Hi,
Title: This reads as you replace all adr_l with load_paddr. So how about:
xen/arm32: head: Replace load_paddr with adr_l when they are equivalent
On 26/10/2023 12:12, Ayan Kumar Halder wrote:
Before the MMU is turned on, PC uses physical address. Thus, one can use adr_l
instead of load_paddr to obtain the physical address of a symbol.
The only exception (for this replacement) is create_table_entry() which is
called before and after MMU is turned on.
Also, in lookup_processor_type() "r10" is no longer used. The reason being
__lookup_processor_type uses adr_l (thus r10 is no longer used to obtain the
physical address offset).
Signed-off-by: Ayan Kumar Halder <[email protected]>
---
Refer https://lists.archive.carbon60.com/xen/devel/682900 for details.
Changes from :-
v1 :- 1. No need to modify create_table_entry().
2. Remove "mov r10, #0 " in lookup_processor_type().
xen/arch/arm/arm32/head.S | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index 33b038e7e0..e0ff46e92f 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -171,7 +171,7 @@ past_zImage:
/* Using the DTB in the .dtb section? */
.ifnes CONFIG_DTB_FILE,""
- load_paddr r8, _sdtb
+ adr_l r8, _sdtb
.endif
/* Initialize the UART if earlyprintk has been enabled. */
@@ -213,7 +213,7 @@ GLOBAL(init_secondary)
mrc CP32(r1, MPIDR)
bic r7, r1, #(~MPIDR_HWID_MASK) /* Mask out flags to get CPU ID */
- load_paddr r0, smp_up_cpu
+ adr_l r0, smp_up_cpu
dsb
2: ldr r1, [r0]
cmp r1, r7
@@ -479,7 +479,7 @@ create_page_tables:
* create_table_entry_paddr() will clobber the register storing
* the physical address of the table to point to.
*/
- load_paddr r5, boot_third
+ adr_l r5, boot_third
mov_w r4, XEN_VIRT_START
.rept XEN_NR_ENTRIES(2)
mov r0, r5 /* r0 := paddr(l3 table) */
@@ -578,7 +578,7 @@ enable_mmu:
flush_xen_tlb_local r0
/* Write Xen's PT's paddr into the HTTBR */
- load_paddr r0, boot_pgtable
+ adr_l r0, boot_pgtable
mov r1, #0 /* r0:r1 is paddr (boot_pagetable) */
mcrr CP64(r0, r1, HTTBR)
isb
@@ -877,7 +877,6 @@ putn: mov pc, lr
/* This provides a C-API version of __lookup_processor_type */
ENTRY(lookup_processor_type)
stmfd sp!, {r4, r10, lr}
Do we still need to save/restore r10?
- mov r10, #0 /* r10 := offset between virt&phys */
bl __lookup_processor_type
mov r0, r1
ldmfd sp!, {r4, r10, pc}
@@ -897,8 +896,8 @@ ENTRY(lookup_processor_type)
*/
__lookup_processor_type:
mrc CP32(r0, MIDR) /* r0 := our cpu id */
- load_paddr r1, __proc_info_start
- load_paddr r2, __proc_info_end
+ adr_l r1, __proc_info_start
+ adr_l r2, __proc_info_end
1: ldr r3, [r1, #PROCINFO_cpu_mask]
and r4, r0, r3 /* r4 := our cpu id with mask */
ldr r3, [r1, #PROCINFO_cpu_val] /* r3 := cpu val in current proc
info */
Cheers,
--
Julien Grall
