From b91da7308171ac4ad2623d371f37288dafbb3bdc Mon Sep 17 00:00:00 2001 From: "Ricardo B. Marliere" Date: Sun, 4 Feb 2024 17:28:58 -0300 Subject: PCI: endpoint: Make pci_epf_bus_type const Now that the driver core can properly handle constant struct bus_type, move the pci_epf_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: Ricardo B. Marliere Reviewed-by: Greg Kroah-Hartman Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20240204-bus_cleanup-pci-v1-1-300267a1e99e@marliere.net [mani: modified subject to reflect subsys prefix] Signed-off-by: Manivannan Sadhasivam --- drivers/pci/endpoint/pci-epf-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index 2c32de667937..bf655383e5ed 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -17,7 +17,7 @@ static DEFINE_MUTEX(pci_epf_mutex); -static struct bus_type pci_epf_bus_type; +static const struct bus_type pci_epf_bus_type; static const struct device_type pci_epf_type; /** @@ -507,7 +507,7 @@ static void pci_epf_device_remove(struct device *dev) epf->driver = NULL; } -static struct bus_type pci_epf_bus_type = { +static const struct bus_type pci_epf_bus_type = { .name = "pci-epf", .match = pci_epf_device_match, .probe = pci_epf_device_probe, -- cgit From e891becdccaa9048b1ab91c08ad5722edd571806 Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Wed, 7 Feb 2024 22:39:14 +0100 Subject: PCI: endpoint: Refactor pci_epf_alloc_space() API Refactor pci_epf_alloc_space() API to accept "epc_features" as a parameter. This is a preparatory work to make the API more robust. Reviewed-by: Frank Li Reviewed-by: Manivannan Sadhasivam Signed-off-by: Niklas Cassel Link: https://lore.kernel.org/r/20240207213922.1796533-2-cassel@kernel.org [mani: reworded commit message] Signed-off-by: Manivannan Sadhasivam --- drivers/pci/endpoint/functions/pci-epf-ntb.c | 2 +- drivers/pci/endpoint/functions/pci-epf-test.c | 5 ++--- drivers/pci/endpoint/functions/pci-epf-vntb.c | 4 ++-- drivers/pci/endpoint/pci-epf-core.c | 6 ++++-- include/linux/pci-epf.h | 4 +++- 5 files changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c index 0553946005c4..43cd309ce22f 100644 --- a/drivers/pci/endpoint/functions/pci-epf-ntb.c +++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c @@ -1067,7 +1067,7 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb, else if (size < ctrl_size + spad_size) return -EINVAL; - base = pci_epf_alloc_space(epf, size, barno, align, type); + base = pci_epf_alloc_space(epf, size, barno, epc_features, type); if (!base) { dev_err(dev, "%s intf: Config/Status/SPAD alloc region fail\n", pci_epc_interface_string(type)); diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 18c80002d3bd..15bfa7d83489 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -848,7 +848,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) } base = pci_epf_alloc_space(epf, test_reg_size, test_reg_bar, - epc_features->align, PRIMARY_INTERFACE); + epc_features, PRIMARY_INTERFACE); if (!base) { dev_err(dev, "Failed to allocated register space\n"); return -ENOMEM; @@ -866,8 +866,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) continue; base = pci_epf_alloc_space(epf, bar_size[bar], bar, - epc_features->align, - PRIMARY_INTERFACE); + epc_features, PRIMARY_INTERFACE); if (!base) dev_err(dev, "Failed to allocate space for BAR%d\n", bar); diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c index e75a2af77328..ba509d67188b 100644 --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c @@ -446,7 +446,7 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb) else if (size < ctrl_size + spad_size) return -EINVAL; - base = pci_epf_alloc_space(epf, size, barno, align, 0); + base = pci_epf_alloc_space(epf, size, barno, epc_features, 0); if (!base) { dev_err(dev, "Config/Status/SPAD alloc region fail\n"); return -ENOMEM; @@ -550,7 +550,7 @@ static int epf_ntb_db_bar_init(struct epf_ntb *ntb) barno = ntb->epf_ntb_bar[BAR_DB]; - mw_addr = pci_epf_alloc_space(ntb->epf, size, barno, align, 0); + mw_addr = pci_epf_alloc_space(ntb->epf, size, barno, epc_features, 0); if (!mw_addr) { dev_err(dev, "Failed to allocate OB address\n"); return -ENOMEM; diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index bf655383e5ed..9da9a1e9c086 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -251,14 +251,16 @@ EXPORT_SYMBOL_GPL(pci_epf_free_space); * @epf: the EPF device to whom allocate the memory * @size: the size of the memory that has to be allocated * @bar: the BAR number corresponding to the allocated register space - * @align: alignment size for the allocation region + * @epc_features: the features provided by the EPC specific to this EPF * @type: Identifies if the allocation is for primary EPC or secondary EPC * * Invoke to allocate memory for the PCI EPF register space. */ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, - size_t align, enum pci_epc_interface_type type) + const struct pci_epc_features *epc_features, + enum pci_epc_interface_type type) { + size_t align = epc_features->align; struct pci_epf_bar *epf_bar; dma_addr_t phys_addr; struct pci_epc *epc; diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h index 77b146e0f672..adee6a1b35db 100644 --- a/include/linux/pci-epf.h +++ b/include/linux/pci-epf.h @@ -15,6 +15,7 @@ #include struct pci_epf; +struct pci_epc_features; enum pci_epc_interface_type; enum pci_barno { @@ -216,7 +217,8 @@ int __pci_epf_register_driver(struct pci_epf_driver *driver, struct module *owner); void pci_epf_unregister_driver(struct pci_epf_driver *driver); void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, - size_t align, enum pci_epc_interface_type type); + const struct pci_epc_features *epc_features, + enum pci_epc_interface_type type); void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar, enum pci_epc_interface_type type); int pci_epf_bind(struct pci_epf *epf); -- cgit From 84b51a6baeaf1ba85e024a5bf145382c02179013 Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Wed, 7 Feb 2024 22:39:15 +0100 Subject: PCI: endpoint: Improve pci_epf_alloc_space() API pci_epf_alloc_space() already performs checks on the requested BAR size, and will allocate and set epf_bar->size to a size higher than the requested BAR size if some constraint deems it necessary. However, there are additional checks done in the function drivers like pci-epf-test.c, other than the existing checks in this API. And similar checks are proposed to other endpoint function drivers, see: https://lore.kernel.org/linux-pci/20240108151015.2030469-1-Frank.Li@nxp.com Having these checks scattered over different locations in multiple EPF drivers is not maintainable and makes the code hard to follow. Since pci_epf_alloc_space() already performs roundups and some checks, let's move the additional checks from pci-epf-test.c to pci_epf_alloc_space(). This makes the API more robust and also offloads the checks from the function drivers. Signed-off-by: Niklas Cassel Reviewed-by: Manivannan Sadhasivam Reviewed-by: Frank Li Link: https://lore.kernel.org/r/20240207213922.1796533-3-cassel@kernel.org [mani: reworded commit message and fixed uninitialized 'dev' pointer issue] Signed-off-by: Manivannan Sadhasivam --- drivers/pci/endpoint/pci-epf-core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index 9da9a1e9c086..f2b4d34454c4 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -260,6 +260,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, const struct pci_epc_features *epc_features, enum pci_epc_interface_type type) { + u64 bar_fixed_size = epc_features->bar_fixed_size[bar]; size_t align = epc_features->align; struct pci_epf_bar *epf_bar; dma_addr_t phys_addr; @@ -270,6 +271,14 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, if (size < 128) size = 128; + if (bar_fixed_size && size > bar_fixed_size) { + dev_err(&epf->dev, "requested BAR size is larger than fixed size\n"); + return NULL; + } + + if (bar_fixed_size) + size = bar_fixed_size; + if (align) size = ALIGN(size, align); else -- cgit From fda826b15c782b6b7d3bd3a9a089c928512ebd3d Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Wed, 7 Feb 2024 22:39:16 +0100 Subject: PCI: endpoint: pci-epf-test: Remove superfluous checks for pci_epf_alloc_space() API Now that the checks are performed by the pci_epf_alloc_space() API, let's remove the superfluous checks in this driver. Signed-off-by: Niklas Cassel Reviewed-by: Manivannan Sadhasivam Reviewed-by: Frank Li Link: https://lore.kernel.org/r/20240207213922.1796533-4-cassel@kernel.org [mani: reworded commit message] Signed-off-by: Manivannan Sadhasivam --- drivers/pci/endpoint/functions/pci-epf-test.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 15bfa7d83489..981894e40681 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -841,12 +841,6 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) } test_reg_size = test_reg_bar_size + msix_table_size + pba_size; - if (epc_features->bar_fixed_size[test_reg_bar]) { - if (test_reg_size > bar_size[test_reg_bar]) - return -ENOMEM; - test_reg_size = bar_size[test_reg_bar]; - } - base = pci_epf_alloc_space(epf, test_reg_size, test_reg_bar, epc_features, PRIMARY_INTERFACE); if (!base) { @@ -888,8 +882,6 @@ static void pci_epf_configure_bar(struct pci_epf *epf, bar_fixed_64bit = !!(epc_features->bar_fixed_64bit & (1 << i)); if (bar_fixed_64bit) epf_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64; - if (epc_features->bar_fixed_size[i]) - bar_size[i] = epc_features->bar_fixed_size[i]; } } -- cgit From c795fd3f3622d276f3cdb7b64e6e6c4042585734 Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Wed, 7 Feb 2024 22:39:17 +0100 Subject: PCI: endpoint: pci-epf-vntb: Remove superfluous checks for pci_epf_alloc_space() API Now that the checks are performed by the pci_epf_alloc_space() API, let's remove the superfluous checks in this driver. Signed-off-by: Niklas Cassel Reviewed-by: Frank Li Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20240207213922.1796533-5-cassel@kernel.org [mani: reworded the commit message] Signed-off-by: Manivannan Sadhasivam --- drivers/pci/endpoint/functions/pci-epf-vntb.c | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c index ba509d67188b..eda4b906868b 100644 --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c @@ -527,7 +527,6 @@ static int epf_ntb_configure_interrupt(struct epf_ntb *ntb) static int epf_ntb_db_bar_init(struct epf_ntb *ntb) { const struct pci_epc_features *epc_features; - u32 align; struct device *dev = &ntb->epf->dev; int ret; struct pci_epf_bar *epf_bar; @@ -538,16 +537,6 @@ static int epf_ntb_db_bar_init(struct epf_ntb *ntb) epc_features = pci_epc_get_features(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no); - align = epc_features->align; - - if (size < 128) - size = 128; - - if (align) - size = ALIGN(size, align); - else - size = roundup_pow_of_two(size); - barno = ntb->epf_ntb_bar[BAR_DB]; mw_addr = pci_epf_alloc_space(ntb->epf, size, barno, epc_features, 0); -- cgit From aebfdfe39b9327a3077d0df8db3beb3160c9bdd0 Mon Sep 17 00:00:00 2001 From: Yang Yingliang Date: Fri, 1 Dec 2023 11:30:56 +0800 Subject: NTB: fix possible name leak in ntb_register_device() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If device_register() fails in ntb_register_device(), the device name allocated by dev_set_name() should be freed. As per the comment in device_register(), callers should use put_device() to give up the reference in the error path. So fix this by calling put_device() in the error path so that the name can be freed in kobject_cleanup(). As a result of this, put_device() in the error path of ntb_register_device() is removed and the actual error is returned. Fixes: a1bd3baeb2f1 ("NTB: Add NTB hardware abstraction layer") Signed-off-by: Yang Yingliang Reviewed-by: Ilpo Järvinen Reviewed-by: Manivannan Sadhasivam Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/20231201033057.1399131-1-yangyingliang@huaweicloud.com [mani: reworded commit message] Signed-off-by: Manivannan Sadhasivam --- drivers/ntb/core.c | 8 +++++++- drivers/pci/endpoint/functions/pci-epf-vntb.c | 6 +----- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/ntb/core.c b/drivers/ntb/core.c index 27dd93deff6e..d702bee78082 100644 --- a/drivers/ntb/core.c +++ b/drivers/ntb/core.c @@ -100,6 +100,8 @@ EXPORT_SYMBOL(ntb_unregister_client); int ntb_register_device(struct ntb_dev *ntb) { + int ret; + if (!ntb) return -EINVAL; if (!ntb->pdev) @@ -120,7 +122,11 @@ int ntb_register_device(struct ntb_dev *ntb) ntb->ctx_ops = NULL; spin_lock_init(&ntb->ctx_lock); - return device_register(&ntb->dev); + ret = device_register(&ntb->dev); + if (ret) + put_device(&ntb->dev); + + return ret; } EXPORT_SYMBOL(ntb_register_device); diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c index eda4b906868b..d4c25b43da23 100644 --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c @@ -1264,15 +1264,11 @@ static int pci_vntb_probe(struct pci_dev *pdev, const struct pci_device_id *id) ret = ntb_register_device(&ndev->ntb); if (ret) { dev_err(dev, "Failed to register NTB device\n"); - goto err_register_dev; + return ret; } dev_dbg(dev, "PCI Virtual NTB driver loaded\n"); return 0; - -err_register_dev: - put_device(&ndev->ntb.dev); - return -EINVAL; } static struct pci_device_id pci_vntb_table[] = { -- cgit From 976dc5ff3018552dcfe58018a0cfdf6376318117 Mon Sep 17 00:00:00 2001 From: Yang Yingliang Date: Fri, 1 Dec 2023 11:30:57 +0800 Subject: PCI: epf-vntb: Return actual error code during pci_vntb_probe() failure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If dma_set_mask_and_coherent() in pci_vntb_probe() fails, return the actual error code instead of -EINVAL. Signed-off-by: Yang Yingliang Reviewed-by: Manivannan Sadhasivam Reviewed-by: Dave Jiang Reviewed-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20231201033057.1399131-2-yangyingliang@huaweicloud.com [mani: reworded commit message and subject] Signed-off-by: Manivannan Sadhasivam --- drivers/pci/endpoint/functions/pci-epf-vntb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c index d4c25b43da23..0675929fc529 100644 --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c @@ -1258,7 +1258,7 @@ static int pci_vntb_probe(struct pci_dev *pdev, const struct pci_device_id *id) ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)); if (ret) { dev_err(dev, "Cannot set DMA mask\n"); - return -EINVAL; + return ret; } ret = ntb_register_device(&ndev->ntb); -- cgit From 2e00fd5487c796db8b8324e80bc5fe8a02c15a15 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Fri, 1 Dec 2023 17:36:14 +0530 Subject: PCI: epf-mhi: Add "pci_epf_mhi_" prefix to the function names Without the prefix, the function name would appear as "/sys/kernel/config/functions/{sdx55/sm8450}". This will be a problem if multiple functions are supported for this endpoint device. So let's add the "pci_epf_mhi_" prefix to identify _this_ function uniquely. Even though it is an ABI breakage, this driver is not used anywhere outside Qcom and myself to my knowledge. So it safe to change the function name. Signed-off-by: Manivannan Sadhasivam Signed-off-by: Mrinmay Sarkar Link: https://lore.kernel.org/r/1701432377-16899-4-git-send-email-quic_msarkar@quicinc.com --- drivers/pci/endpoint/functions/pci-epf-mhi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c index 1c3e4ea76bd2..5c0dba5ba602 100644 --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c @@ -913,8 +913,8 @@ static int pci_epf_mhi_probe(struct pci_epf *epf, } static const struct pci_epf_device_id pci_epf_mhi_ids[] = { - { .name = "sdx55", .driver_data = (kernel_ulong_t)&sdx55_info }, - { .name = "sm8450", .driver_data = (kernel_ulong_t)&sm8450_info }, + { .name = "pci_epf_mhi_sdx55", .driver_data = (kernel_ulong_t)&sdx55_info }, + { .name = "pci_epf_mhi_sm8450", .driver_data = (kernel_ulong_t)&sm8450_info }, {}, }; -- cgit From c670e29f5bfe6c404a5405a0fa8e235de2f4f0c9 Mon Sep 17 00:00:00 2001 From: Mrinmay Sarkar Date: Fri, 1 Dec 2023 17:36:15 +0530 Subject: PCI: epf-mhi: Add support for SA8775P SoC Add support for Qualcomm Snapdragon SA8775P SoC to the EPF driver. SA8775P is currently reusing the PID 0x0306 (the default one hardcoded in the config space header) as the unique PID is not yet allocated. But the host side stack works fine with the default PID. It will get updated once the PID is finalized. Also, it has no fixed PCI class as of now, so it is being advertised as "PCI_CLASS_OTHERS". Signed-off-by: Mrinmay Sarkar Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/1701432377-16899-5-git-send-email-quic_msarkar@quicinc.com Signed-off-by: Manivannan Sadhasivam --- drivers/pci/endpoint/functions/pci-epf-mhi.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c index 5c0dba5ba602..2c54d80107cf 100644 --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c @@ -123,6 +123,22 @@ static const struct pci_epf_mhi_ep_info sm8450_info = { .flags = MHI_EPF_USE_DMA, }; +static struct pci_epf_header sa8775p_header = { + .vendorid = PCI_VENDOR_ID_QCOM, + .deviceid = 0x0306, /* FIXME: Update deviceid for sa8775p EP */ + .baseclass_code = PCI_CLASS_OTHERS, + .interrupt_pin = PCI_INTERRUPT_INTA, +}; + +static const struct pci_epf_mhi_ep_info sa8775p_info = { + .config = &mhi_v1_config, + .epf_header = &sa8775p_header, + .bar_num = BAR_0, + .epf_flags = PCI_BASE_ADDRESS_MEM_TYPE_32, + .msi_count = 32, + .mru = 0x8000, +}; + struct pci_epf_mhi { const struct pci_epc_features *epc_features; const struct pci_epf_mhi_ep_info *info; @@ -913,6 +929,7 @@ static int pci_epf_mhi_probe(struct pci_epf *epf, } static const struct pci_epf_device_id pci_epf_mhi_ids[] = { + { .name = "pci_epf_mhi_sa8775p", .driver_data = (kernel_ulong_t)&sa8775p_info }, { .name = "pci_epf_mhi_sdx55", .driver_data = (kernel_ulong_t)&sdx55_info }, { .name = "pci_epf_mhi_sm8450", .driver_data = (kernel_ulong_t)&sm8450_info }, {}, -- cgit From e01c9797c0ebb307c9bb196c677f6e571335773e Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Fri, 16 Feb 2024 14:45:14 +0100 Subject: PCI: endpoint: Clean up hardware description for BARs The hardware description for BARs is scattered in many different variables in pci_epc_features. Some of these things are mutually exclusive, so it can create confusion over which variable that has precedence over another. Improve the situation by creating a struct pci_epc_bar_desc, and a new enum pci_epc_bar_type, and convert the endpoint controller drivers to use this more well defined format. Additionally, some endpoint controller drivers mark the BAR succeeding a "64-bit only BAR" as reserved, while some do not. By definition, a 64-bit BAR uses the succeeding BAR for the upper 32-bits, so an EPF driver cannot use a BAR succeeding a 64-bit BAR. Ensure that all endpoint controller drivers are uniform, and actually describe a reserved BAR as reserved. Signed-off-by: Niklas Cassel Reviewed-by: Kishon Vijay Abraham I Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20240216134524.1142149-2-cassel@kernel.org Signed-off-by: Manivannan Sadhasivam --- drivers/pci/controller/dwc/pci-imx6.c | 3 ++- drivers/pci/controller/dwc/pci-keystone.c | 12 ++++----- drivers/pci/controller/dwc/pci-layerscape-ep.c | 5 +++- drivers/pci/controller/dwc/pcie-keembay.c | 8 ++++-- drivers/pci/controller/dwc/pcie-rcar-gen4.c | 4 ++- drivers/pci/controller/dwc/pcie-tegra194.c | 10 +++++--- drivers/pci/controller/dwc/pcie-uniphier-ep.c | 15 +++++++++--- drivers/pci/controller/pcie-rcar-ep.c | 14 +++++++---- drivers/pci/endpoint/functions/pci-epf-ntb.c | 4 +-- drivers/pci/endpoint/functions/pci-epf-test.c | 8 +++--- drivers/pci/endpoint/functions/pci-epf-vntb.c | 2 +- drivers/pci/endpoint/pci-epc-core.c | 32 ++++++++++++------------ drivers/pci/endpoint/pci-epf-core.c | 15 ++++++------ include/linux/pci-epc.h | 34 +++++++++++++++++++++----- 14 files changed, 108 insertions(+), 58 deletions(-) diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index dc2c036ab28c..47a9a96484ed 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -1081,7 +1081,8 @@ static const struct pci_epc_features imx8m_pcie_epc_features = { .linkup_notifier = false, .msi_capable = true, .msix_capable = false, - .reserved_bar = 1 << BAR_1 | 1 << BAR_3, + .bar[BAR_1] = { .type = BAR_RESERVED, }, + .bar[BAR_3] = { .type = BAR_RESERVED, }, .align = SZ_64K, }; diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c index c0c62533a3f1..b2b93b4fa82d 100644 --- a/drivers/pci/controller/dwc/pci-keystone.c +++ b/drivers/pci/controller/dwc/pci-keystone.c @@ -924,12 +924,12 @@ static const struct pci_epc_features ks_pcie_am654_epc_features = { .linkup_notifier = false, .msi_capable = true, .msix_capable = true, - .reserved_bar = 1 << BAR_0 | 1 << BAR_1, - .bar_fixed_64bit = 1 << BAR_0, - .bar_fixed_size[2] = SZ_1M, - .bar_fixed_size[3] = SZ_64K, - .bar_fixed_size[4] = 256, - .bar_fixed_size[5] = SZ_1M, + .bar[BAR_0] = { .type = BAR_RESERVED, .only_64bit = true, }, + .bar[BAR_1] = { .type = BAR_RESERVED, }, + .bar[BAR_2] = { .type = BAR_FIXED, .fixed_size = SZ_1M, }, + .bar[BAR_3] = { .type = BAR_FIXED, .fixed_size = SZ_64K, }, + .bar[BAR_4] = { .type = BAR_FIXED, .fixed_size = 256, }, + .bar[BAR_5] = { .type = BAR_FIXED, .fixed_size = SZ_1M, }, .align = SZ_1M, }; diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c index 2e398494e7c0..1f6ee1460ec2 100644 --- a/drivers/pci/controller/dwc/pci-layerscape-ep.c +++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c @@ -250,7 +250,10 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev) pci->dev = dev; pci->ops = pcie->drvdata->dw_pcie_ops; - ls_epc->bar_fixed_64bit = (1 << BAR_2) | (1 << BAR_4); + ls_epc->bar[BAR_2].only_64bit = true; + ls_epc->bar[BAR_3].type = BAR_RESERVED; + ls_epc->bar[BAR_4].only_64bit = true; + ls_epc->bar[BAR_5].type = BAR_RESERVED; ls_epc->linkup_notifier = true; pcie->pci = pci; diff --git a/drivers/pci/controller/dwc/pcie-keembay.c b/drivers/pci/controller/dwc/pcie-keembay.c index 208d3b0ba196..5e8e54f597dd 100644 --- a/drivers/pci/controller/dwc/pcie-keembay.c +++ b/drivers/pci/controller/dwc/pcie-keembay.c @@ -312,8 +312,12 @@ static const struct pci_epc_features keembay_pcie_epc_features = { .linkup_notifier = false, .msi_capable = true, .msix_capable = true, - .reserved_bar = BIT(BAR_1) | BIT(BAR_3) | BIT(BAR_5), - .bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4), + .bar[BAR_0] = { .only_64bit = true, }, + .bar[BAR_1] = { .type = BAR_RESERVED, }, + .bar[BAR_2] = { .only_64bit = true, }, + .bar[BAR_3] = { .type = BAR_RESERVED, }, + .bar[BAR_4] = { .only_64bit = true, }, + .bar[BAR_5] = { .type = BAR_RESERVED, }, .align = SZ_16K, }; diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c index e9166619b1f9..0be760ed420b 100644 --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c @@ -383,7 +383,9 @@ static const struct pci_epc_features rcar_gen4_pcie_epc_features = { .linkup_notifier = false, .msi_capable = true, .msix_capable = false, - .reserved_bar = 1 << BAR_1 | 1 << BAR_3 | 1 << BAR_5, + .bar[BAR_1] = { .type = BAR_RESERVED, }, + .bar[BAR_3] = { .type = BAR_RESERVED, }, + .bar[BAR_5] = { .type = BAR_RESERVED, }, .align = SZ_1M, }; diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index 7afa9e9aabe2..1f7b662cb8e1 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -2007,9 +2007,13 @@ static const struct pci_epc_features tegra_pcie_epc_features = { .core_init_notifier = true, .msi_capable = false, .msix_capable = false, - .reserved_bar = 1 << BAR_2 | 1 << BAR_3 | 1 << BAR_4 | 1 << BAR_5, - .bar_fixed_64bit = 1 << BAR_0, - .bar_fixed_size[0] = SZ_1M, + .bar[BAR_0] = { .type = BAR_FIXED, .fixed_size = SZ_1M, + .only_64bit = true, }, + .bar[BAR_1] = { .type = BAR_RESERVED, }, + .bar[BAR_2] = { .type = BAR_RESERVED, }, + .bar[BAR_3] = { .type = BAR_RESERVED, }, + .bar[BAR_4] = { .type = BAR_RESERVED, }, + .bar[BAR_5] = { .type = BAR_RESERVED, }, }; static const struct pci_epc_features* diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c index 3fced0d3e851..265f65fc673f 100644 --- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c +++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c @@ -411,8 +411,12 @@ static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = { .msi_capable = true, .msix_capable = false, .align = 1 << 16, - .bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4), - .reserved_bar = BIT(BAR_4), + .bar[BAR_0] = { .only_64bit = true, }, + .bar[BAR_1] = { .type = BAR_RESERVED, }, + .bar[BAR_2] = { .only_64bit = true, }, + .bar[BAR_3] = { .type = BAR_RESERVED, }, + .bar[BAR_4] = { .type = BAR_RESERVED, .only_64bit = true, }, + .bar[BAR_5] = { .type = BAR_RESERVED, }, }, }; @@ -425,7 +429,12 @@ static const struct uniphier_pcie_ep_soc_data uniphier_nx1_data = { .msi_capable = true, .msix_capable = false, .align = 1 << 12, - .bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4), + .bar[BAR_0] = { .only_64bit = true, }, + .bar[BAR_1] = { .type = BAR_RESERVED, }, + .bar[BAR_2] = { .only_64bit = true, }, + .bar[BAR_3] = { .type = BAR_RESERVED, }, + .bar[BAR_4] = { .only_64bit = true, }, + .bar[BAR_5] = { .type = BAR_RESERVED, }, }, }; diff --git a/drivers/pci/controller/pcie-rcar-ep.c b/drivers/pci/controller/pcie-rcar-ep.c index e6909271def7..05967c6c0b42 100644 --- a/drivers/pci/controller/pcie-rcar-ep.c +++ b/drivers/pci/controller/pcie-rcar-ep.c @@ -440,11 +440,15 @@ static const struct pci_epc_features rcar_pcie_epc_features = { .msi_capable = true, .msix_capable = false, /* use 64-bit BARs so mark BAR[1,3,5] as reserved */ - .reserved_bar = 1 << BAR_1 | 1 << BAR_3 | 1 << BAR_5, - .bar_fixed_64bit = 1 << BAR_0 | 1 << BAR_2 | 1 << BAR_4, - .bar_fixed_size[0] = 128, - .bar_fixed_size[2] = 256, - .bar_fixed_size[4] = 256, + .bar[BAR_0] = { .type = BAR_FIXED, .fixed_size = 128, + .only_64bit = true, }, + .bar[BAR_1] = { .type = BAR_RESERVED, }, + .bar[BAR_2] = { .type = BAR_FIXED, .fixed_size = 256, + .only_64bit = true, }, + .bar[BAR_3] = { .type = BAR_RESERVED, }, + .bar[BAR_4] = { .type = BAR_FIXED, .fixed_size = 256, + .only_64bit = true, }, + .bar[BAR_5] = { .type = BAR_RESERVED, }, }; static const struct pci_epc_features* diff --git a/drivers/pci/endpoint/functions/pci-epf-ntb.c b/drivers/pci/endpoint/functions/pci-epf-ntb.c index 43cd309ce22f..e01a98e74d21 100644 --- a/drivers/pci/endpoint/functions/pci-epf-ntb.c +++ b/drivers/pci/endpoint/functions/pci-epf-ntb.c @@ -1012,13 +1012,13 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb, epc_features = ntb_epc->epc_features; barno = ntb_epc->epf_ntb_bar[BAR_CONFIG]; - size = epc_features->bar_fixed_size[barno]; + size = epc_features->bar[barno].fixed_size; align = epc_features->align; peer_ntb_epc = ntb->epc[!type]; peer_epc_features = peer_ntb_epc->epc_features; peer_barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD]; - peer_size = peer_epc_features->bar_fixed_size[peer_barno]; + peer_size = peer_epc_features->bar[peer_barno].fixed_size; /* Check if epc_features is populated incorrectly */ if ((!IS_ALIGNED(size, align))) diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 981894e40681..cd4ffb39dcdc 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -729,7 +729,7 @@ static int pci_epf_test_set_bar(struct pci_epf *epf) */ add = (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ? 2 : 1; - if (!!(epc_features->reserved_bar & (1 << bar))) + if (epc_features->bar[bar].type == BAR_RESERVED) continue; ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, @@ -856,7 +856,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) if (bar == test_reg_bar) continue; - if (!!(epc_features->reserved_bar & (1 << bar))) + if (epc_features->bar[bar].type == BAR_RESERVED) continue; base = pci_epf_alloc_space(epf, bar_size[bar], bar, @@ -874,13 +874,11 @@ static void pci_epf_configure_bar(struct pci_epf *epf, const struct pci_epc_features *epc_features) { struct pci_epf_bar *epf_bar; - bool bar_fixed_64bit; int i; for (i = 0; i < PCI_STD_NUM_BARS; i++) { epf_bar = &epf->bar[i]; - bar_fixed_64bit = !!(epc_features->bar_fixed_64bit & (1 << i)); - if (bar_fixed_64bit) + if (epc_features->bar[i].only_64bit) epf_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64; } } diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c index 0675929fc529..8e779eecd62d 100644 --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c @@ -422,7 +422,7 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb) epf->func_no, epf->vfunc_no); barno = ntb->epf_ntb_bar[BAR_CONFIG]; - size = epc_features->bar_fixed_size[barno]; + size = epc_features->bar[barno].fixed_size; align = epc_features->align; if ((!IS_ALIGNED(size, align))) diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c index dcd4e66430c1..7fe8f4336765 100644 --- a/drivers/pci/endpoint/pci-epc-core.c +++ b/drivers/pci/endpoint/pci-epc-core.c @@ -87,7 +87,7 @@ EXPORT_SYMBOL_GPL(pci_epc_get); * @epc_features: pci_epc_features structure that holds the reserved bar bitmap * * Invoke to get the first unreserved BAR that can be used by the endpoint - * function. For any incorrect value in reserved_bar return '0'. + * function. */ enum pci_barno pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features) @@ -102,32 +102,34 @@ EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar); * @bar: the starting BAR number from where unreserved BAR should be searched * * Invoke to get the next unreserved BAR starting from @bar that can be used - * for endpoint function. For any incorrect value in reserved_bar return '0'. + * for endpoint function. */ enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features *epc_features, enum pci_barno bar) { - unsigned long free_bar; + int i; if (!epc_features) return BAR_0; /* If 'bar - 1' is a 64-bit BAR, move to the next BAR */ - if ((epc_features->bar_fixed_64bit << 1) & 1 << bar) + if (bar > 0 && epc_features->bar[bar - 1].only_64bit) bar++; - /* Find if the reserved BAR is also a 64-bit BAR */ - free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit; - - /* Set the adjacent bit if the reserved BAR is also a 64-bit BAR */ - free_bar <<= 1; - free_bar |= epc_features->reserved_bar; - - free_bar = find_next_zero_bit(&free_bar, 6, bar); - if (free_bar > 5) - return NO_BAR; + for (i = bar; i < PCI_STD_NUM_BARS; i++) { + /* If the BAR is not reserved, return it. */ + if (epc_features->bar[i].type != BAR_RESERVED) + return i; + + /* + * If the BAR is reserved, and marked as 64-bit only, then the + * succeeding BAR is also reserved. + */ + if (epc_features->bar[i].only_64bit) + i++; + } - return free_bar; + return NO_BAR; } EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar); diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index f2b4d34454c4..0a28a0b0911b 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -260,7 +260,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, const struct pci_epc_features *epc_features, enum pci_epc_interface_type type) { - u64 bar_fixed_size = epc_features->bar_fixed_size[bar]; + u64 bar_fixed_size = epc_features->bar[bar].fixed_size; size_t align = epc_features->align; struct pci_epf_bar *epf_bar; dma_addr_t phys_addr; @@ -271,13 +271,14 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, if (size < 128) size = 128; - if (bar_fixed_size && size > bar_fixed_size) { - dev_err(&epf->dev, "requested BAR size is larger than fixed size\n"); - return NULL; - } - - if (bar_fixed_size) + if (epc_features->bar[bar].type == BAR_FIXED && bar_fixed_size) { + if (size > bar_fixed_size) { + dev_err(&epf->dev, + "requested BAR size is larger than fixed size\n"); + return NULL; + } size = bar_fixed_size; + } if (align) size = ALIGN(size, align); diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h index 40ea18f5aa02..4ccb4f4f3883 100644 --- a/include/linux/pci-epc.h +++ b/include/linux/pci-epc.h @@ -145,6 +145,32 @@ struct pci_epc { unsigned long function_num_map; }; +/** + * @BAR_PROGRAMMABLE: The BAR mask can be configured by the EPC. + * @BAR_FIXED: The BAR mask is fixed by the hardware. + * @BAR_RESERVED: The BAR should not be touched by an EPF driver. + */ +enum pci_epc_bar_type { + BAR_PROGRAMMABLE = 0, + BAR_FIXED, + BAR_RESERVED, +}; + +/** + * struct pci_epc_bar_desc - hardware description for a BAR + * @type: the type of the BAR + * @fixed_size: the fixed size, only applicable if type is BAR_FIXED_MASK. + * @only_64bit: if true, an EPF driver is not allowed to choose if this BAR + * should be configured as 32-bit or 64-bit, the EPF driver must + * configure this BAR as 64-bit. Additionally, the BAR succeeding + * this BAR must be set to type BAR_RESERVED. + */ +struct pci_epc_bar_desc { + enum pci_epc_bar_type type; + u64 fixed_size; + bool only_64bit; +}; + /** * struct pci_epc_features - features supported by a EPC device per function * @linkup_notifier: indicate if the EPC device can notify EPF driver on link up @@ -152,9 +178,7 @@ struct pci_epc { * for initialization * @msi_capable: indicate if the endpoint function has MSI capability * @msix_capable: indicate if the endpoint function has MSI-X capability - * @reserved_bar: bitmap to indicate reserved BAR unavailable to function driver - * @bar_fixed_64bit: bitmap to indicate fixed 64bit BARs - * @bar_fixed_size: Array specifying the size supported by each BAR + * @bar: array specifying the hardware description for each BAR * @align: alignment size required for BAR buffer allocation */ struct pci_epc_features { @@ -162,9 +186,7 @@ struct pci_epc_features { unsigned int core_init_notifier : 1; unsigned int msi_capable : 1; unsigned int msix_capable : 1; - u8 reserved_bar; - u8 bar_fixed_64bit; - u64 bar_fixed_size[PCI_STD_NUM_BARS]; + struct pci_epc_bar_desc bar[PCI_STD_NUM_BARS]; size_t align; }; -- cgit From 9266514689fe6476423209ee40168db53134101d Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Fri, 16 Feb 2024 14:45:15 +0100 Subject: PCI: endpoint: Drop only_64bit on reserved BARs The definition of a reserved BAR is that EPF drivers should not touch them. The definition of only_64bit is that the EPF driver must configure this BAR as 64-bit. (An EPF driver is not allowed to choose if this BAR should be configured as 32-bit or 64-bit.) Thus, it does not make sense to put only_64bit of a BAR that EPF drivers are not allow to touch. Drop the only_64bit property from hardware descriptions that are of type reserved BAR. Signed-off-by: Niklas Cassel Reviewed-by: Kishon Vijay Abraham I Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20240216134524.1142149-3-cassel@kernel.org Signed-off-by: Manivannan Sadhasivam --- drivers/pci/controller/dwc/pci-keystone.c | 2 +- drivers/pci/controller/dwc/pcie-uniphier-ep.c | 2 +- drivers/pci/endpoint/pci-epc-core.c | 7 ------- include/linux/pci-epc.h | 5 +++++ 4 files changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c index b2b93b4fa82d..844de4418724 100644 --- a/drivers/pci/controller/dwc/pci-keystone.c +++ b/drivers/pci/controller/dwc/pci-keystone.c @@ -924,7 +924,7 @@ static const struct pci_epc_features ks_pcie_am654_epc_features = { .linkup_notifier = false, .msi_capable = true, .msix_capable = true, - .bar[BAR_0] = { .type = BAR_RESERVED, .only_64bit = true, }, + .bar[BAR_0] = { .type = BAR_RESERVED, }, .bar[BAR_1] = { .type = BAR_RESERVED, }, .bar[BAR_2] = { .type = BAR_FIXED, .fixed_size = SZ_1M, }, .bar[BAR_3] = { .type = BAR_FIXED, .fixed_size = SZ_64K, }, diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c index 265f65fc673f..639bc2e12476 100644 --- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c +++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c @@ -415,7 +415,7 @@ static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = { .bar[BAR_1] = { .type = BAR_RESERVED, }, .bar[BAR_2] = { .only_64bit = true, }, .bar[BAR_3] = { .type = BAR_RESERVED, }, - .bar[BAR_4] = { .type = BAR_RESERVED, .only_64bit = true, }, + .bar[BAR_4] = { .type = BAR_RESERVED, }, .bar[BAR_5] = { .type = BAR_RESERVED, }, }, }; diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c index 7fe8f4336765..da3fc0795b0b 100644 --- a/drivers/pci/endpoint/pci-epc-core.c +++ b/drivers/pci/endpoint/pci-epc-core.c @@ -120,13 +120,6 @@ enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features /* If the BAR is not reserved, return it. */ if (epc_features->bar[i].type != BAR_RESERVED) return i; - - /* - * If the BAR is reserved, and marked as 64-bit only, then the - * succeeding BAR is also reserved. - */ - if (epc_features->bar[i].only_64bit) - i++; } return NO_BAR; diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h index 4ccb4f4f3883..cc2f70d061c8 100644 --- a/include/linux/pci-epc.h +++ b/include/linux/pci-epc.h @@ -164,6 +164,11 @@ enum pci_epc_bar_type { * should be configured as 32-bit or 64-bit, the EPF driver must * configure this BAR as 64-bit. Additionally, the BAR succeeding * this BAR must be set to type BAR_RESERVED. + * + * only_64bit should not be set on a BAR of type BAR_RESERVED. + * (If BARx is a 64-bit BAR that an EPF driver is not allowed to + * touch, then both BARx and BARx+1 must be set to type + * BAR_RESERVED.) */ struct pci_epc_bar_desc { enum pci_epc_bar_type type; -- cgit