From 3f31e49dc4588d396023028791e36c23235e1334 Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Thu, 23 Jul 2020 14:38:13 +0530 Subject: [PATCH] powerpc/watchpoint: Remove 512 byte boundary Power10 has removed 512 bytes boundary from match criteria i.e. the watch range can cross 512 bytes boundary. Note: ISA 3.1 Book III 9.4 match criteria includes 512 byte limit but that is a documentation mistake and hopefully will be fixed in the next version of ISA. Though, ISA 3.1 change log mentions about removal of 512B boundary: Multiple DEAW: Added a second Data Address Watchpoint. [H]DAR is set to the first byte of overlap. 512B boundary is removed. Signed-off-by: Ravi Bangoria Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200723090813.303838-11-ravi.bangoria@linux.ibm.com --- arch/powerpc/kernel/hw_breakpoint.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index c55e67bab271..1f4a1efa0074 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -418,8 +418,9 @@ static int hw_breakpoint_validate_len(struct arch_hw_breakpoint *hw) if (dawr_enabled()) { max_len = DAWR_MAX_LEN; - /* DAWR region can't cross 512 bytes boundary */ - if (ALIGN_DOWN(start_addr, SZ_512) != ALIGN_DOWN(end_addr - 1, SZ_512)) + /* DAWR region can't cross 512 bytes boundary on p10 predecessors */ + if (!cpu_has_feature(CPU_FTR_ARCH_31) && + (ALIGN_DOWN(start_addr, SZ_512) != ALIGN_DOWN(end_addr - 1, SZ_512))) return -EINVAL; } else if (IS_ENABLED(CONFIG_PPC_8xx)) { /* 8xx can setup a range without limitation */ -- 2.25.1