ARM: 6225/1: make TCM allocation static and common for all archs

This changes the TCM handling so that a fixed area is reserved at
0xfffe0000-0xfffeffff for TCM. This areas is used by XScale but
XScale does not have TCM so the mechanisms are mutually exclusive.

This change is needed to make TCM detection more dynamic while
still being able to compile code into it, and is a must for the
unified ARM goals: the current TCM allocation at different places
in memory for each machine would be a nightmare if you want to
compile a single image for more than one machine with TCM so it
has to be nailed down in one place.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 48 insertions, 43 deletions

diff --git a/arch/arm/kernel/tcm.c b/arch/arm/kernel/tcm.c
index f2ead32c1aa0..26685c2f7a49 100644
--- a/arch/arm/kernel/tcm.c
+++ b/arch/arm/kernel/tcm.c
@@ -18,32 +18,30 @@
 #include <mach/memory.h>
 #include "tcm.h"
 
-/* Scream and warn about misuse */
-#if !defined(ITCM_OFFSET) || !defined(ITCM_END) || \
-    !defined(DTCM_OFFSET) || !defined(DTCM_END)
-#error "TCM support selected but offsets not defined!"
-#endif
-
 static struct gen_pool *tcm_pool;
 
 /* TCM section definitions from the linker */
 extern char __itcm_start, __sitcm_text, __eitcm_text;
 extern char __dtcm_start, __sdtcm_data, __edtcm_data;
 
+/* These will be increased as we run */
+u32 dtcm_end = DTCM_OFFSET;
+u32 itcm_end = ITCM_OFFSET;
+
 /*
  * TCM memory resources
  */
 static struct resource dtcm_res = {
         .name = "DTCM RAM",
         .start = DTCM_OFFSET,
-        .end = DTCM_END,
+        .end = DTCM_OFFSET,
         .flags = IORESOURCE_MEM
 };
 
 static struct resource itcm_res = {
         .name = "ITCM RAM",
         .start = ITCM_OFFSET,
-        .end = ITCM_END,
+        .end = ITCM_OFFSET,
         .flags = IORESOURCE_MEM
 };
 
@@ -51,7 +49,7 @@ static struct map_desc dtcm_iomap[] __initdata = {
         {
                 .virtual        = DTCM_OFFSET,
                 .pfn            = __phys_to_pfn(DTCM_OFFSET),
-                .length         = (DTCM_END - DTCM_OFFSET + 1),
+                .length         = 0,
                 .type           = MT_MEMORY_DTCM
         }
 };
@@ -60,7 +58,7 @@ static struct map_desc itcm_iomap[] __initdata = {
         {
                 .virtual        = ITCM_OFFSET,
                 .pfn            = __phys_to_pfn(ITCM_OFFSET),
-                .length         = (ITCM_END - ITCM_OFFSET + 1),
+                .length         = 0,
                 .type           = MT_MEMORY_ITCM
         }
 };
@@ -92,8 +90,8 @@ void tcm_free(void *addr, size_t len)
 }
 EXPORT_SYMBOL(tcm_free);
 
-static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
-                                  u32 offset, u32 expected_size)
+static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
+                                  u32 *offset)
 {
         const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
                                     256, 512, 1024, -1, -1, -1, -1 };
@@ -120,8 +118,13 @@ static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
 
         tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
         if (tcm_size < 0) {
-                pr_err("CPU: %sTCM%d of unknown size!\n",
+                pr_err("CPU: %sTCM%d of unknown size\n",
                        type ? "I" : "D", bank);
+                return -EINVAL;
+        } else if (tcm_size > 32) {
+                pr_err("CPU: %sTCM%d larger than 32k found\n",
+                       type ? "I" : "D", bank);
+                return -EINVAL;
         } else {
                 pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
                         type ? "I" : "D",
@@ -131,17 +134,8 @@ static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
                         (tcm_region & 1) ? "" : "not ");
         }
 
-        if (tcm_size != (expected_size >> 10)) {
-                pr_crit("CPU: %sTCM%d was detected %dk but expected %dk!\n",
-                        type ? "I" : "D",
-                        bank,
-                        tcm_size,
-                        (expected_size >> 10));
-                /* Adjust to the expected size? what can we do... */
-        }
-
         /* Force move the TCM bank to where we want it, enable */
-        tcm_region = offset | (tcm_region & 0x00000ffeU) | 1;
+        tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1;
 
         if (!type)
                 asm("mcr        p15, 0, %0, c9, c1, 0"
@@ -152,17 +146,17 @@ static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
                     : /* No output operands */
                     : "r" (tcm_region));
 
+        /* Increase offset */
+        *offset += (tcm_size << 10);
+
         pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
                 type ? "I" : "D",
                 bank,
                 tcm_size,
                 (tcm_region & 0xfffff000U));
+        return 0;
 }
 
-/* We expect to find what is configured for the platform */
-#define DTCM_EXPECTED (DTCM_END - DTCM_OFFSET + 1)
-#define ITCM_EXPECTED (ITCM_END - ITCM_OFFSET + 1)
-
 /*
  * This initializes the TCM memory
  */
@@ -170,40 +164,51 @@ void __init tcm_init(void)
 {
         u32 tcm_status = read_cpuid_tcmstatus();
         u8 dtcm_banks = (tcm_status >> 16) & 0x03;
-        u32 dtcm_banksize = DTCM_EXPECTED / dtcm_banks;
         u8 itcm_banks = (tcm_status & 0x03);
-        u32 itcm_banksize = ITCM_EXPECTED / itcm_banks;
         char *start;
         char *end;
         char *ram;
+        int ret;
         int i;
 
         /* Setup DTCM if present */
-        for (i = 0; i < dtcm_banks; i++) {
-                setup_tcm_bank(0, i, dtcm_banks,
-                               DTCM_OFFSET + (i * dtcm_banksize),
-                               dtcm_banksize);
+        if (dtcm_banks > 0) {
+                for (i = 0; i < dtcm_banks; i++) {
+                        ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
+                        if (ret)
+                                return;
+                }
+                dtcm_res.end = dtcm_end - 1;
                 request_resource(&iomem_resource, &dtcm_res);
+                dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
                 iotable_init(dtcm_iomap, 1);
                 /* Copy data from RAM to DTCM */
                 start = &__sdtcm_data;
                 end   = &__edtcm_data;
                 ram   = &__dtcm_start;
+                /* This means you compiled more code than fits into DTCM */
+                BUG_ON((end - start) > (dtcm_end - DTCM_OFFSET));
                 memcpy(start, ram, (end-start));
                 pr_debug("CPU DTCM: copied data from %p - %p\n", start, end);
         }
 
         /* Setup ITCM if present */
-        for (i = 0; i < itcm_banks; i++) {
-                setup_tcm_bank(1, i, itcm_banks,
-                               ITCM_OFFSET + (i * itcm_banksize),
-                               itcm_banksize);
+        if (itcm_banks > 0) {
+                for (i = 0; i < itcm_banks; i++) {
+                        ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
+                        if (ret)
+                                return;
+                }
+                itcm_res.end = itcm_end - 1;
                 request_resource(&iomem_resource, &itcm_res);
+                itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
                 iotable_init(itcm_iomap, 1);
                 /* Copy code from RAM to ITCM */
                 start = &__sitcm_text;
                 end   = &__eitcm_text;
                 ram   = &__itcm_start;
+                /* This means you compiled more code than fits into ITCM */
+                BUG_ON((end - start) > (itcm_end - ITCM_OFFSET));
                 memcpy(start, ram, (end-start));
                 pr_debug("CPU ITCM: copied code from %p - %p\n", start, end);
         }
@@ -232,9 +237,9 @@ static int __init setup_tcm_pool(void)
 
         /* Add the rest of DTCM to the TCM pool */
         if (tcm_status & (0x03 << 16)) {
-                if (dtcm_pool_start < DTCM_END) {
+                if (dtcm_pool_start < dtcm_end) {
                         ret = gen_pool_add(tcm_pool, dtcm_pool_start,
-                                           DTCM_END - dtcm_pool_start + 1, -1);
+                                           dtcm_end - dtcm_pool_start, -1);
                         if (ret) {
                                 pr_err("CPU DTCM: could not add DTCM " \
                                        "remainder to pool!\n");
@@ -242,16 +247,16 @@ static int __init setup_tcm_pool(void)
                         }
                         pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
                                  "the TCM memory pool\n",
-                                 DTCM_END - dtcm_pool_start + 1,
+                                 dtcm_end - dtcm_pool_start,
                                  dtcm_pool_start);
                 }
         }
 
         /* Add the rest of ITCM to the TCM pool */
         if (tcm_status & 0x03) {
-                if (itcm_pool_start < ITCM_END) {
+                if (itcm_pool_start < itcm_end) {
                         ret = gen_pool_add(tcm_pool, itcm_pool_start,
-                                           ITCM_END - itcm_pool_start + 1, -1);
+                                           itcm_end - itcm_pool_start, -1);
                         if (ret) {
                                 pr_err("CPU ITCM: could not add ITCM " \
                                        "remainder to pool!\n");
@@ -259,7 +264,7 @@ static int __init setup_tcm_pool(void)
                         }
                         pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
                                  "the TCM memory pool\n",
-                                 ITCM_END - itcm_pool_start + 1,
+                                 itcm_end - itcm_pool_start,
                                  itcm_pool_start);
                 }
         }