From: Myron Stowe Date: Fri, 28 Oct 2011 21:48:38 +0000 (-0600) Subject: PCI: Pull PCI 'latency timer' setup up into the core X-Git-Tag: firefly_0821_release~3680^2~3753^2~53 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=96c5590058d;p=firefly-linux-kernel-4.4.55.git PCI: Pull PCI 'latency timer' setup up into the core The 'latency timer' of PCI devices, both Type 0 and Type 1, is setup in architecture-specific code [see: 'pcibios_set_master()']. There are two approaches being taken by all the architectures - check if the 'latency timer' is currently set between 16 and 255 and if not bring it within bounds, or, do nothing (and then there is the gratuitously different PA-RISC implementation). There is nothing architecture-specific about PCI's 'latency timer' so this patch pulls its setup functionality up into the PCI core by creating a generic 'pcibios_set_master()' function using the '__weak' attribute which can be used by all architectures as a default which, if necessary, can then be over-ridden by architecture-specific code. No functional change. Signed-off-by: Myron Stowe Signed-off-by: Jesse Barnes --- diff --git a/arch/blackfin/include/asm/pci.h b/arch/blackfin/include/asm/pci.h index 99cae2e3bac7..74352c4597d9 100644 --- a/arch/blackfin/include/asm/pci.h +++ b/arch/blackfin/include/asm/pci.h @@ -10,10 +10,6 @@ #define PCIBIOS_MIN_IO 0x00001000 #define PCIBIOS_MIN_MEM 0x10000000 -static inline void pcibios_set_master(struct pci_dev *dev) -{ - /* No special bus mastering setup handling */ -} static inline void pcibios_penalize_isa_irq(int irq) { /* We don't do dynamic PCI IRQ allocation */ diff --git a/arch/frv/mb93090-mb00/pci-frv.c b/arch/frv/mb93090-mb00/pci-frv.c index 6b4fb28e9f99..6a0cd644d7cc 100644 --- a/arch/frv/mb93090-mb00/pci-frv.c +++ b/arch/frv/mb93090-mb00/pci-frv.c @@ -195,12 +195,6 @@ void __init pcibios_resource_survey(void) pcibios_assign_resources(); } -/* - * If we set up a device for bus mastering, we need to check the latency - * timer as certain crappy BIOSes forget to set it properly. - */ -unsigned int pcibios_max_latency = 255; - void pcibios_set_master(struct pci_dev *dev) { u8 lat; diff --git a/arch/frv/mb93090-mb00/pci-frv.h b/arch/frv/mb93090-mb00/pci-frv.h index f3fe55914793..089eeba4f3bc 100644 --- a/arch/frv/mb93090-mb00/pci-frv.h +++ b/arch/frv/mb93090-mb00/pci-frv.h @@ -26,8 +26,6 @@ extern unsigned int __nongpreldata pci_probe; /* pci-frv.c */ -extern unsigned int pcibios_max_latency; - void pcibios_resource_survey(void); /* pci-vdk.c */ diff --git a/arch/h8300/include/asm/pci.h b/arch/h8300/include/asm/pci.h index cc9762091c0a..0b2acaa3dd84 100644 --- a/arch/h8300/include/asm/pci.h +++ b/arch/h8300/include/asm/pci.h @@ -9,11 +9,6 @@ #define pcibios_assign_all_busses() 0 -static inline void pcibios_set_master(struct pci_dev *dev) -{ - /* No special bus mastering setup handling */ -} - static inline void pcibios_penalize_isa_irq(int irq, int active) { /* We don't do dynamic PCI IRQ allocation */ diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c index 41af7fa2887b..f93f749b92e3 100644 --- a/arch/mips/pci/pci.c +++ b/arch/mips/pci/pci.c @@ -205,12 +205,6 @@ static int pcibios_enable_resources(struct pci_dev *dev, int mask) return 0; } -/* - * If we set up a device for bus mastering, we need to check the latency - * timer as certain crappy BIOSes forget to set it properly. - */ -static unsigned int pcibios_max_latency = 255; - void pcibios_set_master(struct pci_dev *dev) { u8 lat; diff --git a/arch/mn10300/unit-asb2305/pci-asb2305.c b/arch/mn10300/unit-asb2305/pci-asb2305.c index 8e6763e6f250..2b299c413ae5 100644 --- a/arch/mn10300/unit-asb2305/pci-asb2305.c +++ b/arch/mn10300/unit-asb2305/pci-asb2305.c @@ -213,12 +213,6 @@ void __init pcibios_resource_survey(void) pcibios_allocate_resources(1); } -/* - * If we set up a device for bus mastering, we need to check the latency - * timer as certain crappy BIOSes forget to set it properly. - */ -unsigned int pcibios_max_latency = 255; - void pcibios_set_master(struct pci_dev *dev) { u8 lat; diff --git a/arch/mn10300/unit-asb2305/pci-asb2305.h b/arch/mn10300/unit-asb2305/pci-asb2305.h index c3fa294b6e28..1194fe486b01 100644 --- a/arch/mn10300/unit-asb2305/pci-asb2305.h +++ b/arch/mn10300/unit-asb2305/pci-asb2305.h @@ -31,8 +31,6 @@ extern unsigned int pci_probe; /* pci-asb2305.c */ -extern unsigned int pcibios_max_latency; - extern void pcibios_resource_survey(void); /* pci.c */ diff --git a/arch/sh/drivers/pci/pci.c b/arch/sh/drivers/pci/pci.c index c2691afe8f79..cfdb2f652949 100644 --- a/arch/sh/drivers/pci/pci.c +++ b/arch/sh/drivers/pci/pci.c @@ -243,12 +243,6 @@ int pcibios_enable_device(struct pci_dev *dev, int mask) return pci_enable_resources(dev, mask); } -/* - * If we set up a device for bus mastering, we need to check and set - * the latency timer as it may not be properly set. - */ -static unsigned int pcibios_max_latency = 255; - void pcibios_set_master(struct pci_dev *dev) { u8 lat; diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h index e38197806853..b3a531746026 100644 --- a/arch/x86/include/asm/pci_x86.h +++ b/arch/x86/include/asm/pci_x86.h @@ -44,8 +44,6 @@ enum pci_bf_sort_state { /* pci-i386.c */ -extern unsigned int pcibios_max_latency; - void pcibios_resource_survey(void); void pcibios_set_cache_line_size(void); diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c index 794b092d01ae..dd5806b0fc8b 100644 --- a/arch/x86/pci/i386.c +++ b/arch/x86/pci/i386.c @@ -254,12 +254,6 @@ void __init pcibios_resource_survey(void) */ fs_initcall(pcibios_assign_resources); -/* - * If we set up a device for bus mastering, we need to check the latency - * timer as certain crappy BIOSes forget to set it properly. - */ -unsigned int pcibios_max_latency = 255; - void pcibios_set_master(struct pci_dev *dev) { u8 lat; diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 924193ef4fe1..f9abe84cf5e0 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -88,6 +88,12 @@ enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF; u8 pci_dfl_cache_line_size __devinitdata = L1_CACHE_BYTES >> 2; u8 pci_cache_line_size; +/* + * If we set up a device for bus mastering, we need to check the latency + * timer as certain BIOSes forget to set it properly. + */ +unsigned int pcibios_max_latency = 255; + /** * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children * @bus: pointer to PCI bus structure to search @@ -2595,6 +2601,29 @@ static void __pci_set_master(struct pci_dev *dev, bool enable) dev->is_busmaster = enable; } +/** + * pcibios_set_master - enable PCI bus-mastering for device dev + * @dev: the PCI device to enable + * + * Enables PCI bus-mastering for the device. This is the default + * implementation. Architecture specific implementations can override + * this if necessary. + */ +void __weak pcibios_set_master(struct pci_dev *dev) +{ + u8 lat; + + pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat); + if (lat < 16) + lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency; + else if (lat > pcibios_max_latency) + lat = pcibios_max_latency; + else + return; + dev_printk(KERN_DEBUG, &dev->dev, "setting latency timer to %d\n", lat); + pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat); +} + /** * pci_set_master - enables bus-mastering for device dev * @dev: the PCI device to enable diff --git a/include/linux/pci.h b/include/linux/pci.h index 569341d2d527..4c16a5788998 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -795,8 +795,11 @@ static inline int pci_is_managed(struct pci_dev *pdev) } void pci_disable_device(struct pci_dev *dev); + +extern unsigned int pcibios_max_latency; void pci_set_master(struct pci_dev *dev); void pci_clear_master(struct pci_dev *dev); + int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); int pci_set_cacheline_size(struct pci_dev *dev); #define HAVE_PCI_SET_MWI