Re: [Qemu-devel] [PATCH] PPC: mpc8544ds: Span initial TLB entry over as much RAM as we need

["Andreas Färber" <afaerber@suse.de>]

Am 19.05.2012 00:53, schrieb Alexander Graf:
> The initial TLB entry is supposed to help us run the guest -kernel payload.
> This means the guest needs to be able to access its own memory, the initrd
> memory and the device tree.
> 
> So far we only statically reserved a TLB entry from [0;256M[. This patch
> fixes it to span from [0;dt_end[, allowing the guest payload to access
> everything initially.
> 
> Reported-by: Stuart Yoder <stuart.yoder@freescale.com>
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  hw/ppce500_mpc8544ds.c |   41 +++++++++++++++++++++++++++--------------
>  1 files changed, 27 insertions(+), 14 deletions(-)
> 
> diff --git a/hw/ppce500_mpc8544ds.c b/hw/ppce500_mpc8544ds.c
> index f1dfbe1..42a63aa 100644
> --- a/hw/ppce500_mpc8544ds.c
> +++ b/hw/ppce500_mpc8544ds.c
> @@ -31,6 +31,7 @@
>  #include "elf.h"
>  #include "sysbus.h"
>  #include "exec-memory.h"
> +#include "host-utils.h"
>  
>  #define BINARY_DEVICE_TREE_FILE    "mpc8544ds.dtb"
>  #define UIMAGE_LOAD_BASE           0
> @@ -55,6 +56,7 @@
>  struct boot_info
>  {
>      uint32_t dt_base;
> +    uint32_t dt_size;
>      uint32_t entry;
>  };
>  
> @@ -164,7 +166,11 @@ static int mpc8544_load_device_tree(CPUPPCState *env,
>      }
>  
>      ret = rom_add_blob_fixed(BINARY_DEVICE_TREE_FILE, fdt, fdt_size, addr);
> +    if (ret < 0) {
> +        goto out;
> +    }
>      g_free(fdt);
> +    ret = fdt_size;
>  
>  out:
>  #endif
> @@ -172,23 +178,27 @@ out:
>      return ret;
>  }
>  
> -/* Create -kernel TLB entries for BookE, linearly spanning 256MB.  */
> +/* Create -kernel TLB entries for BookE.  */
>  static inline target_phys_addr_t booke206_page_size_to_tlb(uint64_t size)
>  {
> -    return ffs(size >> 10) - 1;
> +    return 63 - clz64(size >> 10);
>  }
>  
> -static void mmubooke_create_initial_mapping(CPUPPCState *env,
> -                                     target_ulong va,
> -                                     target_phys_addr_t pa)
> +static void mmubooke_create_initial_mapping(CPUPPCState *env)
>  {
> +    struct boot_info *bi = env->load_info;
>      ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 0);
> -    target_phys_addr_t size;
> -
> -    size = (booke206_page_size_to_tlb(256 * 1024 * 1024) << MAS1_TSIZE_SHIFT);
> +    target_phys_addr_t size, dt_end;
> +    int ps;
> +
> +    /* Our initial TLB entry needs to cover everything from 0 to
> +       the device tree top */
> +    dt_end = bi->dt_base + bi->dt_size;
> +    ps = booke206_page_size_to_tlb(dt_end) + 1;
> +    size = (ps << MAS1_TSIZE_SHIFT);
>      tlb->mas1 = MAS1_VALID | size;
> -    tlb->mas2 = va & TARGET_PAGE_MASK;
> -    tlb->mas7_3 = pa & TARGET_PAGE_MASK;
> +    tlb->mas2 = 0;
> +    tlb->mas7_3 = 0;
>      tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
>  
>      env->tlb_dirty = true;
> @@ -218,7 +228,7 @@ static void mpc8544ds_cpu_reset(void *opaque)
>      env->gpr[1] = (16<<20) - 8;
>      env->gpr[3] = bi->dt_base;
>      env->nip = bi->entry;
> -    mmubooke_create_initial_mapping(env, 0, 0);
> +    mmubooke_create_initial_mapping(env);
>  }
>  
>  static void mpc8544ds_init(ram_addr_t ram_size,
> @@ -374,13 +384,15 @@ static void mpc8544ds_init(ram_addr_t ram_size,
>      /* If we're loading a kernel directly, we must load the device tree too. */
>      if (kernel_filename) {
>          struct boot_info *boot_info;
> +        int dt_size;
>  
>  #ifndef CONFIG_FDT
>          cpu_abort(env, "Compiled without FDT support - can't load kernel\n");
>  #endif
> -        dt_base = (kernel_size + DTC_LOAD_PAD) & ~DTC_PAD_MASK;
> -        if (mpc8544_load_device_tree(env, dt_base, ram_size,
> -                    initrd_base, initrd_size, kernel_cmdline) < 0) {
> +        dt_base = (loadaddr + kernel_size + DTC_LOAD_PAD) & ~DTC_PAD_MASK;
> +        dt_size = mpc8544_load_device_tree(env, dt_base, ram_size, initrd_base,
> +                                           initrd_size, kernel_cmdline);
> +        if (dt_size < 0) {
>              fprintf(stderr, "couldn't load device tree\n");
>              exit(1);
>          }
> @@ -388,6 +400,7 @@ static void mpc8544ds_init(ram_addr_t ram_size,
>          boot_info = env->load_info;

This is turned into cpu->load_info in my series. Since this patch is not
marked 1.1, please ack and apply my patches first, so that we don't run
into conflicts with qom-next. Thanks.

Andreas

>          boot_info->entry = entry;
>          boot_info->dt_base = dt_base;
> +        boot_info->dt_size = dt_size;
>      }
>  
>      if (kvm_enabled()) {


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg