| Message ID | 20210425201318.15447-8-julien@xen.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/arm: mm: Remove open-coding mappings | expand |
On Sun, 25 Apr 2021, Julien Grall wrote: > From: Julien Grall <julien.grall@arm.com> > > Now that map_pages_to_xen() has been extended to support 2MB mappings, > we can replace the create_mappings() calls by map_pages_to_xen() calls. > > The mapping can also be marked read-only has Xen as no business to > modify the host Device Tree. I think that's good. Just FYI there is some work at Xilinx to make changes to the device tree at runtime but we'll cross that bridge when we come to it. Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > Signed-off-by: Julien Grall <julien.grall@arm.com> > Signed-off-by: Julien Grall <jgrall@amazon.com> > > --- > Changes in v2: > - Add my AWS signed-off-by > - Fix typo in the commit message > --- > xen/arch/arm/mm.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > > diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c > index 2cbfbe25240e..8fac24d80086 100644 > --- a/xen/arch/arm/mm.c > +++ b/xen/arch/arm/mm.c > @@ -558,6 +558,7 @@ void * __init early_fdt_map(paddr_t fdt_paddr) > paddr_t offset; > void *fdt_virt; > uint32_t size; > + int rc; > > /* > * Check whether the physical FDT address is set and meets the minimum > @@ -573,8 +574,12 @@ void * __init early_fdt_map(paddr_t fdt_paddr) > /* The FDT is mapped using 2MB superpage */ > BUILD_BUG_ON(BOOT_FDT_VIRT_START % SZ_2M); > > - create_mappings(xen_second, BOOT_FDT_VIRT_START, paddr_to_pfn(base_paddr), > - SZ_2M >> PAGE_SHIFT, SZ_2M); > + rc = map_pages_to_xen(BOOT_FDT_VIRT_START, maddr_to_mfn(base_paddr), > + SZ_2M >> PAGE_SHIFT, > + PAGE_HYPERVISOR_RO | _PAGE_BLOCK); > + if ( rc ) > + panic("Unable to map the device-tree.\n"); > + > > offset = fdt_paddr % SECOND_SIZE; > fdt_virt = (void *)BOOT_FDT_VIRT_START + offset; > @@ -588,9 +593,12 @@ void * __init early_fdt_map(paddr_t fdt_paddr) > > if ( (offset + size) > SZ_2M ) > { > - create_mappings(xen_second, BOOT_FDT_VIRT_START + SZ_2M, > - paddr_to_pfn(base_paddr + SZ_2M), > - SZ_2M >> PAGE_SHIFT, SZ_2M); > + rc = map_pages_to_xen(BOOT_FDT_VIRT_START + SZ_2M, > + maddr_to_mfn(base_paddr + SZ_2M), > + SZ_2M >> PAGE_SHIFT, > + PAGE_HYPERVISOR_RO | _PAGE_BLOCK); > + if ( rc ) > + panic("Unable to map the device-tree\n"); > } > > return fdt_virt; > -- > 2.17.1 >
Hi Stefano, On 12/05/2021 22:41, Stefano Stabellini wrote: > On Sun, 25 Apr 2021, Julien Grall wrote: >> From: Julien Grall <julien.grall@arm.com> >> >> Now that map_pages_to_xen() has been extended to support 2MB mappings, >> we can replace the create_mappings() calls by map_pages_to_xen() calls. >> >> The mapping can also be marked read-only has Xen as no business to >> modify the host Device Tree. > > I think that's good. Just FYI there is some work at Xilinx to make > changes to the device tree at runtime but we'll cross that bridge when > we come to it. This particular mapping is only used during early boot. After the DT has been unflatten, this region is unmapped and the physical memory released. So if the DT needs to be modified at runtime, then you would most likely want to modify the unflatten version. > > Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Thank you! Cheers,
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 2cbfbe25240e..8fac24d80086 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -558,6 +558,7 @@ void * __init early_fdt_map(paddr_t fdt_paddr) paddr_t offset; void *fdt_virt; uint32_t size; + int rc; /* * Check whether the physical FDT address is set and meets the minimum @@ -573,8 +574,12 @@ void * __init early_fdt_map(paddr_t fdt_paddr) /* The FDT is mapped using 2MB superpage */ BUILD_BUG_ON(BOOT_FDT_VIRT_START % SZ_2M); - create_mappings(xen_second, BOOT_FDT_VIRT_START, paddr_to_pfn(base_paddr), - SZ_2M >> PAGE_SHIFT, SZ_2M); + rc = map_pages_to_xen(BOOT_FDT_VIRT_START, maddr_to_mfn(base_paddr), + SZ_2M >> PAGE_SHIFT, + PAGE_HYPERVISOR_RO | _PAGE_BLOCK); + if ( rc ) + panic("Unable to map the device-tree.\n"); + offset = fdt_paddr % SECOND_SIZE; fdt_virt = (void *)BOOT_FDT_VIRT_START + offset; @@ -588,9 +593,12 @@ void * __init early_fdt_map(paddr_t fdt_paddr) if ( (offset + size) > SZ_2M ) { - create_mappings(xen_second, BOOT_FDT_VIRT_START + SZ_2M, - paddr_to_pfn(base_paddr + SZ_2M), - SZ_2M >> PAGE_SHIFT, SZ_2M); + rc = map_pages_to_xen(BOOT_FDT_VIRT_START + SZ_2M, + maddr_to_mfn(base_paddr + SZ_2M), + SZ_2M >> PAGE_SHIFT, + PAGE_HYPERVISOR_RO | _PAGE_BLOCK); + if ( rc ) + panic("Unable to map the device-tree\n"); } return fdt_virt;