From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Tue, 28 Jun 2016 15:51:45 +0100 Subject: [PATCH v3 2/7] arm64: vmlinux.ld: Add .mmuoff.{text,data} sections In-Reply-To: <1467125510-18758-1-git-send-email-james.morse@arm.com> References: <1467125510-18758-1-git-send-email-james.morse@arm.com> Message-ID: <1467125510-18758-3-git-send-email-james.morse@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Resume from hibernate needs to clean any text executed by the kernel with the MMU off to the PoC. Collect these functions together into a new .mmuoff.text section. __boot_cpu_mode and secondary_holding_pen_release are data that is read or written with the MMU off. Add these to a new .mmuoff.data section. This covers booting of secondary cores and the cpu_suspend() path used by cpu-idle and suspend-to-ram. The bulk of head.S is not included, as the primary boot code is only ever executed once, the kernel never needs to ensure it is cleaned to a particular point in the cache. Signed-off-by: James Morse --- Changes since v2: * mmuoff.data section added * secondary_holding_pen_release initialisation moved to head.S * secondary_holding_pen and set_cpu_boot_mode_flag moved into mmuoff.text arch/arm64/include/asm/sections.h | 2 ++ arch/arm64/kernel/head.S | 10 +++++++++- arch/arm64/kernel/sleep.S | 2 ++ arch/arm64/kernel/smp_spin_table.c | 2 +- arch/arm64/kernel/vmlinux.lds.S | 8 ++++++++ arch/arm64/mm/proc.S | 4 ++++ 6 files changed, 26 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/sections.h b/arch/arm64/include/asm/sections.h index cb68eb348566..7eecfa110330 100644 --- a/arch/arm64/include/asm/sections.h +++ b/arch/arm64/include/asm/sections.h @@ -24,5 +24,7 @@ extern char __hibernate_exit_text_start[], __hibernate_exit_text_end[]; extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[]; extern char __hyp_text_start[], __hyp_text_end[]; extern char __idmap_text_start[], __idmap_text_end[]; +extern char __mmuoff_text_start[], __mmuoff_text_end[]; +extern char __mmuoff_data_start[], __mmuoff_data_end[]; #endif /* __ASM_SECTIONS_H */ diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 2c6e598a94dc..6e56cd136d27 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -52,6 +52,9 @@ #error TEXT_OFFSET must be less than 2MB #endif +/* INVALID_HWID is defined as ULONG_MAX, but we can't include linux/kernel.h */ +#define ULONG_MAX ~0 + /* * Kernel startup entry point. * --------------------------- @@ -477,6 +480,7 @@ ENTRY(kimage_vaddr) * Returns either BOOT_CPU_MODE_EL1 or BOOT_CPU_MODE_EL2 in x20 if * booted in EL1 or EL2 respectively. */ + .pushsection ".mmuoff.text", "ax" ENTRY(el2_setup) mrs x0, CurrentEL cmp x0, #CurrentEL_EL2 @@ -627,11 +631,14 @@ ENDPROC(set_cpu_boot_mode_flag) * This is not in .bss, because we set it sufficiently early that the boot-time * zeroing of .bss would clobber it. */ - .pushsection .data..cacheline_aligned + .pushsection ".mmuoff.data", "aw" .align L1_CACHE_SHIFT ENTRY(__boot_cpu_mode) .long BOOT_CPU_MODE_EL2 .long BOOT_CPU_MODE_EL1 + +ENTRY(secondary_holding_pen_release) + .quad INVALID_HWID .popsection /* @@ -687,6 +694,7 @@ __secondary_switched: mov x29, #0 b secondary_start_kernel ENDPROC(__secondary_switched) + .popsection /* * The booting CPU updates the failed status @__early_cpu_boot_status, diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S index 9a3aec97ac09..e66ce9b7bbde 100644 --- a/arch/arm64/kernel/sleep.S +++ b/arch/arm64/kernel/sleep.S @@ -97,6 +97,7 @@ ENTRY(__cpu_suspend_enter) ENDPROC(__cpu_suspend_enter) .ltorg + .pushsection ".mmuoff.text", "ax" ENTRY(cpu_resume) bl el2_setup // if in EL2 drop to EL1 cleanly /* enable the MMU early - so we can access sleep_save_stash by va */ @@ -106,6 +107,7 @@ ENTRY(cpu_resume) adrp x26, swapper_pg_dir b __cpu_setup ENDPROC(cpu_resume) + .popsection ENTRY(_cpu_resume) mrs x1, mpidr_el1 diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c index 18a71bcd26ee..04b465c72538 100644 --- a/arch/arm64/kernel/smp_spin_table.c +++ b/arch/arm64/kernel/smp_spin_table.c @@ -29,7 +29,7 @@ #include extern void secondary_holding_pen(void); -volatile unsigned long secondary_holding_pen_release = INVALID_HWID; +extern volatile unsigned long secondary_holding_pen_release; static phys_addr_t cpu_release_addr[NR_CPUS]; diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 0de7be4f1a9d..7db9c94213a9 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -118,6 +118,9 @@ SECTIONS __exception_text_end = .; IRQENTRY_TEXT SOFTIRQENTRY_TEXT + __mmuoff_text_start = .; + *(.mmuoff.text) + __mmuoff_text_end = .; TEXT_TEXT SCHED_TEXT LOCK_TEXT @@ -193,6 +196,11 @@ SECTIONS _sdata = .; RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE) PECOFF_EDATA_PADDING + .mmuoff.data : { + __mmuoff_data_start = .; + *(.mmuoff.data) + __mmuoff_data_end = .; + } _edata = .; BSS_SECTION(0, 0, 0) diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index c4317879b938..655ff3ec90f2 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -83,6 +83,7 @@ ENDPROC(cpu_do_suspend) * * x0: Address of context pointer */ + .pushsection ".mmuoff.text", "ax" ENTRY(cpu_do_resume) ldp x2, x3, [x0] ldp x4, x5, [x0, #16] @@ -111,6 +112,7 @@ ENTRY(cpu_do_resume) isb ret ENDPROC(cpu_do_resume) + .popsection #endif /* @@ -172,6 +174,7 @@ ENDPROC(idmap_cpu_replace_ttbr1) * Initialise the processor for turning the MMU on. Return in x0 the * value of the SCTLR_EL1 register. */ + .pushsection ".mmuoff.text", "ax" ENTRY(__cpu_setup) tlbi vmalle1 // Invalidate local TLB dsb nsh @@ -255,3 +258,4 @@ ENDPROC(__cpu_setup) crval: .word 0xfcffffff // clear .word 0x34d5d91d // set + .popsection -- 2.8.0.rc3