| Message ID | 1452883415-24452-4-git-send-email-pprakash@codeaurora.org (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
Hi Prashanth,
[auto build test ERROR on pm/linux-next]
[also build test ERROR on v4.4 next-20160115]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]
url: https://github.com/0day-ci/linux/commits/Prashanth-Prakash/acpi-cppc-optimization-patches/20160116-024434
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: i386-allmodconfig (attached as .config)
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
drivers/mailbox/pcc.c: In function 'read_register':
>> drivers/mailbox/pcc.c:195:10: error: implicit declaration of function 'readq' [-Werror=implicit-function-declaration]
*val = readq(vaddr);
^
drivers/mailbox/pcc.c: In function 'write_register':
>> drivers/mailbox/pcc.c:221:3: error: implicit declaration of function 'writeq' [-Werror=implicit-function-declaration]
writeq(val, vaddr);
^
cc1: some warnings being treated as errors
vim +/readq +195 drivers/mailbox/pcc.c
189 *val = readw(vaddr);
190 break;
191 case 32:
192 *val = readl(vaddr);
193 break;
194 case 64:
> 195 *val = readq(vaddr);
196 break;
197 default:
198 pr_debug("Error: Cannot read register of %u bit width",
199 bit_width);
200 ret_val = -EFAULT;
201 break;
202 }
203 return ret_val;
204 }
205
206 static int write_register(void *vaddr, u64 val, unsigned int bit_width)
207 {
208 int ret_val = 0;
209
210 switch (bit_width) {
211 case 8:
212 writeb(val, vaddr);
213 break;
214 case 16:
215 writew(val, vaddr);
216 break;
217 case 32:
218 writel(val, vaddr);
219 break;
220 case 64:
> 221 writeq(val, vaddr);
222 break;
223 default:
224 pr_debug("Error: Cannot write register of %u bit width",
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On 15 January 2016 at 14:33, kbuild test robot <lkp@intel.com> wrote: > Hi Prashanth, > > [auto build test ERROR on pm/linux-next] > [also build test ERROR on v4.4 next-20160115] > [if your patch is applied to the wrong git tree, please drop us a note to help improving the system] > > url: https://github.com/0day-ci/linux/commits/Prashanth-Prakash/acpi-cppc-optimization-patches/20160116-024434 > base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next > config: i386-allmodconfig (attached as .config) > reproduce: > # save the attached .config to linux build tree > make ARCH=i386 > > All errors (new ones prefixed by >>): > > drivers/mailbox/pcc.c: In function 'read_register': >>> drivers/mailbox/pcc.c:195:10: error: implicit declaration of function 'readq' [-Werror=implicit-function-declaration] > *val = readq(vaddr); > ^ > drivers/mailbox/pcc.c: In function 'write_register': >>> drivers/mailbox/pcc.c:221:3: error: implicit declaration of function 'writeq' [-Werror=implicit-function-declaration] > writeq(val, vaddr); > ^ > cc1: some warnings being treated as errors You probably need to include asm-generic/io.h Thanks, Ashwin. > > vim +/readq +195 drivers/mailbox/pcc.c > > 189 *val = readw(vaddr); > 190 break; > 191 case 32: > 192 *val = readl(vaddr); > 193 break; > 194 case 64: > > 195 *val = readq(vaddr); > 196 break; > 197 default: > 198 pr_debug("Error: Cannot read register of %u bit width", > 199 bit_width); > 200 ret_val = -EFAULT; > 201 break; > 202 } > 203 return ret_val; > 204 } > 205 > 206 static int write_register(void *vaddr, u64 val, unsigned int bit_width) > 207 { > 208 int ret_val = 0; > 209 > 210 switch (bit_width) { > 211 case 8: > 212 writeb(val, vaddr); > 213 break; > 214 case 16: > 215 writew(val, vaddr); > 216 break; > 217 case 32: > 218 writel(val, vaddr); > 219 break; > 220 case 64: > > 221 writeq(val, vaddr); > 222 break; > 223 default: > 224 pr_debug("Error: Cannot write register of %u bit width", > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 1/20/2016 3:29 PM, Ashwin Chaugule wrote: >>>> drivers/mailbox/pcc.c:221:3: error: implicit declaration of function 'writeq' [-Werror=implicit-function-declaration] >> writeq(val, vaddr); >> ^ >> cc1: some warnings being treated as errors > You probably need to include asm-generic/io.h > Thanks! I will update, test and re-post the patch set. -Prashanth -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index 45d85ae..150e18e 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -70,6 +70,9 @@ static struct mbox_chan *pcc_mbox_channels; +/*Array of cached virtual address for doorbell registers*/ +static void **pcc_doorbell_vaddr; + static struct mbox_controller pcc_mbox_ctrl = {}; /** * get_pcc_channel - Given a PCC subspace idx, get @@ -166,6 +169,66 @@ void pcc_mbox_free_channel(struct mbox_chan *chan) } EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); +/* + * PCC can be used with perf critical drivers such as CPPC + * So it makes sense to locally cache the virtual address and + * use it to read/write to PCC registers such as doorbell register + * + * The below read_register and write_registers are used to read and + * write from perf critical registers such as PCC doorbell register + */ +static int read_register(void *vaddr, u64 *val, unsigned int bit_width) +{ + int ret_val = 0; + + switch (bit_width) { + case 8: + *val = readb(vaddr); + break; + case 16: + *val = readw(vaddr); + break; + case 32: + *val = readl(vaddr); + break; + case 64: + *val = readq(vaddr); + break; + default: + pr_debug("Error: Cannot read register of %u bit width", + bit_width); + ret_val = -EFAULT; + break; + } + return ret_val; +} + +static int write_register(void *vaddr, u64 val, unsigned int bit_width) +{ + int ret_val = 0; + + switch (bit_width) { + case 8: + writeb(val, vaddr); + break; + case 16: + writew(val, vaddr); + break; + case 32: + writel(val, vaddr); + break; + case 64: + writeq(val, vaddr); + break; + default: + pr_debug("Error: Cannot write register of %u bit width", + bit_width); + ret_val = -EFAULT; + break; + } + return ret_val; +} + /** * pcc_send_data - Called from Mailbox Controller code. Used * here only to ring the channel doorbell. The PCC client @@ -181,21 +244,39 @@ EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); static int pcc_send_data(struct mbox_chan *chan, void *data) { struct acpi_pcct_hw_reduced *pcct_ss = chan->con_priv; - struct acpi_generic_address doorbell; + struct acpi_generic_address *doorbell; u64 doorbell_preserve; u64 doorbell_val; u64 doorbell_write; + u32 id = chan - pcc_mbox_channels; + int ret = 0; + + if (id >= pcc_mbox_ctrl.num_chans) { + pr_debug("pcc_send_data: Invalid mbox_chan passed\n"); + return -ENOENT; + } - doorbell = pcct_ss->doorbell_register; + doorbell = &pcct_ss->doorbell_register; doorbell_preserve = pcct_ss->preserve_mask; doorbell_write = pcct_ss->write_mask; /* Sync notification from OS to Platform. */ - acpi_read(&doorbell_val, &doorbell); - acpi_write((doorbell_val & doorbell_preserve) | doorbell_write, - &doorbell); - - return 0; + if (pcc_doorbell_vaddr[id]) { + ret = read_register(pcc_doorbell_vaddr[id], &doorbell_val, + doorbell->bit_width); + if (ret) + return ret; + ret = write_register(pcc_doorbell_vaddr[id], + (doorbell_val & doorbell_preserve) | doorbell_write, + doorbell->bit_width); + } else { + ret = acpi_read(&doorbell_val, doorbell); + if (ret) + return ret; + ret = acpi_write((doorbell_val & doorbell_preserve) | doorbell_write, + doorbell); + } + return ret; } static const struct mbox_chan_ops pcc_chan_ops = { @@ -271,14 +352,29 @@ static int __init acpi_pcc_probe(void) return -ENOMEM; } + pcc_doorbell_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL); + if (!pcc_doorbell_vaddr) { + kfree(pcc_mbox_channels); + return -ENOMEM; + } + /* Point to the first PCC subspace entry */ pcct_entry = (struct acpi_subtable_header *) ( (unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct)); for (i = 0; i < count; i++) { + struct acpi_generic_address *db_reg; + struct acpi_pcct_hw_reduced *pcct_ss; pcc_mbox_channels[i].con_priv = pcct_entry; pcct_entry = (struct acpi_subtable_header *) ((unsigned long) pcct_entry + pcct_entry->length); + + /* If doorbell is in system memory cache the virt address */ + pcct_ss = (struct acpi_pcct_hw_reduced *)pcct_entry; + db_reg = &pcct_ss->doorbell_register; + if (db_reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) + pcc_doorbell_vaddr[i] = acpi_os_ioremap(db_reg->address, + db_reg->bit_width/8); } pcc_mbox_ctrl.num_chans = count;
pcc_send_data can be invoked during the execution of performance critical code as in cppc_cpufreq driver. With acpi_* APIs, the doorbell register accessed in pcc_send_data if present in system memory will be searched (in cached virt to phys addr mapping), mapped, read/written and then unmapped. These operations take significant amount of time. This patch maps the performance critical doorbell register during init and then reads/writes to it directly using the mapped virtual address. This patch + similar changes to CPPC acpi driver reduce the time per freq. transition from around 200us to about 20us for cppc cpufreq driver Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> --- drivers/mailbox/pcc.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 103 insertions(+), 7 deletions(-)