From ae2031fb29d12d02e9ce4220d5e03e75bb6b7bdf Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Mon, 5 Aug 2013 14:33:17 -0400 Subject: [PATCH] tile PCI RC: reduce driver's vmalloc space usage We can take advantage of the fact that bit 29 is hard-wired to zero in register TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR. This is handy since at the moment we only allocate one 4GB region for vmalloc, and with this change we can allocate four or more TRIO MACs without using up all the vmalloc space. Signed-off-by: Chris Metcalf --- arch/tile/kernel/pci_gx.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/tile/kernel/pci_gx.c b/arch/tile/kernel/pci_gx.c index f2bf200b641b..48438818d696 100644 --- a/arch/tile/kernel/pci_gx.c +++ b/arch/tile/kernel/pci_gx.c @@ -860,9 +860,15 @@ int __init pcibios_init(void) #endif + /* + * To save VMALLOC space, we take advantage of the fact that + * bit 29 in the PIO CFG address format is reserved 0. With + * TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR__MAC_SHIFT being 30, + * this cuts VMALLOC space usage from 1GB to 512MB per mac. + */ trio_context->mmio_base_pio_cfg[mac] = - iorpc_ioremap(trio_context->fd, offset, - (1 << TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR__MAC_SHIFT)); + iorpc_ioremap(trio_context->fd, offset, (1UL << + (TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR__MAC_SHIFT - 1))); if (trio_context->mmio_base_pio_cfg[mac] == NULL) { pr_err("PCI: PIO map failure for mac %d on TRIO %d\n", mac, trio_index); -- 2.20.1