[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] xen/arm32: Create the same boot-time MPU regions as arm64
commit 76e9dd7cdccbe427dc31d508001f6fe7c5f5fb8a Author: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx> AuthorDate: Mon Apr 14 17:45:13 2025 +0100 Commit: Michal Orzel <michal.orzel@xxxxxxx> CommitDate: Wed Apr 16 08:36:10 2025 +0200 xen/arm32: Create the same boot-time MPU regions as arm64 Create Boot-time MPU protection regions (similar to Armv8-R AArch64) for Armv8-R AArch32. Also, defined *_PRBAR macros for arm32. The only difference from arm64 is that XN is 1-bit for arm32. Define the system registers and macros in mpu/cpregs.h. Introduce WRITE_SYSREG_ASM() to write to system registers in assembly. Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx> Reviewed-by: Luca Fancellu <luca.fancellu@xxxxxxx> Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx> Tested-by: Luca Fancellu <luca.fancellu@xxxxxxx> --- xen/arch/arm/arm32/Makefile | 1 + xen/arch/arm/arm32/mpu/Makefile | 1 + xen/arch/arm/arm32/mpu/head.S | 104 +++++++++++++++++++++++++++++++ xen/arch/arm/include/asm/arm32/sysregs.h | 13 +++- xen/arch/arm/include/asm/cpregs.h | 2 + xen/arch/arm/include/asm/mpu/cpregs.h | 32 ++++++++++ 6 files changed, 151 insertions(+), 2 deletions(-) diff --git a/xen/arch/arm/arm32/Makefile b/xen/arch/arm/arm32/Makefile index 40a2b4803f..537969d753 100644 --- a/xen/arch/arm/arm32/Makefile +++ b/xen/arch/arm/arm32/Makefile @@ -1,5 +1,6 @@ obj-y += lib/ obj-$(CONFIG_MMU) += mmu/ +obj-$(CONFIG_MPU) += mpu/ obj-$(CONFIG_EARLY_PRINTK) += debug.o obj-y += domctl.o diff --git a/xen/arch/arm/arm32/mpu/Makefile b/xen/arch/arm/arm32/mpu/Makefile new file mode 100644 index 0000000000..3340058c08 --- /dev/null +++ b/xen/arch/arm/arm32/mpu/Makefile @@ -0,0 +1 @@ +obj-y += head.o diff --git a/xen/arch/arm/arm32/mpu/head.S b/xen/arch/arm/arm32/mpu/head.S new file mode 100644 index 0000000000..b2c5245e51 --- /dev/null +++ b/xen/arch/arm/arm32/mpu/head.S @@ -0,0 +1,104 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Start-of-day code for an Armv8-R-AArch32 MPU system. + */ + +#include <asm/arm32/macros.h> +#include <asm/arm32/sysregs.h> +#include <asm/cpregs.h> +#include <asm/mpu.h> +#include <asm/mpu/regions.inc> +#include <asm/page.h> + +/* + * Set up the memory attribute type tables and enable EL2 MPU and data cache. + * If the Background region is enabled, then the MPU uses the default memory + * map as the Background region for generating the memory + * attributes when MPU is disabled. + * Since the default memory map of the Armv8-R AArch32 architecture is + * IMPLEMENTATION DEFINED, we intend to turn off the Background region here. + * + * Clobbers r0 + */ +FUNC_LOCAL(enable_mpu) + /* Set up memory attribute type tables */ + mov_w r0, MAIR0VAL + mcr CP32(r0, HMAIR0) + mov_w r0, MAIR1VAL + mcr CP32(r0, HMAIR1) + + mrc CP32(r0, HSCTLR) + bic r0, r0, #SCTLR_ELx_BR /* Disable Background region */ + orr r0, r0, #SCTLR_Axx_ELx_M /* Enable MPU */ + orr r0, r0, #SCTLR_Axx_ELx_C /* Enable D-cache */ + mcr CP32(r0, HSCTLR) + isb + + ret +END(enable_mpu) + +/* + * Maps the various sections of Xen (described in xen.lds.S) as different MPU + * regions. + * + * Clobbers r0 - r5 + * + */ +FUNC(enable_boot_cpu_mm) + /* Get the number of regions specified in MPUIR_EL2 */ + mrc CP32(r5, MPUIR_EL2) + and r5, r5, #NUM_MPU_REGIONS_MASK + + /* x0: region sel */ + mov r0, #0 + /* Xen text section. */ + mov_w r1, _stext + mov_w r2, _etext + prepare_xen_region r0, r1, r2, r3, r4, r5, attr_prbar=REGION_TEXT_PRBAR + + /* Xen read-only data section. */ + mov_w r1, _srodata + mov_w r2, _erodata + prepare_xen_region r0, r1, r2, r3, r4, r5, attr_prbar=REGION_RO_PRBAR + + /* Xen read-only after init and data section. (RW data) */ + mov_w r1, __ro_after_init_start + mov_w r2, __init_begin + prepare_xen_region r0, r1, r2, r3, r4, r5 + + /* Xen code section. */ + mov_w r1, __init_begin + mov_w r2, __init_data_begin + prepare_xen_region r0, r1, r2, r3, r4, r5, attr_prbar=REGION_TEXT_PRBAR + + /* Xen data and BSS section. */ + mov_w r1, __init_data_begin + mov_w r2, __bss_end + prepare_xen_region r0, r1, r2, r3, r4, r5 + +#ifdef CONFIG_EARLY_PRINTK + /* Xen early UART section. */ + mov_w r1, CONFIG_EARLY_UART_BASE_ADDRESS + mov_w r2, (CONFIG_EARLY_UART_BASE_ADDRESS + CONFIG_EARLY_UART_SIZE) + prepare_xen_region r0, r1, r2, r3, r4, r5, attr_prbar=REGION_DEVICE_PRBAR, attr_prlar=REGION_DEVICE_PRLAR +#endif + + b enable_mpu +END(enable_boot_cpu_mm) + +/* + * We don't yet support secondary CPUs bring-up. Implement a dummy helper to + * please the common code. + */ +FUNC(enable_secondary_cpu_mm) + PRINT("- SMP not enabled yet -\r\n") +1: wfe + b 1b +END(enable_secondary_cpu_mm) + +/* + * Local variables: + * mode: ASM + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/arch/arm/include/asm/arm32/sysregs.h b/xen/arch/arm/include/asm/arm32/sysregs.h index 22871999af..ef1a870fd6 100644 --- a/xen/arch/arm/include/asm/arm32/sysregs.h +++ b/xen/arch/arm/include/asm/arm32/sysregs.h @@ -20,7 +20,16 @@ * uses r0 as a placeholder register. */ #define CMD_CP32(name...) "mcr " __stringify(CP32(r0, name)) ";" -#ifndef __ASSEMBLY__ +#define REGION_TEXT_PRBAR 0x18 /* SH=11 AP=10 XN=0 */ +#define REGION_RO_PRBAR 0x1D /* SH=11 AP=10 XN=1 */ +#define REGION_DATA_PRBAR 0x19 /* SH=11 AP=00 XN=1 */ +#define REGION_DEVICE_PRBAR 0x11 /* SH=10 AP=00 XN=1 */ + +#ifdef __ASSEMBLY__ + +#define WRITE_SYSREG_ASM(v, name) mcr CP32(v, name) + +#else /* __ASSEMBLY__ */ /* C wrappers */ #define READ_CP32(name...) ({ \ @@ -84,7 +93,7 @@ /* MVFR2 is not defined on ARMv7 */ #define MVFR2_MAYBE_UNDEFINED -#endif /* __ASSEMBLY__ */ +#endif /* !__ASSEMBLY__ */ #endif /* __ASM_ARM_ARM32_SYSREGS_H */ /* diff --git a/xen/arch/arm/include/asm/cpregs.h b/xen/arch/arm/include/asm/cpregs.h index aec9e8f329..a7503a190f 100644 --- a/xen/arch/arm/include/asm/cpregs.h +++ b/xen/arch/arm/include/asm/cpregs.h @@ -1,6 +1,8 @@ #ifndef __ASM_ARM_CPREGS_H #define __ASM_ARM_CPREGS_H +#include <asm/mpu/cpregs.h> + /* * AArch32 Co-processor registers. * diff --git a/xen/arch/arm/include/asm/mpu/cpregs.h b/xen/arch/arm/include/asm/mpu/cpregs.h new file mode 100644 index 0000000000..d5cd0e04d5 --- /dev/null +++ b/xen/arch/arm/include/asm/mpu/cpregs.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __ARM_MPU_CPREGS_H +#define __ARM_MPU_CPREGS_H + +/* CP15 CR0: MPU Type Register */ +#define HMPUIR p15,4,c0,c0,4 + +/* CP15 CR6: MPU Protection Region Base/Limit/Select Address Register */ +#define HPRSELR p15,4,c6,c2,1 +#define HPRBAR p15,4,c6,c3,0 +#define HPRLAR p15,4,c6,c8,1 + +/* Aliases of AArch64 names for use in common code */ +#ifdef CONFIG_ARM_32 +/* Alphabetically... */ +#define MPUIR_EL2 HMPUIR +#define PRBAR_EL2 HPRBAR +#define PRLAR_EL2 HPRLAR +#define PRSELR_EL2 HPRSELR +#endif /* CONFIG_ARM_32 */ + +#endif /* __ARM_MPU_CPREGS_H */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ -- generated by git-patchbot for /home/xen/git/xen.git#staging
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