Messages in this thread | | | From | "Ren, Qiaowei" <> | Subject | RE: [PATCH v3] x86, tboot: iomem fixes | Date | Thu, 18 Jul 2013 12:42:00 +0000 |
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On 2013-07-18, Ingo Molnar wrote: > > * Qiaowei Ren <qiaowei.ren@intel.com> wrote: > >> Current code doesn't use specific interface to access I/O space. >> So some potential bugs can be caused. We can fix this by using >> specific API. > > This is still very vague. > >> >> Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com> >> --- >> arch/x86/kernel/tboot.c | 21 ++++++++++++--------- >> 1 file changed, 12 insertions(+), 9 deletions(-) >> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index >> 3ff42d2..afe8cf8 100644 >> --- a/arch/x86/kernel/tboot.c >> +++ b/arch/x86/kernel/tboot.c >> @@ -466,9 +466,12 @@ struct sinit_mle_data { >> u32 vtd_dmars_off; >> } __packed; >> +#define SINIT_MLE_DATA_VTD_DMAR_OFF 140 >> + >> struct acpi_table_header *tboot_get_dmar_table(struct >> acpi_table_header *dmar_tbl) { >> - void *heap_base, *heap_ptr, *config; >> + void __iomem *heap_base, *heap_ptr, *config; >> + u32 dmar_tbl_off; >> >> if (!tboot_enabled()) >> return dmar_tbl; >> @@ -485,25 +488,25 @@ struct acpi_table_header > *tboot_get_dmar_table(struct acpi_table_header *dmar_tb >> return NULL; >> >> /* now map TXT heap */ >> - heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), >> - *(u64 *)(config + TXTCR_HEAP_SIZE)); >> + heap_base = ioremap(readl(config + TXTCR_HEAP_BASE), >> + readl(config + TXTCR_HEAP_SIZE)); >> iounmap(config); >> if (!heap_base) >> return NULL; >> >> /* walk heap to SinitMleData */ >> /* skip BiosData */ >> - heap_ptr = heap_base + *(u64 *)heap_base; >> + heap_ptr = heap_base + readq(heap_base); >> /* skip OsMleData */ >> - heap_ptr += *(u64 *)heap_ptr; >> + heap_ptr += readq(heap_ptr); >> /* skip OsSinitData */ >> - heap_ptr += *(u64 *)heap_ptr; >> + heap_ptr += readq(heap_ptr); >> /* now points to SinitMleDataSize; set to SinitMleData */ >> heap_ptr += sizeof(u64); >> /* get addr of DMAR table */ >> - dmar_tbl = (struct acpi_table_header *)(heap_ptr + >> - ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - >> - sizeof(u64)); >> + dmar_tbl_off = readl(heap_ptr + SINIT_MLE_DATA_VTD_DMAR_OFF); >> + memcpy_fromio(dmar_tbl, heap_ptr + dmar_tbl_off - sizeof(u64), >> + sizeof(struct acpi_table_header)); > > That memcpy (or an equivalent of it) was not in the code before, AFAICS. > > How can this be an 'interface fix'? It adds in new code... > Sorry, current code only need to get addr of DMAR table, so memcpy_fromio may be removed, even though this will also work. So "memcpy_fromio" line will be changed to dmar_tbl = (struct acpi_table_header *)(heap_ptr + dmar_tbl_off + - sizeof(u64)); If so, no new interface will be added, and the changelog at the beginning of this patch is engouch?
Thanks, Qiaowei
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