Re: [PATCH v1 6/8] crypto: ccp - Add vdata for platform device

Jeremi Piotrowski
2023-02-01T19:24:24Z

On Tue, Jan 31, 2023 at 02:36:01PM -0600, Tom Lendacky wrote:
> On 1/23/23 09:22, Jeremi Piotrowski wrote:
> >When matching the "psp" platform_device, determine the register offsets
> >at runtime from the ASP ACPI table. Pass the parsed register offsets
> >from the ASPT through platdata.
> >
> >To support this scenario, mark the members of 'struct sev_vdata' and
> >'struct psp_vdata' non-const so that the probe function can write the
> >values. This does not affect the other users of sev_vdata/psp_vdata as
> >they define the whole struct const and the pointer in struct
> >sp_dev_vdata stays const too.
> >
> >Signed-off-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
> >---
> > arch/x86/kernel/psp.c | 3 ++
> > drivers/crypto/ccp/sp-dev.h | 12 +++----
> > drivers/crypto/ccp/sp-platform.c | 57 +++++++++++++++++++++++++++++++-
> > 3 files changed, 65 insertions(+), 7 deletions(-)
> >
> >diff --git a/arch/x86/kernel/psp.c b/arch/x86/kernel/psp.c
> >index 24181d132bae..68511a14df63 100644
> >--- a/arch/x86/kernel/psp.c
> >+++ b/arch/x86/kernel/psp.c
> >@@ -199,6 +199,9 @@ static int __init psp_init_platform_device(void)
> > if (err)
> > return err;
> > err = platform_device_add_resources(&psp_device, res, 2);
> >+ if (err)
> >+ return err;
> >+ err = platform_device_add_data(&psp_device, &pdata, sizeof(pdata));
> > if (err)
> > return err;
> >diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h
> >index 20377e67f65d..aaa651364425 100644
> >--- a/drivers/crypto/ccp/sp-dev.h
> >+++ b/drivers/crypto/ccp/sp-dev.h
> >@@ -40,9 +40,9 @@ struct ccp_vdata {
> > };
> > struct sev_vdata {
> >- const unsigned int cmdresp_reg;
> >- const unsigned int cmdbuff_addr_lo_reg;
> >- const unsigned int cmdbuff_addr_hi_reg;
> >+ unsigned int cmdresp_reg;
> >+ unsigned int cmdbuff_addr_lo_reg;
> >+ unsigned int cmdbuff_addr_hi_reg;
> > };
> > struct tee_vdata {
> >@@ -56,9 +56,9 @@ struct tee_vdata {
> > struct psp_vdata {
> > const struct sev_vdata *sev;
> > const struct tee_vdata *tee;
> >- const unsigned int feature_reg;
> >- const unsigned int inten_reg;
> >- const unsigned int intsts_reg;
> >+ unsigned int feature_reg;
> >+ unsigned int inten_reg;
> >+ unsigned int intsts_reg;
> > };
> > /* Structure to hold SP device data */
> >diff --git a/drivers/crypto/ccp/sp-platform.c b/drivers/crypto/ccp/sp-platform.c
> >index ea8926e87981..281dbf6b150c 100644
> >--- a/drivers/crypto/ccp/sp-platform.c
> >+++ b/drivers/crypto/ccp/sp-platform.c
> >@@ -22,6 +22,7 @@
> > #include <linux/of.h>
> > #include <linux/of_address.h>
> > #include <linux/acpi.h>
> >+#include <linux/platform_data/psp.h>
> > #include "ccp-dev.h"
> >@@ -30,11 +31,31 @@ struct sp_platform {
> > unsigned int irq_count;
> > };
> >+#ifdef CONFIG_CRYPTO_DEV_SP_PSP
> >+static struct sev_vdata sev_platform = {
> >+ .cmdresp_reg = -1,
> >+ .cmdbuff_addr_lo_reg = -1,
> >+ .cmdbuff_addr_hi_reg = -1,
> >+};
> >+static struct psp_vdata psp_platform = {
> >+ .sev = &sev_platform,
> >+ .feature_reg = -1,
> >+ .inten_reg = -1,
> >+ .intsts_reg = -1,
> >+};
> >+#endif
> >+
> > static const struct sp_dev_vdata dev_vdata[] = {
> > {
> > .bar = 0,
> > #ifdef CONFIG_CRYPTO_DEV_SP_CCP
> > .ccp_vdata = &ccpv3_platform,
> >+#endif
> >+ },
> >+ {
> >+ .bar = 0,
> >+#ifdef CONFIG_CRYPTO_DEV_SP_PSP
> >+ .psp_vdata = &psp_platform,
> > #endif
> > },
> > };
> >@@ -57,7 +78,7 @@ MODULE_DEVICE_TABLE(of, sp_of_match);
> > #endif
> > static const struct platform_device_id sp_plat_match[] = {
> >- { "psp" },
> >+ { "psp", (kernel_ulong_t)&dev_vdata[1] },
> > { },
> > };
> > MODULE_DEVICE_TABLE(platform, sp_plat_match);
> >@@ -86,6 +107,38 @@ static struct sp_dev_vdata *sp_get_acpi_version(struct platform_device *pdev)
> > return NULL;
> > }
> >+static struct sp_dev_vdata *sp_get_plat_version(struct platform_device *pdev)
> >+{
> >+ struct sp_dev_vdata *drvdata = (struct sp_dev_vdata *)pdev->id_entry->driver_data;
>
> s/drvdata/vdata/
>

ok

> >+ struct device *dev = &pdev->dev;
> >+
>
> Should check for null vdata and return NULL, e.g.:
>
> if (!vdata)
> return NULL;
>

ok

> >+ if (drvdata == &dev_vdata[1]) {
>
> This should be a check for vdata->psp_vdata being non-NULL and
> vdata->psp_vdata->sev being non-NULL, e.g.:
>
> if (vdata->psp_vdata && vdata->psp_vdata->sev) {
>
> >+ struct psp_platform_data *pdata = dev_get_platdata(dev);
> >+
> >+ if (!pdata) {
> >+ dev_err(dev, "missing platform data\n");
> >+ return NULL;
> >+ }
> >+#ifdef CONFIG_CRYPTO_DEV_SP_PSP
>
> No need for this with the above checks
>
> >+ psp_platform.feature_reg = pdata->feature_reg;
>
> These should then be:
>
> vdata->psp_vdata->inten_reg = pdata->feature_reg;
> ...

I see where you're going with this and the above suggestions, but
the psp_vdata pointer is const in struct sp_dev_vdata and so is the
sev pointer in struct psp_vdata. I find these consts to be important
and doing it this way would require casting away the const. I don't
think that's worth doing.

>
> >+ psp_platform.inten_reg = pdata->irq_en_reg;
> >+ psp_platform.intsts_reg = pdata->irq_st_reg;
> >+ sev_platform.cmdresp_reg = pdata->sev_cmd_resp_reg;
>
> And this should be:
>
> vdata->psp_vdata->sev->cmdbuff_addr_lo = ...
>
> >+ sev_platform.cmdbuff_addr_lo_reg = pdata->sev_cmd_buf_lo_reg;
> >+ sev_platform.cmdbuff_addr_hi_reg = pdata->sev_cmd_buf_hi_reg;
> >+ dev_dbg(dev, "GLBL feature:\t%x\n", pdata->feature_reg);
>
> s/GLBL feature/PSP feature register/
>
> >+ dev_dbg(dev, "GLBL irq en:\t%x\n", pdata->irq_en_reg);
>
> s/GLBL irq en/PSP IRQ enable register/
>
> >+ dev_dbg(dev, "GLBL irq st:\t%x\n", pdata->irq_st_reg);
>
> s/GLBL irq st/PSP IRQ status register/
>
> >+ dev_dbg(dev, "SEV cmdresp:\t%x\n", pdata->sev_cmd_resp_reg);
>
> s/SEV cmdresp/SEV cmdresp register/
>
> >+ dev_dbg(dev, "SEV cmdbuf lo:\t%x\n", pdata->sev_cmd_buf_lo_reg);
>
> s/SEV cmdbuf lo/SEV cmdbuf lo register/
>
> >+ dev_dbg(dev, "SEV cmdbuf hi:\t%x\n", pdata->sev_cmd_buf_hi_reg);
>
> s/SEV cmdbuf hi/SEV cmdbuf hi register/
>
> >+ dev_dbg(dev, "SEV mbox:\t%x\n", pdata->mbox_irq_id);
>
> s/SEV mbox/SEV cmdresp IRQ/
>

ok to all the above rewordings

>
> >+ dev_dbg(dev, "ACPI cmdresp:\t%x\n", pdata->acpi_cmd_resp_reg);
>
> Duplicate entry

I don't see it. This is the ACPI register (the one used for the IRQ config).
Here's how these prints look when the module is loaded with dyndbg=+p:

ccp psp: GLBL feature: 0
ccp psp: GLBL irq en: 4
ccp psp: GLBL irq st: 8
ccp psp: SEV cmdresp: 10
ccp psp: SEV cmdbuf lo: 14
ccp psp: SEV cmdbuf hi: 18
ccp psp: SEV mbox: 1
ccp psp: ACPI cmdresp: 20

>
> >+#endif
> >+ }
> >+ return drvdata;
> >+}
> >+
> > static int sp_get_irqs(struct sp_device *sp)
> > {
> > struct sp_platform *sp_platform = sp->dev_specific;
> >@@ -137,6 +190,8 @@ static int sp_platform_probe(struct platform_device *pdev)
> > sp->dev_specific = sp_platform;
> > sp->dev_vdata = pdev->dev.of_node ? sp_get_of_version(pdev)
> > : sp_get_acpi_version(pdev);
> >+ if (!sp->dev_vdata && pdev->id_entry)
>
> Move this pdev->id_entry check into sp_get_plat_version(), returning
> NULL if not set.
>

ok

> Thanks,
> Tom
>
> >+ sp->dev_vdata = sp_get_plat_version(pdev);
> > if (!sp->dev_vdata) {
> > ret = -ENODEV;
> > dev_err(dev, "missing driver data\n");