From 914a1951d88968371c7d43400c9d936382cd7d69 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Thu, 7 May 2020 14:05:44 -0500 Subject: PCI: Replace zero-length array with flexible-array The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these as a flexible array member [1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that dynamic memory allocations won't be affected by this change: Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero. [1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type [1]. There are some instances of code in which the sizeof() operator is being incorrectly/erroneously applied to zero-length arrays, and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Link: https://lore.kernel.org/r/20200507190544.GA15633@embeddedor Signed-off-by: Gustavo A. R. Silva Signed-off-by: Bjorn Helgaas --- include/linux/pci.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/pci.h b/include/linux/pci.h index 83ce1cdf5676..0453ee458ab1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -279,7 +279,7 @@ struct pci_cap_saved_data { u16 cap_nr; bool cap_extended; unsigned int size; - u32 data[0]; + u32 data[]; }; struct pci_cap_saved_state { @@ -532,7 +532,7 @@ struct pci_host_bridge { resource_size_t start, resource_size_t size, resource_size_t align); - unsigned long private[0] ____cacheline_aligned; + unsigned long private[] ____cacheline_aligned; }; #define to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev) -- cgit v1.2.3 From 6ae72bfa656ea04806f98ef85cb44b0789064362 Mon Sep 17 00:00:00 2001 From: Yicong Yang Date: Sat, 9 May 2020 18:19:28 +0800 Subject: PCI: Unify pcie_find_root_port() and pci_find_pcie_root_port() Previously we used pcie_find_root_port() to find a Root Port from a PCIe device and pci_find_pcie_root_port() to find a Root Port from a Conventional PCI device. Unify the two functions and use pcie_find_root_port() to find a Root Port from either a Conventional PCI device or a PCIe device. Then there is no need to distinguish the type of the device. Link: https://lore.kernel.org/r/1589019568-5216-1-git-send-email-yangyicong@hisilicon.com Signed-off-by: Yicong Yang Signed-off-by: Bjorn Helgaas Acked-by: Kalle Valo # wireless Acked-by: Mika Westerberg # thunderbolt --- drivers/pci/pci-acpi.c | 2 +- drivers/pci/pci.c | 24 ------------------------ drivers/pci/probe.c | 2 +- drivers/pci/quirks.c | 2 +- drivers/thunderbolt/switch.c | 4 ++-- include/linux/pci.h | 23 ++++++++++++++--------- 6 files changed, 19 insertions(+), 38 deletions(-) (limited to 'include/linux') diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index d21969fba6ab..d820a55ae71c 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -948,7 +948,7 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev) * Look for a special _DSD property for the root port and if it * is set we know the hierarchy behind it supports D3 just fine. */ - root = pci_find_pcie_root_port(dev); + root = pcie_find_root_port(dev); if (!root) return false; diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index bb78f580814e..227a3a979ec4 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -751,30 +751,6 @@ struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res) } EXPORT_SYMBOL(pci_find_resource); -/** - * pci_find_pcie_root_port - return PCIe Root Port - * @dev: PCI device to query - * - * Traverse up the parent chain and return the PCIe Root Port PCI Device - * for a given PCI Device. - */ -struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev) -{ - struct pci_dev *bridge, *highest_pcie_bridge = dev; - - bridge = pci_upstream_bridge(dev); - while (bridge && pci_is_pcie(bridge)) { - highest_pcie_bridge = bridge; - bridge = pci_upstream_bridge(bridge); - } - - if (pci_pcie_type(highest_pcie_bridge) != PCI_EXP_TYPE_ROOT_PORT) - return NULL; - - return highest_pcie_bridge; -} -EXPORT_SYMBOL(pci_find_pcie_root_port); - /** * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos * @dev: the PCI device to operate on diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 77b8a145c39b..cdff469ba070 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2056,7 +2056,7 @@ static void pci_configure_relaxed_ordering(struct pci_dev *dev) * For now, we only deal with Relaxed Ordering issues with Root * Ports. Peer-to-Peer DMA is another can of worms. */ - root = pci_find_pcie_root_port(dev); + root = pcie_find_root_port(dev); if (!root) return; diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 28c9a2409c50..885044d050a6 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4319,7 +4319,7 @@ DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_AMD, 0x1a02, PCI_CLASS_NOT_DEFINED, */ static void quirk_disable_root_port_attributes(struct pci_dev *pdev) { - struct pci_dev *root_port = pci_find_pcie_root_port(pdev); + struct pci_dev *root_port = pcie_find_root_port(pdev); if (!root_port) { pci_warn(pdev, "PCIe Completion erratum may cause device errors\n"); diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index a2ce99051c51..d92c7554520b 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -263,7 +263,7 @@ static void nvm_authenticate_start_dma_port(struct tb_switch *sw) * itself. To be on the safe side keep the root port in D0 during * the whole upgrade process. */ - root_port = pci_find_pcie_root_port(sw->tb->nhi->pdev); + root_port = pcie_find_root_port(sw->tb->nhi->pdev); if (root_port) pm_runtime_get_noresume(&root_port->dev); } @@ -272,7 +272,7 @@ static void nvm_authenticate_complete_dma_port(struct tb_switch *sw) { struct pci_dev *root_port; - root_port = pci_find_pcie_root_port(sw->tb->nhi->pdev); + root_port = pcie_find_root_port(sw->tb->nhi->pdev); if (root_port) pm_runtime_put(&root_port->dev); } diff --git a/include/linux/pci.h b/include/linux/pci.h index 0453ee458ab1..bbd6510065a7 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1025,7 +1025,6 @@ void pci_bus_add_device(struct pci_dev *dev); void pci_read_bridge_bases(struct pci_bus *child); struct resource *pci_find_parent_resource(const struct pci_dev *dev, struct resource *res); -struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev); u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin); int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge); u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp); @@ -2143,17 +2142,23 @@ static inline int pci_pcie_type(const struct pci_dev *dev) return (pcie_caps_reg(dev) & PCI_EXP_FLAGS_TYPE) >> 4; } +/** + * pcie_find_root_port - Get the PCIe root port device + * @dev: PCI device + * + * Traverse up the parent chain and return the PCIe Root Port PCI Device + * for a given PCI/PCIe Device. + */ static inline struct pci_dev *pcie_find_root_port(struct pci_dev *dev) { - while (1) { - if (!pci_is_pcie(dev)) - break; - if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) - return dev; - if (!dev->bus->self) - break; - dev = dev->bus->self; + struct pci_dev *bridge = pci_upstream_bridge(dev); + + while (bridge) { + if (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT) + return bridge; + bridge = pci_upstream_bridge(bridge); } + return NULL; } -- cgit v1.2.3 From 3910ebaca8eae0cb9d41a20efe1bcb375ec64dfb Mon Sep 17 00:00:00 2001 From: Krzysztof Wilczyński Date: Tue, 26 May 2020 21:39:05 +0000 Subject: PCI: Rename _DSM constants to align with spec MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rename PCI-related _DSM constants to align them with the PCI Firmware Spec, r3.2, sec 4.6. No functional change intended. Link: https://lore.kernel.org/r/20200526213905.2479381-1-kw@linux.com Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas --- drivers/acpi/pci_root.c | 2 +- drivers/pci/pci-acpi.c | 4 ++-- drivers/pci/pci-label.c | 4 ++-- include/linux/pci-acpi.h | 10 ++++++---- 4 files changed, 11 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index ac8ad6cb82aa..191204a4abe9 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -938,7 +938,7 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root, * assignments made by firmware for this host bridge. */ obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1, - IGNORE_PCI_BOOT_CONFIG_DSM, NULL); + DSM_PCI_PRESERVE_BOOT_CONFIG, NULL); if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0) host_bridge->preserve_config = 1; ACPI_FREE(obj); diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index d820a55ae71c..7224b1e5f2a8 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -1128,7 +1128,7 @@ void acpi_pci_add_bus(struct pci_bus *bus) return; obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 3, - RESET_DELAY_DSM, NULL); + DSM_PCI_POWER_ON_RESET_DELAY, NULL); if (!obj) return; @@ -1193,7 +1193,7 @@ static void pci_acpi_optimize_delay(struct pci_dev *pdev, pdev->d3cold_delay = 0; obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 3, - FUNCTION_DELAY_DSM, NULL); + DSM_PCI_DEVICE_READINESS_DURATIONS, NULL); if (!obj) return; diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c index a5910f942857..707dd9808676 100644 --- a/drivers/pci/pci-label.c +++ b/drivers/pci/pci-label.c @@ -178,7 +178,7 @@ static int dsm_get_label(struct device *dev, char *buf, return -1; obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 0x2, - DEVICE_LABEL_DSM, NULL); + DSM_PCI_DEVICE_NAME, NULL); if (!obj) return -1; @@ -218,7 +218,7 @@ static bool device_has_dsm(struct device *dev) return false; return !!acpi_check_dsm(handle, &pci_acpi_dsm_guid, 0x2, - 1 << DEVICE_LABEL_DSM); + 1 << DSM_PCI_DEVICE_NAME); } static umode_t acpi_index_string_exist(struct kobject *kobj, diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h index 2d155bfb8fbf..a3bb8e768778 100644 --- a/include/linux/pci-acpi.h +++ b/include/linux/pci-acpi.h @@ -107,10 +107,12 @@ static inline void acpiphp_check_host_bridge(struct acpi_device *adev) { } #endif extern const guid_t pci_acpi_dsm_guid; -#define IGNORE_PCI_BOOT_CONFIG_DSM 0x05 -#define DEVICE_LABEL_DSM 0x07 -#define RESET_DELAY_DSM 0x08 -#define FUNCTION_DELAY_DSM 0x09 + +/* _DSM Definitions for PCI */ +#define DSM_PCI_PRESERVE_BOOT_CONFIG 0x05 +#define DSM_PCI_DEVICE_NAME 0x07 +#define DSM_PCI_POWER_ON_RESET_DELAY 0x08 +#define DSM_PCI_DEVICE_READINESS_DURATIONS 0x09 #ifdef CONFIG_PCIE_EDR void pci_acpi_add_edr_notifier(struct pci_dev *pdev); -- cgit v1.2.3