target/cortex_a: remove buggy memory AP accesses

The armv7m debug port provides a direct access to the CPU memory
bus, allowing the debugger to bypass the CPU for every memory
operation.
The armv7a debug port doesn't offer the same feature, mainly
because CPU caches and MMU makes the direct memory access more
tricky. Nevertheless most SoC with armv7a provide direct memory
access through an AHB bus available on another DAP access port,
different from the debug port.

The original port of cortex_a in OpenOCD was inspired from the
working cortex_m code, and provided optional memory access
through the AHB, if present.
The code for AHB access is problematic and partially buggy due
to incomplete management of cache coherency and missing check of
page boundary during virtual address operations.

With the commit 5d458cf72734a4474f38bbed10eea4d9acfe93a2
("target/mem_ap: generic mem-ap target") we have a clean support
for memory access through system buses connected to DAP AP, which
obsoletes the buggy memory AP hack in cortex_a.

Remove any code that uses the memory AP accesses in cortex_a.

Change-Id: I7cd1f94885e5817448058953e043d8da90dea3cc
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/4748
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

diff --git a/src/target/armv7a.h b/src/target/armv7a.h
index 57779c61ad8aec822bdb9dda6ddef19d87e55025..cf938809a221781a986bf4d004a78532d64c0032 100644 (file)
--- a/src/target/armv7a.h
+++ b/src/target/armv7a.h
@@ -106,8 +106,6 @@ struct armv7a_common {
        struct arm_dpm dpm;
        uint32_t debug_base;
        struct adiv5_ap *debug_ap;
-       struct adiv5_ap *memory_ap;
-       bool memory_ap_available;
        /* mdir */
        uint8_t multi_processor_system;
        uint8_t cluster_id;

diff --git a/src/target/cortex_a.c b/src/target/cortex_a.c
index 21943f220118112a3c8aaa7a9aa45b5e7fc71049..2768e18cf91055f8d19b2572d7b07dd71b6f6973 100644 (file)
--- a/src/target/cortex_a.c
+++ b/src/target/cortex_a.c
@@ -2622,9 +2622,6 @@ static int cortex_a_read_phys_memory(struct target *target,
        target_addr_t address, uint32_t size,
        uint32_t count, uint8_t *buffer)
 {
-       struct armv7a_common *armv7a = target_to_armv7a(target);
-       struct adiv5_dap *swjdp = armv7a->arm.dap;
-       uint8_t apsel = swjdp->apsel;
        int retval;
 
        if (!count || !buffer)
@@ -2633,9 +2630,6 @@ static int cortex_a_read_phys_memory(struct target *target,
        LOG_DEBUG("Reading memory at real address " TARGET_ADDR_FMT "; size %" PRId32 "; count %" PRId32,
                address, size, count);
 
-       if (armv7a->memory_ap_available && (apsel == armv7a->memory_ap->ap_num))
-               return mem_ap_read_buf(armv7a->memory_ap, buffer, size, count, address);
-
        /* read memory through the CPU */
        cortex_a_prep_memaccess(target, 1);
        retval = cortex_a_read_cpu_memory(target, address, size, count, buffer);
@@ -2660,57 +2654,10 @@ static int cortex_a_read_memory(struct target *target, target_addr_t address,
        return retval;
 }
 
-static int cortex_a_read_memory_ahb(struct target *target, target_addr_t address,
-       uint32_t size, uint32_t count, uint8_t *buffer)
-{
-       int mmu_enabled = 0;
-       target_addr_t virt, phys;
-       int retval;
-       struct armv7a_common *armv7a = target_to_armv7a(target);
-       struct adiv5_dap *swjdp = armv7a->arm.dap;
-       uint8_t apsel = swjdp->apsel;
-
-       if (!armv7a->memory_ap_available || (apsel != armv7a->memory_ap->ap_num))
-               return target_read_memory(target, address, size, count, buffer);
-
-       /* cortex_a handles unaligned memory access */
-       LOG_DEBUG("Reading memory at address " TARGET_ADDR_FMT "; size %" PRId32 "; count %" PRId32,
-               address, size, count);
-
-       /* determine if MMU was enabled on target stop */
-       if (!armv7a->is_armv7r) {
-               retval = cortex_a_mmu(target, &mmu_enabled);
-               if (retval != ERROR_OK)
-                       return retval;
-       }
-
-       if (mmu_enabled) {
-               virt = address;
-               retval = cortex_a_virt2phys(target, virt, &phys);
-               if (retval != ERROR_OK)
-                       return retval;
-
-               LOG_DEBUG("Reading at virtual address. "
-                         "Translating v:" TARGET_ADDR_FMT " to r:" TARGET_ADDR_FMT,
-                         virt, phys);
-               address = phys;
-       }
-
-       if (!count || !buffer)
-               return ERROR_COMMAND_SYNTAX_ERROR;
-
-       retval = mem_ap_read_buf(armv7a->memory_ap, buffer, size, count, address);
-
-       return retval;
-}
-
 static int cortex_a_write_phys_memory(struct target *target,
        target_addr_t address, uint32_t size,
        uint32_t count, const uint8_t *buffer)
 {
-       struct armv7a_common *armv7a = target_to_armv7a(target);
-       struct adiv5_dap *swjdp = armv7a->arm.dap;
-       uint8_t apsel = swjdp->apsel;
        int retval;
 
        if (!count || !buffer)
@@ -2719,9 +2666,6 @@ static int cortex_a_write_phys_memory(struct target *target,
        LOG_DEBUG("Writing memory to real address " TARGET_ADDR_FMT "; size %" PRId32 "; count %" PRId32,
                address, size, count);
 
-       if (armv7a->memory_ap_available && (apsel == armv7a->memory_ap->ap_num))
-               return mem_ap_write_buf(armv7a->memory_ap, buffer, size, count, address);
-
        /* write memory through the CPU */
        cortex_a_prep_memaccess(target, 1);
        retval = cortex_a_write_cpu_memory(target, address, size, count, buffer);
@@ -2748,51 +2692,6 @@ static int cortex_a_write_memory(struct target *target, target_addr_t address,
        return retval;
 }
 
-static int cortex_a_write_memory_ahb(struct target *target, target_addr_t address,
-       uint32_t size, uint32_t count, const uint8_t *buffer)
-{
-       int mmu_enabled = 0;
-       target_addr_t virt, phys;
-       int retval;
-       struct armv7a_common *armv7a = target_to_armv7a(target);
-       struct adiv5_dap *swjdp = armv7a->arm.dap;
-       uint8_t apsel = swjdp->apsel;
-
-       if (!armv7a->memory_ap_available || (apsel != armv7a->memory_ap->ap_num))
-               return target_write_memory(target, address, size, count, buffer);
-
-       /* cortex_a handles unaligned memory access */
-       LOG_DEBUG("Writing memory at address " TARGET_ADDR_FMT "; size %" PRId32 "; count %" PRId32,
-               address, size, count);
-
-       /* determine if MMU was enabled on target stop */
-       if (!armv7a->is_armv7r) {
-               retval = cortex_a_mmu(target, &mmu_enabled);
-               if (retval != ERROR_OK)
-                       return retval;
-       }
-
-       if (mmu_enabled) {
-               virt = address;
-               retval = cortex_a_virt2phys(target, virt, &phys);
-               if (retval != ERROR_OK)
-                       return retval;
-
-               LOG_DEBUG("Writing to virtual address. "
-                         "Translating v:" TARGET_ADDR_FMT " to r:" TARGET_ADDR_FMT,
-                         virt,
-                         phys);
-               address = phys;
-       }
-
-       if (!count || !buffer)
-               return ERROR_COMMAND_SYNTAX_ERROR;
-
-       retval = mem_ap_write_buf(armv7a->memory_ap, buffer, size, count, address);
-
-       return retval;
-}
-
 static int cortex_a_read_buffer(struct target *target, target_addr_t address,
                                uint32_t count, uint8_t *buffer)
 {
@@ -2802,7 +2701,7 @@ static int cortex_a_read_buffer(struct target *target, target_addr_t address,
         * will have something to do with the size we leave to it. */
        for (size = 1; size < 4 && count >= size * 2 + (address & size); size *= 2) {
                if (address & size) {
-                       int retval = cortex_a_read_memory_ahb(target, address, size, 1, buffer);
+                       int retval = target_read_memory(target, address, size, 1, buffer);
                        if (retval != ERROR_OK)
                                return retval;
                        address += size;
@@ -2815,7 +2714,7 @@ static int cortex_a_read_buffer(struct target *target, target_addr_t address,
        for (; size > 0; size /= 2) {
                uint32_t aligned = count - count % size;
                if (aligned > 0) {
-                       int retval = cortex_a_read_memory_ahb(target, address, size, aligned / size, buffer);
+                       int retval = target_read_memory(target, address, size, aligned / size, buffer);
                        if (retval != ERROR_OK)
                                return retval;
                        address += aligned;
@@ -2836,7 +2735,7 @@ static int cortex_a_write_buffer(struct target *target, target_addr_t address,
         * will have something to do with the size we leave to it. */
        for (size = 1; size < 4 && count >= size * 2 + (address & size); size *= 2) {
                if (address & size) {
-                       int retval = cortex_a_write_memory_ahb(target, address, size, 1, buffer);
+                       int retval = target_write_memory(target, address, size, 1, buffer);
                        if (retval != ERROR_OK)
                                return retval;
                        address += size;
@@ -2849,7 +2748,7 @@ static int cortex_a_write_buffer(struct target *target, target_addr_t address,
        for (; size > 0; size /= 2) {
                uint32_t aligned = count - count % size;
                if (aligned > 0) {
-                       int retval = cortex_a_write_memory_ahb(target, address, size, aligned / size, buffer);
+                       int retval = target_write_memory(target, address, size, aligned / size, buffer);
                        if (retval != ERROR_OK)
                                return retval;
                        address += aligned;
@@ -2927,21 +2826,6 @@ static int cortex_a_examine_first(struct target *target)
 
        armv7a->debug_ap->memaccess_tck = 80;
 
-       /* Search for the AHB-AB.
-        * REVISIT: We should search for AXI-AP as well and make sure the AP's MEMTYPE says it
-        * can access system memory. */
-       armv7a->memory_ap_available = false;
-       retval = dap_find_ap(swjdp, AP_TYPE_AHB_AP, &armv7a->memory_ap);
-       if (retval == ERROR_OK) {
-               retval = mem_ap_init(armv7a->memory_ap);
-               if (retval == ERROR_OK)
-                       armv7a->memory_ap_available = true;
-       }
-       if (retval != ERROR_OK) {
-               /* AHB-AP not found or unavailable - use the CPU */
-               LOG_DEBUG("No AHB-AP available for memory access");
-       }
-
        if (!target->dbgbase_set) {
                uint32_t dbgbase;
                /* Get ROM Table base */
@@ -3185,10 +3069,7 @@ static int cortex_a_mmu(struct target *target, int *enabled)
 static int cortex_a_virt2phys(struct target *target,
        target_addr_t virt, target_addr_t *phys)
 {
-       int retval = ERROR_FAIL;
-       struct armv7a_common *armv7a = target_to_armv7a(target);
-       struct adiv5_dap *swjdp = armv7a->arm.dap;
-       uint8_t apsel = swjdp->apsel;
+       int retval;
        int mmu_enabled = 0;
 
        /*
@@ -3203,23 +3084,12 @@ static int cortex_a_virt2phys(struct target *target,
                return ERROR_OK;
        }
 
-       if (armv7a->memory_ap_available && (apsel == armv7a->memory_ap->ap_num)) {
-               uint32_t ret;
-               retval = armv7a_mmu_translate_va(target,
-                               virt, &ret);
-               if (retval != ERROR_OK)
-                       goto done;
-               *phys = ret;
-       } else {/*  use this method if armv7a->memory_ap not selected
-                *  mmu must be enable in order to get a correct translation */
-               retval = cortex_a_mmu_modify(target, 1);
-               if (retval != ERROR_OK)
-                       goto done;
-               retval = armv7a_mmu_translate_va_pa(target, (uint32_t)virt,
+       /* mmu must be enable in order to get a correct translation */
+       retval = cortex_a_mmu_modify(target, 1);
+       if (retval != ERROR_OK)
+               return retval;
+       return armv7a_mmu_translate_va_pa(target, (uint32_t)virt,
                                                    (uint32_t *)phys, 1);
-       }
-done:
-       return retval;
 }
 
 COMMAND_HANDLER(cortex_a_handle_cache_info_command)