From 6b7c095a51e1bad8b27fa1bc8753af0b613464a3 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Mon, 16 Sep 2019 20:25:41 +0000 Subject: powerpc/83xx: map IMMR with a BAT. On mpc83xx with a QE, IMMR is 2Mbytes and aligned on 2Mbytes boundarie. On mpc83xx without a QE, IMMR is 1Mbyte and 1Mbyte aligned. Each driver will map a part of it to access the registers it needs. Some drivers will map the same part of IMMR as other drivers. In order to reduce TLB misses, map the full IMMR with a BAT. If it is 2Mbytes aligned, map 2Mbytes. If there is no QE, the upper part will remain unused, but it doesn't harm as it is mapped as guarded memory. When the IMMR is not aligned on a 2Mbytes boundarie, only map 1Mbyte. Signed-off-by: Christophe Leroy Acked-by: Scott Wood Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/269a00951328fb6fa1be2fa3cbc76c19745019b7.1568665466.git.christophe.leroy@c-s.fr --- arch/powerpc/platforms/83xx/misc.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/powerpc/platforms') diff --git a/arch/powerpc/platforms/83xx/misc.c b/arch/powerpc/platforms/83xx/misc.c index f46d7bf3b140..6399865a625e 100644 --- a/arch/powerpc/platforms/83xx/misc.c +++ b/arch/powerpc/platforms/83xx/misc.c @@ -18,6 +18,8 @@ #include #include +#include + #include "mpc83xx.h" static __be32 __iomem *restart_reg_base; @@ -145,6 +147,15 @@ void __init mpc83xx_setup_arch(void) if (ppc_md.progress) ppc_md.progress("mpc83xx_setup_arch()", 0); + if (!__map_without_bats) { + phys_addr_t immrbase = get_immrbase(); + int immrsize = IS_ALIGNED(immrbase, SZ_2M) ? SZ_2M : SZ_1M; + unsigned long va = fix_to_virt(FIX_IMMR_BASE); + + setbat(-1, va, immrbase, immrsize, PAGE_KERNEL_NCG); + update_bats(); + } + mpc83xx_setup_pci(); } -- cgit v1.2.3-59-g8ed1b