Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754796AbZGDFHw (ORCPT ); Sat, 4 Jul 2009 01:07:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750791AbZGDFHm (ORCPT ); Sat, 4 Jul 2009 01:07:42 -0400 Received: from hera.kernel.org ([140.211.167.34]:39411 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750789AbZGDFHl (ORCPT ); Sat, 4 Jul 2009 01:07:41 -0400 Message-ID: <4A4EE3E9.7090205@kernel.org> Date: Sat, 04 Jul 2009 14:08:57 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Greg KH , Robert Hancock , Alan Cox , linux-pci@vger.kernel.org, Linux Kernel , Daniel Ritz , Dominik Brodowski , Kenji Kaneshige , Axel Birndt , Benjamin Herrenschmidt , Ingo Molnar , Thomas Gleixner , Tony Luck , David Miller , Ingo Molnar Subject: [PATCH 1/3] pci: determine CLS more intelligently X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Sat, 04 Jul 2009 05:06:59 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6688 Lines: 198 Till now, CLS has been determined either by arch code or as L1_CACHE_BYTES. Only x86 and ia64 set CLS explicitly and x86 doesn't always get it right. On most configurations, the chance is that firmware configures the correct value during boot. This patch makes pci_init() determine CLS by looking at what firmware has configured. It scans all devices and if all non-zero values agree, the value is used. If none is configured or there is a disagreement, pci_dfl_cache_line_size is used. arch can set the dfl value (via PCI_CACHE_LINE_BYTES or pci_dfl_cache_line_size) or override the actual one. ia64, x86 and sparc64 updated to set the default cls instead of the actual one. While at it, declare pci_cache_line_size and pci_dfl_cache_line_size in pci.h and drop private declarations from arch code. Signed-off-by: Tejun Heo Acked-by: David Miller Acked-by: Greg KH Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Tony Luck --- Private declarations dropped. Greg, please schedule for the next merge window. Thanks. arch/ia64/pci/pci.c | 9 +++------ arch/x86/pci/common.c | 8 +++----- drivers/pci/pci.c | 49 +++++++++++++++++++++++++++++++++++++++++-------- include/linux/pci.h | 2 ++ 4 files changed, 49 insertions(+), 19 deletions(-) Index: work/arch/ia64/pci/pci.c =================================================================== --- work.orig/arch/ia64/pci/pci.c +++ work/arch/ia64/pci/pci.c @@ -715,9 +715,6 @@ int ia64_pci_legacy_write(struct pci_bus return ret; } -/* It's defined in drivers/pci/pci.c */ -extern u8 pci_cache_line_size; - /** * set_pci_cacheline_size - determine cacheline size for PCI devices * @@ -726,7 +723,7 @@ extern u8 pci_cache_line_size; * * Code mostly taken from arch/ia64/kernel/palinfo.c:cache_info(). */ -static void __init set_pci_cacheline_size(void) +static void __init set_pci_dfl_cacheline_size(void) { unsigned long levels, unique_caches; long status; @@ -746,7 +743,7 @@ static void __init set_pci_cacheline_siz "(status=%ld)\n", __func__, status); return; } - pci_cache_line_size = (1 << cci.pcci_line_size) / 4; + pci_dfl_cache_line_size = (1 << cci.pcci_line_size) / 4; } u64 ia64_dma_get_required_mask(struct device *dev) @@ -777,7 +774,7 @@ EXPORT_SYMBOL_GPL(dma_get_required_mask) static int __init pcibios_init(void) { - set_pci_cacheline_size(); + set_pci_dfl_cacheline_size(); return 0; } Index: work/arch/x86/pci/common.c =================================================================== --- work.orig/arch/x86/pci/common.c +++ work/arch/x86/pci/common.c @@ -410,8 +410,6 @@ struct pci_bus * __devinit pcibios_scan_ return bus; } -extern u8 pci_cache_line_size; - int __init pcibios_init(void) { struct cpuinfo_x86 *c = &boot_cpu_data; @@ -426,11 +424,11 @@ int __init pcibios_init(void) * and P4. It's also good for 386/486s (which actually have 16) * as quite a few PCI devices do not support smaller values. */ - pci_cache_line_size = 32 >> 2; + pci_dfl_cache_line_size = 32 >> 2; if (c->x86 >= 6 && c->x86_vendor == X86_VENDOR_AMD) - pci_cache_line_size = 64 >> 2; /* K7 & K8 */ + pci_dfl_cache_line_size = 64 >> 2; /* K7 & K8 */ else if (c->x86 > 6 && c->x86_vendor == X86_VENDOR_INTEL) - pci_cache_line_size = 128 >> 2; /* P4 */ + pci_dfl_cache_line_size = 128 >> 2; /* P4 */ pcibios_resource_survey(); Index: work/drivers/pci/pci.c =================================================================== --- work.orig/drivers/pci/pci.c +++ work/drivers/pci/pci.c @@ -41,6 +41,19 @@ int pci_domains_supported = 1; unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE; unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE; +#ifndef PCI_CACHE_LINE_BYTES +#define PCI_CACHE_LINE_BYTES L1_CACHE_BYTES +#endif + +/* + * The default CLS is used if arch didn't set CLS explicitly and not + * all pci devices agree on the same value. Arch can override either + * the dfl or actual value as it sees fit. Don't forget this is + * measured in 32-bit words, not bytes. + */ +u8 pci_dfl_cache_line_size __initdata = PCI_CACHE_LINE_BYTES >> 2; +u8 pci_cache_line_size; + /** * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children * @bus: pointer to PCI bus structure to search @@ -1848,14 +1861,6 @@ void pci_clear_mwi(struct pci_dev *dev) #else -#ifndef PCI_CACHE_LINE_BYTES -#define PCI_CACHE_LINE_BYTES L1_CACHE_BYTES -#endif - -/* This can be overridden by arch code. */ -/* Don't forget this is measured in 32-bit words, not bytes */ -u8 pci_cache_line_size = PCI_CACHE_LINE_BYTES / 4; - /** * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed * @dev: the PCI device for which MWI is to be enabled @@ -2631,9 +2636,37 @@ int __attribute__ ((weak)) pci_ext_cfg_a static int __devinit pci_init(void) { struct pci_dev *dev = NULL; + u8 cls = 0; + u8 tmp; + + if (pci_cache_line_size) + printk(KERN_DEBUG "PCI: CLS %u bytes\n", + pci_cache_line_size << 2); while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { pci_fixup_device(pci_fixup_final, dev); + /* + * If arch hasn't set it explicitly yet, use the CLS + * value shared by all PCI devices. If there's a + * mismatch, fall back to the default value. + */ + if (!pci_cache_line_size) { + pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &tmp); + if (!cls) + cls = tmp; + if (!tmp || cls == tmp) + continue; + + printk(KERN_DEBUG "PCI: CLS mismatch (%u != %u), " + "using %u bytes\n", cls << 2, tmp << 2, + pci_dfl_cache_line_size << 2); + pci_cache_line_size = pci_dfl_cache_line_size; + } + } + if (!pci_cache_line_size) { + printk(KERN_DEBUG "PCI: CLS %u bytes, default %u\n", + cls << 2, pci_dfl_cache_line_size << 2); + pci_cache_line_size = cls; } return 0; Index: work/include/linux/pci.h =================================================================== --- work.orig/include/linux/pci.h +++ work/include/linux/pci.h @@ -1235,6 +1235,8 @@ extern int pci_pci_problems; extern unsigned long pci_cardbus_io_size; extern unsigned long pci_cardbus_mem_size; +extern u8 pci_dfl_cache_line_size; +extern u8 pci_cache_line_size; int pcibios_add_platform_entries(struct pci_dev *dev); void pcibios_disable_device(struct pci_dev *dev); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/