| Message ID | 20121110154224.2836.21775.stgit@chazy-air (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Nov 10, 2012 at 03:42:24PM +0000, Christoffer Dall wrote: > Add a method (hyp_idmap_setup) to populate a hyp pgd with an > identity mapping of the code contained in the .hyp.idmap.text > section. > > Offer a method to drop this identity mapping through > hyp_idmap_teardown. > > Make all the above depend on CONFIG_ARM_VIRT_EXT and CONFIG_ARM_LPAE. > > Cc: Will Deacon <will.deacon@arm.com> > Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> > --- > arch/arm/include/asm/idmap.h | 5 ++ > arch/arm/include/asm/pgtable-3level-hwdef.h | 1 > arch/arm/kernel/vmlinux.lds.S | 6 ++ > arch/arm/mm/idmap.c | 74 +++++++++++++++++++++++---- > 4 files changed, 73 insertions(+), 13 deletions(-) > > diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h > index bf863ed..36708ba 100644 > --- a/arch/arm/include/asm/idmap.h > +++ b/arch/arm/include/asm/idmap.h > @@ -11,4 +11,9 @@ extern pgd_t *idmap_pgd; > > void setup_mm_for_reboot(void); > > +#ifdef CONFIG_ARM_VIRT_EXT > +void hyp_idmap_teardown(pgd_t *hyp_pgd); > +void hyp_idmap_setup(pgd_t *hyp_pgd); > +#endif I wonder whether the dependency is quite right here. Functionally, we're only dependent on LPAE but it doesn't make sense if !ARM_VIRT_EXT. In fact, I start to question whether CONFIG_ARM_VIRT_EXT is worthwhile at all as it stands. Maybe it would be better to add the LPAE dependency there and make the hyp_stub stuff that's currently in mainline unconditional? > +/* > + * This version actually frees the underlying pmds for all pgds in range and > + * clear the pgds themselves afterwards. > + */ > +void hyp_idmap_teardown(pgd_t *hyp_pgd) > +{ > + unsigned long addr, end; > + unsigned long next; > + pgd_t *pgd = hyp_pgd; > + > + addr = virt_to_phys(__hyp_idmap_text_start); > + end = virt_to_phys(__hyp_idmap_text_end); > + > + pgd += pgd_index(addr); > + do { > + next = pgd_addr_end(addr, end); > + if (!pgd_none_or_clear_bad(pgd)) > + hyp_idmap_del_pmd(pgd, addr); > + } while (pgd++, addr = next, addr < end); > +} > +EXPORT_SYMBOL_GPL(hyp_idmap_teardown); > + > +void hyp_idmap_setup(pgd_t *hyp_pgd) > +{ > + identity_mapping_add(hyp_pgd, __hyp_idmap_text_start, > + __hyp_idmap_text_end, PMD_SECT_AP1); > +} > +EXPORT_SYMBOL_GPL(hyp_idmap_setup); > +#endif Again, do we need these exports? I also think it might be cleaner to declare the hyp_pgd next to the idmap_pgd then add the hyp_idmap_setup code to init_static_idmap, so that we don't add new entry points to this file. The teardown can all be moved into the kvm/ code as it doesn't need any of the existing idmap functions. Will
On 11/10/2012 09:42 AM, Christoffer Dall wrote: > Add a method (hyp_idmap_setup) to populate a hyp pgd with an > identity mapping of the code contained in the .hyp.idmap.text > section. > > Offer a method to drop this identity mapping through > hyp_idmap_teardown. > > Make all the above depend on CONFIG_ARM_VIRT_EXT and CONFIG_ARM_LPAE. > > Cc: Will Deacon <will.deacon@arm.com> > Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> > --- > arch/arm/include/asm/idmap.h | 5 ++ > arch/arm/include/asm/pgtable-3level-hwdef.h | 1 > arch/arm/kernel/vmlinux.lds.S | 6 ++ > arch/arm/mm/idmap.c | 74 +++++++++++++++++++++++---- > 4 files changed, 73 insertions(+), 13 deletions(-) > > diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h > index bf863ed..36708ba 100644 > --- a/arch/arm/include/asm/idmap.h > +++ b/arch/arm/include/asm/idmap.h > @@ -11,4 +11,9 @@ extern pgd_t *idmap_pgd; > > void setup_mm_for_reboot(void); > > +#ifdef CONFIG_ARM_VIRT_EXT > +void hyp_idmap_teardown(pgd_t *hyp_pgd); > +void hyp_idmap_setup(pgd_t *hyp_pgd); > +#endif Minor nit. You don't need ifdefs around declarations. Rob
diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h index bf863ed..36708ba 100644 --- a/arch/arm/include/asm/idmap.h +++ b/arch/arm/include/asm/idmap.h @@ -11,4 +11,9 @@ extern pgd_t *idmap_pgd; void setup_mm_for_reboot(void); +#ifdef CONFIG_ARM_VIRT_EXT +void hyp_idmap_teardown(pgd_t *hyp_pgd); +void hyp_idmap_setup(pgd_t *hyp_pgd); +#endif + #endif /* __ASM_IDMAP_H */ diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h index d795282..a2d404e 100644 --- a/arch/arm/include/asm/pgtable-3level-hwdef.h +++ b/arch/arm/include/asm/pgtable-3level-hwdef.h @@ -44,6 +44,7 @@ #define PMD_SECT_XN (_AT(pmdval_t, 1) << 54) #define PMD_SECT_AP_WRITE (_AT(pmdval_t, 0)) #define PMD_SECT_AP_READ (_AT(pmdval_t, 0)) +#define PMD_SECT_AP1 (_AT(pmdval_t, 1) << 6) #define PMD_SECT_TEX(x) (_AT(pmdval_t, 0)) /* diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 36ff15b..12fd2eb 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -19,7 +19,11 @@ ALIGN_FUNCTION(); \ VMLINUX_SYMBOL(__idmap_text_start) = .; \ *(.idmap.text) \ - VMLINUX_SYMBOL(__idmap_text_end) = .; + VMLINUX_SYMBOL(__idmap_text_end) = .; \ + ALIGN_FUNCTION(); \ + VMLINUX_SYMBOL(__hyp_idmap_text_start) = .; \ + *(.hyp.idmap.text) \ + VMLINUX_SYMBOL(__hyp_idmap_text_end) = .; #ifdef CONFIG_HOTPLUG_CPU #define ARM_CPU_DISCARD(x) diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c index ab88ed4..ea7430e 100644 --- a/arch/arm/mm/idmap.c +++ b/arch/arm/mm/idmap.c @@ -1,4 +1,6 @@ +#include <linux/module.h> #include <linux/kernel.h> +#include <linux/slab.h> #include <asm/cputype.h> #include <asm/idmap.h> @@ -6,6 +8,7 @@ #include <asm/pgtable.h> #include <asm/sections.h> #include <asm/system_info.h> +#include <asm/virt.h> pgd_t *idmap_pgd; @@ -59,11 +62,20 @@ static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end, } while (pud++, addr = next, addr != end); } -static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) +static void identity_mapping_add(pgd_t *pgd, const char *text_start, + const char *text_end, unsigned long prot) { - unsigned long prot, next; + unsigned long addr, end; + unsigned long next; + + addr = virt_to_phys(text_start); + end = virt_to_phys(text_end); + + pr_info("Setting up static %sidentity map for 0x%llx - 0x%llx\n", + prot ? "HYP " : "", + (long long)addr, (long long)end); + prot |= PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF; - prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF; if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) prot |= PMD_BIT4; @@ -78,24 +90,62 @@ extern char __idmap_text_start[], __idmap_text_end[]; static int __init init_static_idmap(void) { - phys_addr_t idmap_start, idmap_end; - idmap_pgd = pgd_alloc(&init_mm); if (!idmap_pgd) return -ENOMEM; - /* Add an identity mapping for the physical address of the section. */ - idmap_start = virt_to_phys((void *)__idmap_text_start); - idmap_end = virt_to_phys((void *)__idmap_text_end); - - pr_info("Setting up static identity map for 0x%llx - 0x%llx\n", - (long long)idmap_start, (long long)idmap_end); - identity_mapping_add(idmap_pgd, idmap_start, idmap_end); + identity_mapping_add(idmap_pgd, __idmap_text_start, + __idmap_text_end, 0); return 0; } early_initcall(init_static_idmap); +#if defined(CONFIG_ARM_VIRT_EXT) && defined(CONFIG_ARM_LPAE) +static void hyp_idmap_del_pmd(pgd_t *pgd, unsigned long addr) +{ + pud_t *pud; + pmd_t *pmd; + + pud = pud_offset(pgd, addr); + pmd = pmd_offset(pud, addr); + pud_clear(pud); + clean_pmd_entry(pmd); + pmd_free(NULL, (pmd_t *)((unsigned long)pmd & PAGE_MASK)); +} + +extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[]; + +/* + * This version actually frees the underlying pmds for all pgds in range and + * clear the pgds themselves afterwards. + */ +void hyp_idmap_teardown(pgd_t *hyp_pgd) +{ + unsigned long addr, end; + unsigned long next; + pgd_t *pgd = hyp_pgd; + + addr = virt_to_phys(__hyp_idmap_text_start); + end = virt_to_phys(__hyp_idmap_text_end); + + pgd += pgd_index(addr); + do { + next = pgd_addr_end(addr, end); + if (!pgd_none_or_clear_bad(pgd)) + hyp_idmap_del_pmd(pgd, addr); + } while (pgd++, addr = next, addr < end); +} +EXPORT_SYMBOL_GPL(hyp_idmap_teardown); + +void hyp_idmap_setup(pgd_t *hyp_pgd) +{ + identity_mapping_add(hyp_pgd, __hyp_idmap_text_start, + __hyp_idmap_text_end, PMD_SECT_AP1); +} +EXPORT_SYMBOL_GPL(hyp_idmap_setup); +#endif + /* * In order to soft-boot, we need to switch to a 1:1 mapping for the * cpu_reset functions. This will then ensure that we have predictable