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[Xen-devel] [PATCH MM-PART3 v3 1/9] xen/arm: Rework HSCTLR_BASE

From: Julien Grall <julien.grall@xxxxxxx>

Date: Fri, 14 Jun 2019 18:51:36 +0100

Cc: Oleksandr_Tyshchenko@xxxxxxxx, Julien Grall <julien.grall@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Andrii_Anisov@xxxxxxxx, Andrii Anisov <andrii.anisov@xxxxxxxx>

Delivery-date: Fri, 14 Jun 2019 17:52:02 +0000

List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

The current value of HSCTLR_BASE for Arm64 is pretty wrong. It would actually turn on SCTLR_EL2.nAA (bit 6) on hardware implementing ARMv8.4-LSE. Furthermore, the documentation of what is cleared/set in SCTLR_EL2 is also not correct and looks like to be a verbatim copy from Arm32. HSCTLR_BASE is replaced with a bunch of per-architecture new defines helping to understand better what is the initial value for SCTLR_EL2/HSCTLR. Note the defines *_CLEAR are only used to check the state of each bits are known. Lastly, the documentation is dropped from arm{32,64}/head.S as it would be pretty easy to get out-of-sync with the definitions. Signed-off-by: Julien Grall <julien.grall@xxxxxxx> Reviewed-by: Andrii Anisov <andrii.anisov@xxxxxxxx> --- Note this patch was part of MM-PART2 before. As this was the only patch of the series not merged, it is now part of MM-PART3. Changes in v3: - Add comment on top of HSCTLR_CLEAR/SCTLR_CLEAR to explain that it is only used one time at pre-processing time - Fix typo in the commit message - Add Andrii's reviewed-by Changes in v2: - Use BIT(..., UL) instead of _BITUL --- xen/arch/arm/arm32/head.S | 12 +-------- xen/arch/arm/arm64/head.S | 10 +------- xen/include/asm-arm/processor.h | 56 ++++++++++++++++++++++++++++++++++++++++- 3 files changed, 57 insertions(+), 21 deletions(-) diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S index 5f817d473e..18ded49a04 100644 --- a/xen/arch/arm/arm32/head.S +++ b/xen/arch/arm/arm32/head.S @@ -224,17 +224,7 @@ cpu_init_done: ldr r0, =(TCR_RES1|TCR_SH0_IS|TCR_ORGN0_WBWA|TCR_IRGN0_WBWA|TCR_T0SZ(0)) mcr CP32(r0, HTCR) - /* - * Set up the HSCTLR: - * Exceptions in LE ARM, - * Low-latency IRQs disabled, - * Write-implies-XN disabled (for now), - * D-cache disabled (for now), - * I-cache enabled, - * Alignment checking enabled, - * MMU translation disabled (for now). - */ - ldr r0, =(HSCTLR_BASE|SCTLR_Axx_ELx_A) + ldr r0, =HSCTLR_SET mcr CP32(r0, HSCTLR) /* diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S index ddd3a33108..08094a273e 100644 --- a/xen/arch/arm/arm64/head.S +++ b/xen/arch/arm/arm64/head.S @@ -352,15 +352,7 @@ skip_bss: msr tcr_el2, x0 - /* Set up the SCTLR_EL2: - * Exceptions in LE ARM, - * Low-latency IRQs disabled, - * Write-implies-XN disabled (for now), - * D-cache disabled (for now), - * I-cache enabled, - * Alignment checking disabled, - * MMU translation disabled (for now). */ - ldr x0, =(HSCTLR_BASE) + ldr x0, =SCTLR_EL2_SET msr SCTLR_EL2, x0 /* Ensure that any exceptions encountered at EL2 diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h index bbcba061ca..e9d2ae2715 100644 --- a/xen/include/asm-arm/processor.h +++ b/xen/include/asm-arm/processor.h @@ -127,6 +127,9 @@ #define SCTLR_A32_ELx_TE BIT(30, UL) #define SCTLR_A32_ELx_FI BIT(21, UL) +/* Common bits for SCTLR_ELx for Arm64 */ +#define SCTLR_A64_ELx_SA BIT(3, UL) + /* Common bits for SCTLR_ELx on all architectures */ #define SCTLR_Axx_ELx_EE BIT(25, UL) #define SCTLR_Axx_ELx_WXN BIT(19, UL) @@ -135,7 +138,58 @@ #define SCTLR_Axx_ELx_A BIT(1, UL) #define SCTLR_Axx_ELx_M BIT(0, UL) -#define HSCTLR_BASE _AC(0x30c51878,U) +#ifdef CONFIG_ARM_32 + +#define HSCTLR_RES1 (BIT( 3, UL) | BIT( 4, UL) | BIT( 5, UL) |\ + BIT( 6, UL) | BIT(11, UL) | BIT(16, UL) |\ + BIT(18, UL) | BIT(22, UL) | BIT(23, UL) |\ + BIT(28, UL) | BIT(29, UL)) + +#define HSCTLR_RES0 (BIT(7, UL) | BIT(8, UL) | BIT(9, UL) | BIT(10, UL) |\ + BIT(13, UL) | BIT(14, UL) | BIT(15, UL) | BIT(17, UL) |\ + BIT(20, UL) | BIT(24, UL) | BIT(26, UL) | BIT(27, UL) |\ + BIT(31, UL)) + +/* Initial value for HSCTLR */ +#define HSCTLR_SET (HSCTLR_RES1 | SCTLR_Axx_ELx_A | SCTLR_Axx_ELx_I) + +/* Only used a pre-processing time... */ +#define HSCTLR_CLEAR (HSCTLR_RES0 | SCTLR_Axx_ELx_M |\ + SCTLR_Axx_ELx_C | SCTLR_Axx_ELx_WXN |\ + SCTLR_A32_ELx_FI | SCTLR_Axx_ELx_EE |\ + SCTLR_A32_ELx_TE) + +#if (HSCTLR_SET ^ HSCTLR_CLEAR) != 0xffffffffU +#error "Inconsistent HSCTLR set/clear bits" +#endif + +#else + +#define SCTLR_EL2_RES1 (BIT( 4, UL) | BIT( 5, UL) | BIT(11, UL) |\ + BIT(16, UL) | BIT(18, UL) | BIT(22, UL) |\ + BIT(23, UL) | BIT(28, UL) | BIT(29, UL)) + +#define SCTLR_EL2_RES0 (BIT( 6, UL) | BIT( 7, UL) | BIT( 8, UL) |\ + BIT( 9, UL) | BIT(10, UL) | BIT(13, UL) |\ + BIT(14, UL) | BIT(15, UL) | BIT(17, UL) |\ + BIT(20, UL) | BIT(21, UL) | BIT(24, UL) |\ + BIT(26, UL) | BIT(27, UL) | BIT(30, UL) |\ + BIT(31, UL) | (0xffffffffULL << 32)) + +/* Initial value for SCTLR_EL2 */ +#define SCTLR_EL2_SET (SCTLR_EL2_RES1 | SCTLR_A64_ELx_SA |\ + SCTLR_Axx_ELx_I) + +/* Only used a pre-processing time... */ +#define SCTLR_EL2_CLEAR (SCTLR_EL2_RES0 | SCTLR_Axx_ELx_M |\ + SCTLR_Axx_ELx_A | SCTLR_Axx_ELx_C |\ + SCTLR_Axx_ELx_WXN | SCTLR_Axx_ELx_EE) + +#if (SCTLR_EL2_SET ^ SCTLR_EL2_CLEAR) != 0xffffffffffffffffUL +#error "Inconsistent SCTLR_EL2 set/clear bits" +#endif + +#endif /* HCR Hyp Configuration Register */ #define HCR_RW (_AC(1,UL)<<31) /* Register Width, ARM64 only */ -- 2.11.0 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel

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