mach-k3: add dynamic mmu fixups for SPL stage

On platforms with spl splash support i.e CONFIG_VIDEO=y, the top of DDR
is reserved for the framebuffer.

The size for the framebuffer is computed at runtime by video_reserve.
During the MMU configuration an entry corresponding to the framebuffer
should be dynamically created to properly map the required space for the
framebuffer.

Therefore this patch adds k3_spl_mem_map_init which adds the required
MMU entry by querying the gd after the framebuffer size has been
computed in spl_reserve_video_from_ram_top.

For non VIDEO=y platforms, the added k3_spl_mem_map_init function gets
optimized out of the final binary so overall, the spl size is not
impacted[1].

[1]: Tested on clang 19.1.7 and gcc 15.1.1

Signed-off-by: Anshul Dalal <anshuld@ti.com>

diff --git a/arch/arm/mach-k3/arm64/arm64-mmu.c b/arch/arm/mach-k3/arm64/arm64-mmu.c
index 2fdd106fec4912344cceae152a3d39cb4e879d73..74c855852e94f713b714b1808f79e77ba7220a98 100644 (file)
--- a/arch/arm/mach-k3/arm64/arm64-mmu.c
+++ b/arch/arm/mach-k3/arm64/arm64-mmu.c
@@ -50,6 +50,10 @@ struct mm_region k3_mem_map[K3_MMU_REGIONS_COUNT] = {
                .size = SZ_128M,
                .attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) |
                         PTE_BLOCK_INNER_SHARE
+       }, {
+               /* Framebuffer reserved, size set at runtime */
+               .attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) |
+                        PTE_BLOCK_INNER_SHARE
        }, {
                /* List terminator */
                0,
@@ -58,6 +62,46 @@ struct mm_region k3_mem_map[K3_MMU_REGIONS_COUNT] = {
 
 struct mm_region *mem_map = k3_mem_map;
 
+int k3_spl_mem_map_init(void)
+{
+       unsigned int i;
+       int k3_map_idx = -EINVAL;
+
+       for (i = 0; i < K3_MMU_REGIONS_COUNT; i++) {
+               if (k3_mem_map[i].virt == 0 && k3_mem_map[i].phys == 0 &&
+                   k3_mem_map[i].size == 0) {
+                       k3_map_idx = i;
+                       break;
+               }
+       }
+
+       if (k3_map_idx == -EINVAL) {
+               pr_err("%s: Failed to find fixup region in MMU memory map\n",
+                      __func__);
+               return -EINVAL;
+       }
+
+       if (k3_map_idx >= K3_MMU_REGIONS_COUNT - 1) {
+               pr_err("%s: Not enough space in MMU map for the added entry\n",
+                      __func__);
+               return -ENOMEM;
+       }
+
+       if (CONFIG_IS_ENABLED(VIDEO)) {
+               k3_mem_map[k3_map_idx].virt = gd_video_bottom();
+               k3_mem_map[k3_map_idx].phys = gd_video_bottom();
+               k3_mem_map[k3_map_idx].size =
+                       gd_video_top() - gd_video_bottom();
+               k3_mem_map[k3_map_idx].attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) |
+                                              PTE_BLOCK_INNER_SHARE;
+               k3_map_idx++;
+       }
+
+       k3_mem_map[k3_map_idx] = (const struct mm_region){ 0 };
+
+       return 0;
+}
+
 static int dt_reserved_cmp(const void *a, const void *b)
 {
        const struct fdt_resource *val_a = a, *val_b = b;

diff --git a/arch/arm/mach-k3/common.c b/arch/arm/mach-k3/common.c
index f8c53b286eb778554789349fff53a2cdb0466ee0..723076ee87490473e1894e4ba3b64bf143eb9195 100644 (file)
--- a/arch/arm/mach-k3/common.c
+++ b/arch/arm/mach-k3/common.c
@@ -15,6 +15,7 @@
 #include <asm/global_data.h>
 #include <linux/printk.h>
 #include "common.h"
+#include "mach/k3-ddr.h"
 #include <dm.h>
 #include <remoteproc.h>
 #include <asm/cache.h>
@@ -268,9 +269,6 @@ void spl_enable_cache(void)
 
        dram_init();
 
-       /* reserve TLB table */
-       gd->arch.tlb_size = PGTABLE_SIZE;
-
        gd->ram_top += get_effective_memsize();
        gd->relocaddr = gd->ram_top;
 
@@ -278,6 +276,15 @@ void spl_enable_cache(void)
        if (ret)
                panic("Failed to reserve framebuffer memory (%d)\n", ret);
 
+       if (IS_ENABLED(CONFIG_ARM64)) {
+               ret = k3_spl_mem_map_init();
+               if (ret)
+                       panic("Failed to perform MMU fixups: %d\n", ret);
+       }
+
+       /* reserve TLB table */
+       gd->arch.tlb_size = PGTABLE_SIZE;
+
        gd->arch.tlb_addr = gd->relocaddr - gd->arch.tlb_size;
        gd->arch.tlb_addr &= ~(0x10000 - 1);
        debug("TLB table from %08lx to %08lx\n", gd->arch.tlb_addr,

diff --git a/arch/arm/mach-k3/include/mach/k3-ddr.h b/arch/arm/mach-k3/include/mach/k3-ddr.h
index 0b164ebf5e648f4a68223c87d8290b674bc1bdf9..375a1a8594578ed3162d13428c44a15335f22b54 100644 (file)
--- a/arch/arm/mach-k3/include/mach/k3-ddr.h
+++ b/arch/arm/mach-k3/include/mach/k3-ddr.h
@@ -17,6 +17,9 @@ int dram_init_banksize(void);
 void fixup_ddr_driver_for_ecc(struct spl_image_info *spl_image);
 void fixup_memory_node(struct spl_image_info *spl_image);
 
+/* Performs MMU memory map fixups at SPL stage */
+int k3_spl_mem_map_init(void);
+
 /*
  * Modifies the MMU memory map based on DDR size and reserved-memory
  * nodes in DT