Skip to content

Commit

Permalink
target-arm: Add v8 mmu translation support
Browse files Browse the repository at this point in the history 
Add support for v8 page table walks. This supports stage 1 translations
for 4KB, 16KB and 64KB page sizes starting with 0 or 1 level.

Signed-off-by: Rob Herring <rob.herring@linaro.org>
[PMM: fix style nits, fold in 16/64K page support patch, use
 arm_el_is_aa64() to decide whether to do 64 bit page table walk]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
  • Loading branch information
@pm215
Rob Herring authored and pm215 committed Apr 17, 2014
1 parent 2c7ffc4 commit 2c8dd31
Showing 1 changed file with 77 additions and 32 deletions.
109 changes: 77 additions & 32 deletions target-arm/helper.c
View file
Expand Up @@ -10,7 +10,7 @@
#include <zlib.h> /* For crc32 */

#ifndef CONFIG_USER_ONLY
static inline int get_phys_addr(CPUARMState *env, uint32_t address,
static inline int get_phys_addr(CPUARMState *env, target_ulong address,
int access_type, int is_user,
hwaddr *phys_ptr, int *prot,
target_ulong *page_size);
Expand Down Expand Up @@ -1151,14 +1151,15 @@ static void par_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value)
#ifndef CONFIG_USER_ONLY
/* get_phys_addr() isn't present for user-mode-only targets */

/* Return true if extended addresses are enabled, ie this is an
* LPAE implementation and we are using the long-descriptor translation
* table format because the TTBCR EAE bit is set.
/* 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.
*/
static inline bool extended_addresses_enabled(CPUARMState *env)
{
return arm_feature(env, ARM_FEATURE_LPAE)
&& (env->cp15.c2_control & (1U << 31));
return arm_el_is_aa64(env, 1)
|| ((arm_feature(env, ARM_FEATURE_LPAE)
&& (env->cp15.c2_control & (1U << 31))));
}

static CPAccessResult ats_access(CPUARMState *env, const ARMCPRegInfo *ri)
Expand Down Expand Up @@ -3402,7 +3403,7 @@ typedef enum {
permission_fault = 3,
} MMUFaultType;

static int get_phys_addr_lpae(CPUARMState *env, uint32_t address,
static int get_phys_addr_lpae(CPUARMState *env, target_ulong address,
int access_type, int is_user,
hwaddr *phys_ptr, int *prot,
target_ulong *page_size_ptr)
Expand All @@ -3412,26 +3413,46 @@ static int get_phys_addr_lpae(CPUARMState *env, uint32_t address,
MMUFaultType fault_type = translation_fault;
uint32_t level = 1;
uint32_t epd;
uint32_t tsz;
int32_t tsz;
uint32_t tg;
uint64_t ttbr;
int ttbr_select;
int n;
hwaddr descaddr;
hwaddr descaddr, descmask;
uint32_t tableattrs;
target_ulong page_size;
uint32_t attrs;
int32_t granule_sz = 9;
int32_t va_size = 32;
int32_t tbi = 0;

if (arm_el_is_aa64(env, 1)) {
va_size = 64;
if (extract64(address, 55, 1))
tbi = extract64(env->cp15.c2_control, 38, 1);
else
tbi = extract64(env->cp15.c2_control, 37, 1);
tbi *= 8;
}

/* Determine whether this address is in the region controlled by
* TTBR0 or TTBR1 (or if it is in neither region and should fault).
* This is a Non-secure PL0/1 stage 1 translation, so controlled by
* TTBCR/TTBR0/TTBR1 in accordance with ARM ARM DDI0406C table B-32:
*/
uint32_t t0sz = extract32(env->cp15.c2_control, 0, 3);
uint32_t t1sz = extract32(env->cp15.c2_control, 16, 3);
if (t0sz && !extract32(address, 32 - t0sz, t0sz)) {
uint32_t t0sz = extract32(env->cp15.c2_control, 0, 6);
if (arm_el_is_aa64(env, 1)) {
t0sz = MIN(t0sz, 39);
t0sz = MAX(t0sz, 16);
}
uint32_t t1sz = extract32(env->cp15.c2_control, 16, 6);
if (arm_el_is_aa64(env, 1)) {
t1sz = MIN(t1sz, 39);
t1sz = MAX(t1sz, 16);
}
if (t0sz && !extract64(address, va_size - t0sz, t0sz - tbi)) {
/* there is a ttbr0 region and we are in it (high bits all zero) */
ttbr_select = 0;
} else if (t1sz && !extract32(~address, 32 - t1sz, t1sz)) {
} else if (t1sz && !extract64(~address, va_size - t1sz, t1sz - tbi)) {
/* there is a ttbr1 region and we are in it (high bits all one) */
ttbr_select = 1;
} else if (!t0sz) {
Expand All @@ -3457,45 +3478,64 @@ static int get_phys_addr_lpae(CPUARMState *env, uint32_t address,
ttbr = env->cp15.ttbr0_el1;
epd = extract32(env->cp15.c2_control, 7, 1);
tsz = t0sz;

tg = extract32(env->cp15.c2_control, 14, 2);
if (tg == 1) { /* 64KB pages */
granule_sz = 13;
}
if (tg == 2) { /* 16KB pages */
granule_sz = 11;
}
} else {
ttbr = env->cp15.ttbr1_el1;
epd = extract32(env->cp15.c2_control, 23, 1);
tsz = t1sz;

tg = extract32(env->cp15.c2_control, 30, 2);
if (tg == 3) { /* 64KB pages */
granule_sz = 13;
}
if (tg == 1) { /* 16KB pages */
granule_sz = 11;
}
}

if (epd) {
/* Translation table walk disabled => Translation fault on TLB miss */
goto do_fault;
}

/* If the region is small enough we will skip straight to a 2nd level
* lookup. This affects the number of bits of the address used in
* combination with the TTBR to find the first descriptor. ('n' here
* matches the usage in the ARM ARM sB3.6.6, where bits [39..n] are
* from the TTBR, [n-1..3] from the vaddr, and [2..0] always zero).
/* The starting level depends on the virtual address size which can be
* up to 48-bits and the translation granule size.
*/
if (tsz > 1) {
level = 2;
n = 14 - tsz;
if ((va_size - tsz) > (granule_sz * 4 + 3)) {
level = 0;
} else if ((va_size - tsz) > (granule_sz * 3 + 3)) {
level = 1;
} else {
n = 5 - tsz;
level = 2;
}

/* 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
* first descriptor address.
*/
address &= (0xffffffffU >> tsz);
if (tsz) {
address &= (1ULL << (va_size - tsz)) - 1;
}

descmask = (1ULL << (granule_sz + 3)) - 1;

/* Now we can extract the actual base address from the TTBR */
descaddr = extract64(ttbr, 0, 40);
descaddr &= ~((1ULL << n) - 1);
descaddr = extract64(ttbr, 0, 48);
descaddr &= ~((1ULL << (va_size - tsz - (granule_sz * (4 - level)))) - 1);

tableattrs = 0;
for (;;) {
uint64_t descriptor;

descaddr |= ((address >> (9 * (4 - level))) & 0xff8);
descaddr |= (address >> (granule_sz * (4 - level))) & descmask;
descaddr &= ~7ULL;
descriptor = ldq_phys(cs->as, descaddr);
if (!(descriptor & 1) ||
(!(descriptor & 2) && (level == 3))) {
Expand All @@ -3518,11 +3558,16 @@ static int get_phys_addr_lpae(CPUARMState *env, uint32_t address,
* These are basically the same thing, although the number
* of bits we pull in from the vaddr varies.
*/
page_size = (1 << (39 - (9 * level)));
page_size = (1 << ((granule_sz * (4 - level)) + 3));
descaddr |= (address & (page_size - 1));
/* Extract attributes from the descriptor and merge with table attrs */
attrs = extract64(descriptor, 2, 10)
| (extract64(descriptor, 52, 12) << 10);
if (arm_feature(env, ARM_FEATURE_V8)) {
attrs = extract64(descriptor, 2, 10)
| (extract64(descriptor, 53, 11) << 10);
} else {
attrs = extract64(descriptor, 2, 10)
| (extract64(descriptor, 52, 12) << 10);
}
attrs |= extract32(tableattrs, 0, 2) << 11; /* XN, PXN */
attrs |= extract32(tableattrs, 3, 1) << 5; /* APTable[1] => AP[2] */
/* The sense of AP[1] vs APTable[0] is reversed, as APTable[0] == 1
Expand Down Expand Up @@ -3656,7 +3701,7 @@ static int get_phys_addr_mpu(CPUARMState *env, uint32_t address,
* @prot: set to the permissions for the page containing phys_ptr
* @page_size: set to the size of the page containing phys_ptr
*/
static inline int get_phys_addr(CPUARMState *env, uint32_t address,
static inline int get_phys_addr(CPUARMState *env, target_ulong address,
int access_type, int is_user,
hwaddr *phys_ptr, int *prot,
target_ulong *page_size)
Expand Down Expand Up @@ -3705,7 +3750,7 @@ int arm_cpu_handle_mmu_fault(CPUState *cs, vaddr address,
if (ret == 0) {
/* Map a single [sub]page. */
phys_addr &= ~(hwaddr)0x3ff;
address &= ~(uint32_t)0x3ff;
address &= ~(target_ulong)0x3ff;
tlb_set_page(cs, address, phys_addr, prot, mmu_idx, page_size);
return 0;
}
Expand Down

0 comments on commit 2c8dd31

Please sign in to comment.