From 1853d5a9dcac910322c6cc5b2fddec45fd052d25 Mon Sep 17 00:00:00 2001 From: "Edgar E. Iglesias" Date: Mon, 26 Oct 2015 14:02:00 +0100 Subject: target-arm: Add computation of starting level for S2 PTW The starting level for S2 pagetable walks is computed differently from the S1 starting level. Implement the S2 variant. Signed-off-by: Edgar E. Iglesias Message-id: 1445864527-14520-8-git-send-email-edgar.iglesias@gmail.com Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- target-arm/helper.c | 114 +++++++++++++++++++++++++++++++++++++++++++------ target-arm/internals.h | 25 +++++++++++ 2 files changed, 126 insertions(+), 13 deletions(-) (limited to 'target-arm') diff --git a/target-arm/helper.c b/target-arm/helper.c index 2af126ff4a..8714724488 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -6470,12 +6470,72 @@ typedef enum { permission_fault = 3, } MMUFaultType; +/* + * check_s2_startlevel + * @cpu: ARMCPU + * @is_aa64: True if the translation regime is in AArch64 state + * @startlevel: Suggested starting level + * @inputsize: Bitsize of IPAs + * @stride: Page-table stride (See the ARM ARM) + * + * Returns true if the suggested starting level is OK and false otherwise. + */ +static bool check_s2_startlevel(ARMCPU *cpu, bool is_aa64, int level, + int inputsize, int stride) +{ + /* Negative levels are never allowed. */ + if (level < 0) { + return false; + } + + if (is_aa64) { + unsigned int pamax = arm_pamax(cpu); + + switch (stride) { + case 13: /* 64KB Pages. */ + if (level == 0 || (level == 1 && pamax <= 42)) { + return false; + } + break; + case 11: /* 16KB Pages. */ + if (level == 0 || (level == 1 && pamax <= 40)) { + return false; + } + break; + case 9: /* 4KB Pages. */ + if (level == 0 && pamax <= 42) { + return false; + } + break; + default: + g_assert_not_reached(); + } + } else { + const int grainsize = stride + 3; + int startsizecheck; + + /* AArch32 only supports 4KB pages. Assert on that. */ + assert(stride == 9); + + if (level == 0) { + return false; + } + + startsizecheck = inputsize - ((3 - level) * stride + grainsize); + if (startsizecheck < 1 || startsizecheck > stride + 4) { + return false; + } + } + return true; +} + static bool get_phys_addr_lpae(CPUARMState *env, target_ulong address, int access_type, ARMMMUIdx mmu_idx, hwaddr *phys_ptr, MemTxAttrs *txattrs, int *prot, target_ulong *page_size_ptr, uint32_t *fsr) { - CPUState *cs = CPU(arm_env_get_cpu(env)); + ARMCPU *cpu = arm_env_get_cpu(env); + CPUState *cs = CPU(cpu); /* Read an LPAE long-descriptor translation table. */ MMUFaultType fault_type = translation_fault; uint32_t level = 1; @@ -6630,18 +6690,46 @@ static bool get_phys_addr_lpae(CPUARMState *env, target_ulong address, goto do_fault; } - /* The starting level depends on the virtual address size (which can be - * up to 48 bits) and the translation granule size. It indicates the number - * of strides (stride bits at a time) needed to consume the bits - * of the input address. In the pseudocode this is: - * level = 4 - RoundUp((inputsize - grainsize) / stride) - * where their 'inputsize' is our 'inputsize', 'grainsize' is - * our 'stride + 3' and 'stride' is our 'stride'. - * Applying the usual "rounded up m/n is (m+n-1)/n" and simplifying: - * = 4 - (inputsize - stride - 3 + stride - 1) / stride - * = 4 - (inputsize - 4) / stride; - */ - level = 4 - (inputsize - 4) / stride; + if (mmu_idx != ARMMMUIdx_S2NS) { + /* The starting level depends on the virtual address size (which can + * be up to 48 bits) and the translation granule size. It indicates + * the number of strides (stride bits at a time) needed to + * consume the bits of the input address. In the pseudocode this is: + * level = 4 - RoundUp((inputsize - grainsize) / stride) + * where their 'inputsize' is our 'inputsize', 'grainsize' is + * our 'stride + 3' and 'stride' is our 'stride'. + * Applying the usual "rounded up m/n is (m+n-1)/n" and simplifying: + * = 4 - (inputsize - stride - 3 + stride - 1) / stride + * = 4 - (inputsize - 4) / stride; + */ + level = 4 - (inputsize - 4) / stride; + } else { + /* For stage 2 translations the starting level is specified by the + * VTCR_EL2.SL0 field (whose interpretation depends on the page size) + */ + int startlevel = extract32(tcr->raw_tcr, 6, 2); + bool ok; + + if (va_size == 32 || stride == 9) { + /* AArch32 or 4KB pages */ + level = 2 - startlevel; + } else { + /* 16KB or 64KB pages */ + level = 3 - startlevel; + } + + /* Check that the starting level is valid. */ + ok = check_s2_startlevel(cpu, va_size == 64, level, + inputsize, stride); + if (!ok) { + /* AArch64 reports these as level 0 faults. + * AArch32 reports these as level 1 faults. + */ + level = va_size == 64 ? 0 : 1; + fault_type = translation_fault; + goto do_fault; + } + } /* Clear the vaddr bits which aren't part of the within-region address, * so that we don't have to special case things when calculating the diff --git a/target-arm/internals.h b/target-arm/internals.h index 36a56aadb0..8bd37eba65 100644 --- a/target-arm/internals.h +++ b/target-arm/internals.h @@ -152,6 +152,31 @@ static inline void update_spsel(CPUARMState *env, uint32_t imm) aarch64_restore_sp(env, cur_el); } +/* + * arm_pamax + * @cpu: ARMCPU + * + * Returns the implementation defined bit-width of physical addresses. + * The ARMv8 reference manuals refer to this as PAMax(). + */ +static inline unsigned int arm_pamax(ARMCPU *cpu) +{ + static const unsigned int pamax_map[] = { + [0] = 32, + [1] = 36, + [2] = 40, + [3] = 42, + [4] = 44, + [5] = 48, + }; + unsigned int parange = extract32(cpu->id_aa64mmfr0, 0, 4); + + /* id_aa64mmfr0 is a read-only register so values outside of the + * supported mappings can be considered an implementation error. */ + assert(parange < ARRAY_SIZE(pamax_map)); + return pamax_map[parange]; +} + /* Return true if extended addresses are enabled. * This is always the case if our translation regime is 64 bit, * but depends on TTBCR.EAE for 32 bit. -- cgit v1.2.3