[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] xen/arm32: heap: Rework adr_l so it doesn't rely on where Xen is loaded
commit a571c1aab5a11a238eb190d20390435d49cdd50b Author: Julien Grall <jgrall@xxxxxxxxxx> AuthorDate: Fri Aug 12 20:24:43 2022 +0100 Commit: Julien Grall <julien@xxxxxxx> CommitDate: Wed Aug 31 20:16:22 2022 +0100 xen/arm32: heap: Rework adr_l so it doesn't rely on where Xen is loaded At the moment, the macro addr_l needs to know whether the caller is running with the MMU on. This is fine today because there are only two possible cases: 1) MMU off 2) MMU on and linked to the virtual address This is still cumbersome to use for the developer as they need to know if the MMU is on. Thankfully, Linux developpers came up with a great way to allow adr_l to work within the range +/- 4GB of PC by emitting a PC-relative reference [1]. Re-use the same approach on Arm and drop the parameter 'mmu'. [1] 0b1674638a5c ("ARM: assembler: introduce adr_l, ldr_l and str_l macros") Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx> --- xen/arch/arm/arm32/head.S | 38 +++++++++++++++----------------------- 1 file changed, 15 insertions(+), 23 deletions(-) diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S index 50f6fa4eb3..27d02ac8d6 100644 --- a/xen/arch/arm/arm32/head.S +++ b/xen/arch/arm/arm32/head.S @@ -49,20 +49,16 @@ .endm /* - * There are no easy way to have a PC relative address within the range - * +/- 4GB of the PC. + * Pseudo-op for PC relative adr <reg>, <symbol> where <symbol> is + * within the range +/- 4GB of the PC. * - * This macro workaround it by asking the user to tell whether the MMU - * has been turned on or not. - * - * When the MMU is turned off, we need to apply the physical offset - * (r10) in order to find the associated physical address. + * @dst: destination register + * @sym: name of the symbol */ -.macro adr_l, dst, sym, mmu - ldr \dst, =\sym - .if \mmu == 0 - add \dst, \dst, r10 - .endif +.macro adr_l, dst, sym + mov_w \dst, \sym - .Lpc\@ + .set .Lpc\@, .+ 8 /* PC bias */ + add \dst, \dst, pc .endm .macro load_paddr rb, sym @@ -383,7 +379,6 @@ ENDPROC(cpu_init) * tbl: table symbol to point to * virt: virtual address * lvl: page-table level - * mmu: Is the MMU turned on/off. If not specified it will be off * * Preserves \virt * Clobbers r1 - r4 @@ -392,7 +387,7 @@ ENDPROC(cpu_init) * * Note that \virt should be in a register other than r1 - r4 */ -.macro create_table_entry, ptbl, tbl, virt, lvl, mmu=0 +.macro create_table_entry, ptbl, tbl, virt, lvl get_table_slot r1, \virt, \lvl /* r1 := slot in \tlb */ lsl r1, r1, #3 /* r1 := slot offset in \tlb */ @@ -402,7 +397,7 @@ ENDPROC(cpu_init) orr r2, r2, r4 /* + \tlb paddr */ mov r3, #0 - adr_l r4, \ptbl, \mmu + adr_l r4, \ptbl strd r2, r3, [r4, r1] .endm @@ -415,17 +410,14 @@ ENDPROC(cpu_init) * virt: virtual address * phys: physical address * type: mapping type. If not specified it will be normal memory (PT_MEM_L3) - * mmu: Is the MMU turned on/off. If not specified it will be off * * Preserves \virt, \phys * Clobbers r1 - r4 * - * * Also use r10 for the phys offset. - * * Note that \virt and \paddr should be in other registers than r1 - r4 * and be distinct. */ -.macro create_mapping_entry, ptbl, virt, phys, type=PT_MEM_L3, mmu=0 +.macro create_mapping_entry, ptbl, virt, phys, type=PT_MEM_L3 mov_w r2, XEN_PT_LPAE_ENTRY_MASK lsr r1, \virt, #THIRD_SHIFT and r1, r1, r2 /* r1 := slot in \tlb */ @@ -438,7 +430,7 @@ ENDPROC(cpu_init) orr r2, r2, r4 /* + PAGE_ALIGNED(phys) */ mov r3, #0 - adr_l r4, \ptbl, \mmu + adr_l r4, \ptbl strd r2, r3, [r4, r1] .endm @@ -468,7 +460,7 @@ create_page_tables: create_table_entry boot_second, boot_third, r0, 2 /* Setup boot_third: */ - adr_l r4, boot_third, mmu=0 + adr_l r4, boot_third lsr r2, r9, #THIRD_SHIFT /* Base address for 4K mapping */ lsl r2, r2, #THIRD_SHIFT @@ -632,11 +624,11 @@ setup_fixmap: #if defined(CONFIG_EARLY_PRINTK) /* Add UART to the fixmap table */ ldr r0, =EARLY_UART_VIRTUAL_ADDRESS - create_mapping_entry xen_fixmap, r0, r11, type=PT_DEV_L3, mmu=1 + create_mapping_entry xen_fixmap, r0, r11, type=PT_DEV_L3 #endif /* Map fixmap into boot_second */ mov_w r0, FIXMAP_ADDR(0) - create_table_entry boot_second, xen_fixmap, r0, 2, mmu=1 + create_table_entry boot_second, xen_fixmap, r0, 2 /* Ensure any page table updates made above have occurred. */ dsb nshst -- generated by git-patchbot for /home/xen/git/xen.git#master
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