On Fri, Jun 14, 2024 at 10:18 AM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote: > > > > 在2024年6月14日六月 上午3:13，Huacai Chen写道： > > Hi, Jiaxun, > > > > On Fri, Jun 14, 2024 at 12:41 AM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote: > >> > >> DMW 2 & 3 are unused by kernel, however firmware may leave > >> garbage in them and interfere kernel's address mapping. > >> > >> Clear them as necessary. > > I think the current status is as expected, we don't want kernel access > > to non-8000 and non-9000 addresses. And low-end chips may have only > > two DMWs. > > I see, I'll remove U-Boot's dependency to DMW 2 and 3 then. I was told that DMW2&3 are probably exist (but cannot used for instruction fetch), so I applied this patch and implement DMW-based ioremap_wc(). https://github.com/chenhuacai/linux/commit/fa9f4109bf19a19736877d01e3e3529756a96095 Huacai > > Thanks > - Jiaxun > > > > > Huacai > > > > > > Huacai > > > >> > >> Cc: stable@xxxxxxxxxxxxxxx > >> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> > >> --- > >> arch/loongarch/include/asm/loongarch.h | 4 ++++ > >> arch/loongarch/include/asm/stackframe.h | 11 +++++++++++ > >> arch/loongarch/kernel/head.S | 12 ++---------- > >> arch/loongarch/power/suspend_asm.S | 6 +----- > >> drivers/firmware/efi/libstub/loongarch.c | 2 ++ > >> 5 files changed, 20 insertions(+), 15 deletions(-) > >> > >> diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h > >> index eb09adda54b7..3720096efcf9 100644 > >> --- a/arch/loongarch/include/asm/loongarch.h > >> +++ b/arch/loongarch/include/asm/loongarch.h > >> @@ -889,6 +889,10 @@ > >> #define CSR_DMW1_BASE (CSR_DMW1_VSEG << DMW_PABITS) > >> #define CSR_DMW1_INIT (CSR_DMW1_BASE | CSR_DMW1_MAT | CSR_DMW1_PLV0) > >> > >> +/* Direct Map window 2/3 - unused */ > >> +#define CSR_DMW2_INIT 0 > >> +#define CSR_DMW3_INIT 0 > >> + > >> /* Performance Counter registers */ > >> #define LOONGARCH_CSR_PERFCTRL0 0x200 /* 32 perf event 0 config */ > >> #define LOONGARCH_CSR_PERFCNTR0 0x201 /* 64 perf event 0 count value */ > >> diff --git a/arch/loongarch/include/asm/stackframe.h b/arch/loongarch/include/asm/stackframe.h > >> index d9eafd3ee3d1..10c5dcf56bc7 100644 > >> --- a/arch/loongarch/include/asm/stackframe.h > >> +++ b/arch/loongarch/include/asm/stackframe.h > >> @@ -38,6 +38,17 @@ > >> cfi_restore \reg \offset \docfi > >> .endm > >> > >> + .macro SETUP_DMWS temp1 > >> + li.d \temp1, CSR_DMW0_INIT > >> + csrwr \temp1, LOONGARCH_CSR_DMWIN0 > >> + li.d \temp1, CSR_DMW1_INIT > >> + csrwr \temp1, LOONGARCH_CSR_DMWIN1 > >> + li.d \temp1, CSR_DMW2_INIT > >> + csrwr \temp1, LOONGARCH_CSR_DMWIN2 > >> + li.d \temp1, CSR_DMW3_INIT > >> + csrwr \temp1, LOONGARCH_CSR_DMWIN3 > >> + .endm > >> + > >> /* Jump to the runtime virtual address. */ > >> .macro JUMP_VIRT_ADDR temp1 temp2 > >> li.d \temp1, CACHE_BASE > >> diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S > >> index 4677ea8fa8e9..1a71fc09bfd6 100644 > >> --- a/arch/loongarch/kernel/head.S > >> +++ b/arch/loongarch/kernel/head.S > >> @@ -44,11 +44,7 @@ SYM_DATA(kernel_fsize, .long _kernel_fsize); > >> SYM_CODE_START(kernel_entry) # kernel entry point > >> > >> /* Config direct window and set PG */ > >> - li.d t0, CSR_DMW0_INIT # UC, PLV0, 0x8000 xxxx xxxx xxxx > >> - csrwr t0, LOONGARCH_CSR_DMWIN0 > >> - li.d t0, CSR_DMW1_INIT # CA, PLV0, 0x9000 xxxx xxxx xxxx > >> - csrwr t0, LOONGARCH_CSR_DMWIN1 > >> - > >> + SETUP_DMWS t0 > >> JUMP_VIRT_ADDR t0, t1 > >> > >> /* Enable PG */ > >> @@ -124,11 +120,7 @@ SYM_CODE_END(kernel_entry) > >> * function after setting up the stack and tp registers. > >> */ > >> SYM_CODE_START(smpboot_entry) > >> - li.d t0, CSR_DMW0_INIT # UC, PLV0 > >> - csrwr t0, LOONGARCH_CSR_DMWIN0 > >> - li.d t0, CSR_DMW1_INIT # CA, PLV0 > >> - csrwr t0, LOONGARCH_CSR_DMWIN1 > >> - > >> + SETUP_DMWS t0 > >> JUMP_VIRT_ADDR t0, t1 > >> > >> #ifdef CONFIG_PAGE_SIZE_4KB > >> diff --git a/arch/loongarch/power/suspend_asm.S b/arch/loongarch/power/suspend_asm.S > >> index e2fc3b4e31f0..6fdd74eb219b 100644 > >> --- a/arch/loongarch/power/suspend_asm.S > >> +++ b/arch/loongarch/power/suspend_asm.S > >> @@ -73,11 +73,7 @@ SYM_FUNC_START(loongarch_suspend_enter) > >> * Reload all of the registers and return. > >> */ > >> SYM_INNER_LABEL(loongarch_wakeup_start, SYM_L_GLOBAL) > >> - li.d t0, CSR_DMW0_INIT # UC, PLV0 > >> - csrwr t0, LOONGARCH_CSR_DMWIN0 > >> - li.d t0, CSR_DMW1_INIT # CA, PLV0 > >> - csrwr t0, LOONGARCH_CSR_DMWIN1 > >> - > >> + SETUP_DMWS t0 > >> JUMP_VIRT_ADDR t0, t1 > >> > >> /* Enable PG */ > >> diff --git a/drivers/firmware/efi/libstub/loongarch.c b/drivers/firmware/efi/libstub/loongarch.c > >> index d0ef93551c44..3782d0a187d1 100644 > >> --- a/drivers/firmware/efi/libstub/loongarch.c > >> +++ b/drivers/firmware/efi/libstub/loongarch.c > >> @@ -74,6 +74,8 @@ efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image, > >> /* Config Direct Mapping */ > >> csr_write64(CSR_DMW0_INIT, LOONGARCH_CSR_DMWIN0); > >> csr_write64(CSR_DMW1_INIT, LOONGARCH_CSR_DMWIN1); > >> + csr_write64(CSR_DMW2_INIT, LOONGARCH_CSR_DMWIN2); > >> + csr_write64(CSR_DMW3_INIT, LOONGARCH_CSR_DMWIN3); > >> > >> real_kernel_entry = (void *)kernel_entry_address(kernel_addr, image); > >> > >> > >> -- > >> 2.43.0 > >> > >> > > -- > - Jiaxun >
