Hi Julien > -----Original Message----- > From: Julien Grall <[email protected]> > Sent: Monday, February 6, 2023 5:32 AM > To: Penny Zheng <[email protected]>; [email protected] > Cc: Wei Chen <[email protected]>; Stefano Stabellini > <[email protected]>; Bertrand Marquis <[email protected]>; > Volodymyr Babchuk <[email protected]> > Subject: Re: [PATCH v2 16/40] xen/arm: introduce setup_mm_mappings > > Hi, > > On 13/01/2023 05:28, Penny Zheng wrote: > > Function setup_pagetables is responsible for boot-time pagetable setup > > in MMU system. > > But in MPU system, we have already built up start-of-day Xen MPU > > memory region mapping at the very beginning in assembly. > > > > So in order to keep only one codeflow in arm/setup.c, > > setup_mm_mappings , with a more generic name, is introduced and act as > > an empty stub in MPU system. > > is the empty stub temporarily? > > > > > Signed-off-by: Penny Zheng <[email protected]> > > Signed-off-by: Wei Chen <[email protected]> > > --- > > xen/arch/arm/include/asm/mm.h | 2 ++ > > xen/arch/arm/include/asm/mm_mpu.h | 16 ++++++++++++++++ > > xen/arch/arm/setup.c | 2 +- > > 3 files changed, 19 insertions(+), 1 deletion(-) > > create mode 100644 xen/arch/arm/include/asm/mm_mpu.h > > > > diff --git a/xen/arch/arm/include/asm/mm.h > > b/xen/arch/arm/include/asm/mm.h index 1b9fdb6ff5..9b4c07d965 100644 > > --- a/xen/arch/arm/include/asm/mm.h > > +++ b/xen/arch/arm/include/asm/mm.h > > @@ -243,6 +243,8 @@ static inline void __iomem *ioremap_wc(paddr_t > > start, size_t len) > > > > #ifndef CONFIG_HAS_MPU > > #include <asm/mm_mmu.h> > > +#else > > +#include <asm/mm_mpu.h> > > #endif > > > > /* Page-align address and convert to frame number format */ diff > > --git a/xen/arch/arm/include/asm/mm_mpu.h > > b/xen/arch/arm/include/asm/mm_mpu.h > > new file mode 100644 > > index 0000000000..1f3cff7743 > > --- /dev/null > > +++ b/xen/arch/arm/include/asm/mm_mpu.h > > @@ -0,0 +1,16 @@ > > +/* SPDX-License-Identifier: GPL-2.0-or-later */ #ifndef > > +__ARCH_ARM_MM_MPU__ #define __ARCH_ARM_MM_MPU__ > > + > > +#define setup_mm_mappings(boot_phys_offset) > > +((void)(boot_phys_offset)) > > + > > +#endif /* __ARCH_ARM_MM_MPU__ */ > > + > > +/* > > + * Local variables: > > + * mode: C > > + * c-file-style: "BSD" > > + * c-basic-offset: 4 > > + * indent-tabs-mode: nil > > + * End: > > + */ > > diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c index > > 1f26f67b90..d7d200179c 100644 > > --- a/xen/arch/arm/setup.c > > +++ b/xen/arch/arm/setup.c > > @@ -1003,7 +1003,7 @@ void __init start_xen(unsigned long > boot_phys_offset, > > /* Initialize traps early allow us to get backtrace when an error > > occurred > */ > > init_traps(); > > > > - setup_pagetables(boot_phys_offset); > > + setup_mm_mappings(boot_phys_offset); > > You are renaming the caller but not the function. Why? >
It is a reorg mistake. MMU-related implementation has been mistakenly put in previous commit "[PATCH v2 15/40] xen/arm: move MMU-specific memory management code to mm_mmu.c/mm_mmu.h"(https://lists.xenproject.org/archives/html/xen-devel/2023-01/msg00776.html ) Sorry for that. I'll extract the relative codes from the previous commit: ''' +/* Boot-time pagetable setup */ +#define setup_mm_mappings(boot_phys_offset) setup_pagetables(boot_phys_offset) ''' > > > > smp_clear_cpu_maps(); > > > > Cheers, > > -- > Julien Grall
