{"id":2221949,"url":"http://patchwork.ozlabs.org/api/patches/2221949/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-pci/patch/20260410-sdxi-base-v1-15-1d184cb5c60a@amd.com/","project":{"id":28,"url":"http://patchwork.ozlabs.org/api/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,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260410-sdxi-base-v1-15-1d184cb5c60a@amd.com>","list_archive_url":null,"date":"2026-04-10T13:07:25","name":"[15/23] dmaengine: sdxi: Per-context access key (AKey) table entry allocator","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"344599da962a8b9d96428363d3e347b9141e23c1","submitter":{"id":91626,"url":"http://patchwork.ozlabs.org/api/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-v1-15-1d184cb5c60a@amd.com/mbox/","series":[{"id":499458,"url":"http://patchwork.ozlabs.org/api/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/2221949/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2221949/checks/","tags":{},"related":[],"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=n2484PuZ;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; 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charset=\"utf-8\"","Content-Transfer-Encoding":"7bit","Message-Id":"<20260410-sdxi-base-v1-15-1d184cb5c60a@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=3996;\n i=nathan.lynch@amd.com; s=20260410; h=from:subject:message-id;\n bh=xM2FGHLq6TQB7ArRAf3V9Xhjrb67k3x/AkY1HQPO5Q4=;\n b=rTIQiw+zTFxDWBJcNZ1EhzZHuGqJ/VcHG0jcXFMHnx9gZ0q7el1Y4xTktMb48O5pJLc0z6jWz\n mxATmGFkhIWBSOQU4z+Y2mBWMmA1NhqSQFaNRipagID+VrPDfEAFsh3","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\nEach SDXI context has a table of access keys (AKeys). SDXI descriptors\nsubmitted to a context may refer to an AKey associated with that\ncontext by its index in the table. AKeys describe properties of the\naccess that the descriptor is to perform, such as PASID or a target\nSDXI function, or an interrupt to trigger.\n\nUse a per-context IDA to keep track of used entries in the table.\nProvide sdxi_alloc_akey(), which claims an AKey table entry for the\ncaller to program directly; sdxi_akey_index(), which returns the\nentry's index for programming into descriptors the caller intends to\nsubmit; and sdxi_free_akey(), which clears the entry and makes it\navailable again.\n\nThe DMA engine provider is currently the only user and allocates a\nsingle entry that encodes the access properties for copy operations\nand a completion interrupt. More complex use patterns are possible\nwhen user space gains access to SDXI contexts (not in this series).\n\nCo-developed-by: Wei Huang \nSigned-off-by: Wei Huang \nSigned-off-by: Nathan Lynch \n---\n drivers/dma/sdxi/context.c | 5 +++++\n drivers/dma/sdxi/context.h | 24 ++++++++++++++++++++++++\n 2 files changed, 29 insertions(+)","diff":"diff --git a/drivers/dma/sdxi/context.c b/drivers/dma/sdxi/context.c\nindex 792b5032203b..04e0d3e6a337 100644\n--- a/drivers/dma/sdxi/context.c\n+++ b/drivers/dma/sdxi/context.c\n@@ -15,6 +15,7 @@\n #include \n #include \n #include \n+#include \n #include \n #include \n #include \n@@ -61,6 +62,7 @@ static void sdxi_free_cxt(struct sdxi_cxt *cxt)\n \t\tdma_free_coherent(sdxi_to_dev(sdxi), sq->ring_size,\n \t\t\t\t sq->desc_ring, sq->ring_dma);\n \tkfree(cxt->sq);\n+\tida_destroy(&cxt->akey_ida);\n \tkfree(cxt->ring_state);\n \tkfree(cxt);\n }\n@@ -381,6 +383,7 @@ int sdxi_admin_cxt_init(struct sdxi_dev *sdxi)\n \tcxt->db = sdxi->dbs + cxt->id * sdxi->db_stride;\n \tsdxi_ring_state_init(cxt->ring_state, &sq->cxt_sts->read_index,\n \t\t\t sq->write_index, sq->ring_entries, sq->desc_ring);\n+\tida_init(&cxt->akey_ida);\n \n \terr = sdxi_publish_cxt(cxt);\n \tif (err)\n@@ -406,6 +409,8 @@ struct sdxi_cxt *sdxi_cxt_new(struct sdxi_dev *sdxi)\n \tsq = cxt->sq;\n \tsdxi_ring_state_init(cxt->ring_state, &sq->cxt_sts->read_index,\n \t\t\t sq->write_index, sq->ring_entries, sq->desc_ring);\n+\tida_init(&cxt->akey_ida);\n+\n \tif (register_cxt(sdxi, cxt))\n \t\treturn NULL;\n \ndiff --git a/drivers/dma/sdxi/context.h b/drivers/dma/sdxi/context.h\nindex 9779b9aa4f86..5310e51a668c 100644\n--- a/drivers/dma/sdxi/context.h\n+++ b/drivers/dma/sdxi/context.h\n@@ -6,7 +6,10 @@\n #ifndef DMA_SDXI_CONTEXT_H\n #define DMA_SDXI_CONTEXT_H\n \n+#include \n #include \n+#include \n+#include \n #include \n \n #include \"hw.h\"\n@@ -50,6 +53,7 @@ struct sdxi_cxt {\n \tstruct sdxi_cxt_ctl *cxt_ctl;\n \tdma_addr_t cxt_ctl_dma;\n \n+\tstruct ida akey_ida;\n \tstruct sdxi_akey_table *akey_table;\n \tdma_addr_t akey_table_dma;\n \n@@ -75,4 +79,24 @@ static inline bool sdxi_cxt_is_admin(const struct sdxi_cxt *cxt)\n \n void sdxi_cxt_push_doorbell(struct sdxi_cxt *cxt, u64 index);\n \n+static inline struct sdxi_akey_ent *sdxi_alloc_akey(struct sdxi_cxt *cxt)\n+{\n+\tunsigned int max = ARRAY_SIZE(cxt->akey_table->entry) - 1;\n+\tint idx = ida_alloc_max(&cxt->akey_ida, max, GFP_KERNEL);\n+\n+\treturn idx < 0 ? NULL : &cxt->akey_table->entry[idx];\n+}\n+\n+static inline unsigned int sdxi_akey_index(const struct sdxi_cxt *cxt,\n+\t\t\t\t\t const struct sdxi_akey_ent *akey)\n+{\n+\treturn akey - &cxt->akey_table->entry[0];\n+}\n+\n+static inline void sdxi_free_akey(struct sdxi_cxt *cxt, struct sdxi_akey_ent *akey)\n+{\n+\tmemset(akey, 0, sizeof(*akey));\n+\tida_free(&cxt->akey_ida, sdxi_akey_index(cxt, akey));\n+}\n+\n #endif /* DMA_SDXI_CONTEXT_H */\n","prefixes":["15/23"]}