{"id":2221933,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2221933/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-pci/patch/20260410-sdxi-base-v1-19-1d184cb5c60a@amd.com/","project":{"id":28,"url":"http://patchwork.ozlabs.org/api/1.1/projects/28/?format=json","name":"Linux PCI development","link_name":"linux-pci","list_id":"linux-pci.vger.kernel.org","list_email":"linux-pci@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<20260410-sdxi-base-v1-19-1d184cb5c60a@amd.com>","date":"2026-04-10T13:07:29","name":"[19/23] dmaengine: sdxi: Provide context start and stop APIs","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"463508c975f4a4d48b78a47977d70f2fbdba9d89","submitter":{"id":91626,"url":"http://patchwork.ozlabs.org/api/1.1/people/91626/?format=json","name":"Nathan Lynch via B4 Relay","email":"devnull+nathan.lynch.amd.com@kernel.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-pci/patch/20260410-sdxi-base-v1-19-1d184cb5c60a@amd.com/mbox/","series":[{"id":499458,"url":"http://patchwork.ozlabs.org/api/1.1/series/499458/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-pci/list/?series=499458","date":"2026-04-10T13:07:10","name":"dmaengine: Smart Data Accelerator Interface (SDXI) basic support","version":1,"mbox":"http://patchwork.ozlabs.org/series/499458/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2221933/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2221933/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-pci@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=N761tDkd;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c04:e001:36c::12fc:5321; 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charset=\"utf-8\"","Content-Transfer-Encoding":"7bit","Message-Id":"<20260410-sdxi-base-v1-19-1d184cb5c60a@amd.com>","References":"<20260410-sdxi-base-v1-0-1d184cb5c60a@amd.com>","In-Reply-To":"<20260410-sdxi-base-v1-0-1d184cb5c60a@amd.com>","To":"Vinod Koul ","Cc":"Wei Huang ,\n Mario Limonciello ,\n Bjorn Helgaas ,\n Jonathan Cameron ,\n Stephen Bates , PradeepVineshReddy.Kodamati@amd.com,\n John.Kariuki@amd.com, linux-pci@vger.kernel.org,\n linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,\n Nathan Lynch ","X-Mailer":"b4 0.15.2","X-Developer-Signature":"v=1; a=ed25519-sha256; t=1775826467; l=3798;\n i=nathan.lynch@amd.com; s=20260410; h=from:subject:message-id;\n bh=NeYLcmQw7HQppd+LlGj+2pU9LWwFhUvZx4tcjqsRFVc=;\n b=iJxM3l1UrL7p8blwG8tjlRGafKFKuhh34SWyhSQPNXnZNlzsrC8HfmeXIHSfiaX3hD3oR7wH+\n fcrcbMH0lPfALdsnzRJaGfk0HXAy+BmN8S3ZimAp1aaVo3koAnETkVx","X-Developer-Key":"i=nathan.lynch@amd.com; a=ed25519;\n pk=PK4ozhq+/z9/2Jl5rgDmvHa9raVomv79qM8p1RAFpEw=","X-Endpoint-Received":"by B4 Relay for nathan.lynch@amd.com/20260410 with\n auth_id=728","X-Original-From":"Nathan Lynch ","Reply-To":"nathan.lynch@amd.com"},"content":"From: Nathan Lynch \n\nStarting and stopping SDXI client contexts is implemented by submitting\nspecial-purpose descriptors to a function's admin context.\n\nIntroduce high-level context start and stop APIs that operate on\nstruct sdxi_cxt objects, encapsulating the administrative descriptor\nsubmission and completion signaling. These are intended for use by\nclients such as the DMA engine provider to come.\n\nCo-developed-by: Wei Huang \nSigned-off-by: Wei Huang \nSigned-off-by: Nathan Lynch \n---\n drivers/dma/sdxi/context.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++\n drivers/dma/sdxi/context.h | 3 ++\n 2 files changed, 80 insertions(+)","diff":"diff --git a/drivers/dma/sdxi/context.c b/drivers/dma/sdxi/context.c\nindex 04e0d3e6a337..fc6291f12ffe 100644\n--- a/drivers/dma/sdxi/context.c\n+++ b/drivers/dma/sdxi/context.c\n@@ -23,7 +23,9 @@\n #include \n #include \n \n+#include \"completion.h\"\n #include \"context.h\"\n+#include \"descriptor.h\"\n #include \"hw.h\"\n #include \"ring.h\"\n #include \"sdxi.h\"\n@@ -394,6 +396,81 @@ int sdxi_admin_cxt_init(struct sdxi_dev *sdxi)\n \treturn devm_add_action_or_reset(sdxi_to_dev(sdxi), free_admin_cxt, sdxi);\n }\n \n+int sdxi_start_cxt(struct sdxi_cxt *cxt)\n+{\n+\tstruct sdxi_cxt *adm = to_admin_cxt(cxt);\n+\tstruct sdxi_desc *desc;\n+\tstruct sdxi_ring_resv resv;\n+\tint err;\n+\n+\tmight_sleep();\n+\n+\tstruct sdxi_completion *sc __free(sdxi_completion) =\n+\t\tsdxi_completion_alloc(cxt->sdxi);\n+\n+\tif (!sc)\n+\t\treturn -ENOMEM;\n+\n+\t/* This is not how to start the admin context. */\n+\tif (WARN_ON(adm == cxt))\n+\t\treturn -EINVAL;\n+\n+\terr = sdxi_ring_reserve(adm->ring_state, 1, &resv);\n+\tif (err)\n+\t\treturn err;\n+\n+\tdesc = sdxi_ring_resv_next(&resv);\n+\tsdxi_encode_cxt_start(desc, &(const struct sdxi_cxt_start) {\n+\t\t\t.range = sdxi_cxt_range_single(cxt->id),\n+\t\t});\n+\tsdxi_completion_attach(desc, sc);\n+\tsdxi_desc_make_valid(desc);\n+\tsdxi_cxt_push_doorbell(adm, sdxi_ring_resv_dbval(&resv));\n+\tsdxi_completion_poll(sc);\n+\n+\treturn 0;\n+}\n+\n+void sdxi_stop_cxt(struct sdxi_cxt *cxt)\n+{\n+\tstruct sdxi_cxt *adm = to_admin_cxt(cxt);\n+\tstruct sdxi_desc *stop, *sync;\n+\tstruct sdxi_ring_resv resv;\n+\tint err;\n+\n+\tmight_sleep();\n+\n+\tstruct sdxi_completion *sc __free(sdxi_completion) =\n+\t\tsdxi_completion_alloc(cxt->sdxi);\n+\n+\tif (!sc)\n+\t\treturn;\n+\n+\t/* This is not how to stop the admin context. */\n+\tif (WARN_ON(adm == cxt))\n+\t\treturn;\n+\n+\terr = sdxi_ring_reserve(adm->ring_state, 2, &resv);\n+\tif (WARN_ON_ONCE(err))\n+\t\treturn;\n+\n+\tstop = sdxi_ring_resv_next(&resv);\n+\tsync = sdxi_ring_resv_next(&resv);\n+\n+\tsdxi_encode_cxt_stop(stop, &(const struct sdxi_cxt_stop) {\n+\t\t\t.range = sdxi_cxt_range_single(cxt->id),\n+\t\t});\n+\tsdxi_encode_sync(sync, &(const struct sdxi_sync) {\n+\t\t\t.filter = SDXI_SYNC_FLT_STOP,\n+\t\t\t.range = sdxi_cxt_range_single(cxt->id),\n+\t\t});\n+\tsdxi_completion_attach(sync, sc);\n+\tsdxi_desc_make_valid(stop);\n+\tsdxi_desc_make_valid(sync);\n+\tsdxi_cxt_push_doorbell(adm, sdxi_ring_resv_dbval(&resv));\n+\tsdxi_completion_poll(sc);\n+}\n+\n /*\n * Allocate a context for in-kernel use. Starting the context is the\n * caller's responsibility.\ndiff --git a/drivers/dma/sdxi/context.h b/drivers/dma/sdxi/context.h\nindex 5310e51a668c..9061221e86cb 100644\n--- a/drivers/dma/sdxi/context.h\n+++ b/drivers/dma/sdxi/context.h\n@@ -67,6 +67,9 @@ int sdxi_admin_cxt_init(struct sdxi_dev *sdxi);\n struct sdxi_cxt *sdxi_cxt_new(struct sdxi_dev *sdxi);\n void sdxi_cxt_exit(struct sdxi_cxt *cxt);\n \n+int sdxi_start_cxt(struct sdxi_cxt *cxt);\n+void sdxi_stop_cxt(struct sdxi_cxt *cxt);\n+\n static inline struct sdxi_cxt *to_admin_cxt(const struct sdxi_cxt *cxt)\n {\n \treturn cxt->sdxi->admin_cxt;\n","prefixes":["19/23"]}