On 01/11/17 23:47, Mathieu Poirier wrote:
On Thu, Oct 19, 2017 at 06:15:42PM +0100, Suzuki K Poulose wrote:
Make the ETR SG table Circular buffer so that we could start at any of the SG pages and use the entire buffer for tracing. This can be achieved by :
- Keeping an additional LINK pointer at the very end of the
SG table, i.e, after the LAST buffer entry, to point back to the beginning of the first table. This will allow us to use the buffer normally when we start the trace at offset 0 of the buffer, as the LAST buffer entry hints the TMC-ETR and it automatically wraps to the offset 0.
- If we want to start at any other ETR SG page aligned offset,
we could : a) Make the preceding page entry as LAST entry. b) Make the original LAST entry a normal entry. c) Use the table pointer to the "new" start offset as the base of the table address. This works as the TMC doesn't mandate that the page table base address should be 4K page aligned.
Cc: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com
+static int __maybe_unused +tmc_etr_sg_table_rotate(struct etr_sg_table *etr_table, u64 base_offset) +{
- u32 last_entry, first_entry;
- u64 last_offset;
- struct tmc_sg_table *sg_table = etr_table->sg_table;
- sgte_t *table_ptr = sg_table->table_vaddr;
- ssize_t buf_size = tmc_sg_table_buf_size(sg_table);
- /* Offset should always be SG PAGE_SIZE aligned */
- if (base_offset & (ETR_SG_PAGE_SIZE - 1)) {
pr_debug("unaligned base offset %llx\n", base_offset);return -EINVAL;- }
- /* Make sure the offset is within the range */
- if (base_offset < 0 || base_offset > buf_size) {
base_offset = (base_offset + buf_size) % buf_size;pr_debug("Resetting offset to %llx\n", base_offset);- }
- first_entry = tmc_etr_sg_offset_to_table_index(base_offset);
- if (first_entry == etr_table->first_entry) {
pr_debug("Head is already at %llx, skipping\n", base_offset);return 0;- }
- /* Last entry should be the previous one to the new "base" */
- last_offset = ((base_offset - ETR_SG_PAGE_SIZE) + buf_size) % buf_size;
- last_entry = tmc_etr_sg_offset_to_table_index(last_offset);
- /* Reset the current Last page to Normal and new Last page to NORMAL */
- tmc_etr_sg_update_type(&table_ptr[etr_table->last_entry],
ETR_SG_ET_NORMAL);- tmc_etr_sg_update_type(&table_ptr[last_entry], ETR_SG_ET_LAST);
- etr_table->hwaddr = tmc_etr_sg_table_index_to_daddr(sg_table,
first_entry);- etr_table->first_entry = first_entry;
- etr_table->last_entry = last_entry;
- pr_debug("table rotated to offset %llx-%llx, entries (%d - %d), dba: %llx\n",
base_offset, last_offset, first_entry, last_entry,etr_table->hwaddr);The above line generates a warning when compiling for ARMv7.
Where you running with LPAE off ? That could probably be the case, where hwaddr could be 32bit or 64bit depending on whether LPAE is enabled. I will fix it.
I have fixed some other warnings with ARMv7 with LPAE.
Suzuki