Hi Prabhakar, Thanks for your feedback!
> -----Original Message----- > From: Prabhakar Kushwaha > Sent: 2016年1月19日 21:54 > To: Zhiqiang Hou <zhiqiang....@freescale.com>; u-boot@lists.denx.de; > albert.u.b...@aribaud.net; mingkai...@freescale.com; york...@freescale.com > Cc: le...@freescale.com; prabha...@freescale.com; > bhupesh.sha...@freescale.com; s...@chromium.org; bmeng...@gmail.com; > h...@denx.de; joe.hershber...@ni.com; ma...@denx.de; Zhiqiang Hou > <zhiqiang....@nxp.com>; Hou Zhiqiang <b48...@freescale.com> > Subject: RE: [PATCH 1/3] ARMv8/layerscape: Add mmu_init API > > > -----Original Message----- > > From: Zhiqiang Hou [mailto:zhiqiang....@freescale.com] > > Sent: Tuesday, January 19, 2016 6:10 PM > > To: u-boot@lists.denx.de; albert.u.b...@aribaud.net; > > mingkai...@freescale.com; york...@freescale.com > > Cc: le...@freescale.com; prabha...@freescale.com; > > bhupesh.sha...@freescale.com; s...@chromium.org; bmeng...@gmail.com; > > h...@denx.de; joe.hershber...@ni.com; ma...@denx.de; Zhiqiang Hou > > <zhiqiang....@nxp.com>; Hou Zhiqiang <b48...@freescale.com> > > Subject: [PATCH 1/3] ARMv8/layerscape: Add mmu_init API > > > > From: Hou Zhiqiang <b48...@freescale.com> > > > > Expose this API to make it reuseable when u-boot turn into other EL > > from EL3. > > > > Signed-off-by: Hou Zhiqiang <b48...@freescale.com> > > --- > > arch/arm/cpu/armv8/fsl-layerscape/cpu.c | 24 > > ++++++++++++++++++++++++ > > include/common.h | 1 + > > 2 files changed, 25 insertions(+) > > > > diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c > > b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c > > index 6ea28ed..df5670f 100644 > > --- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c > > +++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c > > @@ -403,6 +403,30 @@ void enable_caches(void) > > final_mmu_setup(); > > __asm_invalidate_tlb_all(); > > } > > + > > +static void mmu_disable(void) > > +{ > > + if (get_sctlr() & CR_M) > > + set_sctlr(get_sctlr() & ~CR_M); > > +} > > + > > +static void mmu_enable(void) > > +{ > > + if (!(get_sctlr() & CR_M)) > > + set_sctlr(get_sctlr() | CR_M); > > +} > > + > > +void mmu_init(void) > > Name of function is not mapping about what it is doing. > This function assume MMU is already enabled with early_table and it will setup > final_mmu_setup. > This function map basically with what it is doing except some I-cache operations that will be remove from this func, and not assume the early_mmu_setup. It assumes the relocation has been done. > > +{ > > + mmu_disable(); > > + dcache_disable(); > > + icache_disable(); > > + final_mmu_setup(); > > + __asm_invalidate_tlb_all(); > > + mmu_enable(); > > + icache_enable(); > > + set_sctlr(get_sctlr() | CR_C); > > +} > > #endif > > If I am correct board_init_r deploy final_mmu_setup via enable_caches(). > Why cannot existing framework be used. > This patch aims to make final_mmu_setup() can be called flexibly in case as When it return from PPA and execute at EL2, the MMU must be initialized for the current EL. Yes, the enable_caches() will call the __weak__ mmu_setup() if MMU wasn't enabled. But for fsl layerscape platforms, the MMU has been enabled by early mmu setup, so the __weak__ mmu_setup won't be called. I am not know cache and mmu so much, and have some question: For ARM: Why there isn't a isolate API for mmu_setup, but invoke it from dcache_enable()? If data cache won't be used, the MMU also cannot be used? > > > > static inline u32 initiator_type(u32 cluster, int init_id) diff --git > > a/include/common.h b/include/common.h index 75c78d5..57a9b30 100644 > > --- a/include/common.h > > +++ b/include/common.h > > @@ -757,6 +757,7 @@ void flush_dcache_range(unsigned long start, > > unsigned long stop); > > void invalidate_dcache_range(unsigned long start, unsigned long > > stop); > > void invalidate_dcache_all(void); > > void invalidate_icache_all(void); > > +void mmu_init(void); > > > > enum { > > /* Disable caches (else flush caches but leave them active) */ > > -- > > 2.1.0.27.g96db324 Thanks, Zhiqiang _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
