On Mon, Oct 08, 2012 at 02:59:17PM +0100, Jon Medhurst (Tixy) wrote:

From: Jon Medhurst tixy@linaro.org

Check all the CPU affinity fields of MPIDR, so we select only the first CPU of the first cluster as the one to boot on.

Shame, we can't run this on pre-v7 CPUs now ;) (Well, v6T2).

The chance of us wanting to do that (motivating bic instead of bfc) is minimal, though.

Acked-by: Dave Martin dave.martin@linaro.org

Signed-off-by: Jon Medhurst tixy@linaro.org

boot.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/boot.S b/boot.S index 727119a..40ebd33 100644 --- a/boot.S +++ b/boot.S @@ -121,7 +121,7 @@ start: @ Check CPU nr again mrc p15, 0, r0, c0, c0, 5 @ MPIDR (ARMv7 only)

• and r0, r0, #15 @ CPU number

• bfc r0, #24, #8 @ CPU number, taking multicluster into account cmp r0, #0 @ primary CPU? beq 2f

1.7.10.4

On Mon, Oct 08, 2012 at 02:59:18PM +0100, Jon Medhurst (Tixy) wrote:

From: Jon Medhurst tixy@linaro.org

A subsequent patch will also need to obtain address-cells and size-cells, so lets factor out this code into a handy function.

The code looks ok. There are a couple of stylistic things that could be tweaked, but it's not a big issue.

Cheers ---Dave

Signed-off-by: Jon Medhurst tixy@linaro.org

semi_loader.c | 56 ++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 34 insertions(+), 22 deletions(-)

diff --git a/semi_loader.c b/semi_loader.c index cbe911c..c9750be 100644 --- a/semi_loader.c +++ b/semi_loader.c @@ -97,6 +97,39 @@ static int _fdt_make_node(void *fdt, int parentoffset, const char *name) return fdt_add_subnode(fdt, parentoffset, name); } +static void _fdt_address_and_size_cells(void *fdt, int* addrcells, int* sizecells)

Minor quibble: the rest of the code uses the type *decl spacing, not type* decl.

+{

• int e;
• uint32_t const *p;
• if(!(p = fdt_getprop(fdt, 0, "#address-cells", &e)))

• goto libfdt_error;
  

• else if(e != 4)

• goto size_error;
  

Another minor quibble: this could be simplified slightly by dropping any else which directly follows a goto.

(The superfluous elses were in the original code too, though.)

• *addrcells = fdt32_to_cpu(*p);
• if(!(p = fdt_getprop(fdt, 0, "#size-cells", &e)))

• goto libfdt_error;
  

• else if(e != 4)

• goto size_error;
  

• *sizecells = fdt32_to_cpu(*p);
• /*

• * Sanity-check address sizes, since addresses and sizes which do
  

• * not take up exactly 4 or 8 bytes are not supported.
  

• */
  

• if ((*addrcells != 1 && *addrcells != 2) ||

•    (*sizecells != 1 && *sizecells != 2))
  

• goto size_error;
  

• return;

+libfdt_error:

• fatal("libfdt: ", fdt_strerror(e), ", while looking for #address-cells/#size-cells\n");

+size_error:

• fatal("Unexpected/invalid #address-cells/#size-cells in device tree\n");

+}

static void update_fdt(void **dest, struct loader_info *info) { int e; @@ -112,25 +145,7 @@ static void update_fdt(void **dest, struct loader_info *info) if((e = fdt_open_into((void *)info->fdt_start, fdt, FDT_SIZE_MAX)) < 0) goto libfdt_error;

• /*

• * Sanity-check address sizes, since addresses and sizes which do
  

• * not take up exactly 4 or 8 bytes are not supported.
  

• */
  

• {

• if(!(p = fdt_getprop(fdt, 0, "#address-cells", &e)))
  

• 	goto libfdt_error;
  

• else if(e != 4)
  

• 	goto size_error;
  

• addrcells = fdt32_to_cpu(*p);
  

• if(!(p = fdt_getprop(fdt, 0, "#size-cells", &e)))
  

• 	goto libfdt_error;
  

• else if(e != 4)
  

• 	goto size_error;
  

• sizecells = fdt32_to_cpu(*p);
  

• if ((addrcells != 1 && addrcells != 2) ||
  

•     (sizecells != 1 && sizecells != 2))
  

• 	goto size_error;
  

• }

• _fdt_address_and_size_cells(fdt, &addrcells, &sizecells);

/* * Add a memory node, but only if there isn't one already. If @@ -225,9 +240,6 @@ no_add_memory: libfdt_error: fatal("libfdt: ", fdt_strerror(e), ", while updating device tree\n");

-size_error:

• fatal("Unexpected/invalid #address-cells/#size-cells in device tree\n");

} static int is_space(char c) -- 1.7.10.4

On Mon, Oct 08, 2012 at 02:59:19PM +0100, Jon Medhurst (Tixy) wrote:

From: Jon Medhurst tixy@linaro.org

The A15xA7 models simulate a Cache Coherent Interconnect (CCI) and this needs to be initialised correctly for Linux to boot.

To perform this initiation we add the new function configure_from_fdt() which will look in the fdt for devices to initialise. In this first case we look for the CCI node and if found then setup this device.

Acked-by: Dave Martin dave.martin@linaro.org

(Commentary below, but the patch looks OK to me.)

Signed-off-by: Jon Medhurst tixy@linaro.org

semi_loader.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+)

diff --git a/semi_loader.c b/semi_loader.c index c9750be..b0c064c 100644 --- a/semi_loader.c +++ b/semi_loader.c @@ -242,6 +242,61 @@ libfdt_error: fatal("libfdt: ", fdt_strerror(e), ", while updating device tree\n"); } +/* For accessing 32-bit device ports */ +#define io32(p) (*(volatile uint32_t *)(p))

I had a vague memory of something like this already existing somewhere, but I think I may be confusing this with another codebase.

+static void init_cci(unsigned cci) +{

• info("Initialising CCI\n");
• /*

• * Ideally, the CCI device tree binding would include suitable
  

• * information so we can correctly configure the CCI, but for
  

• * now we'll just hard-code settings for the present A15xA7
  

• * models.
  

• */
  

• /* Turn on CCI snoops and DVM messages */
• io32(cci+0x4000) = 0x3; /* A15 cluster */
• io32(cci+0x5000) = 0x3; /* A7 cluster */

We may want to be more sophisticated about this at some point, but this is a sensible compromise for now.

There is no official CCI binding yet, but this code makes reasonable- looking, minimal assumptions about its final form.

• /* Wait while change pending bit of status register is set */
• while(io32(cci+0xc) & 0x1)

• {}
  

+}

+static void configure_from_fdt(struct loader_info *info) +{

• void *fdt = (void *)info->fdt_start;
• uint32_t const *p;
• int addrcells, sizecells;
• int offset, len;
• if(!fdt)

• return;
  

• _fdt_address_and_size_cells(fdt, &addrcells, &sizecells);
• /* See if there is a CCI device to initialise */
• offset = fdt_node_offset_by_compatible(fdt, 0, "arm,cci");
• if (offset >= 0) {

• p = fdt_getprop(fdt, offset, "reg", &len);
  

• if(len != (addrcells + sizecells) * 4)
  

• 	info("Failed parsing device-tree node for CCI\n");
  

• else {
  

• 	/*
  

• 	 * p[addrcells - 1] is the least significant 32-bits of
  

• 	 * the address for the CCI. On 32-bit CPUs any additional
  

• 	 * address bits had  better be zero otherwise we can't
  

• 	 * access it as we don't enable the MMU.
  

• 	 */
  

• 	init_cci(fdt32_to_cpu(p[addrcells - 1]));
  

• }
  

• }
• return;

+}

static int is_space(char c) { return c == ' '; @@ -598,4 +653,6 @@ args_done: atag_append(&atagp, ATAG_NONE, 0, 0); update_fdt(&phys, info);

• configure_from_fdt(info);

}

1.7.10.4