From c6972fb9ba8aab384568665411015b7deb8a8609 Mon Sep 17 00:00:00 2001 From: Huang Pei Date: Sat, 13 Mar 2021 09:39:27 +0800 Subject: [PATCH] MIPS: clean up CONFIG_MIPS_PGD_C0_CONTEXT handling +. LOONGSON64 use 0x98xx_xxxx_xxxx_xxxx as xphys cached, instread of 0xa8xx_xxxx_xxxx_xxxx +. let CONFIG_MIPS_PGD_C0_CONTEXT depend on 64bit +. cast CAC_BASE into u64 to silence warning on MIPS32 CP0 Context has enough room for wraping pgd into its 41-bit PTEBase field. +. For XPHYS, the trick is that pgd is 4kB aligned, and the PABITS <= 53, only save 53 - 12 = 41 bits, aka : bit[63:59] | 0000 00 | bit[53:12] | 0000 0000 0000 +. for CKSEG0, only save 29 - 12 = 17 bits when switching pgd, only need to save bit[53:12] or bit[28:12] into CP0 Context's bit[63:23], see folling asm generated at run time tlbmiss_handler_setup_pgd: .set push .set noreorder dsra a2, a0, 29 move a3, a0 dins a0, zero, 29, 35 daddiu a2, a2, 4 //for CKSEG0, a2 from 0xfffffffffffffffc //into 0 movn a0, a3, a2 dsll a0, a0, 11 jr ra dmtc0 a0, CP0_CONTEXT .set pop when using it on page walking dmfc0 k0, CP0_CONTEXT dins k0, zero, 0, 23 // zero badv2 ori k0, k0, (CAC_BASE >> 53) // *prefix* with bit[63:59] drotr k0, k0, 11 // kick it in the right place Signed-off-by: Huang Pei Signed-off-by: Thomas Bogendoerfer --- arch/mips/Kconfig | 3 ++- arch/mips/mm/tlbex.c | 9 +++++---- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index b9ae8e7d95e0..160b3a890840 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2188,7 +2188,8 @@ config CPU_SUPPORTS_HUGEPAGES depends on !(32BIT && (ARCH_PHYS_ADDR_T_64BIT || EVA)) config MIPS_PGD_C0_CONTEXT bool - default y if 64BIT && (CPU_MIPSR2 || CPU_MIPSR6) && !CPU_XLP + depends on 64BIT + default y if (CPU_MIPSR2 || CPU_MIPSR6) && !CPU_XLP # # Set to y for ptrace access to watch registers. diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 0fb1db8a8ef7..cd4afcdf3725 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -849,8 +849,8 @@ void build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, /* Clear lower 23 bits of context. */ uasm_i_dins(p, ptr, 0, 0, 23); - /* 1 0 1 0 1 << 6 xkphys cached */ - uasm_i_ori(p, ptr, ptr, 0x540); + /* insert bit[63:59] of CAC_BASE into bit[11:6] of ptr */ + uasm_i_ori(p, ptr, ptr, ((u64)(CAC_BASE) >> 53)); uasm_i_drotr(p, ptr, ptr, 11); #elif defined(CONFIG_SMP) UASM_i_CPUID_MFC0(p, ptr, SMP_CPUID_REG); @@ -1165,8 +1165,9 @@ build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l, if (pgd_reg == -1) { vmalloc_branch_delay_filled = 1; - /* 1 0 1 0 1 << 6 xkphys cached */ - uasm_i_ori(p, ptr, ptr, 0x540); + /* insert bit[63:59] of CAC_BASE into bit[11:6] of ptr */ + uasm_i_ori(p, ptr, ptr, ((u64)(CAC_BASE) >> 53)); + uasm_i_drotr(p, ptr, ptr, 11); }