ea\u4e9b\u603b\u7ebf\u53ef\u4ee5\u5728datasheet\u4e0a\u67e5\u5230\uff09\uff1b\u4ee5\u53ca\u6570\u636e\u4f20\u8f93\u7ed3\u675f\u4e4b\u540e\u8d77\u59cb\u5730\u5740\u8fd8\u539f\u5230\u53d1\u9001\u524d\u7684\u8d77\u59cb\u5730\u5740\u5462\uff0c\u8fd8\u662f\u5728\u73b0\u4eca\u7684\u672b\u5c3e+1\u4f5c\u4e3a\u65b0\u7684\u8d77\u59cb\u5730\u5740\u3002\u8fd9\u79cd\u8bbe\u7f6e\u5728DISRCCx\u4e0eDIDSTCx\u4e24\u4e2a\u5bc4\u5b58\u5668\u4e0a\u9762\u914d\u7f6e\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>3.\u6570\u636e\u4ee5\u54ea\u4e9b\u65b9\u6cd5\u4f20\u8f93\uff1f\u59cb\u4e8e\u54ea\u4e9b\u76ee\u7684\u662f\u54ea\u4e9b\u5462\uff1f\u8981\u4e0d\u8981\u624b\u52a8\u91cd\u8f7d\uff1f<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u987b\u8981\u786e\u5b9a\u6570\u636e\u7684\u4f20\u8f93\u65b9\u6cd5\u6709\u6073\u6c42\u8fd8\u662f\u63e1\u624b,\u6309\u7167\u524d\u9762\u7684\u603b\u7ebf\u786e\u5b9a\u4e0e\u54ea\u4e9b\u65f6\u949f\u540c\u6b65\uff08HCLK\uff0cPCLK\uff09\uff0c\u662f\u5355\u5143\u4f20\u8f93\u8fd8\u662f\u7a81\u53d1\u4f20\u8f93\uff0c\u662f\u4ee5\u5b57\u8282\u4f20\u8f93\u8fd8\u662f\u5b57\u4f20\u8f93\uff0c\u662f\u5426\u91cd\u8f7d\u3002\u662f\u5355\u670d\u52a1\uff08\u53ea\u53d1\u9001\u4e00\u6b21\uff09\u8fd8\u662f\u591a\u670d\u52a1\uff08\u4e0d\u505c\u5faa\u73af\u53d1\u9001\uff09\uff0c\u4ee5\u53ca\u6570\u636e\u7684\u4f20\u9001\u5927\u5c0f\u3002\u9009\u62e9\u6e90\u4e0e\u76ee\u7684\u8bbe\u5907\u3002\u6700\u540e\u8fd8\u8981\u786e\u5b9a\u4e2d\u65ad\u662f\u4e0d\u662f\u4f20\u8f93\u7ed3\u675f\u53d1\u751f\uff08CURR_TC\u8bb0\u6570\u662f\u4e0d\u662f0\uff09\u3002\u90a3\u4e9b\u90fd\u5728DCONx\u4e2d\u8bbe\u7f6e\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>4.\u5982\u4f55\u5f00\u59cb\u4f20\u8f93DMA\u548c\u505c\u6b62DMA\uff0c\u90a3\u4e9b\u5728DMASKTRIG\u4e2d\u8bbe\u7f6e\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u66f4\u591aLinux\u5185\u6838\u89c6\u9891\u6559\u7a0b\u6587\u6863\u8d44\u6599\u514d\u8d39\u53d1\u653e\u540e\u53f0\u79c1\u4fe1\u3010\u5185\u6838\u3011\u81ea\u884c\u83b7\u53d6\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_3.jpg' alt='linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48_linux\u7f51\u7edc\u5185\u6838_linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1' \/><\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u5185\u6838\u5b66\u4e60\u7f51\u7ad9\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>Linux\u5185\u6838\u6e90\u7801\/\u663e\u5b58\u8c03\u4f18\/\u6587\u4ef6\u7cfb\u7edf\/\u8fdb\u7a0b\u7ba1\u7406\/\u8bbe\u5907\u9a71\u52a8\/\u7f51\u8def\u5408\u540c\u6808-\u5b66\u4e60\u89c6\u9891\u6559\u7a0b-\u817e\u8baf\u8bfe\u5802<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u7b2c\u4e8c\u90e8\u4efd\uff1a\u5728\u5185\u6838\u4e2d\u600e\u6837\u901a\u8fc7\u4ee3\u7801\u5b9e\u73b0DMA\u6570\u636e\u4f20\u9012\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u901a\u8fc7\u524d\u9762\u5bf9DMA\u7684\u4ecb\u7ecd\uff0c\u6211\u5bf9DMA\u6709\u4e86\u4e00\u5b9a\u7684\u8ba4\u8bc6\u3002\u8fd9\u4e48\u6211\u5c06\u5728\u8fd9\u4e00\u90e8\u4efd\u7528\u4ee3\u7801\u5b9e\u73b0\u5bf9DMA\u7684\u7b80\u5355\u63a7\u5236\u3002\u5982\u4eca\u6211\u5199\u4e00\u4e0b\u6211\u5728\u4ee3\u7801\u4e2d\u8981\u5b9e\u73b0\u7684\u529f\u80fd\uff1a\u5bf9\u6bd4\u4e8e\u4f7f\u7528\u548c\u4e0d\u4f7f\u7528DMA\u6765\u4f20\u9012\u663e\u5b58\u4e2d\u7684\u6570\u636e\uff0c\u6765\u786e\u5b9aDMA\u5bf9\u4e8e\u89e3\u653eCPU\u7684\u91cd\u8981\u6027\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u6211\u4eec\u5c06\u5229\u7528\u4e8e\u5b57\u7b26\u8bbe\u5907\u9a71\u52a8\u5728\u4ed6\u7684\u64cd\u4f5c\u51fd\u6570\u4e2d\u5b9e\u73b0\u5bf9DMA\u7684\u63a7\u5236\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_4.jpg' alt='linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48_linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1_linux\u7f51\u7edc\u5185\u6838' \/><\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u6240\u4ee5\u6211\u4eec\u53ef\u4ee5\u5927\u4f53\u603b\u7ed3\u51fa\u8fd9\u4e2a\u7a0b\u5e8f\u7684\u5199\u4f5c\u6b65\u9aa4\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u800c\u6b64\u5904\u987b\u8981\u975e\u5e38\u8bf4\u660e\u7684\u4e00\u70b9\u662f\uff0c\u5728\u4f7f\u7528DMA\u65f6\u6211\u4eec\u8981\u6c42DMA\u64cd\u4f5c\u7684\u6570\u636e\u7684\u6570\u5b66\u5730\u5740\u548c\u865a\u62df\u5730\u5740\u90fd\u662f\u8981\u8fde\u7eed\u7684\u3002\u4e3a\u6b64\u6211\u4eec\u4f7f\u7528dma_alloc_writecombine\u51fd\u6570\u6765\u4e3aDMA\u5206\u914d\u663e\u5b58\u7f13\u51b2\u533a\u3002\u800c\u4e0d\u7528\u6211\u4eec\u5e38\u4f7f\u7528\u7684kmalloc\u6765\u7533\u8bf7\u7a7a\u95f4\u3002\u800c\u6211\u5728\u53f3\u56fe\u4e2d\u505a\u4e86\u8fd9\u4e24\u4e2a\u51fd\u6570\u7684\u5bf9\u6bd4\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_5.jpg' alt='linux\u7f51\u7edc\u5185\u6838_linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1_linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48' \/><\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4ece\u4e0a\u56fe\u53ef\u4ee5\u770b\u51fakmalloc\u548cdma_alloc_writecombine\u8fd9\u4e24\u4e2a\u51fd\u6570\u7533\u8bf7\u7684\u865a\u62df\u5730\u5740\u90fd\u662f\u8fde\u7eed\u7684\uff0c\u800c\u4e14\u5979\u4eec\u7684\u6570\u5b66\u5730\u5740\u5374\u4e0d\u76f8\u540c\uff0ckmalloc\u7684\u6570\u5b66\u5730\u5740\u662f\u79bb\u6563\u7684\uff0c\u800cdma_alloc_writecombine\u7684\u5316\u5b66\u5730\u5740\u662f\u8fde\u7eed\u7684\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4e0b\u8fb9\u662fdma_alloc_writecombine\u51fd\u6570\u7684\u4ecb\u7ecd\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\n<pre><code>\/*\u8be5\u51fd\u6570\u53ea\u7981\u6b62cache\u7f13\u51b2,\u4fdd\u6301\u5199\u7f13\u51b2\u533a,\u4e5f\u5c31\u662f\u5bf9\u6ce8\u518c\u7684\u7269\u7406\u533a\u5199\u5165\u6570\u636e,\u4e5f\u4f1a\u66f4\u65b0\u5230\u5bf9\u5e94\u7684\u865a\u62df\u7f13\u5b58\u533a\u4e0a*\/\nvoid *dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp); \n\/\/\u5206\u914dDMA\u7f13\u5b58\u533a\n\/\/\u8fd4\u56de\u503c\u4e3a:\u7533\u8bf7\u5230\u7684DMA\u7f13\u51b2\u533a\u7684\u865a\u62df\u5730\u5740,\u82e5\u4e3aNULL,\u8868\u793a\u5206\u914d\u5931\u8d25,\u9700\u8981\u91ca\u653e,\u907f\u514d\u5185\u5b58\u6cc4\u6f0f\n\/\/\u53c2\u6570\u5982\u4e0b:\n\u3000\u3000\/\/*dev:\u6307\u9488,\u8fd9\u91cc\u586b0,\u8868\u793a\u8fd9\u4e2a\u7533\u8bf7\u7684\u7f13\u51b2\u533a\u91cc\u6ca1\u6709\u5185\u5bb9\n\u3000\u3000\/\/size:\u5206\u914d\u7684\u5730\u5740\u5927\u5c0f(\u5b57\u8282\u5355\u4f4d)\n\u3000\u3000\/\/*handle:\u7533\u8bf7\u5230\u7684\u7269\u7406\u8d77\u59cb\u5730\u5740\n\u3000\u3000\/\/gfp:\u5206\u914d\u51fa\u6765\u7684\u5185\u5b58\u53c2\u6570,\u6807\u5fd7\u5b9a\u4e49\u5728,\u5e38\u7528\u6807\u5fd7\u5982\u4e0b:\n    \u3000\u3000\u3000\u3000\/\/GFP_ATOMIC    \u7528\u6765\u4ece\u4e2d\u65ad\u5904\u7406\u548c\u8fdb\u7a0b\u4e0a\u4e0b\u6587\u4e4b\u5916\u7684\u5176\u4ed6\u4ee3\u7801\u4e2d\u5206\u914d\u5185\u5b58. \u4ece\u4e0d\u7761\u7720.\n    \u3000\u3000\u3000\u3000\/\/GFP_KERNEL    \u5185\u6838\u5185\u5b58\u7684\u6b63\u5e38\u5206\u914d. \u53ef\u80fd\u7761\u7720.\n\u3000\u3000\u3000\u3000\u3000\u3000\/\/GFP_USER      \u7528\u6765\u4e3a\u7528\u6237\u7a7a\u95f4\u9875\u6765\u5206\u914d\u5185\u5b58; \u5b83\u53ef\u80fd\u7761\u7720. <\/code><\/pre>\n<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u597d\u4e86\uff0c\u6709\u4e86\u524d\u9762\u7684\u77e5\u8bc6\u6211\u4eec\u5c31\u53ef\u4ee5\u4e0a\u4ee3\u7801\u4e86\u3002\u6211\u4eec\u8fd8\u662f\u6309\u7740\u8001\u5e08\u7684\u6b65\u9aa4\u6765\u8bb2\uff0c\u6211\u4eec\u5148\u770b\u5165\u53e3\u51fd\u6570\u4e2d\u505a\u4e86\u54ea\u4e9b\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\n<pre><code>static int s3c_dma_init(void)\n{\n\t\/* \u7533\u8bf7DMA\u5185\u5b58 *\/\n\tif(request_irq(IRQ_DMA3,s3c_dma_irq,0,\"s3c_dma\",1)){\n\t\tfree_irq(IRQ_DMA3,1);\n\t\tprintk(\"can&#039;t request_irq for DMA n\");\n\t\treturn -ENOMEM;\n\t}\n \n\t\/* \u4e3a\u6e90\u5206\u914d\u5185\u5b58\u5bf9\u5e94\u7684\u7f13\u5b58\u533a *\/\n\tsrc = dma_alloc_writecombine(NULL,BUF_SIZE,&amp;src_phys,GFP_KERNEL);\n\tif(NULL == src){\n\t\tprintk(\"can&#039;t alloc buffer for src n\");\n\t\t\n\t\treturn -ENOMEM;\n\t}\n \n\t\/* \u4e3a\u76ee\u7684\u5206\u914d\u5185\u5b58\u5bf9\u5e94\u7684\u7f13\u5b58\u533a *\/\n\tdst = dma_alloc_writecombine(NULL,BUF_SIZE,&amp;dst_phys,GFP_KERNEL);\n\tif(NULL == dst){\n\t\tprintk(\"can&#039;t alloc buffer for dst n\");\n\t\tdma_free_writecombine(NULL,BUF_SIZE, src, src_phys);\n\t\n\t\treturn -ENOMEM;\n\t}\n \n\t\/* \u5bf9DMA\u5bc4\u5b58\u5668\u505a\u91cd\u6620\u5c04 *\/\n\tdma_regs = ioremap(DMA3_BASE_ADDR, sizeof(struct s3c_dma_regs));\n\t\n\t\/* \u6ce8\u518c\u5b57\u7b26\u8bbe\u5907 *\/\n\tauto_major = register_chrdev(auto_major,\"s3c_dma\",&amp;dma_fops);\n\t\n\t\/* \u521b\u5efa\u8bbe\u5907\u8282\u70b9 *\/\n\tcls = class_create(THIS_MODULE,\"s3c_dma\");\n\tclass_device_create(cls,NULL,MKDEV(auto_major,0),NULL,\"s3c_dma\");\n \n\treturn 0;\n}<\/code><\/pre>\n<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4ece\u91cc\u9762\u770b\u6211\u4eec\u505a\u4e86\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u5728\u524d\u9762\u6211\u4eec\u5206\u914d\u4e3a\u6e90\u548c\u76ee\u7684\u5206\u914d\u663e\u5b58\u5bf9\u5e94\u7684\u7f13\u51b2\u533a\uff0c\u5e76\u5bf92440\u4e2dDMA\u76f8\u5173\u7684\u5bc4\u5b58\u5668\u505a\u4e86\u91cd\u6620\u5c04\uff0c\u8fd9\u662f\u4e3a\u4e0b\u8fb9\u5bf9DMA\u7684\u64cd\u4f5c\u505a\u6253\u7b97\uff0c\u800c\u4e0eDMA\u76f8\u5173\u7684\u5bc4\u5b58\u5668\u6211\u4eec\u5c06\u5979\u4eec\u653e\u5728\u4e86\u4e00\u4e2a\u7ed3\u6784\u4f53\u4e2d\uff0c\u8fd9\u6837\u4fbf\u6377\u6211\u4eec\u7684\u8c03\u7528\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\n<pre><code>#define DMA0_BASE_ADDR 0x4b000000      \/* DMA0 \u5bc4\u5b58\u5668\u7684\u57fa\u5730\u5740 *\/\n#define DMA1_BASE_ADDR 0x4b000040      \/* DMA1 \u5bc4\u5b58\u5668\u7684\u57fa\u5730\u5740 *\/\n#define DMA2_BASE_ADDR 0x4b000080      \/* DMA2 \u5bc4\u5b58\u5668\u7684\u57fa\u5730\u5740 *\/\n#define DMA3_BASE_ADDR 0x4b0000c0      \/* DMA3 \u5bc4\u5b58\u5668\u7684\u57fa\u5730\u5740 *\/\n \nstruct s3c_dma_regs{\n\tunsigned long disrc; \n\tunsigned long disrcc;\n\tunsigned long didst;\n\tunsigned long didstc;\n\tunsigned long dcon;\n\tunsigned long dstat;\n\tunsigned long dcsrc;\n\tunsigned long dcdst;\n\tunsigned long dmasktrig;\n};\n \nstatic volatile struct s3c_dma_regs *dma_regs;<\/code><\/pre>\n<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u91cc\u9762\u5c31\u662f\u6211\u4eec\u5b9a\u4e49\u7684DMA\u5bc4\u5b58\u5668\u7684\u57fa\u5730\u5740\u548c\u5bc4\u5b58\u5668\u7ed3\u6784\u4f53\u3002\u6211\u4eec\u4f1a\u4f9d\u7167DMA\u6073\u6c42\u6e90\u7684\u4e0d\u540c\u800c\u8c03\u7528\u4e0d\u540c\u7684DMA\u57fa\u5730\u5740\u3002\u56e0\u800c\u64cd\u4f5c\u4e0d\u540cDMA\u7684\u5bc4\u5b58\u5668\uff0c\u5728\u672c\u5b9e\u4f8b\u4e2d\u6211\u4eec\u4f7f\u7528DMA3\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4e0b\u8fb9\u6211\u4eec\u770bfile_operations\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\n<pre><code>static struct file_operations dma_fops = {\n\t.owner = THIS_MODULE,\n\t.ioctl = s3c_dma_ioctl,\n \n};<\/code><\/pre>\n<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_6.jpg' alt='linux\u7f51\u7edc\u5185\u6838_linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48_linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1' \/><\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u7531\u4e8e\u8fd9\u4e2a\u53ea\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u4e8b\u4f8b<strong>linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1<\/strong>\uff0c\u6240\u4ee5\u6211\u4eec\u5e76\u6ca1\u6709\u505a\u592a\u591a\u7684\u64cd\u4f5c\u51fd\u6570\uff0c\u800c\u53ea\u662f\u4f7f\u7528ioctl\u8fd9\u4e2a\u51fd\u6570\u6765\u5b9e\u73b0\u6211\u4eec\u524d\u9762\u8bf4\u7684\uff1a\u5bf9\u6bd4\u4f7f\u7528\u548c\u4e0d\u4f7f\u7528DMA\u6765\u5b9e\u73b0\u663e\u5b58\u6570\u636e\u7684\u62f7\u8d1d\u3002\u4e0b\u8fb9\u6211\u4eec\u8fdbioctl\u4e2d\u77a7\u77a7\u4ed6\u662f\u5982\u4f55\u5b9e\u73b0\u7684\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\n<pre><code>int s3c_dma_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)\n{\n \n\tint i;\n\tstatic int cnt;\n\tmemset(src,0xaa,BUF_SIZE);\n\tmemset(dst,0x55,BUF_SIZE);\n \n\tswitch(cmd){\n\t\tcase MEM_CPY_NO_DMA :\n\t\t{\n\t\t\tfor(i=0;i= 30){\n\t\t\t\tcnt = 0;\n\t\t\t\tif(memcmp(src,dst,BUF_SIZE)==0){\n\t\t\t\t\tprintk(\"MEM_CPY_NO_DMA ok n\");\n\t\t\t\t}else{\n\t\t\t\t\tprintk(\"MEM_CPY_NO_DMA file n\");\n\t\t\t\t}\n\t\t\t}\n \n\t\t\tbreak;\n\t\t}\n \n\t\tcase MEM_CPY_DMA :\n\t\t{\n\t\t\t\/* \u628a\u6e90\uff0c\u76ee\u7684\uff0c\u957f\u5ea6\u544a\u8bc9DMA *\/\n\t\t\t\/* \u6e90\u7684\u7269\u7406\u5730\u5740 *\/\n\t\t\tdma_regs-&gt;disrc   = src_phys;\n\t\t\t\/* \u6e90\u4f4d\u4e8eAHB\u603b\u7ebf\uff0c\u539f\u5730\u5740\u9012\u589e *\/\n\t\t\tdma_regs-&gt;disrcc  = (0&lt;&lt;1) | (0&lt;didst   = dst_phys;\n\t\t\t\/* \u76ee\u7684\u4f4d\u4e8eAHB\u603b\u7ebf\uff0c\u76ee\u7684\u5730\u5740\u9012\u589e *\/\n\t\t\tdma_regs-&gt;didstc  = (0&lt;&lt;2) | (0&lt;&lt;1) | (0&lt;&lt;0);\n \n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_7.jpg' alt='linux\u7f51\u7edc\u5185\u6838_linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48_linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1' \/><\/p>\n\t\t\t\/* \u4f7f\u80fd\u4e2d\u65ad\uff0c\u5355\u4e2a\u4f20\u8f93\uff0c\u8f6f\u4ef6\u89e6\u53d1\uff0c\u8bfb\u5199\u5355\u4f4d\u4e3abyte *\/\n\t\t\tdma_regs-&gt;dcon  = (1&lt;&lt;30) | (1&lt;&lt;29) | (0&lt;&lt;28) | (1&lt;&lt;27) | (0&lt;&lt;23) | (0&lt;&lt;20) | (BUF_SIZE &lt;dmasktrig = (1&lt;&lt;1) | (1&lt;= 30){\n\t\t\t\tcnt = 0;\n\t\t\t\tif(memcmp(src,dst,BUF_SIZE)==0){\n\t\t\t\t\tprintk(\"MEM_CPY_DMA ok n\");\n\t\t\t\t}else{\n\t\t\t\t\tprintk(\"MEM_CPY_DMA file n\");\n\t\t\t\t}\n\t\t\t}\n\t\t\tbreak;\n\t\t}\n\t}\n \n\treturn 0;\n}<\/code><\/pre>\n<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u901a\u8fc7switch\u53e5\u5b50\u5224\u5b9a\uff0c\u5f53\u6211\u4eec\u4ece\u5e94\u7528\u7a0b\u5e8f\u7684ioctl\u4e2d\u63a5\u6536\u5230cmd\u5e76\u5c06\u5176\u4f20\u8f93\u5230\u6211\u4eec\u9a71\u52a8\u4e2d\u7684ioctl\u4e2dlinux\u91cd\u542f\u547d\u4ee4\uff0c\u8fdb\u800c\u5224\u5b9a\u662fMEM_CPY_NO_DMA\u8fd8\u662fMEM_CPY_DMA\u3002\u5f53cmd\u4e3aMEM_CPY_NO_DMA\u65f6\uff0c\u6211\u4eec\u4e0d\u4f7f\u7528DMA\u800c\u662f\u7528CPU\u6765\u5c06\u6570\u636e\u4ece\u6e90\u62f7\u8d1d\u5230\u76ee\u7684\uff0c\u800c\u5f53cmd\u4e3aMEM_CPY_DMA\u65f6\uff0c\u6211\u4eec\u4f7f\u7528DMA\u5c06\u6e90\u4e2d\u7684\u6570\u636e\u62f7\u8d1d\u5230\u76ee\u7684\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u8bb2\u89e3\u5230\u8fd9\u513f\uff0c\u6211\u60f3\u597d\u591a\u4eba\u8981\u95ee\u4e86\uff0c\u6211\u4eec\u65e2\u7136\u5199\u4e86ioctl\uff0c\u8fd9\u4e48\u6211\u4eec\u53bb\u54ea\u513f\u4f7f\u7528\u8fd9\u4e2aioctl\u51fd\u6570\u5462\uff1f<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u6240\u4ee5\u6211\u4eec\u8fd8\u8981\u5199\u4e00\u4e2a\u6d4b\u8bd5\u7a0b\u5e8f\u5728\u5e94\u7528\u5c42\u6d4b\u8bd5\u8fd9\u4e2a\u9a71\u52a8\u7a0b\u5e8f\u3002\u800c\u5177\u4f53\u7684\u6d4b\u8bd5\u7a0b\u5e8f\u4e3a\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\n<pre><code>\/*\n* \u7528\u6cd5\uff1a\n* .\/s3c_dma_test \n*\/\n \n#include \n#include \n#include \n#include \n#include \n \n#define MEM_CPY_NO_DMA 0\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'><img style='max-height:500px;max-width:80%;margin: 10px auto' src='https:\/\/lrxjmw.cn\/wp-content\/uploads\/2024\/12\/1734206728752_8.jpg' alt='linux\u5185\u6838\u5f00\u53d1\u662f\u4ec0\u4e48_linux\u7f51\u7edc\u5185\u6838_linux\u7f51\u7edc\u5185\u6838\u5206\u6790\u4e0e\u5f00\u53d1' \/><\/p>\n#define MEM_CPY_DMA    1\n \nvoid print_usage(char *data)\n{\n\tprintf(\"usage: n\");\n\tprintf(\"%s  n\",data);\t\n}\n \nint main(int argc,char **argv)\n{\n\tint fd;\n        \/* \u5224\u65ad\u8f93\u5165\u7684\u53c2\u6570\u662f\u4e0d\u662f\u4e24\u4e2a *\/\n\tif(2 != argc){\n\t\tprint_usage(argv[0]);\n\t\treturn -1;\n\t}\n        \/* \u6253\u5f00DMA\u8bbe\u5907 *\/\n\tfd = open(\"\/dev\/s3c_dma\",O_RDWR);\n\tif(fd&lt;0){\n\t\tprintf(&quot;can&#039;t open \/dev\/s3c_dma . n&quot;);\n\t}\n        \/* \u5224\u65ad\u53c2\u6570\u5e76\u8c03\u7528ioctl\u51fd\u6570 *\/\n\tif(strcmp(argv[1], &quot;nodma&quot;) == 0){\n\t\twhile(1){\n\t\t\tioctl(fd,MEM_CPY_NO_DMA);\n\t\t}\n\t}else if(strcmp(argv[1], &quot;dma&quot;) == 0){\n\t\twhile(1){\n\t\t\tioctl(fd,MEM_CPY_DMA);\n\t\t}\n\t}else{\n\t\tprint_usage(argv[0]);\n\t}\n \n\treturn 0;\n}<\/code><\/pre>\n<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4ece\u524d\u9762\u770b\u4ed6\u505a\u7684\u662f\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u6d4b\u8bd5\uff1a<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4e0b\u8fb9\u6211\u4ecb\u7ecd\u5982\u4f55\u901a\u8fc7\u8fd9\u4e2a\u6d4b\u8bd5\u7a0b\u5e8f\u6d4b\u8bd5DMA\u9a71\u52a8\u3002<\/p>\n<p style='margin-bottom:16px;color:#555555;font-size:16px;line-height:200%;text-indent:2em'>\u4e4b\u540e\u6bd4\u8f83\u4e24\u6b21\u7684\u53cd\u5e94\u65f6\u95f4\u5c31\u53ef\u4ee5\u770b\u51fa\u4f7f\u7528DMA\u7684\u4f18\u8d8a\u6027\u4e86\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u672c\u6587\u4e3b\u8981\u4ecb\u7ecd\u5728\u5185\u6838\u4e2d\u7b80\u5355\u4f7f\u7528DMA\u5b9e\u73b0\u5185\u5b58\u6570\u636e\u4f20\u9012\u3002\u800c\u7b2c\u4e8c\u90e8\u5206\u8bb2\u89e3\u5728\u5185\u6838\u4e2d\u5982\u4f55\u901a\u8fc7\u4ee3\u7801\u5b9e\u73b0DMA\u7684\u6570\u636e\u4f20\u9012\u3002\u5728S3C2440A\u4e2d\uff0c\u6211\u4eec\u96c6\u6210\u4e86DMA\u6a21\u5757\uff0c\u53ef\u4ee5\u7528\u6765\u4f20\u9012\u9ad8\u901f\u4f20\u8f93\u6570\u636e\u3002\u7b2c\u4e8c\u90e8\u5206\uff1a\u5728\u5185\u6838\u4e2d\u5982\u4f55\u901a\u8fc7\u4ee3\u7801\u5b9e\u73b0DMA\u6570\u636e\u4f20\u9012\u3002<\/p>\n","protected":false},"author":1,"featured_media":294985,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[988],"tags":[4923,4921,4922,1076,4924],"class_list":["post-294984","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tougao","tag-czy","tag-DMA","tag-ncsjcd","tag-nh","tag-sjcsgs"],"acf":[],"_links":{"self":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/294984","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/comments?post=294984"}],"version-history":[{"count":0,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/294984\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/media\/294985"}],"wp:attachment":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/media?parent=294984"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/categories?post=294984"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/tags?post=294984"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}