From ac1aa47b131416a6ff37eb1005a0a1d2541aad6c Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Mon, 26 Oct 2009 13:20:44 -0700 Subject: PCI: determine CLS more intelligently 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 Signed-off-by: Jesse Barnes --- arch/ia64/pci/pci.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'arch/ia64/pci/pci.c') diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c index c0fca2c1c858..d60e7195b7dd 100644 --- a/arch/ia64/pci/pci.c +++ b/arch/ia64/pci/pci.c @@ -720,9 +720,6 @@ int ia64_pci_legacy_write(struct pci_bus *bus, u16 port, u32 val, u8 size) 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 * @@ -731,7 +728,7 @@ 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; @@ -751,7 +748,7 @@ static void __init set_pci_cacheline_size(void) "(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) @@ -782,7 +779,7 @@ EXPORT_SYMBOL_GPL(dma_get_required_mask); static int __init pcibios_init(void) { - set_pci_cacheline_size(); + set_pci_dfl_cacheline_size(); return 0; } -- cgit v1.2.3